Envir onmental and Ef fluent Monitoring at ANSTO Sites2002-2003 General Contact Details:ANSTO Australian Nuclear Science and T echnology Organisation Lucas Heights Science and T echnology Centr e New Illawarra Road, Lucas Heights, NSW 2234, Australia Postal Addr ess: ANSTO, Private Mail Bag 1Menai, NSW , 2234 Australia T elephone: + 61 2 9717 3111 Facsimile: + 61 2 9717 9210 Email: enquiries@ansto.gov .au Inter net: www .ansto.gov .au GUIDED TOURS of the ANSTO site and laboratories ar e available to individuals, gr oups and schools at no cost. Bookings and infor mation: T elephone + 61 2 9717 3626 ? Commonwealth of Australia 2003This work is copyright. Y ou may download, display , print and r epr oduce this material in unalter ed for m only (r etaining this notice) for your personal, non-commer cial use or use within your organisation. Apar t fr om any use as per mitted under the Copyright Act 1968, all other rights ar e r eserved. Requests for fur ther authorisation should be dir ected to the Commonwealth Copyright Administration, Intellectual Pr oper ty Branch, Depar tment of Communications, Infor mation T echnology and the Ar ts, GPO Box 2154, Canberra ACT 2601 or posted at http://www .dcita.gov .au/cca. Fr ont Cover W o r onora River , downstr eam of Lucas Heights, Sutherland Shir e, Sydney , Australia Photography Mark Alcor n ISSN: 1030 7745 ISBN 0-642-5999-8 E- 752 Envir onmental and Ef fluent Monitoring at ANSTO Sites 2002-2003 INIS DescriptorsThe following descriptors have been selected fr om the INIS Thesaurus to describe the subject matter of this r epor t for infor mat ion r etrieval purposes. For fur ther details please r efer to IAEA-INIS-12 (INIS Manual for Indexing) and IAEA-INIS-13 (INIS Thesaurus) publish ed in V ienna by the Inter national Atomic Energy Agency . Airbor ne Par ticulates, Algae, Alpha Decay Radioisotopes, Alpha Par ticles, ANS TO, Argon-41, Australia, Cesium-137, Cobalt-60, Contamination, Cyclotr ons, Dose-Constraint, Dose Limits, Drinking W ater , Envir onmen tal Exposur e Pathway , Envir onmental Impacts, Fishes, Fission Pr oduct Release, Gaseous W astes, Gr ound W ater , Iodine-123, Iodine-131, Iodine-132, Iodine-133, Liquid W astes, Noble Gases, Public Health, Radiation Doses, Radiation Monitoring, Radioactive Ef fluents , Sampling, Seawater , Sediments, Soils, Stack Disposal, Standar ds, Str ontium-90, Sur face W aters, Ther moluminescent Dosimetr y , T r i tium, Uranium-238, W ater Quality , Wind. Environmental and Effluent Monitoring at ANSTO Sites, 2002?2003 Emmy L Hoffmann, John M Ferris, Scott J Markich Abstract This report presents the results of environmental and effluent monitoring at the Lucas Heights Science and Technology Centre (LHSTC) and the National Medical Cyclotron (NMC) from January 2002 to June 2003. Potential effective dose rates to the general public from airborne discharges from the LHSTC site were less than 0.01 mSv/year, well below the 1 mSv/year dose rate limit for long term exposure that is recommended by the Australian National Occupational Health and Safety Commission. The effective dose rates to hypothetical individuals potentially exposed to radiation in routine liquid effluent discharges from the LHSTC were recently calculated to be less than 0.001 mSv/year. This is much less than dose rates estimated for members of public potentially exposed to airborne emissions. The levels of tritium detected in groundwater and stormwater at the LHSTC were less than the Australian drinking water guidelines. The airborne and liquid effluent emissions from the NMC were below the ARPANSA-approved notification levels and NSW EPA limits, respectively. ANSTO's routine operations at the LHSTC and the NMC make only a very small addition to the natural background radiation dose experienced by members of the Australian public. 2 ANSTO E-752 > TABLE OF CONTENTS List of Tables _________________________________________________________________________ 4 List of Figures ________________________________________________________________________ 5 List of Abbreviations __________________________________________________________________ 6 1. Introduction ________________________________________________________________________ 7 2. ANSTO Facilities____________________________________________________________________ 7 2.1 HIFAR 7 2.2 Radioisotope Production 7 2.3 National Medical Cyclotron 7 2.4 Waste Operations and Technology Development 8 2.5 Little Forest Burial Ground 8 3. Regulatory and Legal Framework ___________________________________________________ 8 4. Assessment of Potential Exposure __________________________________________________10 4.1 Background Radiation 10 4.2 Exposure Pathways and Critical Groups 10 5. Sampling of Emissions and Environment ____________________________________________ 11 5.1 Air and Liquid Emissions 11 5.2 Environment 13 5.3 Meteorology 13 6. Environmental Monitoring (January 2002- June 2003) ________________________________ 13 6.1 Airborne Emissions 19 6.2 Liquid Effluent 19 6.2.1 Lucas Heights Science and Technology Centre 19 6.2.2 Effluent Dilution ? LHSTC to the Cronulla STP 20 6.2.3 National Medical Cyclotron 21 6.3 Air 21 6.3.1 Ambient I-131 21 6.3.2 Little Forest Burial Ground ? Airborne Particulates 21 6.3.3 External Gamma Radiation 21 6.3.4 Aerosol Particles (PM 2.5) 22 6.3.5 Radiological Characterisation of the LHSTC and Buffer Zone 23 6.4 Surface Waters 23 6.4.1 Tritium in Surface Waters 23 6.4.2 Gross Alpha and Beta Radioactivity in Surface Waters 24 6.4.3 Gamma-Emitting Radionuclides in Surface Waters 25 6.5 Estuarine and Sea Waters 25 6.6 Groundwater 25 6.6.1 Lucas Heights Science and Technology Centre 25 6.6.2 Little Forest Burial Ground 30 6.7 Soil and Sediment 30 6.7.1 Bund Sediments 30 6.7.2 Sediment from Local Streams 30 6.7.3 Gamma Dose Survey ? Little Forest Burial Ground 32 6.7.4 Gamma Dose Survey - Liquid Effluent Pipeline 32 6.8 Biota (Potter Point) 32 7. Potential Doses to The Public and The Environment ________________________________ 32 7.1 Airborne Discharges 32 7.2 Liquid Effluent Discharges 34 8. Conclusion _______________________________________________________________________ 34 9. Acknowledgements _______________________________________________________________ 34 10. References ______________________________________________________________________ 34 Data Tables _________________________________________________________________________ 36 Appendix A ? Quality Assurance and Control __________________________________________ 70 ANSTO E-752 3 LIST OF TABLES TABLES IN MAIN TEXT Table A. Key legislative and regulatory requirements at ANSTO facilities in relation to environmental protection Table B. Summary of environmental monitoring at ANSTO sites, July 2001 to June 2003 Table C. Effluent dilution studies at the Cronulla sewage treatment plant, 2002-2003 DATA TABLES Table 1. Median detection limits for environmental media Table 2. Annual airborne activity discharge report, LHSTC and NMC, July 2001 to June 2002 Table 3. Annual airborne activity discharge report, LHSTC and NMC, July 2002 to June 2003 Table 4. Radioactivity in liquid effluent discharged to the Sydney Water Sewer, LHSTC, January 2002 to June 2003 Table 5. Gamma-emitters in liquid effluent, monthly pipeline composite samples, LHSTC, January 2002 to June 2003 Table 6. Non-radioactive components of liquid effluent discharged to the Sydney Water Sewer, LHSTC, January 2002 to June 2003 Table 7. Average activity of radionuclides in liquid effluent, NMC, January 2002 to June 2003 Table 8. Ambient iodine-131 in air, LHSTC, January 2002 to June 2003 Table 9. Radioactivity in airborne particles, LFBG, January 2002 to June 2003 Table 10. External gamma radiation, LHSTC and local area, annual effective dose for 2001-2002 and 2002-2003 Table 11. Tritium in stormwater bunds, monthly composites, LHSTC, January 2002 to June 2003 Table 12. Tritium in stormwater, bund C, LHSTC, January 2002 to June 2003 Table 13. Tritium in surface water, MDP+60m, LHSTC, January 2002 to June 2003 Table 14. Tritium in surface water, Bardens Creek Weir, January 2002 to June 2003 Table 15. Radioactivity in stormwater, bund C monthly composites, LHSTC, January 2002 to June 2003 Table 16. Radioactivity in surface water, MDP+ 60m monthly composite, LHSTC, January 2002 to June 2003 Table 17. Radioactivity in surface water, SPCC sampling points, January 2002 to June 2003 Table 18. Radioactivity in creeks north of the LFBG, January 2002 to June 2003 Table 19. Tritium in waters, Woronora River estuary and Forbes Creek, January 2002 to June 2003 Table 20. Radioactivity in groundwater from the vicinity of Building 27, January 2002 to June 2003 Table 21. Field parameters in groundwater, LHSTC, September 2002 Table 22. Major ions in groundwater, LHSTC, September 2002 Table 23. Radioactivity in groundwater, LHSTC, September 2002 Table 24. Rainfall and evaporation data, LHSTC, January 1992 to June 2003. Table 25. Field parameters in groundwater, LFBG, May 2002 Table 26. Field parameters in groundwater, LFBG, October 2002 Table 27. Field parameters in groundwater, LFBG, April-June 2003 Table 28. Radioactivity in groundwater, LFBG, May 2002 4 ANSTO E-752 Table 29. Radioactivity in groundwater, LFBG, October 2002 Table 30. Radioactivity in groundwater, LFBG, April-June 2003 Table 31. Radioactivity in sediment, LHSTC stormwater bunds, January 2002 to June 2003 Table 32. Gamma dose-rate survey, LFBG trenches, December 2002 Table 33. Gamma dose-rate surveys, liquid effluent pipeline, LHSTC, January 2002 to June 2003 Table 34. Radioactivity in fish, Potter Point and The Royal National Park, January 2002 to June 2003 Table 35. Radioactivity in algae, Potter Point and The Royal National Park, January 2002 to June 2003 Table 36. Radioactivity in barnacles, Potter Point and The Royal National Park, January 2002 to June 2003 Table 37. Estimated effective doses from LHSTC airborne discharges, 2001-2002 and 2002-2003 LIST OF FIGURES Figure 1. Location of the LHSTC and off-site sampling points Figure 2. Location of stormwater, air and external radiation monitoring points at the LHSTC Figure 3. Location of groundwater monitoring piezometers at the LHSTC Figure 4. Little Forest Burial Ground ? configuration of bores currently sampled and location of the burial trenches, including S1 and S2 Figure 5. Location of the Cronulla Sewage Treatment Plant and sampling zones at Potter Point Ocean Outfall and The Royal National Park Figure 6. Monthly quotients for alpha, beta and tritium radioactivity in liquid effluent at the LHSTC, January 2002 to June 2003 Figure 7. Average monthly mass of fine aerosol particles (less than 2.5 microns in diameter) collected over 24-hour periods, Lucas Heights, 2002 Figure 8. Gross alpha activity in surface water at the LHSTC, January 2002 to June 2003 Figure 9. Gross beta activity in surface water at the LHSTC, January 2002 to June 2003 Figure 10. General construction details for type 1 and type 2 Piezometers at the LHSTC Figure 11. LHSTC potentiometric surface for the deeper sandstone aquifer (February 2000) Figure 12. Groundwater hydrograph for piezometer MW 6s and concurrent rainfall at the LHSTC Figure 13. Little Forest Burial Ground ? groundwater flow paths Figure 14. Estimated effective dose to the public from LHSTC airborne discharges, at 1.6 km radius from HIFAR, 2001-2002 and 2002-2003 ANSTO E-752 5 LIST OF ABBREVIATIONS AAEC The former Australian Atomic Energy Commission, now ANSTO ADWG Australian Drinking Water Guidelines ALARA As Low As Reasonably Achievable ANSTO Australian Nuclear Science and Technology Organisation ARI Australian Radiopharmaceuticals and Industrials ARMCANZ Agriculture and Resource Management Council of Australia and New Zealand ARPANSA Australian Radiation Protection and Nuclear Safety Agency ASP Aerosol Sampling Program DDT Dichloro-diphenyl-trichloroethane EPA Environment Protection Authority HIFAR High Flux Australian Reactor IAEA International Atomic Energy Agency ICRP International Commission on Radiological Protection INIS International Nuclear Information System IQR Interquartile range (range from 25 th to 75 th percentile) ISO International Organisation for Standardisation LFBG Little Forest Burial Ground LHSTC Lucas Heights Science and Technology Centre MDA Minimum Detectable Activity MDP Main Disposal Pipeline LFBG Little Forest Burial Ground ML Mega Litre NHMRC National Health and Medical Research Council NMC National Medical Cyclotron NOHSC National Occupational Health and Safety Commission NSW New South Wales PM Particulate Matter RRR Replacement Research Reactor SPCC The former State Pollution Control Commission (now the NSW Environment Protection Agency) STP Sewage Treatment Plant TLD Thermo-Luminescent Dosimeters UNSCEAR United Nations Scientific Committee on the Effects of Atomic Radiation USEPA United States Environmental Protection Agency WHO World Health Organisation 6 ANSTO E-752 1. Introduction The Australian Nuclear Science and Technology Organisation (ANSTO) operates several national facilities, including Australia?s only research reactor, HIFAR (the High Flux Australian Reactor), produces radioisotopes and radiopharmaceuticals and carries out research in nuclear science and technology. ANSTO is an agency of the Commonwealth Government of Australia. Most of the ANSTO facilities are located at the Lucas Heights Science and Technology Centre (LHSTC), some 40 km south west of the Sydney city centre. The LHSTC occupies 70 hectares and is surrounded by a 1.6 km buffer zone (see Figure 1, section 5). ANSTO also operates the National Medical Cyclotron (NMC), located in the grounds of the Royal Prince Alfred Hospital in Camperdown, Sydney, to produce certain short-lived radioisotopes for medical investigations. ANSTO activities are regulated by the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) under the Australian Radiation Protection and Nuclear Safety Act (1998). ANSTO is committed to undertaking its activities in a manner that protects human health and the environment and is consistent with national and international standards. This commitment is described in the ANSTO Health, Safety and Environment Policy. ANSTO provides verifiable evidence of the fulfilment of the environmental commitment through a program of monitoring and audit, and publication of these results in its annual Environmental and Effluent Monitoring reports. The monitoring program is also designed to detect and quantify any accidental releases of radioactive materials, should they occur. This report summarises the results from the environmental and effluent surveys carried out at the LHSTC and the NMC from January 2002 to June 2003, and assesses the potential effects of radioactive discharges, particularly as they might affect local residents. The eighteen-month period covered by this report represents a transition from calender to fiscal year-end reporting. Data published in previous years are publicly available either from the Sutherland Shire Central Library or by request from ANSTO?s Communications Manager. 2. ANSTO Facilities 2.1 HIFAR The HIFAR research reactor produces radioisotopes for medical and industrial use and employs neutrons for research applications. HIFAR is authorised by ARPANSA to release low levels of radionuclides to the atmosphere via stacks. The main radionuclides are tritium and argon-41 (a noble gas). There are small quantities of iodine-131, arsenic-76, bromine-82, mercury-197 and mercury-203. The tritium occurs as tritiated water vapour that can exchange with rainwater, resulting in the presence of tritium at very low levels in stormwater. Low level liquid waste is treated on-site by ANSTO Waste Operations and Technology Development and discharged via the Sydney Water Corporation sewer (see below). 2.2 RADIOISOTOPE PRODUCTION The production of radioisotopes for medical and industrial use by ANSTO Radiopharmaceuticals and Industrials (ARI) results in the release of small quantities of radionuclides to the environment. ARPANSA regulates the atmospheric releases of radionuclides including iodine-131, xenon-133, xenon-135 and krypton-85 from stacks in the radioisotope and radiopharmaceutical production area at the LHSTC. Low level liquid waste is treated on-site by ANSTO Waste Operations and Technology Development and discharged via the Sydney Water Corporation sewer (see below). 2.3 NATIONAL MEDICAL CYCLOTRON ANSTO also manufactures radiopharmaceuticals at the NMC (Camperdown, Sydney). Airborne emissions from the NMC are regulated by ARPANSA under the ANSTO Airborne Radioactivity Discharge Authorisation. The liquid waste discharges from the NMC to the sewer are covered by a trade wastewater agreement with Sydney Water Corporation that incorporates limits set by the New South Wales Environment Protection Authority (NSWEPA) for specific radionuclides in the discharges. The radiopharmaceutical products made at the NMC are short-lived, with half-lives ranging from minutes to hours. Consequently, a system of delayed liquid effluent releases allows ANSTO E-752 7 > > radionuclides to decay significantly prior to being released to the sewer. The radionuclides produced by the NMC include thallium-201, thallium-202, gallium-67, cobalt-57, zinc-65 and iodine-123. Atmospheric releases of radionuclides include iodine-123, fluorine-18, thallium-201 and gallium-67, all of which are very short-lived. 2.4 WASTE OPERATIONS AND TECHNOLOGY DEVELOPMENT Waste Operations and Technology Development, within the Nuclear Technology Division of ANSTO, is responsible for radioactive waste treatment at the LHSTC. All liquid effluent generated on-site is analysed and treated if necessary before authorised discharge to the sewer. The total annual discharge is typically 100 ML/year - 50 ML of sewage, 45 ML of non-active trade waste effluent and 5 ML of low level active wastewater from laboratories where radioactive materials are routinely handled. The allowable levels of radioactivity in the effluent released to the sewer are governed by a trade wastewater agreement and are independently checked for compliance by Sydney Water Corporation and ARPANSA (ANSTO and Sydney Water Corporation, 2002a). The effluent contains low levels of radionuclides, mainly tritium, and also cobalt-60, chromium-51, cesium-137, strontium-90, radium-226, and occasionally iodine-131 and cesium-134. The sewage, including ANSTO?s effluent, is tertiary-treated at the Cronulla Sewage Treatment Plant (STP) before being released to the sea at the Potter Point ocean outfall. The acceptable limits for eleven radioisotopes (tritium, cobalt-60, strontium-89, strontium-90, iodine-131, cesium-134, cesium-137, radium-226, radium-228, uranium-238 and plutonium-239) are based on the 1993 World Health Organisation "Guidelines for Drinking Water Quality" (WHO 1993), as specified in the Sydney Water Corporation trade wastewater agreement with ANSTO. Radioisotopes, which decay by alpha or beta emissions and do not belong to the above set of eleven, are classified as "unspecified" radioisotopes - these are considered to be present as the most restrictive isotopes for each decay type, ie radium-226 (alpha decay) and strontium-90 (beta decay). Typical monthly effluent discharges for gross-alpha and gross-beta emitting radionuclides are < 0.8 Bq/L and 7.0 Bq/L, respectively ? significantly lower than the limits set by Sydney Water Corporation. The major contributing radioisotopes to the gross-alpha activities are uranium-238, uranium-234, thorium-230, thorium-228, polonium-210 and radium-226 (all naturally-occurring). The major contributors to the gross-beta activities are cobalt-60, chromium-51, cesium-137 and iodine-131. As specified in the Sydney Water Corporation trade wastewater agreement with ANSTO the wastewaters are analysed for certain non-radionuclide components (pH, ammonia, biological oxygen demand, grease, suspended solids, total dissolved solids and zinc) and are further processed if necessary to meet the acceptance criteria before discharge to the sewer. 2.5 LITTLE FOREST BURIAL GROUND Between 1960 and 1968 the Australian Atomic Energy Commission (AAEC, the precursor to ANSTO) used a small area locally known as Little Forest (see Figure 1, section 5) for the disposal, by burial, of solid waste with low levels of radioactivity and beryllium oxide (non-radioactive) that was generated predominantly at the LHSTC. Regular surveillance and monitoring of the Little Forest Burial Ground (LFBG) is designed to detect any off-site transport of radionuclides by windborne transport of soil particles or surface or ground waters. 3. Regulatory and Legal Framework The Australian Nuclear Science and Technology Organisation (ANSTO) was formed in 1987 and is a Commonwealth Government Statutory Authority. It superseded the AAEC, which originated in 1953. In accordance with Section 7a of the Australian Nuclear Science and Technology Organisation Act (1987), ANSTO is exempt from the application of State laws where those laws relate to the use of land, environmental consequences of the activities of ANSTO, radioactive materials and dangerous goods, or certain types of licensing. Notwithstanding this, ANSTO has a policy of satisfying relevant NSW statutory requirements, where no Commonwealth legislation exists. Key legislative and regulatory requirements at ANSTO facilities in relation to environmental protection are summarised in Table A. 8 ANSTO E-752 > Table A. Key legislative and regulatory requirements relevant to ANSTO facilities in relation to environmental protection ANSTO reports to ARPANSA under an Airborne Radioactive Discharge Authorisation that incorporates a multi-layer system of radiological protection, designed to ensure that doses to the public are kept As Low As Reasonably Achievable (the ALARA principle). For practical implementation of the ALARA objective, the airborne discharge authorisation incorporates a system of notification levels for discharges. Annual notification levels for the LHSTC and NMC are such that the effective dose rate to the public would not exceed the ALARA objective of 0.02 mSv/year, even if all releases from a site were at the notification level. The ALARA objective is 2% of the 1 mSv/year limit for annual effective dose to members of the public recommended by the National Occupational Health and Safety Commission, NOHSC, (ARPANSA 2002). Notification levels are applied to individual discharge points on the basis of radionuclide type. Four-weekly, quarterly and annual notification levels are effectively trend indicators that, if reached, trigger further investigation of airborne emissions from a particular stack. Notification levels are considered in more detail in the Licence Conditions Handbook issued by ARPANSA (31 May 2001). Routine discharges of treated, low-level liquid effluent from the LHSTC and NMC are made to the sewer under the terms of trade wastewater agreements, negotiated with Sydney Water Corporation. Liquid effluent discharges from the LHSTC are required to comply with (a) drinking water quality levels for radioactivity at the Cronulla STP and (b) concentration limits for non- radiological components of the effluent. Liquid effluent discharges from the NMC are subject to limits set for specific radionuclides stipulated in the trade wastewater agreement with Sydney Water Corporation. Stormwater from the LHSTC flows into small local streams that are classified as Class C surface waters under regulations associated with the NSW Protection of the Environment Operations Act (1997). The act sets out relevant limits for gross alpha and beta radioactivity in these waters. The Australian Drinking Water Guidelines (ADWG; NHMRC and ARMCANZ, 1996) are used to provide context for the presence of tritium and some other radionuclides in surface and groundwaters, although there are no legal or other requirements to meet these levels. ANSTO E-752 9 Driver Australian Radiation Protection and Nuclear Safety Act (1998) Airborne Radioactive Discharge Authorisation (2001) Trade Wastewater Agreement (No. 4423, 2001/2002) (ANSTO and Sydney Water Corporation 2002a) Trade Wastewater Agreement (No. 13966, 2001/2002) (ANSTO and Sydney Water Corporation 2002b) NSW Protection of the Environment Operations Act (1997) Crown Lands Act (1989) Environment Protection and Biodiversity Conservation Act (1999) National Biodiversity Strategy (1996) Native Vegetation Conservation Act (1997) Rural Fires Act (1997) Organisation ARPANSA ARPANSA Sydney Water Corporation Sydney Water Corporation NSW EPA Commonwealth Government Commonwealth Government Commonwealth Government Commonwealth Government State Government Summary Regulates facility licence conditions at all ANSTO sites; specifies exemption levels for radioactive materials. Reports against facility licence conditions. Incorporates a multi-layer system of radiological protection, designed to ensure that doses to the public are kept as low as reasonably achievable (ALARA) for LHSTC and NMC (ARPANSA 2001). Authorisation to discharge treated liquid effluent from LHSTC to the sewer. Authorisation to discharge treated liquid effluent from the NMC to the sewer. Provides radiological limits for Class C stormwater/surface water drainage. Environmental protection principles are observed in relation to the management and administration of ANSTO sites. Environmental assessment of projects having national importance (Replacement Research Reactor). Integration of biodiversity conservation with natural resource management. Conservation and management of native vegetation. Bushfire hazard management. 4. Assessment of Potential Exposure 4.1 BACKGROUND RADIATION Background radiation is naturally present in our environment. The average natural background effective dose rate to the Australian public (~1.5 mSv/year; Webb et al. 1999) consists of ~0.9 mSv/year from external radiation sources (such as terrestrial and cosmic radiation) and ~0.6 mSv/year from internal radiation sources (such as potassium-40 and radon). Natural background radiation varies from place to place on the earth (eg with rock type and altitude) and is affected by lifestyle (eg choice of building materials, ventilation of homes, frequency of flying). The radiation dose from natural background is estimated at ~3.5 mSv/year, averaged worldwide, but can be greater than 50 mSv/year (see http://www.arpansa.gov.au/baseline.htm). 4.2 EXPOSURE PATHWAYS AND CRITICAL GROUPS Nuclear facilities contribute radioactivity that is additional to the background radiation we all experience and, consequently, such facilities are subject to very strict controls. In Australia, the recommended maximum additional public dose rate is 1 mSv/year (ARPANSA 2002). ANSTO has a site dose rate constraint of 0.3 mSv/year (LHSTC) and a much lower ALARA objective for dose rate to the public from airborne emissions from the LHSTC and NMC sites. The concepts of exposure pathways (the possible avenues by which members of the public could be exposed to radioactivity originating from a given source) and critical groups (people at greatest potential risk of radiation exposure) are used internationally to derive levels for release of radioactivity into the environment, and form the basis for ARPANSA regulations. Potential exposure pathways by which radionuclides routinely discharged from ANSTO sites could lead to radiation exposure of members of the public, are: ? airborne emissions causing external radiation doses from dispersing radioactive gases; ? wash-out or deposition of airborne radionuclides entering the food chain leading to exposure by drinking water or eating food; ? discharge of low-levels of radioactivity through the Sydney Water Corporation sewage treatment system and into the sea, leading to exposure of workers at the sewage treatment plant, uptake by fish and accidental ingestion of seawater by swimmers; and ? contamination of groundwater or soil used for drinking or food production leading to exposure by ingestion/inhalation. Impact assessments due to any activity associated with a nuclear facility are estimated as radiation doses to members of the public. A critical group is defined as a reasonably homogeneous group of members of the public typical of individuals who are likely to receive the highest radiation dose via a given exposure pathway from a given source (IAEA 1996). The size of a critical group will usually be up to a few tens of persons but may consist of a single hypothetical individual (ICRP 1984). In order to satisfy the homogeneity criterion the ratio of the maximum to minimum dose values should not exceed an order of magnitude across the critical group. A recent study, based on previous effluent and environmental monitoring, identified critical groups for assessing the potential impact of ANSTO?s releases by (a) reviewing internationally recognised principles, (b) convening expert focus groups to consider possible airborne and aqueous effluent pathways and exposure and (c) estimating realistic doses from airborne and liquid discharges. Hypothetical individuals (excluding ANSTO employees) were identified for routine airborne discharges to the environment from the LHSTC. These included adults living at the Steven?s Hall Motel (near ANSTO?s front gate) and adults living in Engadine or Barden Ridge (near the boundary of ANSTO?s 1.6 km radius buffer zone) who also work at the Lucas Heights Waste Management Centre (located adjacent to the LHSTC) and use the nearby bike track for recreation (within ANSTO?s buffer zone) (Figure 1). Children and infants were also considered - children living in Engadine or Barden Ridge who attend Engadine Primary School or Lucas Heights Community School and also use the bike track for recreation, and infants living in Engadine or Barden Ridge. The transport and dose-estimation model PC-CREAM was used to estimate the doses for these individuals. These calculations showed that the small ANSTO contribution to public dose was largely in the form of an external dose due to gamma radiation from the passing airborne plume 10 ANSTO E-752 > of radionuclides (primarily the noble gas argon-41). The assessed dose rates for the hypothetical individuals ranged from 0.0008 to 0.003 mSv/year, with the maximum potential dose rate to those individuals resident at the Stevens Hall Motel (see Figure 2, section 5), who could therefore be considered the Critical Group. However, the full range of doses covers less than a factor of ten and so it would be in keeping with international practice to consider all the hypothetical individuals as a single Critical Group, potentially affected by airborne releases. Note that the recent study used more realistic exposure scenarios than the conservative ones routinely used for calculating dose from airborne emissions and reported here (see below). For example, the routinely estimated dose from airborne emissions to people living at the Stevens Hall Motel assumes that a hypothetical individual is outdoors (i.e. unshielded from gamma radiation) for 100% of a year and so estimates a higher dose than is realistic, given that people spend significant time indoors. Also note that the routine dose estimation for airborne emissions does include residents at Stevens Hall. Sydney Water Corporation has upgraded the Cronulla STP to provide tertiary treatment of sewage. Operational plans include recycling the sewage sludge for application as a slow release fertiliser (biosolids) on agricultural land, and use of the treated water for non-potable purposes. Hypothetical individuals potentially exposed to radiation associated with ANSTO?s liquid effluent discharge were therefore identified on the basis of the potential exposure pathways relevant to routine liquid discharges from the LHSTC and with consideration of the Cronulla STP?s operational plans. These hypothetical individuals included an STP worker handling biosolids, a farmer with child and infant whose food is grown on land with the allowed single application of biosolids and a person eating seafood (30 kg of fish and 10 kg of shellfish) taken near the Potter Point ocean outfall. Dose assessments for the liquid effluent discharge were made using either the generic model described in the International Atomic Energy Agency?s Safety Report Series 19 (IAEA 2001) or the ANSTO-developed RadCon model (Crawford et al. 2000). The assessed dose rates ranged from 0.000001 to 0.0002 mSv/year and were all much less than those estimated for the critical group identified, above, for routine airborne releases. Note that dose assessment for hypothetical individuals potentially exposed to radiation from liquid effluent discharges from the LHSTC is not routinely carried out or reported in the Effluent and Environmental Monitoring Report. 5. Sampling of Emissions and Environment The ANSTO routine monitoring program for the 2001-2002 and 2002-2003 financial years is summarised in Table B. The table describes the media sampled, the range of analyses performed, and the location and frequency of sampling. A total of approximately 6000 samples were taken and some 10,000 analyses performed. Detailed descriptions of sampling and analytical methods are given in Hoffmann et al. (2001). 5.1 AIR AND LIQUID EMISSIONS Airborne radionuclide emissions are passed through HEPA-filters to remove particles and charcoal filters to remove vapour, prior to discharge through ?stacks?. The stacks were sampled continuously by drawing off a proportion of the airflow and accumulating weekly data for specific radionuclides from either real-time measurement or after physico-chemical trapping over a week. Tritiated water vapour was trapped from air bubbled through a series of water-filled bottles. Radio-iodine was sampled using charcoal-filled ?Maypack? cartridges, also fitted with particle filters. Noble gases were measured in situ using a gamma detector and recording daily accumulations of counts. Airflow through each stack was measured on a quarterly basis using a hot-wire anemometer. Combined, these measurements enable reporting of total radionuclide releases from each stack. The different liquid waste streams at the LHSTC (treated low-activity liquids, trade effluent and sewage) are combined in holding tanks at the on-site liquid effluent plant prior to discharge into the Sydney Water Corporation sewer. Proportional samples of all liquid effluent discharges were collected and analysed for gross alpha and gross beta radioactivity, pH, biological oxygen demand, grease, suspended solids, ammonia and zinc. A volume-weighted composite sample was also produced from all pipeline samples each month and analysed for gross alpha/beta, tritium and gamma radioactivity. ANSTO E-752 11 > 12 ANSTO E-752 SAMPLE TYPES ANAL YSES LOCA TIONS SAMPLING FREQUENCY ESTIMA TED SAMPLES ESTIMA TED ANAL YSES per year per year per year SOURCE MONITORING Airborne Gases & particles (Maypacks) GA, GB, Gamma 15 Stacks (LHSTC); 1 Stack (NMC) Daily (work; NMC) and W eekly(LHSTC) 2050 5170 Air flow Flow 15 Stacks (LHSTC) W eekly(Maypacks) and Quarterly(Stack) 840 840 Gases Gamma 3 Stacks (LHSTC); 1 Stack (NMC) Daily(work) 980 980 Gas (water vapour) HTO 4 Stacks (LHSTC) W eekly 208 208 Liquid W astewater HTO, GA, GB 1-2 Holding T anks (LHSTC W aste Optns) Daily(work) 368 1104 W astewater HTO, GA, GB, Chem 1 Sample T ank (LHSTC W aste Optns) Ever y 3-4 Days 104 416 W astewater HTO, GA, GB, Gamma 1 Sample T ank (LHSTC W aste Optns) Monthly(from pipeline composites) 12 48 ENVIRONMENT AL MONITORING W aters Rainfall volume 1 Site (LHSTC) 15 minute inter vals Stormwater HTO 3 Bunds (A, B, C) Daily(work) to give Monthly composite 735 36 Stormwater HTO, GA, GB, Gamma 1 Bund (C); 1 Site (MDP+60m) W eekly and Monthly composite (from weekly samples) 128 512 Creek or river or estuar y HTO 3 Sites (Barden's Ck, Forbes Ck, W o ronora R) W eekly(B Ck) and Monthly(F Ck, W R) 76 76 Creek or river or estuar y GA, GB 4 Sites (B Ck, MDP Ck, Strassman Ck, B&Mill Cks jnctn) Monthly(B, M & S Cks) and Y early(B&M Cks j nctn) 37 74 Creek or river or estuar y Gamma 1 Site (B&Mill Cks jnctn) Y early 1 1 Seawater HTO 1 Site (Potter Pt; ~12 samples) 6 Monthly ( ie twice per year) 24 24 W astewater HTO 1 Sewage T r eatment Plant (Cronulla; ~24 samples) 6 Monthly 48 48 Groundwater HTO, GA, GB, Gamma 15 Bores (LFBG) 6 Monthly 30 120 Groundwater HTO, GA, GB, Gamma, Chem ~20 Bores (LHSTC & Buffer Zone) Y early 20 100 Groundwater WQ ~20 Bores (LHSTC & Buffer Zone) Quarterly 80 80 Sump water HTO, Gamma 1 Sump (B27) Monthly 12 24 Air Wind speed & direction 1 Site (LHSTC at 10 and 49m) 15 minute inter vals Air temperature, humidity 1 Site (LHSTC at 2, 10 and 49m) 15 minute inter vals Gases (Maypacks) Gamma 4 Stations (LHSTC) W eekly 208 208 Particles Pu, Be 1 Site (LFBG) Quarterly(Be) and Y early(Pu) 5 5 Soil/Sediment Sediment GA, GB, Gamma 3 Bunds (A, B, C); 2 Cks (Bardens, Mill Ck) Y early 5 1 5 Biota Algae & fish & barnacles Gamma 2 Sites (Potter Pt, RNP) 6 Monthly 12 12 Dosimetr y Rate sur vey 2 Sites (Effluent Pipeline, LFBG) 6 Monthly(E-pipe) and Y early(LFBG) 3 3 TLD 19 Sites (LHSTC, Suburbs, Cronulla STP) Quarterly 76 76 INVESTIGA TIONS Soil/Sediment Soil/Sediment Gamma 2 Areas (LFBG, Effluent Pipeline) As indicated by dose-rate sur vey APPROXIMA TE TOT ALS APPROXIMA TE TOT ALS 6100 10200 T able B. Summar y of envir onmental monitoring at ANSTO sites, July 2001 to June 2003 Notes: W orking days assumed to be 245, excluding weekends and public holidays Analyses: HTO = tritium analysis (after distillation) GA = Gr oss Alpha counting; GB = Gr oss Beta counting Gamma = Gamma spectr ometr y that varies in number of nuclides targetted (can include specific noble gases like Ar -41 or individu al radionuclides like I-131) Chem = non-radiological analysis that varies in number of analytes (can include major ions, selected metals, organics, plant nu trients, pH, conductivity , suspended solids) W ater Quality (WQ) = field WQ parameters ( eg water level, pH, conductivity) Flow thr ough Maypacks is measur ed using a floating ball gauge, and in stacks using a hot-wir e an emometer 5.2 ENVIRONMENT Environmental sampling is carried out primarily to determine where and in what quantities radioactive emissions from the LHSTC are found in the local environment. Environmental sampling is focussed according to our knowledge of potential radionuclide emission sources and the environmental pathways that may disperse radionuclides in a way conferring potential dose to the public. Samples of various media, including water, air and soil, plus some biota, are collected at locations in and around the LHSTC and these sample sites are shown in Figures 1-5. Sampling locations include local creeks (eg Mill, Bardens and Forbes Creeks), the Woronora River, the LFBG and Potter Point. Radioactive analyses of environmental samples include tritium analysis of water samples, gross alpha and beta analysis of surface water and groundwater, and gamma spectrometric measurements of various media. Water sampling formed the greater part of the environmental sampling in the period from January 2002 to June 2003. The stormwater bunds at the LHSTC (A, B and C in Figure 2) were sampled on working days, prior to the bunds being emptied. These daily samples were combined to give representative monthly samples of stormwater. Weekly samples were taken at Bund C, on the main disposal pipeline (MDP) creek that drains ANSTO?s waste operations area, and at a natural pool some 60 metres further downstream. Weekly samples were also collected at the Bardens Creek weir, downstream of the stormwater Bund A. For some analyses, weekly samples were combined into monthly composites. Monthly water samples were taken from the State Pollution Control Commission (SPCC) sampling points (named for having been selected by the then SPCC in 1975; see Figure 2) at Bardens Creek weir, Strassman Creek and MDP Creek weir. These sites lie on the drainage lines leaving the LHSTC but are within ANSTO?s 1.6 km Buffer Zone. Sampling also occurs in the local area beyond the Buffer Zone, with monthly samples of estuarine water collected from Forbes Creek and the Woronora River. Samples were collected annually from near the junction of Mill and Bardens Creek, which drain the LFBG. 5.3 METEOROLOGY In common with similar organisations operating nuclear facilities, ANSTO undertakes a program of meteorological measurements. The prime reason for such a program is to allow estimates to be made of the downwind concentration of any airborne pollutants, particularly radionuclides, released from the LHSTC through routine operations or under accident conditions. The data collected from this program provide the necessary input to the atmospheric dispersion and dose- estimation model, PC-CREAM, which is used to compute the effective dose to an individual due to the routine airborne release of radionuclides. The on-site meteorological tower and associated laboratory are shown in Figure 2. Two off-site meteorological stations are also used to measure the influence of the local terrain on wind flow, dispersion patterns and temperatures. These stations (Figure 1) are located at the Boys Town School (Engadine) and at the "Shackels Estate" in the Woronora River valley. The meteorology program includes measurements of wind speed, direction and variability, as well as precipitation, evaporation, temperature, pressure and humidity. These data are collected and analysed continuously, and are displayed on ANSTO's web site in addition to being reported to the Australian Bureau of Meteorology. The long-term climatology data for the LHSTC are updated and published approximately every five years. The most recent report available is from 1975 to 1996 (Clark 1997). 6. Environmental Monitoring (January 2002- June 2003) Monitoring data in this report covers an 18-month period from January 2002 to June 2003. For data routinely collated over financial years, the data tables for the full 2001-2002 period are included. For some environmental samples, analytical results were below the minimum detectable activity (MDA) for a radionuclide. The detection limit can differ for each individual analysis. Indicative, median, MDAs for various radionuclides and environmental media are given in Table 1 (see Data Tables section, below). In general, data are summarised as median ? interquartile range (IQR), where IQR is the 75 th minus the 25 th percentile of the data, a similar concept to a standard deviation relative to the mean. ANSTO E-752 13 > 14 ANSTO E-752 Figure 1. Location of the LHSTC & off-site sampling points ANSTO E-752 15 Figure 2. Location of stormwater, air & external radiation monitoring points at the LHSTC 16 ANSTO E-752 Figure 3. Location of groundwater monitoring piezometers at the LHSTC ANSTO E-752 17 Figure 4. Little Forest Burial Ground ? Configuration of bores currently sampled and location of the burial trenches including S1 and S2. 18 ANSTO E-752 Figure 5. Location of the Cronulla Sewage Treatment Plant and sampling zones at Potter Point Ocean Outfall and The Royal National Park 6.1 AIRBORNE EMISSIONS Tables 2 and 3 show the airborne activity discharges for the 2001-2002 and 2002-2003 financial years for the 15 stacks at the LHSTC and the single stack at the NMC. They show the total amount of radioactivity discharged and the discharges expressed as a percentage of the relevant annual notification levels. The "all other nuclides" column includes all radionuclides for which there is no specific notification level. Notification levels act as conservative triggers for follow-up investigation and are more fully explained in section 3, above. In the 2001-2002 financial year, argon-41 emission from stack 15M, the least significant of the two HIFAR stacks, reached the annual notification level (Table 2) and the CEO ARPANSA was notified. In October 2002, ARPANSA agreed that the notification level for stack 15M should be increased to 20 TBq. Argon-41 emissions from stack 15M were at 53% of the revised notification level for 2002-2003 (Table 3). In 2002-2003, annual notification levels were reached for specific radionuclides from two stacks and the CEO ARPANSA was notified. Tritium emissions from Building 20, the decontamination facility, reached 161% of the notification level. Noble gas emissions from Building 54 increased in the latter half of the 2002-2003 financial year and xenon-133 discharges reached 107% of the annual notification level (Table 3). In both cases there were appropriate investigations and follow-up. 6.2 LIQUID EFFLUENT 6.2.1 Lucas Heights Science and Technology Centre A trade wastewater agreement with Sydney Water Corporation allows ANSTO to discharge treated liquid effluent from the LHSTC to the sewer (see section 3). The low activity effluent undergoes an alum-based chemical treatment process for the removal of radionuclides. The trade wastewater is tested and chemically-treated if necessary. Sewage is partially treated by aeration on-site. Prior to every discharge, the radioactive content and specified non-radiological water-quality parameters are measured. Table 4 shows the average monthly activities of gross alpha, gross beta and tritium radioactivity in liquid effluent prior to discharge. The alpha values are all less than the minimum detectable activity, hence the combined quotients in the last column are also shown as less-than values. The combined monthly activity quotients for alpha, beta and tritium activity ranged from < 0.06 to < 0.19, with a median value of < 0.12, ie less than 12% of the allowed limit (ie a quotient of one). Figure 6 charts the monthly quotients for alpha, beta and tritium activities in liquid effluent discharges for the period January 2002 to June 2003. ANSTO E-752 19 Figure 6. Monthly quotients for alpha, beta and tritium radioactivity in liquid effluent at the LHSTC, January 2002 to June 2003 Quotient V alue The activities of gamma-emitting radionuclides in the monthly pipeline composite samples are given in Table 5. Of the radionuclides listed, only cobalt-60, cesium-137 and iodine-131 were detected in more than 50% of samples. The activity of cobalt-60 ranged from less than the minimum detectable activity (0.15 Bq/L) to 3.03 Bq/L, with a median (? IQR) of 0.66 ? 0.46 Bq/L. Cesium-137 ranged from less than the minimum detectable activity (0.11 Bq/L) to 4.0 Bq/L, with a median (? IQR) of 0.39 ? 0.45 Bq/L. Iodine-131 was detected in only 61% of samples, its overall range was from less than the minimum detectable activity (0.10 Bq/L) to 0.74 Bq/L, with a median (? IQR) of 0.22 ? 0.33 Bq/L. The results for non-radioactive parameters of the liquid effluent (suspended solids, pH, ammonia, biological oxygen demand, grease and zinc) are shown in Table 6, along with the relevant standards for acceptance to the Sydney Water Corporation sewer. The range of values is reported, along with the mean and median. Of the samples analysed, 95% must be less than or equal to the relevant standards for acceptance. For the period January 2002 to June 2003, all median values were within acceptable bounds, although the ranges of pH, biological oxygen demand and grease indicate that occasional samples fell outside the standards. A recent study was made of longer-term trends in liquid effluent radioactivity. The study found that discharge trends for unspecified alpha, beta-emitting nuclides and tritium, from January 1998 to March 2002 were within the limits for allowable discharge. The higher quotients in mid-2001 reflect ANSTO?s operations and were attributed to HIFAR shut-down and subsequent contamination of effluent water by HIFAR-based operations. The tritium and beta activities in liquid discharges, during this period, increased the quotient-value. The average monthly discharge of tritium in liquid effluent during 2001 was 1.62 x 10 7 Bq/m 3 (range from 1.23 x 10 6 to 9.90 x 10 7 Bq/m 3 ) which was well below the limit of 1.95 x 10 8 Bq/m 3 as set out in the trade wastewater agreement. Release trends for tritium since 1998 show a number of maxima resulting from HIFAR shut-down activities, however all are well below the allowable limits. Typically, approximately 0.008 Bq/L of radium-226, an alpha-emitter, was found in liquid effluent samples, much less than the allowable limit (12.5 Bq/L) under the trade wastewater agreement. The non-radioactive components of the liquid effluent were also studied recently, over a 6?9 month period in 2002. The chemicals of interest were soluble ionic species, plus organic-based residues arising from waste treatment activities within the local area. There was no endeavour to analyse for contaminants in liquid effluent that would be relevant to other industries. All analyses were conducted by an independent, NATA registered, laboratory. Although past operations on-site have involved quantities of tellurium, arsenic and mercury, the levels of these soluble species in discharged effluent are detectable at extremely low concentrations (< 1 ?g/L). Chromium is of particular interest because of its past use as an anodic corrosion inhibitor in HIFAR cooling towers and because of the environmental toxicity of hexavalent chromium; however it has been replaced by phosphate since July 2000. Zinc is currently used as a cathodic corrosion inhibitor in the cooling towers. The replacement of chromium is reflected in the reduced concentrations of this soluble metal species found in the ANSTO effluent. All organic-based residues in ANSTO effluent were below the level of detection and reporting for specific pesticide and herbicide residues. Pesticides were typically below a concentration of 0.5 ?g/L (limit imposed < 10 ?g/L total pesticides). The once popular organochlorine-pesticides, Aldrin, Dieldrin and Endrin were below 0.5 ?g/L and DDT (dichlorodiphenyltrichloro ethane) pesticide was less than 2 ?g/L. Herbicide defoliant residues were typically < 10 ?g/L (limit < 100 ?g/L). Levels of radioactivity and non-radioactive components of all liquid effluent discharges to the sewer from January 2002 to June 2003 met the standards for acceptance specified in the trade wastewater agreement with Sydney Water Corporation. 6.2.2 Effluent Dilution ? LHSTC to the Cronulla STP The Cronulla STP receives sewage and wastewaters from the Sutherland Shire, including treated effluent from the LHSTC. ANSTO is required to comply with the Sydney Water Corporation trade wastewater agreement, which nominates a minimum value of 25 for the dilution factor between the ANSTO discharge tanks and the Cronulla STP. Compliance is confirmed at least twice each year by direct measurement of tritium levels in the plant. The Cronulla STP was upgraded to provide tertiary treatment from July 2001 and two additional effluent dilution studies were 20 ANSTO E-752 undertaken (Table C). There were some problems with sampling equipment and low levels of tritium in the effluent released which meant that the dilution factors were only calculable for two of four studies attempted. The maximum activity of tritium observed in the Cronulla STP was 204 Bq/L and the minimum dilution factor was 61. Table C. Effluent dilution studies at Cronulla Sewage Treatment Plant, January 2002 to June 2003 Notes: 1. In each case, 210 kL of effluent was released from the LHSTC, over 3 hours. 2. The data relates to samples collected at the ?interstage? location in the Cronulla STP, ie following the sedimentation tank, in the vicinity of the interstage lift pump. The levels of tritium observed within the Cronulla STP are an order of magnitude less than those stipulated in the Sydney Water Corporation trade wastewater agreement. This confirms that ANSTO is in full compliance with its obligations under the agreement. During June 2003, samples were collected at the plant exit over a 48 h period commencing 1500 hr 17 June 2003. Over this period, the mean tritium value was 16 ? 1 Bq/L. This value is very low compared with the Australian drinking water guideline (NHMRC and ARMCANZ 1996) of 7600 Bq/L, and will depend on the history of ANSTO releases over the previous couple of days and the dynamics of the water flow through the plant. 6.2.3 National Medical Cyclotron Liquid effluent is discharged from the NMC to the Sydney Water Corporation sewer under the terms of a trade wastewater agreement that incorporates limits set by the NSW EPA for specific radionuclides. The radiopharmaceutical products made at the NMC are relatively short-lived, with half-lives ranging from minutes to hours in most cases. Consequently, a system of delayed liquid effluent releases ensures that most radionuclides have decayed significantly prior to being released. The average levels of radionuclides discharged to sewer each month from the NMC are shown in Table 7, along with calculated mean and median values. The average discharges contained very low levels of radionuclides, 5% or less of the NSW EPA monthly limits for thallium-201, thallium-202, gallium-67, cobalt-57, zinc-65 and iodine-123. Liquid effluent discharges from the NMC were therefore well within the required limits in the period from January 2002 to June 2003. 6.3 AIR 6.3.1 Ambient I-131 No iodine-131 was detected in ambient air sampled continuously at four locations on the LHSTC boundary fence during the reporting period (Table 8). All results for the 78 weekly measurements were below the minimum detectable level of 0.0025 Bq/m 3 . 6.3.2 LITTLE FOREST BURIAL GROUND ? AIRBORNE PARTICULATES Quarterly samples of airborne particles were collected on windy days (to maximise particulate collection) using a mobile high-volume air sampler (Table 9). The total volume of air sampled during the period was 2617 m 3 . The exposed filters were analysed for stable beryllium and plutonium-239/240; however, neither was detected within the 18-month reporting period. 6.3.3 External Gamma Radiation Thermoluminescent dosimeters were used to measure ambient gamma radiation (including the ANSTO E-752 21 Tritium activity at Maximum tritium Date (1) LHSTC release point activity in Cronulla STP (2) (Bq/L) (Bq/L ) Dilution Factor Comments July 8 2002 4630 Bq/L 70 Bq/L 61 The transit time to the interstage within the plant (12.00 pm) was 18 hours. A second release commenced at 15:15 hours (8 July 02). This did not affect the calculation of the dilution factor. June 17 2003 18,300 Bq/L 204 Bq/L 90 The effluent transit time from LHSTC to Cronulla (9.00 am) STP was 10 hours. contribution from natural background radioactivity) at various locations around the LHSTC (Figure 2), at three private residences in the nearby suburbs of Barden Ridge, Engadine and Woronora and at the Cronulla STP (Figure 1). Measurements at the three local residences, which can be taken as indicative of local background for the LHSTC, showed median external dose rates of 1.04 ? 0.20 and 1.09 ? 0.13 mSv/year for the 2001-2002 and 2002-2003 financial years, respectively (Table 10). The local absorbed dose rates in air were consistent with the background levels reported for Australian capital cities by the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR 2000). The absorbed dose to air at one site on the southern sector of the LHSTC perimeter fence (Location 2, see Figure 2) is affected by nearby stored radioactive material. An annual dose rate of 3.23 mSv/year was recorded at the site for 2001-2002 and 2.94 mSv/year for the 2002-2003 financial year - this part of the site is not readily accessed by the general public. The dose rates for other locations were in the ranges 0.80 to 1.54 mSv/year and 0.93 to 2.15 mSv/year for the two years (Table 10) ie generally within the local background range. 6.3.4 Aerosol Particles (PM 2.5) ANSTO has been measuring and characterising fine aerosol particles at the LHSTC for the international Aerosol Sampling Program (ASP) for well over 10 years. The ASP is a study to determine the elemental composition of fine suspended particulates with aerodynamic diameters less than 2.5 microns (1 micron is one 1 millionth of a metre) often referred to as PM2.5. At high levels, fine aerosol particles affect human health, reduce visibility and have been shown to play a key role in global climate change processes. Particles in the PM2.5 size range mainly originate from anthropogenic combustion sources such as motor vehicle exhausts, fossil fuel burning and other high temperature industrial processes, producing sulphates, lead, bromine, organics, potassium and heavy metals. Some natural aerosol sources such as airborne soils and sea spray will have size components below and above 2.5 ?m in diameter. Figure 7 shows the average monthly mass of PM2.5 particles collected at the LHSTC in the 2002 calendar year. Currently there is no Australian or NSW standard for PM2.5 fine particles. However, in July 1997 the United States Environmental Protection Agency introduced a national air quality standard for PM2.5 particulates (USEPA 2002). This standard is mainly based on health-related issues and specifies an annual average of 15,000 ng/m 3 with a maximum 24-hour average, at the 2nd percentile, of no more than 65,000 ng/m 3 (depending on the sampling frequency). Thus, for 22 ANSTO E-752 Figure 7. Average monthly mass of fine aerosol particles (less than 2.5 microns in diameter) collected over 24-hour periods, Lucas Heights, 2002 ng/m 3 Mean Monthly PM2.5 data - Lucas Heights, 2002 weekly sampling no more than two exceedances per year of 65,000 ng/m 3 would be allowed in order to comply with the standard. The levels of PM2.5 fine particles observed at the LHSTC in the calendar year 2002 were well within the requirements of the US EPA air quality standard. Analyses of the particulate composition demonstrates that most of the aerosol particles do not originate from ANSTO. 6.3.5 Radiological Characterisation of the LHSTC and Buffer Zone Under site licence and Environmental Impact Statement (EIS) conditions for the Replacement Research Reactor (RRR), ANSTO was required to establish a radiological characterisation of the RRR site and Buffer Zone, to provide a fundamental basis for ongoing radiological monitoring programs and the detection of radiological trends over time. An extensive survey, using a helicopter equipped with an airborne gamma detection system, was supported by ground- based, more intensive gamma surveys of areas of interest. The ground-based studies also covered areas where the helicopter was not permitted to fly, ie the HIFAR security area. Since gamma ray emissions are affected by groundwater content, soil moisture analyses at representative locations in the buffer zone established the conditions under which any future airborne surveys should be conducted. These soil samples were also subjected to gamma spectroscopy analysis to determine the presence of natural and man-made radionuclides. The studies revealed that all man-made radionuclides were contained within, or close to, the LHSTC boundary. The locations of man-made radionuclides in the LHSTC could be related to various processing and waste operations. The locations of naturally occurring radionuclides (potassium- 40, uranium-238 and thorium-232) were consistent with the geological rock structures and soil types in the region. 6.4 SURFACE WATERS Surface waters include stormwater runoff as well as flows of near-surface groundwater, with the proportion depending on the weather in the preceding days. Concrete bunds (of about 2 m 3 capacity) on the three main stormwater outlets at the LHSTC (A, B and C in Figure 2) temporarily retain surface water before its release off-site. These bunds are inspected and emptied each week-day morning to facilitate on-site containment and treatment of any small accidental releases of contaminated liquid. The bunds are also used as environmental monitoring points. 6.4.1 Tritium in surface waters Tritiated water vapour released to air from HIFAR operations, readily exchanges with rainwater and other surface waters and is present in stormwater and groundwater at the LHSTC. Tritium was detected in monthly composite water samples (work-daily samples combined) from Bunds A, B and C (Table 11) at levels ranging from less than the minimum detectable activity (10 Bq/L) to 610 ? 20 Bq/L, with a median activity (? IQR) of 120 ? 148 Bq/L. Weekly samples from Bund C, situated at the top of MDP Creek, were analysed for tritium and the results are shown in Table 12. Tritium activity ranged from less than the minimum detectable activity (10 Bq/L) to 2550 ? 50 Bq/L, with a median activity (? IQR) of 175 ? 220 Bq/L. Weekly samples were also collected from a natural pool on the same drainage line but some 60 m downslope from Bund C ? this was the stormwater sampling point prior to 1994 when the bunds were constructed. The tritium levels in weekly samples from this site, MDP+60 m (Table 13), ranged from less than the minimum detectable activity (10 Bq/L) to 1920 Bq/L, with a median (? IQR) of 100 ? 120 Bq/L. Similarly, weekly water samples were collected from the Bardens Creek Weir, downstream of Bund A on the north side of New Illawarra Rd (Figure 2). The results are given in Table 14. The tritium activity in weekly samples from Bardens Creek weir ranged from less than the minimum detectable activity (10 Bq/L) to 250 Bq/L, with a median activity (? IQR) of 50 ? 70 Bq/L. The range of tritium activities recorded in these water samples from January 2002 to June 2003 were typical of recent years at the LHSTC. The maximum tritium activity in any of the samples from stormwater bunds and nearby sampling points was less than 40% of the ADWG level of 7600 Bq/L (NHMRC and ARMCANZ 1996), given here for context only - this water is not collected and supplied as potable water. The median (50 th percentile) tritium activities for surface waters at LHSTC are much lower, in the range from 50 to 175 Bq/L, ie they are typically less than 3% of the ADWG levels (NHMRC and ARMCANZ 1996). ANSTO E-752 23 6.4.2 Gross alpha and beta radioactivity in surface waters Stormwater from the LHSTC flows into three small streams (Bardens, Strassman and MDP Creeks; Figure 2), that are classified as Class C waters under the regulations associated with the NSW Protection of the Environment Operations Act (1997). As such, there are regulatory limits for gross alpha and beta radioactivity (ie total measures of alpha and beta activity, without discriminating between contributing radionuclides). Gross alpha and beta data for monthly composite samples (combined weekly samples) at Bund C are given in Table 15 from January 2002 to June 2003. The gross alpha activities ranged from 0.017 to 0.081 Bq/L, with a median (? IQR) of 0.034 ? 0.009 Bq/L. For gross beta, the range of activities was from 0.24 to 1.54 Bq/L and the median (? IQR) was 0.68 ? 0.36 Bq/L. Gross alpha and beta data for monthly composite samples (combined weekly samples) at MDP+60 m are given in Table 16 from January 2002 to June 2003. The gross alpha activities ranged from less than the minimum detectable activity to 0.091 Bq/L, with a median (? IQR) of 0.03 ? 0.02 Bq/L. For gross beta, the range of activities was from 0.17 to 0.42 Bq/L and the median 0.30 ? 0.11 Bq/L. The results of gross alpha and gross beta analyses of monthly samples from Bardens Creek weir, Strassman Creek and MDP Creek weir (the SPCC sampling points) are given in Table 17. Figures 8 and 9 graph these results. Taking the three creeks together, gross alpha levels ranged from less than the minimum detectable activity to 0.043 Bq/L, with a median value (? IQR) of 0.016 ? 0.008 Bq/L. Gross beta radioactivity ranged from 0.024 to 1.01 Bq/L, with a median of 0.081 ? 0.132 Bq/L. The maximum gross beta activity was found for Strassman Creek in September 2002. This was an outlier (more than ten times the median value) due to sampling turbid water in very dry conditions when only a very shallow pool remained (samples were analysed unfiltered). The enhanced beta activity almost certainly resulted from incorporation of natural radioactivity associated with uranium thorium series nuclides or potassium-40. Water samples collected near the junction of Mill and Bardens Creeks, which drain the LFBG, showed only natural background levels of gross alpha, gross beta, gamma and tritium activity (Table 18). All results from January 2002 to June 2003 were well below the limits for gross alpha and gross beta activity in the relevant NSW regulations (1.1 Bq/L for gross alpha activity and 11.1 Bq/L for gross beta activity). 24 ANSTO E-752 Figure 8. Gross alpha activity in surface water at the LHSTC, January 2002 to June 2003 Gross Alpha Bq/L Gross Alpha Activity in Surface Water, SPCC Creeks Monthly samples 6.4.3 Gamma-emitting radionuclides in surface waters Gamma spectrometry of monthly composite samples from Bund C (Table 15) showed low but detectable levels of cesium-137, ranging from less than the minimum detectable activity (0.021 Bq/L) to 0.153 Bq/L and, less often, cobalt-60 ranging from less than the minimum detectable activity (0.019 Bq/L) to 0.045 Bq/L. The only other gamma-emitters detected were potassium-40 and beryllium-7, both of natural origin. Cesium-137 was detected with a median activity of 0.01 ? 0.01 Bq/L in monthly composite samples (January 2002 to June 2003) from MDP+60 m (Table 16). Low levels of the natural gamma-emitters, potassium-40 and beryllium-7 were also detected in some samples. No other gamma-emitters were detected. Similarly low levels of cesium-137 and cobalt-60 have been reported in previous years. 6.5 ESTUARINE AND SEA WATERS Monthly samples of brackish/estuarine waters were collected from Forbes Creek (a tributary of the Woronora River) and the Woronora River and analysed for tritium however, as in previous years, none was detected (< 10 Bq/L). The results are presented in Table 19. Offshore sampling for tritium was also conducted near the Potter Point ocean outfall on 9 July 2002 between 0800 and 1500 hr at three locations 10, 90 and 270 m from the outfall in a line bearing 182 degrees. All tritium activities were below the MDA except the following: 10 m from the outfall at 08:00 and 13:00 h (25 Bq/L and 1.1 Bq/L, respectively); 90 m from the outfall at 09:00 and 10:00 h (5.0 and 3.6 Bq/L, respectively); 270 m from the outfall at 10:00 h (5.5 Bq/L). These data indicate the further dilution that occurs between the Cronulla STP and the nearshore area at Potter Point. 6.6 GROUNDWATER 6.6.1 Lucas Heights Science and Technology Centre Groundwater level and quality monitoring at the LHSTC was established in 2000 with the installation and development of a groundwater piezometer network (Figure 3) followed by collection of preliminary data during 2001. Installation of additional piezometers took place in 2002. General piezometer construction details are outlined in Figure 10, illustrating Type 1 (shallow and deep) and Type 2 (open) piezometer construction. There are 28 type 1 piezometers and three Type 2 piezometers within the groundwater monitoring network, which has been designed to monitor some specific facilities, cover all areas within and adjacent to the LHSTC, ANSTO E-752 25 Figure 9. Gross beta activity in surface water at the LHSTC, January 2002 to June 2003 Gross Beta Bq/L Gross Beta Activity in Surface Water, SPCC Creeks Monthly samples and to sample representative groundwater flows from LHSTC (Figure 3). 26 ANSTO E-752 Figure 10. General construction details of Type 1 and Type 2 piezometers at the LHSTC Groundwater flow at the LHSTC is primarily dependent on topographic features. LHSTC is situated on top of a gently north-sloping ridge, with several steep gullies draining into the Woronora River on the eastern side, and shallow depressions forming the headwaters of Bardens and Mill creeks to the west (Figure 11). A significant proportion of the LHSTC site has building and road cover, with the remainder covered by grass or sparse native vegetation. After heavy rain, the stormwater system receives surface flows from roads, buildings and surface drainage lines, and the soil absorbs rain falling on the vegetated portion of LHSTC. For several days following heavy rain, water seeps from the soil into the heads of the gullies surrounding the LHSTC. Discharge via a deeper groundwater path, over a much longer time scale and further down the gullies, ultimately forms the base-flow of the Woronora River. The response of the LHSTC groundwater to heavy rainfall has also been assessed. Groundwater seepage from the general vicinity of the intermediate waste storage facility (Building 27) is routinely collected. The samples were measured each month for gamma-emitting isotopes (americium-241, cesium-137, cobalt-60 and potassium-40) and tritium (Table 20). Cesium-137 was detected occasionally, at levels within the range reported for LHSTC surface water samples (see section 6.4.3) and naturally occurring potassium-40. Tritium activities were stable and well below drinking water guideline levels, with a median (? IQR) of 415 ? 85 Bq/L. Hydrogeochemistry The data for field parameters and major ions for September 2002 are presented in Tables 21 and 22. Groundwater quality at LHSTC is typical of what would be expected for a sandstone aquifer. Groundwaters are acidic to slightly acidic, ranging in pH from 3.88 to 6.30. The aquifer is low in total dissolved solids as reflected by the electrical conductivity values, which range from 300 to1000 ?S/cm. The pH and electrical conductivity values reflect fresh groundwater originating from local rainfall, flowing through the system at a slow rate (ranging from 0.01 to 4 m/year, depending on hydraulic conductivity at the location). The LHSTC groundwaters are predominantly sodium-chloride-sulphate type waters. The source of these ions in these waters would be from marine aerosol input (ie from rainfall originating from the sea). Piezometers monitoring groundwater to the north and north east (ie MW2s,d, MW3s,d, MW4s,d, and MW5s) show a predominance of magnesium with some calcium and bicarbonate type waters. This could ANSTO E-752 27 Figure 11. LHSTC potentiometric surface for the deeper sandstone aquifer (February 2000). Groundwater flow directions (arrows) and flow velocity (m/year) are also marked. reflect a more calcite rich source, possibly from the cementing material of the sandstone in this area. Furthermore, there are no significant trace elements or nutrients identified from the analysis of groundwaters at the LHSTC. In summary, the field chemical data and major ion data confirms that the rate of groundwater movement from rainfall to discharge is small, as also reflected in the generally low ionic concentrations of the groundwater in the area. Radioactivity Groundwater samples were collected at the LHSTC in September 2002, following purging of the wells. These samples were then analysed for alpha, beta, tritium and gamma radioactivity (americium-241, cesium-137 and cobalt-60 in particular). Radioactivity data are given in Table 23. Levels of alpha, beta and gamma radioactivity were found to be negligible in groundwaters in the LHSTC. The few small detections of radioactivity are attributed to natural background levels in particular potassium-40, uranium-238 and thorium-232. Potassium-40 and uranium-238 are commonly associated with the clay fractions of the sediments, while thorium-232 is associated with heavy minerals found in the sand fraction of sediments. Tritium activity in the LHSTC groundwaters ranged from 2.6 to 611 Bq/L. Shallower piezometers (represented as 'S' series) display higher tritium levels than the deep piezometers in nested sets. This reflects a vertical downward hydraulic gradient with tritium levels in recent rainwater decaying as it moves downward and also mixing with less tritiated (older) water. The tritium activities are higher than normal rainfall background in Australian waters, which is approximately 0.4 Bq/L, but the maximum activity is less than 10% of the ADWG (NHMRC and ARMCANZ 1996). The elevated levels of tritium in these waters reflect the contribution from emissions of tritiated water vapour to air associated with HIFAR operations. Rain that falls in the vicinity of the reactor can contain elevated tritium levels. The groundwater regime at the LHSTC can be described in terms of three layers consisting of: ? a near-surface soil and regolith layer, typically less than 2 metres deep; ? a weathered sandstone layer of variable thickness and degree of weathering, from around 1-10 m; and ? an unweathered sandstone layer, greater than 10 metres. A seismic survey showed variability for these three layers, both in their thickness and in their degree of definition. In places, there is no clear distinction between the layers. These heterogeneities in structure result in variations in hydraulic conductivity throughout the geological profile. Generally, at the surface, a thin highly permeable soil layer absorbs rain. Most of this water then rapidly drains laterally to the topographic lows at the heads of the gullies surrounding the LHSTC. Percolating rainwater cannot effectively flow downward in the sandstone groundwater system because of zones of low hydraulic conductivity, resulting in lateral flow. The contrast in hydraulic conductivity between these layers forms an effective barrier to vertical flow. The characteristic response of the LHSTC groundwater to heavy rainfall is an immediate local rise in groundwater level (caused by saturated soil contributing water directly to the borehole) followed by the falling head as this water is redistributed into the aquifer within a few hours. The hydrograph data for a borehole located near the head of a gully (MW6s), along with concurrent rainfall, is displayed in Figure 12. The data show that groundwater flow from the plateau to the gully peaked a few days after the rainfall event and that the groundwater level returned to its original height after about 10 days. The hydrograph data are consistent with the conceptual model for the LHSTC groundwater developed from earlier seismic and geophysical data. That is, an imperfect multi-layer groundwater flow regime, exhibiting a decrease in flow rate through each layer due to decreasing hydraulic conductivities with depth. Rain and evaporation data for the LHSTC from 1992 to 2003 are summarised in Table 24. These data are used in the interpretation of groundwater hydrology for the LHSTC site. Monthly total rainfall (R Total; mm), the number of days on which rain fell (R Days), monthly total evaporation (E Total; mm) and the maximum daily evaporation (E max; mm) are given. 28 ANSTO E-752 ANSTO E-752 29 Figure 12. Groundwater hydrograph for piezometer MW 6s and concurrent rainfall at the LHSTC. Rain Rain (mm) SWL MW6s SWL (m.below collar) 6.6.2 Little Forest Burial Ground Routine six-monthly groundwater level monitoring and sampling from the Little Forest Burial Ground (Figure 4) bore network is undertaken to measure field parameters, tritium, and gross alpha, gross beta and gamma emitting radionuclides. Results of this monitoring are shown in Tables 25-30. Tritium activities in groundwater from the LFBG were below levels considered safe for drinking water in Australia. The gross alpha and gross beta activities in the groundwater were below the levels prescribed for surface waters in New South Wales. In fact, the majority of gross alpha and gross beta results (Tables 28-30) were below the more restrictive level of 0.5 Bq/L recommended in the ADWG (NHMRC and ARMCANZ 1996). Note that this comparison is made simply to provide context and that these guidelines are not applicable to groundwaters that do not contribute to public water supply. Gamma spectrometry of the unfiltered LFBG groundwater samples showed only low levels of natural potassium-40 and uranium-238 progeny and, in one well, occasional low levels of cobalt-60, americium-241 or cesium-137. Measurement of LFBG groundwater field parameters included pH, electrical conductivity, redox potential and temperature (Tables 25-27). The electrical conductivity of groundwater bores in a direct line with the groundwater flow paths reflect fresh groundwater influence, while bores located away from these paths are more saline and probably reflect older waters. Distinct groundwater flow pathways at the LFBG have been identified to provide a better understanding of movement of radionuclides from the source to the surrounding environment. Little Forest is located in a groundwater recharge area, whereby rain water moves down-gradient from the site. Groundwater will move along pathways of least resistance and for the LFBG these pathways include: ? Surface water runoff ? The zone of aeration and saturation in the Ashfield Shale layer, ? Infiltration into the Hawkesbury Sandstone beneath the shale layer, ? Streamflow into Bardens and Mill Creeks, and ultimately the George?s River. Elevated tritium levels have, currently and historically, been identified in the LFBG groundwaters and are attributed to the buried waste. The tritiated water is not an environmental problem and in fact has been useful in identifying the groundwater flow paths associated with Little Forest. Based on these data, groundwater appears to flow away from the burial trenches in two directions, perpendicular from an east-west groundwater divide that runs through the central position of the burial trenches. Groundwater flows from this recharge zone to discharge areas (surface springs) at lower elevations. Figure 13 illustrates the groundwater flowpaths. The variation in tritium activity through time can be explained in terms of a simple decay process from a point source moving along a flow path with overlying sporadic variations, due to evaporative concentration and rain dilution. Hydrogeological data gathered historically and in recent times indicate that waste products and radionuclides from burial at Little Forest in the 1960?s have not travelled any significant distance in the groundwater and are not a public health issue. 6.7 SOIL AND SEDIMENT 6.7.1 Bund sediments Sediment that accumulates in the stormwater bunds is removed at least once each year. These sediments are analysed, prior to their removal, for gross alpha, gross beta and gamma radioactivity (Table 31). Measured gross alpha/beta activities correspond to background levels for similar sandy soils of the Sydney region. Gamma-emitters that were detected include naturally-occurring potassium-40 and members of the uranium-238 and thorium-232 decay series. As in previous years, levels of fission or activation products were also detected at low levels, far below the relevant ARPANSA exemption levels for classification of radioactive materials. 6.7.2 Sediment from local streams Sediment was collected off-site near the confluence of Mill and Bardens creeks, which ultimately drain the LFBG area. Levels of gross alpha, gross beta and gamma radioactivity were measured (see Table 18) and showed only low levels of natural activity attributable to progeny of the uranium-238 and thorium-232 decay series, and potassium-40. 30 ANSTO E-752 ANSTO E-752 31 Groundwater Divide Groundwater Flow Paths Figure 13. Little Forest Burial Ground ? Groundwater flow paths 6.7.3 Gamma Dose Survey ? Little Forest Burial Ground Levels of gamma radiation over the burial area at the LFBG are surveyed annually to monitor surface soil dose-rates. Routine maintenance of the grassy area includes regular mowing and monitoring, then filling any shallow depressions with clay/shale of local origin. Dose rates over all of the trenches, including S1 and S2, were measured in December 2002 using a hand-held meter (Table 32). Recorded dose rates ranged from 0.08 to 0.15 ?Sv/hour and were consistent with previous measurements and background readings taken at the LFBG gate, approximately 200 metres away from the trench area. The potential radiological exposures to members of the public from the LFBG continue to be assessed as negligible. 6.7.4 Gamma Dose Survey - Liquid Effluent Pipeline The pipeline through which liquid effluent from the LHSTC is discharged to the Sydney Water Corporation sewer is shown, in part, on Figure 2. In addition to the regular inspection and maintenance of the pipeline, surveys of the dose rates along the accessible sections of pipeline were carried out in order to detect any past or present leaks. The results for January 2002 to June 2003 are summarised in Table 33. The measured dose rates ranged from 0.05 to 0.16 ?Sv/hour and were principally due to natural background radiation. No pipeline leaks were detected during the reporting period. 6.8 BIOTA (POTTER POINT) Treated sewage effluent from the Sutherland Shire, including low-level effluent from the LHSTC, passes through the Cronulla STP and is discharged at Potter Point (Figure 5). Sampling of fish, algae (seaweed) and barnacles continued at the Potter Point ocean outfall and a reference site at The Royal National Park in 2002 and 2003, with authorisation from NSW Fisheries. These organisms represent different levels in the food chain and are known to concentrate a variety of elements, including radionuclides, from their environment. Blackfish or luderick (Girella sp.) were filleted and skinned, green algae (mainly Ulva sp. or Enteromorpha sp.) and surf barnacles (Tesseropera rosea) were left whole and unwashed. All samples were dried, ground and analysed for gamma-emitting radioisotopes (Table 34-36). The radioactivity measured in marine fish, algae and barnacles sampled at Potter Point from January 2002 to June 2003 was of natural origin, apart from the low levels of iodine-131 found in the algae. Only naturally occurring radionuclides were detected in samples collected from the reference site. 7. Potential Doses to the Public and Environment The principal sources of potential radiation exposure to members of the public from routine ANSTO operations at the LHSTC and NMC are from airborne emissions and low-level liquid effluent discharges. ANSTO is committed to protecting the environment from the possible effects of ionising radiation and is actively participating in international forums that are supporting the development of a system to achieve this. Currently, there is no internationally agreed approach to assessing doses to non-human species and no established guidelines against which to determine the risks of such doses. Following the ICRP (1991), it is assumed here that demonstrating protection of humans from the potential effects of ionising radiation also demonstrates adequate protection of the environment. 7.1 AIRBORNE DISCHARGES The effective doses to hypothetical individuals potentially exposed to radiation in routine airborne discharges from the LHSTC in 2001-2002 and 2002-2003 financial years were calculated to be less than 0.01 mSv/year (Table 37), based on the LHSTC stack discharge data and concurrent meteorological information. This is well below the ALARA objective of 0.02 mSv/year and much lower than the public dose rate limit of 1 mSv/year and the natural background in Australia of ~1.5 mSv/year (not including medical investigations; Webb et al. 1999). Figure 14 shows the public dose from airborne emissions estimated for hypothetical individuals on a 1.6 km radius from HIFAR, relative to the ALARA objective for the 2001-2002 and 2002-2003 financial years. 32 ANSTO E-752 > ANSTO E-752 33 Figure 14. Estimated effective dose to the public from LHSTC airborne discharges on a 1.6 km radius from HIFAR, 2001-2002 and 2002-2003. 2001-2002 Estimated Effective Dose from LHSTC Airborne Discharges (mSv/year) at 1.6km Radius from HIFAR 2002-2003 Estimated Effective Dose from LHSTC Airborne Discharges (mSv/year) at 1.6km Radius from HIFAR Thermoluminescent dosimeters placed around the LHSTC and at some local residences also indicated that the external gamma radiation levels at residential locations in the vicinity of the LHSTC were not noticeably affected by ANSTO?s operations. Airborne discharges from the NMC were well below the relevant four-weekly, quarterly and annual notification levels ensuring that the potential dose to humans is below the ALARA objective of 0.02 mSv/year. 7.2 LIQUID EFFLUENT DISCHARGES The effective dose rates to hypothetical individuals potentially exposed to radiation in routine liquid effluent discharges from the LHSTC were recently calculated, on the basis of previous effluent monitoring, to be less than 0.001 mSv/year. This is much less than the dose rates estimated for members of the public potentially exposed to airborne emissions (see section 4). Liquid effluent discharged to the Sydney sewerage system from the NMC ultimately enters the sea offshore via the deep ocean outfalls. The small amounts of short-lived radioactivity in the effluent from the NMC and the high dilution in the sewage system means that any potential doses are very small. Since the release is to the ocean, offshore, there is unlikely to be any significant environmental pathway to humans, such as through the consumption of seafood. 8. Conclusion From January 2002 to June 2003 the estimated potential doses to members of the public from airborne discharges at the LHSTC are only a very small fraction of the radiation dose received by everyone each year from naturally-occurring sources of radiation. The monitoring results from Potter Point confirm that the potential radiation dose to members of the public as a result of ANSTO's liquid effluent discharges to the sewer is also very low. The levels of tritium in groundwater and stormwater at the LHSTC are less than Australian drinking water guidelines. The airborne and liquid effluent emissions from the NMC, from January 2002 to June 2003, were below the ARPANSA-approved notification levels and NSW EPA limits, respectively. It is concluded that ANSTO's operations at the LHSTC and the NMC make only a very small addition to the background radiation dose, even for the comparatively few members of the public identified as potentially exposed to radionuclides entering the environment from ANSTO sites. 9. Acknowledgements The environmental and effluent monitoring program at ANSTO is very much a team effort. The following people are sincerely thanked for their contribution: Tom Loosz, Jenny Harrison, Kristy Falconer, Mark Alcorn, Ashley Gillen, Ashley Browne, Richard Barton, Werner Reynolds, Geoff Clark, Jim Pascoe, Peter Airey, Tom Kluss, John Bradd and Chris Waring. Thanks are also extended to those who made contributions to the text and/or provided constructive comments on text drafts. 10. References ANSTO and Sydney Water Corporation (2002a). Consent to Discharge Industrial Trade Wastewater, Agreement No 4423 (2002). Australian Nuclear Science and Technology Organisation and Sydney Water Corporation Pty Ltd, Sydney. ANSTO and Sydney Water Corporation (2002b). Consent to Discharge Industrial Trade Wastewater, Agreement No 13966 (2002). Australian Nuclear Science and Technology Organisation and Sydney Water Corporation Pty Ltd, Sydney. ARPANSA (2001). ANSTO Licence Conditions Handbook. Revision 1, Section 2.4: Airborne Radioactivity Discharge Authorisation for the Australian Nuclear Science and Technology Organisation, May 2001. Australian Radiation Protection and Nuclear Safety Agency, Sydney. ARPANSA (2002). Recommendations for limiting exposure to ionizing radiation (1995; Guidance note NOHSC:3022, 1995) and National standard for limiting occupational exposure to ionizing radiation (NOHSC:1013, 1995). Republished as Radiation Protection Series No 1. Australian Radiation Protection and Nuclear Safety Agency, Sydney. 34 ANSTO E-752 > > > Australian and New Zealand Environment and Conservation Council (1996). National Strategy for the Conservation of Australia's Biological Diversity. Commonwealth Department of the Environment, Sport and Territories, Canberra. Australian Nuclear Science and Technology Organisation Act (1987). Commonwealth Government Printer, Canberra. Australian Radiation Protection and Nuclear Safety Act (1998). Commonwealth Government Printer, Canberra. Clark GH (1997). An Updated Analysis of the Lucas Heights Climatology 1975 to 1996. ANSTO/E731, Australian Nuclear Science and Technology Organisation, Sydney. Crawford J, Domel RU, Harris FF, Twining JT (2000). RadCon: A Radiological Consequences Model, Technical Guide, Version 2.0. ANSTO/E744. Australian Nuclear Science and Technology Organisation, Sydney. Crown Lands Act (1989). Commonwealth Government Printer, Canberra. Environment Protection and Biodiversity Conservation Act (1999). Commonwealth Government Printer, Canberra. Hoffmann EL, Loosz T, Mokhber-Shahin L (2001). Environmental and Effluent Monitoring at ANSTO Sites. ANSTO/E745. Australian Nuclear Science and Technology Organisation, Sydney. IAEA (1996). International Basic Safety Standards for protection against ionizing radiation and for the safety of radiation sources. Safety Series No 115, International Atomic Energy Agency, Vienna. IAEA (2001). Generic Models for Use in Assessing the Impact of Discharges of Radioactive Substances to the Environment. Safety Report Series No 19, International Atomic Energy Agency, Vienna. ICRP (1984). Principles of Monitoring for the Radiation Protection of the Public. Publication 43. International Commission on Radiological Protection. Pergamon Press, Oxford. ICRP (1991). 1990 Recommendations of the International Commission on Radiological Protection. Publication 60. International Commission on Radiological Protection. Pergamon Press, Oxford. Native Vegetation Conservation Act (1997). Commonwealth Government Printer, Canberra. NHMRC and ARMCANZ (1996). Australian Drinking Water Guidelines. National Health and Medical Research Council and Agriculture and Resource Management Council of Australia and New Zealand. Australian Government Publishing Service, Canberra, Amended 2001. NSW Protection of the Environment Operations Act (1997). No 156 as amended. Government Gazette. NSW Government Printery, Sydney. Rural Fires Act (1997). Government Gazette. NSW Government Printery, Sydney. UNSCEAR (2000). Sources, Effects and Risks of Ionising Radiation. Report to the General Assembly. United Nations Scientific Committee on the Effects of Atomic Radiation. United Nations, New York. USEPA (2002). Air Quality Criteria for Particulate Matter. USEPA EPA/600/P-99/002abC. 01 May 2002. United States Environmental Protection Agency, Office of Research and Development, North Carolina, USA. Webb DV, Solomon SB, Thomson JEM. (1999). Background Radiation Levels and Medical Exposure Levels in Australia. Radiation Protection in Australasia, Volume 16(1), whole issue. WHO (1993). Guidelines for Drinking Water Quality. Volumes 1 and 2, 2nd Edition. World Health Organisation, Geneva. ANSTO E-752 35 DATA TABLES 36 ANSTO E-752 ANSTO E-752 37 T able 1. MEDIAN DETECTION LIMITS FOR ENVIRONMENT AL MEDIA Stable Environmental Media Gamma-emitters Gross Gross P u-239/240 Beryllium Am-241 I-131 Cs-137 Co-60 K -40 Be-7 Alpha Beta T ritium (Bq total) ( ? g total) W A TERS (Bq/L) 0.017 - 0.021 0.019 0.33 0.056 0.036 0.14 10 - - SOIL / SEDIMENT (Bq/g) 0.002 - 0.008 0.005 0.20 0.054 - - - - - FISH (Bq/kg fr esh weight) 0.41 0.36 0.60 0.55 162.6 2.8 - - - - - ALGAE (seaweed) (Bq/kg fr esh weight) 0.28 0.52 0.31 0.46 177.8 1.85 - - - - - BARNACLES (Bq/kg fr esh weight) 0.58 0.68 0.68 1.0 46.6 6.54 - - - - - MA YP ACKS (Bq/m 3 ) - 0.0025 - - - - - - - - - AIRBORNE P ARTICLES (Hi-volume air filters) - - - - - - - - - 0.001 0.035 38 ANSTO E-752 Start: 26-Jun-01 End: 25-Jun-02 Sampling period (days): 364 Y ear: 2001/2002 Particulates Gases and V apours Gross Gross I-131 T ritium Ar -41 Hg-197 Hg-203 As-76 Br -82 I-132 I-133 Xe-133 Xe-135 Xe-135m Kr -85m Kr -87 Kr -88 F-18 I-123 Al l Other ST ACK Alpha Beta (MBq) (GBq) (TBq) (MBq) (MBq) (MBq) (MBq) (MBq) (MBq) (TBq) (TBq) ( TBq) (TBq) (GBq) (TBq) (GBq) (GBq) Nuclides (MBq) (MBq) (MBq) 3 N.D. N.D. 2.17 -- 0.4% 15A N.D. 0.72 4.45 1696.0 130.50 56.60 3.97 171.40 5.04 - 1.2% 11.1% 17.0% 72.5% 20.2% 9.9% 68.6% 20.2% 15M N.D. N.D. 0.77 244.80 12.96 - - 7.7% 54.4% 144.0% 19S N.D. N.D. 6.91 N.D. - - 13.8% - 19D N.D. N.D. 0.16 N.D. - - 0.3% - 20 N.D. N.D. 51.37 6.59 - - 23.4% 1.3% 21A N.D. N.D. 0.17 -- 0.0% 21B N.D. N.D. N.D. -- - 23A N.D. 3.06 2028 N.D. - 0.9% 6.1% - 23B N.D. N.D. 1.80 N.D. - - 1.6% - 41A N.D. N.D. 24.90 -- 5.0% 41B N.D. N.D. 9.90 -- 2.0% 54 N.D. N.D. 14970 94400 3886 190.60 42.90 33.01 9.21 N.D. 0.49 N.D. - - 53.5% 39.3% 25.9% 68.1% 10.7% 8.3% 14.2% - 8.2% - 56 N.D. N.D. 2.43 -- 0.5% 57 N.D. N.D. 189.5 0.66 - - 86.1% 0.1% NMC 11.02 49.83 413.65 4.41% 49.83% 82.7% T able 2 . ANNUAL AIRBORNE ACTIVITY DISCHARGE REPOR T , LHSTC & NMC, July 2001 ? June 2002 Notes for tables 2 & 3: N.D. = None Detected. Per centages r epor ted ar e the per centage of the annual notification level. The sampling period for NMC was 1 July 2001 to 28 June 2002. The "All Other Nuclides" column includes all nuclides for which no specific notification level exists. ie It may include the shaded nuclides. ANSTO E-752 39 Start: 25-Jun-02 End: 24-Jun-03 Sampling period (days): 364 Y ear: 2002/2003 Particulates Gases and V apours Gross Gross I-131 T ritium Ar -41 Hg-197 Hg-203 As-76 Br -82 I-132 I-133 Xe-133 Xe-135 Xe-135m Kr -85m Kr -87 Kr -88 F-18 I-123 Al l Other ST ACK Alpha Beta (MBq) (GBq) (TBq) (MBq) (MBq) (MBq) (MBq) (MBq) (MBq) (TBq) (TBq) (TBq) (TBq) (GBq) (TBq) (GBq) (GBq) Nuclides (MBq) (MBq) (MBq) 3 N.D. N.D. 2.92 -- 0.6% 15A N.D. 1.11 4.71 2634.00 96.90 102.10 6.89 134.80 5.58 - 1.9% 11.8% 26.3% 53.8% 36.5% 17.2% 53.9% 22.3% 15M N.D. N.D. 0.19 305.90 10.49 - - 1.9% 68.0% 52.5% 19S N.D. N.D. 9.46 N.D. - - 18.9% - 19D N.D. N.D. 0.45 N.D. - - 0.9% - 20 0.13 0.15 354.60 26.84 1.3% 0.2% 161.2% 5.4% 21A N.D. N.D. 0.19 -- 0.0% 21B N.D. N.D. 0.03 -- 0.0% 23A N.D. 3.30 1597 N.D. - 1.0% 4.8% - 23B N.D. N.D. 6.61 N.D. - - 6.0% - 41A N.D. N.D. 13.76 -- 2.8% 41B N.D. N.D. 2.54 -- 0.5% 54 N.D. N.D. 10670 71600 1393 298.40 65.98 54.35 14.75 N.D. 0.09 N.D. - - 38.1% 29.8% 9.3% 106.6% 16.5% 13.6% 22.7% - 1.5% - 56 N.D. N.D. 4.03 -- 0.8% 57 N.D. N.D. 144.3 2.27 - - 65.6% 0.5% NMC 15.12 50.68 256.45 6.05% 50.68% 51.3% T able 3. ANNUAL AIRBORNE ACTIVITY DISCHARGE REPOR T , LHSTC & NMC, July 2002 ? June 2003 Notes for tables 2 & 3: N.D. = None Detected. Per centages r epor ted ar e the per centage of the annual notification level. The sampling period for NMC was 25 June 2002 to 24 June 2003. The "All Other Nuclides" column includes all nuclides for which no specific notification level exists. ie It may include the shaded nuclides. 40 ANSTO E-752 A VERAGE CONCENTRA TION IN TOT AL DISCHARGES A verage VOL U ME MONTHL Y MONTH Discharged ALPHA (1) BET A (2) TRITIUM Concentration m 3 Bq/m 3 Bq/m 3 Bq/m 3 QUOTIENT (3) Januar y 2002 5932 < 9.0 x 10 2 3.20 x 10 3 5.28 x 10 6 < 0.13 Februar y 2002 9014 < 9.0 x 10 2 5.07 x 10 3 1.58 x 10 6 < 0.12 Mar ch 2002 12219 < 1.0 x 10 3 2.57 x 10 3 2.66 x 10 6 < 0.12 April 2002 10428 < 1.1 x 10 3 3.50 x 10 3 3.57 x 10 6 < 0.13 May 2002 7502 < 1.1 x 10 3 6.10 x 10 3 3.17 x 10 6 < 0.16 June 2002 6945 < 1.1 x 10 3 4.36 x 10 3 2.77 x 10 6 < 0.14 July 2002 8242 < 1.0 x 10 3 4.23 x 10 3 2.92 x 10 6 < 0.13 August 2002 7773 < 1.1 x 10 3 3.73 x 10 3 2.99 x 10 6 < 0.13 September 2002 6211 < 3.0 x 10 2 2.89 x 10 3 2.62 x 10 6 < 0.06 October 2002 7117 < 9.5 x 10 2 1.13 x 10 4 4.75 x 10 6 < 0.19 November 2002 7593 < 8.5 x 10 2 2.00 x 10 3 4.25 x 10 6 < 0.11 December 2002 6990 < 8.5 x 10 2 3.40 x 10 3 5.10 x 10 6 < 0.12 Januar y 2003 6054 < 8.3 x 10 2 4.34 x 10 3 4.59 x 10 6 < 0.12 Februar y 2003 8467 < 6.6 x 10 2 6.76 x 10 3 5.34 x 10 6 < 0.13 Mar ch 2003 7602 < 6.9 x 10 2 5.62 x 10 3 4.60 x 10 6 < 0.12 April 2003 8243 < 5.5 x 10 2 2.70 x 10 3 4.13 x 10 6 < 0.09 May 2003 14278 < 1.0 x 10 3 2.62 x 10 3 4.12 x 10 6 < 0.12 June 2003 8745 < 6.6 x 10 2 4.20 x 10 3 5.73 x 10 6 < 0.12 Regulatory Limit: Activity Concentration 1.25 x 10 4 1.25 x 10 5 1.95 x 10 8 1.00 Equivalent at ANSTO (4) (as 226 Ra) (as 90 Sr) T able 4. RADIOACTIVITY IN LIQUID EFFLUENT DISCHARGED TO THE SYDNEY W A TER SEWER, LHSTC, Januar y 2002 - June 2003 Notes: 1. A mixtur e of unidentified alpha-emitting nuclides, assumed to be all radium-226 ( ie . possible worst case) when calculating the concentration quotient. 2. A mixtur e of unidentified beta-emitting nuclides, assumed to be all str ontium-90 ( ie . possible worst case) when calculating the concentration quotient. 3. Concentration Quotient: the sum of the average monthly concentrations of alpha, beta and tritium radioactivity in the liquid ef fluent divided by the Activity Concentration Equivalent for that radionuclide. The final quotient ter m must be no gr eater tha n one to comply with the r equir ements of the Sydney W ater T rade W astewater Agr eement. 4. All discharges wer e below the r equir ed Activity Concentration Equivalents at ANSTO which ar e based on the WHO Guidelines for Drinking-W ater Quality (WHO 1993). ANSTO E-752 41 Gamma-emitters (Bq/L) MONTH (1) Ce-144 Co-60 Cr-51 Cs-134 Cs-137 I-131 Ra-226 Pb-210 Ra-228 Januar y 2002 < MDA 1.04 ? 0.05 < MDA < MDA 0.44 ? 0.06 0.26 ? 0.04 < MDA < MDA < MDA Februar y 2002 < MDA 0.75 ? 0.06 2.8 ? 0.4 < MDA < MDA < MDA < MDA < MDA < MDA Mar ch 2002 < MDA 1.33 ? 0.07 < MDA < MDA < MDA 0.42 ? 0.05 < MDA < MDA < MDA April 2002 < MDA 0.52 ? 0.05 < MDA < MDA 0.37 ? 0.04 0.32 ? 0.04 < MDA < MDA < MDA May 2002 < MDA 3.03 ? 0.09 < MDA < MDA 1.15 ? 0.06 < MDA < MDA < MDA < MDA June 2002 < MDA 1.80 ? 0.09 < MDA < MDA < MDA 0.10 ? 0.02 < MDA < MDA < MDA July 2002 < MDA 0.90 ? 0.05 < MDA < MDA 0.3 ? 0.05 0.30 ? 0.04 < MDA < MDA < MDA August 2002 < MDA < MDA < MDA < MDA 0.4 ? 0.06 < MDA < MDA < MDA < MDA September 2002 < MDA 0.60 ? 0.05 < MDA < MDA 0.2 ? 0.04 < MDA < MDA < MDA < MDA October 2002 < MDA 0.66 ? 0.05 < MDA < MDA 4.04 ? 0.08 0.58 ? 0.03 7.16 ? 0.79 < MDA < MDA November 2002 < MDA < MDA < MDA < MDA 0.31 ? 0.05 0.17 ? 0.03 < MDA < MDA < MDA December 2002 < MDA < MDA < MDA < MDA 2.05 ? 0.16 < MDA < MDA < MDA < MDA Januar y 2003 < MDA 0.70 ? 0.04 < MDA 0.28 ? 0.03 0.41 ? 0.07 < MDA < MDA < MDA < MDA Februar y 2003 < MDA 0.66 ? 0.05 < MDA < MDA 0.68 ? 0.07 0.42 ? 0.05 < MDA < MDA < MDA Mar ch 2003 < MDA 0.64 ? 0.06 < MDA < MDA 2.28 ? 0.07 < MDA 6.35 ? 0.06 < MDA < MDA April 2003 < MDA 0.39 ? 0.04 < MDA < MDA 0.31 ? 0.06 0.74 ? 0.05 < MDA < MDA < MDA May 2003 < MDA < MDA 2.0 ? 0.4 < MDA < MDA 0.32 ? 0.04 < MDA < MDA < MDA June 2003 < MDA 0.83 ? 0.05 < MDA < MDA 0.67 ? 0.05 0.40 ? 0.04 < MDA < MDA < MDA T able 5. GAMMA-EMITTERS IN LIQUID EFFLUENT , MONTHL Y PIPELINE COMPOSITE SAMPLES, LHSTC, Januar y 2002 to June 2003 Notes: 1. Gamma spectr ometr y was per for med on the "monthly pipeline composite", which is made up of volume-pr opor tional samples fr om a ll tr eated liquid ef fluent discharges during a given month. 2. < MDA: indicates that the r esult was below the minimum detectable activity , calculated with 95% confidence. Median MDA value s for the r elevant radionuclides ar e as follows: 0.40 for Ce-144, 0.15 for Co-60, 0.6 for Cr -51, 0.09 for Cs-134, 0.11 for Cs-137, 0.10 for I-131, 1.8 for Ra-226, 1.7 for Pb-210, and 0. 41 for Ra-228. 42 ANSTO E-752 Monthly A verage Concentration in Liquid Ef fluent (MBq/m 3 ) Tl-201 Tl-202 Ga-67 Co-57 Zn-65 I-123 Half -life (days) 3.0 12.2 3.3 270.9 244.4 0.54 Januar y 2002 4.18 1.63 0.37 0.34 0.27 N D Februar y 2002 57.85 3.75 6.33 0.59 0.20 N D Mar ch 2002 9.51 2.43 0.99 0.69 0.18 N D April 2002 52.63 4.28 1.02 0.41 0.20 N D May 2002 5.23 4.04 1.79 0.59 0.25 N D June 2002 13.55 4.76 1.18 0.64 0.38 N D July 2002 2.86 2.61 1.33 0.63 0.43 N D August 2002 2.39 1.33 0.05 0.41 0.17 N D September 2002 0.50 1.97 ND 1.88 6.23 N D October 2002 0.38 0.38 0.03 0.60 0.37 0.02 November 2002 1.02 0.30 0.11 0.69 0.33 N D December 2002 6.37 1.61 6.36 2.09 0.77 N D Januar y 2003 0.82 2.36 3.42 2.55 0.41 N D Februar y 2003 0.76 0.59 0.10 1.23 0.33 N D Mar ch 2003 1.16 0.45 0.19 0.38 1.10 N D April 2003 1.03 0.53 0.57 0.28 0.12 N D May 2003 1.21 1.85 1.14 1.04 0.24 N D June 2003 20.79 18.93 8.53 1.68 0.82 N D Mean 10.12 2.99 1.86 0.93 0.71 0.02 Median 2.63 1.91 1.00 0.63 0.33 0.02 NSW EP A 200 100 600 400 100 6.00 Monthly Limits Concentration (mg/L) Standard for January 2002 ? June 2003 Acceptance mg/L (2) P arameter Mean (1) Median Range Suspended Solids 24 16 < 1 - 93 600 pH 7.2 7.3 5.2 - 9.9 7 ? 10 Ammonia 9.6 8.6 < 0.5 - 38.7 100 B.O.D. (3) 20.1 14 < 2 - 148 85 (3) Gr ease 7.6 5 < 5 - 57 50 Zinc 0.2 0.2 < 0.1 ? 0.7 5 Notes: 1. The annual mean is conservative because r esults that wer e below the detection limits wer e included. 2. The sampling r egime was ever y 4 days fr om 1 July 2002, when the Sydney W ater T rade W astewater Agr eement was r enegotiated. Of the samples analysed, 95% must be less than or equal to the Standar ds for Acceptance of Liquid T rade W astes to Sewers, specified in the Sydney W ater T rade W aste Policy and Management Plan (1995). 3. The standar ds for acceptance do not stipulate a specific limit for biological oxygen demand (BOD), ther efor e the agr eed limit is applicable in this case. T able 6. NON-RADIOACTIVE COMPONENTS OF LIQUID EFFLUENT DISCHARGED TO THE SYDNEY W A TER SEWER, LHSTC, Januar y 2002 to June 2003 T able 7. A VERAGE ACTIVITY OF RADIONUCLIDES IN LIQUID EFFLUENT , NMC, Januar y 2002 to June 2003 ANSTO E-752 43 Sampled during Iodine-131 (1,2) Sampled during Iodine-131 (1,2) Sampled during Iodine-131 (1,2) the week ending: In Air (Bq/m 3 ) the week ending: In Air (Bq/m 3 ) the week ending: In Air (Bq/m 3 ) 2-1-02 < MDA 3-7-02 < MDA 30-12-02 < MDA 9-1-02 < MDA 9-7-02 < MDA 8-1-03 < MDA 15-1-02 < MDA 16-7-02 < MDA 14-1-03 < MDA 23-1-02 < MDA 23-7-02 < MDA 21-1-03 < MDA 29-1-02 < MDA 30-7-02 < MDA 28-1-03 < MDA 5-2-02 < MDA 6-8-02 < MDA 4-2-03 < MDA 12-2-02 < MDA 13-8-02 < MDA 11-2-03 < MDA 19-2-02 < MDA 20-8-02 < MDA 18-2-03 < MDA 26-2-02 < MDA 27-8-02 < MDA 25-2-03 < MDA 5-3-02 < MDA 3-9-02 < MDA 4-3-03 < MDA 12-3-02 < MDA 10-9-02 < MDA 11-3-03 < MDA 19-3-02 < MDA 17-9-02 < MDA 18-3-03 < MDA 26-3-02 < MDA 24-9-02 < MDA 25-3-03 < MDA 2-4-02 < MDA 1-10-02 < MDA 1-4-03 < MDA 9-4-02 < MDA 8-10-02 < MDA 8-4-03 < MDA 16-4-02 < MDA 15-10-02 < MDA 15-4-03 < MDA 23-4-02 < MDA 22-10-02 < MDA 22-4-03 < MDA 30-4-02 < MDA 29-10-02 < MDA 29-4-03 < MDA 7-5-02 < MDA 5-11-02 < MDA 6-5-03 < MDA 14-5-02 < MDA 12-11-02 < MDA 13-5-03 < MDA 21-5-02 < MDA 19-11-02 < MDA 20-5-03 < MDA 28-5-02 < MDA 26-11-02 < MDA 27-5-03 < MDA 4-6-02 < MDA 3-12-02 < MDA 3-6-03 < MDA 11-6-02 < MDA 10-12-02 < MDA 10-6-03 < MDA 18-6-02 < MDA 17-12-02 < MDA 17-6-03 < MDA 25-6-02 < MDA 23-12-02 < MDA 24-6-03 < MDA T able 8. AMBIENT IODINE-131 IN AIR A T LHSTC, Januar y 2002 to June 2003 Notes: 1. Four air samplers ar e located along the easter n boundar y of the LHSTC site, see Figur e 2. 2. < MDA indicates that the r esult was below the minimum detectable activity (0.0025 Bq/m 3 ). Indicative (median) MDA values for various radionuclides and envir onmental media ar e listed in T able 1. 44 ANSTO E-752 Sampling Equivalent Beryllium (3) Plutonium-239/240 (4) P eriod (1) V olume (2) m 3 ? g (total) ? g/m 3 Bq (total) Bq/m 3 Jan ? Mar 02 (5) 342.7 < MDA (6) < 1.0 x 10 -4 < MDA < 1.3 x 10 -6 Apr ? Jun 02 428.8 < MDA < 8.2 x 10 -5 July ? Sept 02 437.2 < MDA < 8.0 x 10 -5 Oct ? Dec 02 461.1 < MDA < 7.6 x 10 -5 < MDA < 5.4 x 10 -7 Jan ? Mar 03 492.9 < MDA < 7.1 x 10 -5 Apr ? Jun 03 454.5 < MDA < 7.7 x 10 -5 Notes: 1. Airbor ne par ticulates wer e collected using a mobile high-volume air sampler and samples wer e accumulated on a single filter over a period of 3 months. The sampling duration and fr equency was appr oximately 4 hours, ever y 2 weeks. The filter paper was then divided into four equal par ts with one being used per Be & Pu analysis and two r etained as duplicates. 2. The Equivalent V olume is 25% of the total volume of air sampled during the period, since one-quar ter of the total filter was analysed. 3. The W orksafe Australia Exposur e Standar d for atmospheric contaminants such as ber yllium in air is 2 ? g/m 3 (applicable to workers exposed 8 hours per day , 50 weeks per year). 4. The limit of detection for plutonium-239/240 in Bq/m 3 would equate to a committed ef fective dose to adults of < 0.0002 mSv/year , or < 0.02% of the allowable public dose limit of 1 mSv/y . 5 . The 2 quar terly samples for Januar y to June 2002, and the 4 filters for the 2002-3 financial year , wer e combined for plutoni um analyses. 6. < MDA: indicates that the r esult was below the minimum detectable activity , calculated with 95% confidence. Indicative (medi an) MDA values for various radionuclides and envir onmental media ar e listed in T able 1. The concentrations wer e calculated using th e median MDA and the volume of air sampled. T able 9. RADIOACTIVITY IN AIRBORNE P A R TICLES, LFBG, Januar y 2002 to June 2003 ANSTO E-752 45 ANSTO Environmental Thermoluminescent Dosimeters (1) Annual Effective Dose (3) Dosimeter Location: on-site (2) (mSv / year) 2001-2 2002-3 1 H IF AR fence - south east 1.15 ? 0.04 1.13 ? 0.04 2 H IF AR fence - south 3.23 ? 0.10 2.94 ? 0.11 3 P erimeter fence - west 1.50 ? 0.05 2.15 ? 0.08 4 H IF AR fence - west 1.54 ? 0.05 1.45 ? 0.06 5 H IF AR fence - nor th west 1.31 ? 0.04 1.24 ? 0.05 6 Perimeter fence - nor th A 0 .98 ? 0.03 1.05 ? 0.04 7 Inter nal fence - nor th 1.08 ? 0.03 1.09 ? 0.04 8 Perimeter fence - nor th B 1 .07 ? 0.03 1.50 ? 0.06 9 Perimeter fence - nor th east 0.80 ? 0.03 0.93 ? 0.04 10 Perimeter fence - east 1.05 ? 0.03 0.93 ? 0.04 11 Perimeter fence - south east 0.98 ? 0.03 0.97 ? 0.04 12 Cor ner of Curie and Roentgen St 1.23 ? 0.04 1.15 ? 0.04 13 Perimeter fence - south 0.86 ? 0.03 0.94 ? 0.04 14 HIF A R fence - east 1.17 ? 0.04 1.03 ? 0.04 15 HIF A R f ence - nor th east 1.27 ? 0.04 1.10 ? 0.04 Dosimeter Location: off -site 16 Private house - Bar den Ridge 0.95 ? 0.03 0.98 ? 0.04 17 Private house - Engadine 1.33 ? 0.04 1.24 ? 0.05 18 Private house - W o r onora 1.04 ? 0.03 1.09 ? 0.04 19 Cr onulla Sewage T r eatment Plant 0.65 ? 0.02 0.71 ? 0.03 T able 10. EXTERNAL GAMMA RADIA TION, LHSTC and LOCAL AREA, ANNUAL EFFECTIVE DOSE for 2001-2002 and 2002-2003 Notes: 1. Refer to Figur e 2 for the locations of ther moluminescent dosimeters 1 to 15. 2. The ANSTO envir onmental dosimeters contain lithium fluoride and calcium fluoride ther moluminescent materials with energy compensation filters. The uncer tainties have been estimated (at the 95% confidence level) fr om the standar d deviation of the r esults for several dosimeters placed at the same location. 3. The data wer e r epor ted as absorbed dose to air (mGy) and conver ted to ef fective dose for adults (mSv) using a conservative conversion factor of 1. UNSCEAR (1993) uses a factor of 0.72 Sv per Gy for adults, 0.80 for childr en and 0.93 for infants. 46 ANSTO E-752 TRITIUM (Bq/L) Month (1) BUND A BUND B BUND C Januar y 2002 300 ? 1 0 80 ? 1 0 50 ? 1 0 Februar y 2002 440 ? 1 0 50 ? 1 0 60 ? 1 0 Mar ch 2002 310 ? 2 0 70 ? 2 0 370 ? 2 0 April 2002 390 ? 1 0 140 ? 2 0 320 ? 2 0 May 2002 120 ? 2 0 60 ? 1 0 260 ? 1 0 June 2002 200 ? 2 0 70 ? 1 0 130 ? 1 0 July 2002 120 ? 1 0 70 ? 1 0 410 ? 1 0 August 2002 120 ? 1 0 60 ? 1 0 610 ? 2 0 September 2002 70 ? 1 0 70 ? 1 0 130 ? 1 0 October 2002 < MDA 40 ? 1 0 50 ? 1 0 November 2002 30 ? 1 0 40 ? 1 0 130 ? 1 0 December 2002 140 ? 1 0 50 ? 1 0 120 ? 1 0 Januar y 2003 80 ? 1 0 40 ? 1 0 80 ? 1 0 Februar y 2003 260 ? 1 0 80 ? 1 0 420 ? 2 0 Mar ch 2003 210 ? 1 0 60 ? 1 0 580 ? 2 0 April 2003 160 ? 1 0 90 ? 1 0 260 ? 1 0 May 2003 110 ? 1 0 30 ? 1 0 190 ? 1 0 June 2003 150 ? 1 0 60 ? 1 0 190 ? 1 0 T able 11. TRITIUM IN STORMW A TER BUNDS, MONTHL Y COMPOSITES, LHSTC Januar y 2002 to June 2003 Notes: 1. Refer to Figur e 2 for the locations of the bunds. One litr e was collected daily fr om each bund befor e it was discharged (except weekends and public holidays). These daily samples wer e combined to for m a monthly composite fr om each bund for tritium analysis. 2. The Australian guideline value for tritium in drinking water is 7600 Bq/L (NH&MRC 1996). 3. < MDA: indicates that the r esult was below the minimum detectable activity , calculated with 95% confidence. Indicative (median) MDA values for various radionuclides and envir onmental media ar e listed in T able 1. ANSTO E-752 47 Date T ritium Date T ritium Date T ritium Date T ritium Bq/L Bq/L Bq/L Bq/L 02-01-02 110 ? 1 0 14-5-02 390 ? 2 0 1 -10-02 120 ? 1 0 18-2-03 700 ? 2 0 09-01-02 210 ? 1 0 21-5-02 200 ? 1 0 8 -10-02 90 ? 1 0 25-2-03 330 ? 1 0 15-01-02 60 ? 1 0 28-5-02 340 ? 1 0 15-10-02 140 ? 2 0 4-3-03 550 ? 2 0 22-01-02 90 ? 1 0 4-6-02 150 ? 2 0 22-10-02 140 ? 2 0 11-3-03 150 ? 1 0 29-01-02 100 ? 1 0 11-6-02 300 ? 2 0 29-10-02 120 ? 2 0 18-3-03 1480 ? 3 0 5-2-02 < MDA 18-6-02 240 ? 2 0 5 -11-02 170 ? 1 0 25-3-03 970 ? 2 0 12-2-02 80 ? 1 0 25-6-02 250 ? 2 0 12-11-02 2550 ? 5 0 1-4-03 330 ? 1 0 19-2-02 70 ? 1 0 3-7-02 210 ? 2 0 19-11-02 180 ? 2 0 8-4-03 630 ? 2 0 26-2-02 60 ? 1 0 9-7-02 150 ? 1 0 26-11-02 100 ? 1 0 15-4-02 420 ? 1 0 5-3-02 150 ? 1 0 16-7-02 160 ? 1 0 3 -12-02 150 ? 2 0 22-4-03 430 ? 1 0 12-3-02 1400 ? 3 0 23-7-02 1070 ? 30 10-12-02 20 ? 1 0 29-4-03 150 ? 1 0 19-3-02 200 ? 2 0 30-7-02 100 ? 1 0 17-12-02 110 ? 2 0 6-5-03 70 ? 1 0 26-3-02 180 ? 1 0 6-8-02 240 ? 1 0 23-12-02 120 ? 1 0 13-5-03 30 ? 1 0 2-4-02 2450 ?50 13-8-02 1750 ? 5 0 30-12-02 260 ? 1 0 20-5-03 220 ? 1 0 9-4-02 390 ? 1 0 20-8-02 1150 ? 2 0 7-1-03 220 ? 2 0 27-5-03 290 ? 1 0 16-4-02 330 ? 1 0 29-8-02 510 ? 1 0 14-1-03 120 ? 2 0 3-6-03 150 ? 1 0 23-04-02 240 ? 1 0 3-9-02 140 ? 2 0 21-1-03 110 ? 2 0 10-6-03 130 ? 1 0 30-4-02 280 ? 2 0 10-9-02 90 ? 1 0 28-1-03 120 ? 2 0 17-6-03 110 ? 1 0 7-5-02 290 ? 1 0 17-9-02 20 ? 1 0 4-2-03 20 ? 1 0 24-6-03 90 ? 1 0 24-9-02 210 ? 1 0 11-2-03 830 ? 2 0 T able 12. TRITIUM IN STORMW A TER, BUND C, LHSTC, Januar y 2002 to June 2003 Notes: 1. Refer to Figur e 2 for the location of this sampling point. The weekly water samples wer e also combined into monthly composit e samples and analysed for gr oss alpha/beta and gamma activity . 2. < MDA: indicates that the r esult was below the minimum detectable activity , calculated with 95% confidence. Indicative (medi an) MDA values for various radionuclides and envir onmental media ar e listed in T able 1. 48 ANSTO E-752 Date T ritium Date T ritium Date T ritium Date T ritium Bq/L Bq/L Bq/L Bq/L 02-01-02 90 ? 2 0 14-5-02 110 ? 1 0 1 -10-02 60 ? 1 0 18-2-03 240 ? 1 0 09-01-02 70 ? 2 0 21-5-02 190 ? 1 0 8 -10-02 70 ? 1 0 25-2-03 900 ? 2 0 15-01-02 100 ? 2 0 28-5-02 160 ? 2 0 15-10-02 70 ? 1 0 4-3-03 220 ? 1 0 22-01-02 90 ? 1 0 4-6-02 270 ? 1 0 22-10-02 70 ? 1 0 11-3-03 140 ? 1 0 29-01-02 100 ? 1 0 11-6-02 130 ? 1 0 29-10-02 60 ? 1 0 18-3-03 440 ? 1 0 5-2-02 < MDA 18-6-02 220 ? 2 0 5 -11-02 60 ? 1 0 25-3-03 240 ? 1 0 12-2-02 60 ? 1 0 25-6-02 80 ? 1 0 12-11-02 70 ? 1 0 1-4-03 220 ? 1 0 19-2-02 50 ? 1 0 3-7-02 100 ? 1 0 19-11-02 80 ? 1 0 8-4-03 220 ? 1 0 26-2-02 60 ? 1 0 9-7-02 70 ? 1 0 26-11-02 70 ? 1 0 15-4-03 160 ? 1 0 5-3-02 130 ? 1 0 16-7-02 70 ? 1 0 3 -12-02 70 ? 1 0 22-4-03 320 ? 1 0 12-3-02 250 ? 2 0 23-7-02 1070 ? 1 0 10-12-02 60 ? 1 0 29-4-03 160 ? 1 0 19-3-02 140 ? 2 0 30-7-02 100 ? 1 0 17-12-02 100 ? 1 0 6-5-03 30 ? 1 0 26-3-02 140 ? 1 0 6-8-02 120 ? 1 0 23-12-02 90 ? 1 0 13-5-03 30 ? 1 0 2-4-02 1920 ?10 13-8-02 450 ? 2 0 30-12-02 120 ? 1 0 20-5-03 190 ? 1 0 9-4-02 300 ? 1 0 20-8-02 160 ? 2 0 7-1-03 90 ? 1 0 27-5-03 70 ? 1 0 16-4-02 230 ? 1 0 29-8-02 100 ? 1 0 14-1-03 70 ? 1 0 3-6-03 130 ? 1 0 23-04-02 190 ? 1 0 3-9-02 100 ? 1 0 21-1-03 80 ? 1 0 10-6-03 100 ? 1 0 30-4-02 130 ? 2 0 10-9-02 60 ? 2 0 28-1-03 70 ? 1 0 17-6-03 110 ? 1 0 7-5-02 100 ? 1 0 17-9-02 40 ? 1 0 4-2-03 30 ? 1 0 24-6-03 100 ? 1 0 24-9-02 70 ? 1 0 11-2-03 360 ? 1 0 Notes: 1. Refer to Figur e 2 for the location of this sampling point, 60m downstr eam of the MDP Bund. The weekly water samples above we r e also combined into monthly composite samples and analysed for gr oss alpha, beta and gamma activity 2. < MDA indicates that the r esult was below the minimum detectable activity , calculated with 95% confidence. Indicative (media n) MDA values for various radionuclides and envir onmental media ar e listed in T able 1. T able 13. TRITIUM IN SURF ACE W A TER, MDP + 60m, LHSTC, Januar y 2002 to June 2003 ANSTO E-752 49 T able 14. TRITIUM IN SURF ACE W A TER, BARDENS CREEK WEIR, LHSTC, Januar y 2002 to June 2003 Date T ritium Date T ritium Date T ritium Date T ritium Bq/L Bq/L Bq/L Bq/L 2-1-02 140 ? 2 0 14-5-02 70 ? 2 0 1 -10-02 20 ? 1 0 18-2-03 130 ? 1 0 9-1-02 110 ? 2 0 21-5-02 60 ? 1 0 8 -10-02 30 ? 1 0 25-2-03 120 ? 1 0 15-1-02 100 ? 2 0 28-5-02 60 ? 2 0 15-0-02 30 ? 2 0 4-3-03 140 ? 1 0 22-1-02 80 ? 1 0 4-6-02 140 ? 3 0 22-10-02 30 ? 1 0 11-3-03 60 ? 1 0 29-1-02 110 ? 1 0 11-6-02 40 ? 1 0 29-10-02 30 ? 1 0 18-3-03 160 ? 1 0 5-2-02 40 ? 1 0 18-6-02 30 ? 1 0 5 -11-02 20 ? 1 0 25-3-03 100 ? 1 0 12-2-02 80 ? 2 0 25-6-02 50 ? 1 0 12-11-02 20 ? 1 0 1-4-03 100 ? 1 0 19-2-02 70 ? 2 0 3-7-02 < MDA 19-11-02 30 ? 1 0 8-4-03 30 ? 1 0 26-2-02 180 ? 1 0 9-7-02 20 ? 1 0 26-11-02 30 ? 1 0 15-4-03 90 ? 1 0 5-3-02 50 ? 1 0 16-7-02 20 ? 1 0 3 -12-02 50 ? 1 0 22-4-03 90 ? 1 0 12-3-02 40 ? 1 0 23-7-02 30 ? 1 0 10-12-02 50 ? 1 0 29-4-03 50 ? 1 0 19-3-02 < MDA 30-7-02 90 ? 1 0 17-12-02 40 ? 1 0 6-5-03 50 ? 1 0 26-3-02 60 ? 1 0 6-8-02 30 ? 1 0 23-12-02 40 ? 1 0 13-5-03 100 ? 1 0 2-4-02 120 ? 1 0 13-8-02 20 ? 1 0 30-12-02 60 ? 1 0 20-5-03 40 ? 1 0 9-4-02 100 ? 1 0 20-8-02 30 ? 1 0 7-1-03 40 ? 1 0 27-5-03 50 ? 1 0 16-4-02 120 ? 1 0 29-8-02 60 ? 2 0 14-1-03 110 ? 1 0 3-6-03 40 ? 1 0 23-04-02 90 ? 1 0 3-9-02 40 ? 1 0 21-1-03 100 ? 1 0 10-6-03 30 ? 1 0 30-4-02 100 ? 2 0 10-9-02 30 ? 2 0 28-1-03 90 ? 2 0 17-6-03 30 ? 1 0 7-5-02 70 ? 1 0 17-9-02 30 ? 1 0 4-2-03 100 ? 1 0 24-6-03 50 ? 1 0 24-9-02 20 ? 1 0 11-2-03 250 ? 1 0 Notes: 1. Refer to Figur e 2 for the location of this sampling point. 2. < MDA: indicates that the r esult was below the minimum detectable activity , calculated with 95% confidence. Indicative (medi an) MDA values for various radionuclides and envir onmental media ar e listed in T able 1. 50 ANSTO E-752 Gamma-Emitters Month Gross Alpha Gross Beta Bq/L Bq/L Bq/L Am-241 Be-7 Cs-137 Co-60 K -40 Januar y 2002 0.04 ? 0.01 0.74 ? 0.01 < MDA 0.122 ? 0.025 0.079 ? 0.008 0.009 ? 0.003 0.10 ? 0.01 Februar y 2002 0.03 ? 0.01 0.35 ? 0.01 < MDA 0.128 ? 0.031 < MDA < MDA < MDA Mar ch 2002 0.03 ? 0.01 0.33 ? 0.01 < MDA 0.069 ? 0.032 0.046 ? 0.006 0.045 ? 0.006 < MDA April 2002 0.03 ? 0.01 0.37 ? 0.01 < MDA 0.109 ? 0.025 0.009 ? 0.002 < MDA 0.10 ? 0.03 May 2002 0.03 ? 0.01 0.75 ? 0.02 < MDA < MDA 0.046 ? 0.005 0.033 ? 0.005 0.18 ? 0.03 June 2002 0.02 ? 0.01 0.68 ? 0.02 < MDA < MDA 0.014 ? 0.003 < MDA < MDA July 2002 0.02 ? 0.01 0.72 ? 0.02 < MDA 0.065 ? 0.016 0.038 ? 0.004 0.009 ? 0.003 < MDA August 2002 0.02 ? 0.01 0.87 ? 0.02 < MDA 0.065 ? 0.021 0.028 ? 0.004 < MDA 0.11 ? 0.04 September 2002 0.08 ? 0.01 0.68 ? 0.02 < MDA 0.115 ? 0.026 0.029 ? 0.004 < MDA 0.24 ? 0.05 October 2002 0.07 ? 0.01 1.54 ? 0.03 < MDA < MDA 0.153 ? 0.015 0.020 ? 0.005 0.32 ? 0.10 November 2002 0.03 ? 0.01 0.85 ? 0.02 < MDA 0.050 ? 0.021 0.052 ? 0.006 < MDA 0.23 ? 0.05 December 2002 0.04 ? 0.01 0.43 ? 0.01 < MDA 0.197 ? 0.030 0.053 ? 0.006 < MDA < MDA Januar y 2003 0.02 ? 0 .01 0.58 ? 0.01 < MDA < MDA 0.027 ? 0.004 < MDA 0.12 ? 0.04 Februar y 2003 0.04 ? 0.01 0.36 ? 0.01 < MDA 0.463 ? 0.052 0.030 ? 0.004 < MDA < MDA Mar ch 2003 0.03 ? 0.01 1.17 ? 0.02 < MDA 0.137 ? 0.030 0.095 ? 0.010 0.024 ? 0.005 0.10 ? 0.05 April 2003 0.05 ? 0.01 0.47 ? 0.01 < MDA < MDA 0.016 ? 0.003 < MDA 0.41 ? 0.05 May 2003 0.04 ? 0.01 0.69 ? 0.01 < MDA 0.390 ? 0.051 0.100 ? 0.001 0.025 ? 0.006 0.15 ? 0.05 June 2003 0.03 ? 0.01 0.24 ? 0.01 < MDA < MDA 0.013 ? 0.003 < MDA 1.38 ? 0.15 Notes: 1. Refer to Figur e 2 for the MDP Bund C sampling location. The weekly samples wer e analysed for tritium then combined to make t he monthly composites, r epor ted above. 2. The NSW Regulations (Pr ot. Env . Operations Act, 1997) limits for radioactivity in class C waters ar e: Gr oss alpha 1.1 Bq/L; Gr oss beta 11.1 Bq/L. 3. The gr oss beta r esults include the contribution fr om K-40 (a natural beta-gamma emitter). Be-7 is also of natural origin. 4. < MDA indicates that the r esult was below the minimum detectable activity , calculated with 95% confidence. Indicative (media n) MDA values for various radionuclides and envir onmental media ar e listed in T able 1. T able 15. RADIOACTIVITY IN STORMW A TER, BUND C MONTHL Y COMPOSITES, LHSTC, Januar y 2002 to June 2003 ANSTO E-752 51 T able 16. RADIOACTIVITY IN SURF ACE W A TER, MDP+60m MONTHL Y COMPOSITES, LHSTC, Januar y 2002 to June 2003 Notes: 1. Refer to Figur e 2 for the location of this sampling point, 60m downstr eam of the MDP Bund. The weekly samples wer e analysed for tritium, then combined to make the monthly composites, r epor ted above. 2. The NSW Regulations (Pr ot. Env . Operations Act, 1997) limits for radioactivity in class C waters ar e: Gr oss alpha 1.1 Bq/L; Gr oss beta 11.1 Bq/L. 3. The gr oss beta r esults include the contribution fr om K-40 (a natural beta-gamma emitter). Be-7 is also of natural origin. 4. < MDA indicates that the r esult was below the minimum detectable activity , calculated with 95% confidence. Indicative (media n) MDA values for various radionuclides and envir onmental media ar e listed in T able 1. Gamma-Emitters Month Gross Alpha Gross Beta Bq/L Bq/L Bq/L Am-241 Be-7 Cs-137 Co-60 K -40 Januar y 2002 0.02 ? 0.01 0.34 ? 0.01 < MDA 0.039 ? 0.015 0.015 ? 0.003 < MDA 0 .09 ? 0.04 Februar y 2002 0.04 ? 0.01 0.42 ? 0.01 < MDA 0.194 ? 0.044 0.032 ? 0.005 < MDA 0 .14 ? 0.05 Mar ch 2002 0.03 ? 0.01 0.33 ? 0.01 < MDA < MDA 0.008 ? 0.004 < MDA < MDA April 2002 0.05 ? 0.01 0.33 ? 0.01 < MDA < MDA 0.006 ? 0.003 < MDA < MDA May 2002 0.05 ? 0.01 0.35 ? 0.01 < MDA 0.047 ? 0.022 0.012 ? 0.003 0.015 ? 0.003 0.18 ? 0.03 June 2002 0.03 ? 0.01 0.40 ? 0.01 < MDA < MDA < MDA < MDA < MDA July 2002 < MDA 0.31 ? 0.01 < MDA 0.049 ? 0.015 0.007 ? 0.002 < MDA < MDA August 2002 0.03 ? 0.01 0.20 ? 0.01 < MDA < MDA < MDA < MDA < MDA September 2002 0.05 ? 0.01 0.29 ? 0.01 < MDA 0.050 ? 0.019 0.010 ? 0.003 < MDA < MDA October 2002 0.03 ? 0.01 0.19 ? 0.01 < MDA < MDA 0.010 ? 0.003 < MDA 0 .12 ? 0.04 November 2002 0.01 ? 0.01 0.17 ? 0.01 < MDA < MDA 0.009 ? 0.003 < MDA < MDA December 2002 0.04 ? 0.01 0.23 ? 0.01 < MDA 0.085 ? 0.021 0.011 ? 0.003 < MDA < MDA Januar y 2003 0.02 ? 0.01 0.18 ? 0.01 < MDA < MDA 0.009 ? 0.003 < MDA < MDA Februar y 2003 0.01 ? 0.01 0.29 ? 0.01 < MDA 0.163 ? 0.030 0.022 ? 0.004 < MDA < MDA Mar ch 2003 0.02 ? 0.01 0.28 ? 0.01 < MDA 0.089 ? 0.025 0.019 ? 0.003 < MDA < MDA April 2003 0.04 ? 0.01 0.32 ? 0.01 < MDA < MDA 0.015 ? 0.002 < MDA < MDA May 2003 0.09 ? 0.01 0.40 ? 0.01 < MDA 0.169 ? 0.024 0.039 ? 0.005 0.018 ? 0.004 0.08 ? 0.05 June 2003 0.03 ? 0.01 0.24 ? 0.01 < MDA < MDA 0.009 ? 0.003 0.006 ? 0.003 < MDA 52 ANSTO E-752 Strassman Creek Bardens Creek W eir MDP Creek W eir Gross Alpha Gross Beta Gross Alpha Gross Beta Gross Alpha Gross Beta Date Sampled Bq/L Bq/L Bq/L Bq/L Bq/L Bq/L 15-1-02 0.01? 0.01 0.05 ? 0.01 0.02 ? 0.01 0.05 ? 0.01 0.02 ? 0.01 0.25 ? 0.01 27-2-02 0.02 ? 0.01 0.06 ? 0.01 0.01 ? 0.01 0.08 ? 0.01 < MDA 0.11 ? 0.01 26-3-02 0.02 ? 0.01 0.06 ? 0.01 0.04 ? 0.01 0.08 ? 0.01 0.01 ? 0.01 0.22 ? 0.01 23-4-02 0.01 ? 0.01 0.04 ? 0.01 0.01 ? 0.01 0.06 ? 0.01 0.01 ? 0.01 0.19 ? 0.01 29-5-02 0.01 ? 0.01 0.03 ? 0.01 0.01 ? 0.01 0.04 ? 0.01 0.03 ? 0.01 0.19 ? 0.01 25-6-02 0.01 ? 0.01 0.04 ? 0.01 0.02 ? 0.01 0.05 ? 0.01 0.01 ? 0.01 0.20 ? 0.01 23-7-02 0.02 ? 0.01 0.04 ? 0.01 < MDA 0.06 ? 0.01 0.01 ? 0.01 0.20 ? 0.01 13-8-02 0.01 ? 0.01 0.05 ? 0.01 0.01 ? 0.01 0.05 ? 0.01 0.01 ? 0.01 0.18 ? 0.01 20-9-02 0.01 ? 0.01 1.01 ? 0.01 0.02 ? 0.01 0.09 ? 0.01 < MDA 0.19 ? 0.01 28-10-02 0.01 ? 0.01 0.08 ? 0.01 < MDA 0.05 ? 0.01 < MDA 0.30 ? 0.01 29-11-02 0.02 ? 0.01 0.12 ? 0.01 0.04 ? 0.01 0.37 ? 0.01 0.04 ? 0.01 0.41 ? 0.01 10-12-02 0.01 ? 0.01 0.07 ? 0.01 0.03 ? 0.01 0.18 ? 0.01 0.01 ? 0.01 0.17 ? 0.01 28-1-03 < MDA 0.05 ? 0.01 < MDA 0.12 ? 0.01 < MDA 0.21 ? 0.01 25-2-03 0.01 ? 0.01 0.05 ? 0.01 0.01 ? 0.01 0.12 ? 0.01 0.01 ? 0.01 0.17 ? 0.01 7-3-03 0.01 ? 0.01 0.03 ? 0.01 0.02 ? 0.01 0.03 ? 0.01 < MDA 0.18 ? 0.01 11-4-03 0.04 ? 0.01 0.05 ? 0.01 0.03 ? 0.01 0.05 ? 0.01 0.03 ? 0.01 0.13 ? 0.01 25-5-03 0.02 ? 0.01 0.03 ? 0.01 0.04 ? 0.01 0.09 ? 0.01 0.03 ? 0.01 0.08 ? 0.01 12-6-03 0.01 ? 0.01 0.02 ? 0.01 0.02 ? 0.01 0.04 ? 0.01 < MDA 0.15 ? 0.01 T able 17. RADIOACTIVITY IN SURF ACE W A TER, SPCC SAMPLING POINTS, Januar y 2002 to June 2003 Notes: 1. See Figur e 2 for the location of the SPCC sampling points. 2. < MDA: indicates that the r esult was below the minimum detectable activity , calculated with 95% confidence. Indicative (medi an) MDA values for various radionuclides and envir onmental media ar e listed in T able 1. 3. All gr oss beta r esults include the beta activity due to natural potassium-40. 4. The NSW Clean W aters Regulations (1972) specify limits for radioactivity in class C waters: gr oss alpha: 1.1 Bq/L; gr oss bet a: 11.1 Bq/L. ANSTO E-752 53 W A TER (Bq/L) Sample Gamma-emitters Location Date Sampled Gross Alpha Gross Beta Am-241 Cs-137 Co-60 K -40 T ritium Mill Creek 16-12-02 0.04 ? 0.01 0.25 ? 0.01 < MDA < MDA < MDA 0.54 ? 0 .08 < MDA Bardens Creek 16-12-02 0.01 ? 0.01 0.20 ? 0.01 < MDA < MDA < MDA 0.60 ? 0 .11 < MDA SEDIMENT (Bq/g DW) Sample Gamma-emitters Location Date Sampled Gross Alpha Gross Beta Am-241 Cs-137 Co-60 K -40 Mill Creek 16-12-02 0.57 ? 0.08 0.08 ? 0.02 < MDA < MDA < MDA 0.033 ? 0.007 Bardens Creek 16-12-02 1.00 ? 0.09 0.20 ? 0.02 < MDA < MDA < MDA 0.067 ? 0.010 T able 18 . RADIOACTIVITY IN CREEKS NOR TH OF THE LFBG, Januar y 2002 to June 2003 Notes: 1. See Figur e 1 for the location of these sampling points. 2. The cr eeks wer e each sampled appr oximately 20m upstr eam fr om their confluence. 3. < MDA: indicates that the r esult was below the minimum detectable activity , calculated with 95% confidence. Indicative (medi an) MDA values for various radionuclides and envir onmental media ar e listed in T able 1. 54 ANSTO E-752 T ritium (Bq/L) W oronora Estuary Date Sampled Station E5.9 F orbes Creek 16-1-02 < MDA < MDA 7-2-02 < MDA < MDA 20-3-02 < MDA < MDA 30-4-02 < MDA < MDA 21-5-02 < MDA < MDA 26-6-02 < MDA < MDA 23-7-02 < MDA < MDA 30-8-02 < MDA < MDA 30-9-02 < MDA < MDA 28-10-02 < MDA < MDA 3-12-02 < MDA < MDA 23-12-02 < MDA < MDA 22-1-03 < MDA < MDA 14-2-03 < MDA < MDA 13-3-03 < MDA < MDA 1-4-03 < MDA < MDA 6-5-03 < MDA < MDA 10-6-03 < MDA < MDA T able 19. TRITIUM IN W A TERS, WORONORA RIVER ESTUAR Y AND FORBES CREEK, Januar y 2002 to June 2003 Notes: 1. Figur e 1 shows the sampling locations. 2. < MDA: indicates that the r esult was below the minimum detectable activity , calculated with 95% confidence. Indicative (median) MDA values for various radionuclides and envir onmental media ar e listed in T able 1. GAMMA-EMIT TERS Bq/L T ritium Date Sampled Am-241 Cs-137 Co-60 K -40 Bq/L 11-1-02 < MDA < MDA < MDA < MDA 380 ? 2 0 27-2-02 < MDA < MDA < MDA < MDA 460 ? 1 0 26-3-02 < MDA < MDA < MDA < MDA 390 ? 1 0 29-4-02 < MDA < MDA < MDA < MDA 470 ? 1 0 28-5-02 < MDA < MDA < MDA 1.76 ? 0.36 380 ? 2 0 28-6-02 < MDA < MDA < MDA < MDA 390 ? 2 0 31-7-02 < MDA < MDA < MDA < MDA 300 ? 2 0 30-8-02 < MDA < MDA < MDA < MDA 430 ? 1 0 30-9-02 < MDA < MDA < MDA < MDA 440 ? 2 0 31-10-02 < MDA < MDA < MDA < MDA 480 ? 2 0 29-11-02 < MDA < MDA < MDA < MDA 400 ? 2 0 23-12-02 < MDA < MDA < MDA < MDA 460 ? 2 0 23-1-03 < MDA 0.071 ? 0.030 < MDA < MDA 480 ? 2 0 20-2-03 < MDA < MDA < MDA < MDA 560 ? 2 0 25-3-03 < MDA 0.068 ? 0.020 < MDA < MDA 480 ? 2 0 30-4-03 < MDA < MDA < MDA < MDA 390 ? 2 0 26-5-03 < MDA < MDA < MDA < MDA 210 ? 1 0 26-6-03 < MDA < MDA < MDA < MDA 370 ? 1 0 Notes: 1. Building 27 is the inter mediate waste and spent fuel storage facility . 2. The NH&MRC and A WRC (1996) guideline level for tritium in drinking water is 7600 Bq/L. 3. < MDA: indicates that the r esult was below the minimum detectable activity , calculated with 95% confidence. Indicative (median) MDA values for various radionuclides and envir onmental media ar e listed in T able 1. T able 20. RADIOACTIVITY IN GROUNDW A TER FROM THE VICINITY OF BUILDING 27, Januar y 2002 to June 2003 ANSTO E-752 55 Sample Depth SWL pH EC Eh T emperature Piezometer m (mBTOC) ? S/cm mV ? C MW1s 11.5 8.67 5.54 300 195.5 21.71 MW1d 23 8.97 3.88 600 353.2 22.30 MW2s 7.5 3.57 5.09 500 297.8 20.80 MW2d 25 3.22 5.62 800 294.8 23.12 MW3s 5 2.00 4.04 700 393.9 19.16 MW3d 23.5 1.54 5.75 700 349.2 20.19 MW4s 5 1.90 6.30 1000 336.8 20.47 MW4d 18 5.34 5.28 600 331.6 24.58 MW5s 7 2.91 4.87 500 311.7 23.55 MW6s 8 3.74 5.34 400 328.3 21.05 MW6d 23 6.93 5.69 600 348.2 21.43 MW7s 5.5 2.97 4.71 600 404.7 18.34 MW7d 20 13.04 3.88 1000 494.0 19.31 MW8s dr y - - - - - MW8d ~ 25.74 22.74 4.91 600 474.1 24.54 MW9s 17 10.67 4.32 400 462.7 18.62 MW9d 28 12.56 4.19 400 477.7 20.61 MW10s 11.5 6.08 4.56 300 417.0 19.77 MW11 11 8.40 4.42 500 357.8 23.57 MW13 23.5 14.28 4.17 400 400.7 22.54 MW14 24 13.04 5.68 600 163.3 20.67 MW15s 11 5.12 4.07 400 338.3 21.97 MW15d 18 5.84 4.98 500 350.5 21.62 BH3 23.5 15.70 5.06 500 278.5 23.67 BH3A d r y - - - - - BH6 14.5 10.60 4.16 400 368.0 22.40 BH112 ~ 21.76 19.26 4.92 500 285.2 24.05 BH102 ~ 8.26 7.26 6.27 700 288.9 18.54 T able 21. FIELD P ARAMETERS IN GROUNDW A TER, LHSTC, September 2002 Notes: 1. SWL, mBTOC - Standing water level measur ed in metr es below the top of the bor e casing. 2. Field parameters wer e measur ed using a calibrated Y eoKal pr obe. EC is electrical conductivity , measur ed in micr o Siemens per centimetr e; Eh is the oxidation/r eduction potential measur ed in millivolts. 3. ~ Denotes samples collected with hand bailer , ther efor e, appr oximate depths only . 56 ANSTO E-752 Na K M g C a C l S O 4 HCO 3 Piezometer mg/L mg/L mg/L mg/L mg/L mg/L mg/L MW1s 21.8 1.29 2.7 0.7 37.1 17.1 2.7 MW1d 59.8 0.35 8.0 1.0 130.3 25.2 < 0.1 MW2s 20.3 0.33 4.7 0.3 39.6 13.2 1.1 MW2d 38.4 1.29 8.6 1.8 76.6 14.9 6.1 MW3s 36.6 0.32 4.7 0.2 73.0 48.2 < 0.1 MW3d 42.8 1.53 10.9 4.4 79.8 18.3 29.0 MW4s 29.7 2.53 20.2 99.0 41.5 52.1 343.8 MW4d 37.4 0.64 7.1 4.9 62.4 16.3 23.6 MW5s 26.2 0.70 4.1 0.8 38.7 36.9 2.4 MW6s 13.6 0.60 2.6 8.9 13.8 62.4 16.3 MW6d 65.1 1.17 4.6 5.7 74.8 62.4 55.1 MW7s 49.7 1.68 6.7 3.7 71.1 84.8 < 0.1 MW7d 64.4 1.04 11.2 0.9 160.1 58.1 < 0.1 MW8d 21.3 0.91 2.6 2.6 38.9 13.6 3.7 MW9s 35.2 0.53 5.0 0.8 74.5 27.7 < 0.1 MW9d 36.8 0.69 5.5 0.7 78.0 42.9 < 0.1 MW10s 32.9 0.99 2.2 2.0 47.9 40.2 < 0.1 MW11 47.9 0.59 3.7 1.6 45.3 65.6 < 0.1 MW13 42.6 0.50 4.7 0.9 83.1 38.6 < 0.1 MW14 58.6 1.10 6.8 7.0 32.4 126.9 28.7 MW15s 41.9 0.56 5.7 0.6 89.9 36.4 < 0.1 MW15d 48.7 1.89 8.3 1.5 84.7 150.4 10.6 BH3 42.3 3.23 7.8 6.7 91.8 21.2 9.5 BH6 37.4 0.83 6.8 4.2 24.7 130.5 < 0.1 BH112 48.3 3.91 8.6 5.8 90.1 52.9 17.3 BH102 37.6 7.20 7.4 22.2 48.8 47.1 61.8 Notes: 1. Concentrations quoted ar e for dissolved ions. T able 22. MAJOR IONS IN GROUNDW A TER, LHSTC, September 2002 ANSTO E-752 57 T able 23. RADIOACTIVITY IN GROUNDW A TER, LHSTC, September 2002 RADIOACTIVITY (Bq/L) Gamma-Emitters Piezometer Gross Alpha Gross Beta K -40 Am-241 Cs-137 Co-60 T ritium MW1s 0.03 ? 0.01 0.05 ? 0.01 < MDA < MDA < MDA < MDA 23.6 MW1d 0.14 ? 0.01 0.15 ? 0.01 < MDA < MDA < MDA < MDA 7.7 MW2s 0.02 ? 0.01 0.02 ? 0.01 < MDA < MDA < MDA < MDA 54.9 MW2d 0.07 ? 0.01 0.05 ? 0.01 < MDA < MDA < MDA < MDA 2.7 MW3s 0.13 ? 0.01 0.11 ? 0.01 < MDA < MDA < MDA < MDA 34.2 MW3d 0.03 ? 0.01 0.03 ? 0.01 < MDA < MDA < MDA < MDA 4.5 MW4s < MDA 0.11 ? 0.01 < MDA < MDA < MDA < MDA 7.3 MW4d 0.02 ? 0.01 0.01 ? 0.01 < MDA < MDA < MDA < MDA 3.0 MW5s 0.04 ? 0.01 0.04 ? 0.01 < MDA < MDA < MDA < MDA 32.8 MW6s 0.01 ? 0.01 0.06 ? 0.01 < MDA < MDA < MDA < MDA 128.6 MW6d < MDA 0.03 ? 0.01 < MDA < MDA < MDA < MDA 3.6 MW7s 0.06 ? 0.01 0.13 ? 0.01 < MDA < MDA < MDA < MDA 53.7 MW7d 0.21 ? 0.02 0.26 ? 0.01 < MDA < MDA < MDA < MDA 4.0 MW8d 0.02 ? 0.01 0.07 ? 0.01 < MDA < MDA < MDA < MDA 2.6 MW9s 0.06 ? 0.01 0.07 ? 0.01 < MDA < MDA < MDA < MDA 12.5 MW9d 0.20 ? 0.01 0.19 ? 0.01 < MDA < MDA < MDA < MDA 12.8 MW10s 0.06 0.01 0.10 ? 0.01 < MDA < MDA < MDA < MDA 46.7 MW11 0 .04 ? 0.01 0.04 ? 0.01 0.26 ? 0.10 < MDA < MDA < MDA 611.1 MW13 0 .07 ? 0.01 0.06 ? 0.01 < MDA < MDA < MDA < MDA 3.9 MW14 < MDA 0.02 ? 0.01 < MDA < MDA < MDA < MDA 107.6 MW15s 0.12 ? 0.01 0.14 ? 0.01 < MDA < MDA < MDA < MDA 2.6 MW15d 0.10 ? 0.01 0.16 ? 0.01 0.28 ? 0.10 < MDA < MDA < MDA 8.0 BH3 0.08 ? 0.01 0.17 ? 0.01 < MDA < MDA < MDA < MDA 2.6 BH6 0.05 ? 0.01 0.11 ? 0.01 < MDA < MDA < MDA < MDA 44.7 BH112 0.03 ? 0.01 0.07 ? 0.01 0.38 ? 0.12 < MDA < MDA < MDA 10.9 BH102 0.02 ? 0.01 0.23 ? 0.01 < MDA < MDA < MDA < MDA 38.0 Notes: 1. Gr oss beta activity includes any contribution fr om natural potassium-40. T ritium analyses per for med by the low-level ANSTO f acility . 2. < MDA: indicates that the r esult was below the minimum detectable activity , calculated with 95% confidence. Indicative (medi an) MDA values for various radionuclides and envir onmental media ar e listed in T able 1. 58 ANSTO E-752 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 Jan. R T otal 123.2 50.2 11.2 122.1 136.0 113.2 75.0 111.9 29.6 191.0 55.2 22.5 R Days 12 10 7 1 2 1 3 1 1 1 1 1 4 1 2 9 10 6 E T otal 137.5 149.0 205.2 135.8 125.2 151.8 163.9 165.4 138.0 151.3 176.6 173.2 E Max 7.1 9.1 12.6 7.9 7.6 7.8 10.1 10.0 8.0 10.1 13.4 11.0 Feb. R T otal 300.4 88.5 47.3 47.6 64.1 127.7 56.0 196.5 11.0 110.6 295.1 89.1 R Days 12 11 8 1 2 1 5 1 0 8 14 9 1 1 1 8 1 2 E T otal 104.4? 133.4 147.6 122.9 137.5 118.5 154.7 113.1 149.6 108.4 103.4 118.2 E Max 7.9 8.0 10.2 7.6 7.8 11.3 10.0 6.6 9.3 6.4 8.7 8.0 Mar . R T otal 80.2 144.6 151.7 205.4 33.7 61.2 15.5 40.2 217.6 122.0 143.3 89.0 R Days 9 1 7 1 7 1 6 9 10 8 1 0 1 4 2 0 1 5 8 E T otal 99.0 117.0? 118.3? 123.7 101.7 124.0 127.8 94.3 94.6 110.1 90.2 118.1 E Max 6.1 10.4? 8.2? 8.4 6.1 6.2 7.7 5.1 5.1 7.9 5.5 8.5 April R T otal 93.6 30.3 95.5 14.2 33.2 0.5 161.3 94.3 31.9 70.2 15.4 147.2 R Days 13 78261 1 0 1 7 1 2 7 6 1 6 E T otal 77.0 83.0 85.9 91.0 99.2 91.9 94.9 72.0 65.3 78.0 68.8 69.0 E Max 4.7 4.5 5.8 5.5 6.4 7.0 8.1 4.0 4.0 5.0 3.5 4.9 May R T otal 37.8 15.8 25.5 199.9 143.5 96.5 203.7 48.7 34.5 105.3 50.6 358.8 R Days 9 4 5 1 6 1 4 1 6 1 3 1 0 9 10 11 17 E T otal 47.2 55.3 82.0 67.7 60.1 64.7 61.8 44.7 54.9 58.1 61.6 71.7 E Max 2.7 4.9 6.6 6.0 3.9 4.7 4.9 3.4 3.4 4.5 3.7 6.8 June R T otal 70.5 34.3 39.5 40.4 51.8 51.0 80.2 66.6 34.2 9.3 18.1 58.0 R Days 8 6789 1 0 1 1 1 4 9 6 5 7 E T otal 48.7 53.3 51.1 44.1 58.9 54.7 45.5 45.9 45.7 44.4 49.1 49.3 E Max 3.2 3.4 3.5 3.3 3.8 6.4 4.1 2.8 4.5 2.4 3.1 3.5 July R T otal 11.2 64.8 7.4 1.0 78.4 48.2 86.8 163.3 31.4 109.2 26.4 R Days 5 1 0 8466 1 2 1 2 9 1 4 2 E T otal 59.0 42.1 56.7 52.7 60.0 52.7 50.1 47.4 52.1 44.3 57.0 E Max 3.5 2.6 3.1 3.5 3.2 2.6 3.8 4.1 3.8 2.3 3.3 Aug. R T otal 19.2 69.0 8.4 0.0 129.9 18.7 316.3 31.2 19.2 49.4 14.3 R Days 8 92065 1 5 8 1 1 6 7 E T otal 76.3 76.6 85.5 86.1 76.0 82.4 51.0 65.6 59.6 75.4 73.0 E Max 5.7 6.6 6.0 5.2 5.0 6.9 3.3 3.2 4.3 5.5 5.9 Sept. R T otal 17.8 81.8 10.4 249.3 74.8 105.6 37.7 20.7 37.2 18.2 7.0 R Days 9 1 0 2 13 7 1 5 9 5 6 10 4 E T otal 96.9 89.4 130.8 85.8 120.0 78.7 82.5 82.5 120.6 82.9 118.4 E Max 5.2 5.0 6.6 7.0 7.5 6.0 5.5 4.4 7.5 5.0 8.5 Oct. R T otal 33.4 54.6 35.1 34.4 31.2 60.2 26.7 211.0 55.1 39.8 1.4 R Days 12 7 9 10 10 8 8 13 9 8 4 E T otal 106.3 138.2 139.0 121.9 118.1 136.9 121.1 104.1 117.2 128.9 149.8 E Max 7.4 9.9 7.2 6.6 6.8 7.6 6.8 6.3 6.8 7.6 8.5 Nov . R T otal 143.4 57.3 94.2 135.4 70.8 21.7 110.3 32.7 150.3 57.1 14.5 R Days 18 9 1 4 1 5 1 2 9 15 9 1 7 1 1 6 E T otal 127.3 142.4? 164.6 126.4 146.5 150.2 113.6 112.1 100.5 129.6 157.1 E Max 7.9 13.6? 10.5 7.2 7.3 7.5 7.2 5.4 6.0 9.4 10.3 Dec. R T otal 186.0 40.7 50.7 93.9 68.8 27.3 37.8 112.8 46.4 15.9 59.8 R Days 18 12 9 1 3 6 7 9 13 11 8 9 E T otal 125.8 167.3 163.7 155.0 160.6 162.9 148.9 140.4 170.5 150.5 177.2 E Max 7.6 8.8 11.6 8.5 8.2 11.2 9.6 6.8 10.1 10.8 12.7 Annual R T otal 1116.7 731.9 576.2 1143.6 916.2 731.8 695.8 1129.9 698.4 898.0 701.1 R Days 133 112 87 121 113 108 129 139 128 120 97 E T otal 1105.4 1247.0 1430.4 1220.4 1260.5 1269.4 1215.8 1087.5 1168.6 1161.9 1282.2 T able 24. Rainfall (R) and Evaporation (E) Data fr om LHSTC, Januar y 1992 to June 2003 Note: Data labelled with ? denotes uncer tainty in evaporation measur ement. ANSTO E-752 59 SWL pH EC Eh T emp Piezometer mBTOC pH ? S/cm mV ?C MB 11 316 7.5 739 141 21.0 MB 12 191 4.64 154 214 20.9 MB 13 131 4.96 58 129 20.7 MB 14 275 5.6 435 54 21.3 MB 15 351 5.02 199 186 22.0 MB 16 182 4.7 170 108 20.6 MB 17 101 4.96 166 112 21.7 MB 18 307 5.78 613 122 21.8 MB 19 167 5.97 2212 72 19.7 MB 20 143 5.64 540 183 18.4 MB 21 116 5.66 565 86 19.6 BH10 75 4.97 1782 85 21.6 BHF 170 4.92 470 129 19.8 OS 2 105 5.96 116 106 21.2 OS 3 8 6 5.04 85 126 21.4 T able 25. FIELD P ARAMETERS IN GROUNDW A TER, LFBG, May 2002 Notes: 1. SWL, mBTOC - Standing water level measur ed in metr es below the top of the bor e casing. 2. Field parameters wer e measur ed in triplicate (the average r eading is given) using a calibrated Y eoKal pr obe. EC is Electrical conductivity , measur ed in micr o Siemens per centimetr e; Eh is the oxidation/r eduction potential measur ed in millivolts. 60 ANSTO E-752 Sampling Depth SWL pH EC Eh T emp Piezometer m mBTOC ? S/cm mV ?C MB 11 6.5 3.62 5.27 538 168 22.09 MB 12 4.0 2.92 5.32 156 186 25.95 MB 13 5.0 1.87 5.15 111 154 22.32 MB 14 5.2 3.31 5.86 311 -179 22.79 MB 15 6.5 4.38 5.44 111 179 22.07 MB 16 5.0 2.54 5.24 142 111 21.78 MB 17 4.0 1.78 5.19 130 154 24.11 MB 18 5.0 3.91 6.45 316 95 25.00 MB 19 5.0 2.94 6.03 846 46 21.66 MB 20 4.0 2.31 6.18 159 45 18.62 MB 21 3.5 2.04 6.02 205 119 21.6 BH10 5.0 1.59 5.25 402 166 20.87 BHF 8.0 2.45 4.94 197 203 20.6 OS 2 2.5 1.90 6.21 82 115 19.46 OS 3 3.0 1.67 5.08 70 193 22.07 P1S 5.0 3.12 4.74 476 195 22.1 P1D 20.0 3.46 5.29 430 107 22.1 P2D 26.0 12.46 6.22 1956 -55 19.5 CW 11.0 4.66 5.91 509 95 20.4 T able 26. FIELD P ARAMETERS IN GROUNDW A TER, LFBG, October 2002 Notes: 1. SWL, mBTOC - Standing water level measur ed in metr es below the top of the bor e casing. 2. Field parameters wer e measur ed in triplicate (the average r eading is given) using a calibrated Y eoKal pr obe. EC is Electrical conductivity , measur ed in micr o Siemens per centimetr e; Eh is the oxidation/r eduction potential measur ed in millivolts. ANSTO E-752 61 Sampling Depth SWL EC Eh T emp Piezometer m mBTOC pH ? S/cm mV ?C MB 11 5.0 4.15 5.98 109 147 22.83 MB 12 3.8 1.47 6.02 27.3 180 17.61 MB 13 4.8 0.47 6.05 34.3 141 18.00 MB 14 5.5 3.93 6.51 64 48 20.27 MB 15 6.0 4.67 6.05 83 121 20.34 MB 16 5.0 3.04 5.69 68 91 20.52 MB 17 4.0 2.40 5.86 84 151 19.53 MB 18 5.5 4.02 7.11 168 108 19.42 MB 19 4.5 0.35 6.81 70 77 19.95 MB 20 4.0 0.57 6.17 64 57 16.81 MB 21 3.0 0.23 6.55 76 111 17.92 BH10 5.5 1.81 5.98 430 93 18.4 BHF 10.0 3.14 5.91 204 97 17.82 OS 2 2.3 2.03 7.46 45 136 18.57 OS 3 3.0 1.88 5.75 39 178 20.07 P1S 5.0 2.55 4.94 59 192 19.57 P1D 10.0 2.94 6.72 86 107 18.49 P2D 15.5 11.95 5.86 913 163 17.64 CW 11.0 4.57 6.25 535 135 19.25 T able 27. FIELD P ARAMETERS IN GROUNDW A TER, LFBG, April - June 2003 Notes: 1. SWL, mBTOC - Standing water level measur ed in metr es below the top of the bor e casing. 2. Field parameters wer e measur ed in triplicate (the average r eading is given) using a calibrated Y eoKal pr obe. EC is Electrical conductivity , measur ed in micr o Siemens per centimetr e. Eh is the oxidation/r eduction potential measur ed in millivolts. 62 ANSTO E-752 RADIOACTIVITY (Bq/L) Date Gamma-emitters Piezometer Sampled Gross Alpha Gross Beta Am-241 Cs-137 Co-60 K -40 T ritium BHF 9-5-02 0.16 ? 0.02 0.22 ? 0.02 < MDA < MDA < MDA 0.34 ? 0.10 160 ? 2 0 BH10 9-5-02 < MDA 0.25 ? 0.04 < MDA < MDA < MDA 0.29 ? 0.13 6860 ? 5 0 OS2 9-5-02 0.03 ? 0.01 0.10 ? 0.01 < MDA < MDA < MDA 0.44 ? 0.09 660 ? 1 0 OS3 9-5-02 0.02 ? 0.01 0.28 ? 0.01 < MDA < MDA < MDA 0.27 ? 0.08 920 ? 2 0 MB11 9-5-02 0.09 ? 0.01 0.20 ? 0.01 < MDA < MDA < MDA 0.24 ? 0.09 < MDA MB12 9-5-02 < MDA 0.05 ? 0.01 < MDA < MDA < MDA 0.27 ? 0.09 < MDA MB13 9-5-02 0.02 ? 0.01 0.11 ? 0.01 < MDA < MDA < MDA 0.34 ? 0.09 900 ? 3 0 MB14 9-5-02 < MDA 0.09 ? 0.01 < MDA < MDA < MDA 0.37 ? 0.09 < MDA MB15 9-5-02 0.02 ? 0.01 0.03 ? 0.01 < MDA < MDA < MDA 0.39 ? 0.08 < MDA MB16 9-5-02 0.10 ? 0.01 0.51 ? 0.01 < MDA < MDA 0.16 ? 0.01 0.31 ? 0.08 3000 ? 2 0 MB17 9-5-02 0.06 ? 0.01 0.07 ? 0.01 < MDA < MDA < MDA 0.35 ? 0.08 610 ? 1 0 MB18 9-5-02 0.18 ? 0.03 0.34 ? 0.03 < MDA < MDA < MDA 0.58 ? 0.10 140 ? 1 0 MB19 9-5-02 0.11 ? 0.05 0.57 ? 0.06 < MDA < MDA < MDA 0.39 ? 0.15 120 ? 1 0 MB19 DUP 9-5-02 0.11 ? 0.05 0.30 ? 0.04 < MDA < MDA < MDA 0.99 ? 0.15 50 ? 2 0 MB20 9-5-02 0.07 ? 0.01 0.37 ? 0.02 < MDA < MDA < MDA 0.57 ? 0.10 < MDA MB21 9-5-02 0.06 ? 0.01 0.22 ? 0.01 < MDA < MDA < MDA 0.39 ? 0.09 < MDA W ash Blank 9-5-02 < MDA < MDA < MDA < MDA < MDA < MDA < MDA Notes for T ables 28, 29 and 30: 1. See Figur e 4 for the location of the sampling bor es. A "less than" value indicates that the r esult was below the minimum det ectable activity (stated at the 95% confidence level). 2. The wash blank was collected in the field after MB16 was sampled. It consists of water (purified by r everse osmosis) that wa s pumped thr ough the equipment then filter ed. 3. The Australian drinking water guideline (NH&MRC and A WRC, 1996) for tritium in is 7600 Bq/L, and the scr eening level for gr os s alpha and gr oss beta activity is 0.5 Bq/L (less K-40). 4. Gr oss beta r esults include the contribution fr om natural potassium-40. 5. < MDA: indicates that the r esult was below the minimum detectable activity , calculated with 95% confidence. Indicative (medi an) MDA values for various radionuclides and envir onmental media ar e listed in T able 1. T able 28. RADIOACTIVITY IN GROUNDW A TER, LFBG, May 2002 ANSTO E-752 63 T able 29. RADIOACTIVITY IN GROUNDW A TER, LFBG, October 2002 RADIOACTIVITY (Bq/L) Date Gamma-emitters Piezometer Sampled Gross Alpha Gross Beta Am-241 Cs-137 Co-60 K -40 T ritium BHF 23-10-02 0.03 ? 0.02 0.22 ? 0.02 < MDA < MDA < MDA < MDA 270 ? 2 0 BH10 23-10-02 0.08 ? 0.03 0.21 ? 0.03 < MDA < MDA < MDA < MDA 4890 ? 5 0 OS2 23-10-02 0.13 ? 0.01 0.17 ? 0.01 < MDA < MDA < MDA < MDA 620 ? 2 0 OS3 23-10-02 0.10 ? 0.02 0.37 ? 0.02 < MDA < MDA < MDA 0.45 ? 0.02 1330 ? 3 0 MB11 23-10-02 0.02 ? 0.01 0.05 ? 0.01 < MDA < MDA < MDA < MDA < MDA MB12 23-10-02 0.02 ? 0.01 0.07 ? 0.01 < MDA < MDA < MDA < MDA < MDA MB13 23-10-02 0.06 ? 0.01 0.19 ? 0.02 < MDA < MDA < MDA < MDA 2220 ? 3 0 MB14 23-10-02 0.25 ? 0.05 0.28 ? 0.03 < MDA < MDA < MDA 0.39 ? 0.12 40 ? 1 0 MB15 23-10-02 0.10 ? 0.02 0.17 ? 0.01 < MDA < MDA < MDA 0.22 ? 0.09 10 ? 1 0 MB16 23-10-02 0.27 ? 0.03 0.67 ? 0.02 < MDA < MDA 0.30 ? 0.03 < MDA 4230 ? 6 0 MB17 23-10-02 0.05 ? 0.01 < MDA < MDA < MDA < MDA < MDA 720 ? 1 0 MB18 23-10-02 0.03 ? 0.02 0.12 ? 0.02 < MDA < MDA < MDA 0.24 ? 0.11 140 ? 1 0 MB19 24-10-02 < MDA 0.58 ? 0.09 < MDA < MDA < MDA 0.58 ? 0.14 160 ? 2 0 MB20 24-10-02 0.04 ? 0.02 0.33 ? 0.02 < MDA < MDA < MDA 0.42 ? 0.13 < MDA MB21 24-10-02 < MDA 0.26 ? 0.02 < MDA < MDA < MDA 0.45 ? 0.09 < MDA W ash Blank 23-10-02 < MDA < MDA < MDA < MDA < MDA < MDA < MDA 64 ANSTO E-752 RADIOACTIVITY (Bq/L) Date Gamma-emitters Piezometer Sampled Gross Alpha Gross Beta Am-241 Cs-137 Co-60 K -40 T ritium BHF 1-5-03 0.12 ? 0.02 0.18 ? 0.01 < MDA < MDA < MDA < MDA 360 ? 2 0 BH10 1-5-03 0.05 ? 0.03 0.10 ? 0.02 < MDA 0.015 ? 0.006 < MDA < MDA 7180 ? 6 0 OS2 7-5-03 0.12 ? 0.01 0.13 ? 0.01 < MDA < MDA < MDA < MDA 220 ? 1 0 OS3 1-5-03 0.09 ? 0.01 0.12 ? 0.01 < MDA < MDA < MDA < MDA 230 ? 1 0 MB11 28-4-03 0.02 ? 0.01 0.03 ? 0.01 < MDA < MDA < MDA < MDA < MDA MB12 6-6-03 0.01 ? 0.01 0.02 ? 0.01 < MDA < MDA < MDA < MDA < MDA MB13 6-6-03 0.02 ? 0.01 0.11 ? 0.01 < MDA < MDA < MDA < MDA 640 ? 2 0 MB14 28-4-03 0.05 ? 0.01 0.06 ? 0.01 < MDA < MDA < MDA < MDA < MDA MB15 28-4-03 0.13 ? 0.02 0.14 ? 0.01 < MDA < MDA < MDA < MDA 15 ? 5 MB16 28-4-03 0.16 ? 0.02 0.35 ? 0.01 0.017 ? 0.006 0.015 ? 0.007 0.098 ? 0.019 < MDA 5530 ? 5 0 MB17 1-5-03 0.11 ? 0.02 0.06 ? 0.01 < MDA < MDA < MDA < MDA 760 ? 2 0 MB18 1-5-03 0.12 ? 0.03 0.18 ? 0.02 < MDA < MDA < MDA 0.31 ? 0 .11 220 ? 1 0 P1s 6-6-03 3.2 ? 0.3 3.0 ? 0.2 < MDA < MDA < MDA < MDA < MDA P1d 6-6-03 0.09 ? 0.03 0.04 ? 0.02 < MDA < MDA < MDA < MDA 30 ? 1 0 CW 1-5-03 0.40 ? 0.07 0.37 ? 0.03 < MDA < MDA < MDA < MDA 820 ? 2 0 MB19 6-6-03 0.04 ? 0.01 0.11 ? 0.01 < MDA < MDA < MDA < MDA < MDA MB20 6-6-03 0.08 ? 0.01 0.26 ?0.01 < MDA < MDA < MDA < MDA < MDA MB21 6-6-03 0.14 ? 0.02 0.32 ? 0.02 < MDA < MDA < MDA < MDA < MDA P2d 6-6-03 < MDA 0.33 ? 0.05 < MDA < MDA < MDA < MDA 60 ? 1 0 W ash Blank 28-4-03 < MDA < MDA < MDA < MDA < MDA < MDA < MDA W ash Blank 6-6-03 < MDA < MDA < MDA < MDA < MDA < MDA < MDA T able 30. RADIOACTIVITY IN GROUNDW A TER, LFBG, April - June 2003 ANSTO E-752 65 Gamma-emitters (Bq/g DW) Gross Alpha Gross Beta Location (1) Date Sampled Bq/g DW Bq/g DW Am-241 Be-7 Cs-137 Co-60 K -40 BUND A 28-2-02 0.36 ? 0.07 0.40 ? 0.02 < MDA 0.176 ? 0.018 0.0059 ? 0.0008 < MDA 0.22 ? 0.02 24-6-03 0.24 ? 0.01 0.26 ? 0.01 < MDA 0.083 ? 0.009 0.0024 ? 0.0005 < MDA 0.18 ? 0.02 BUND B 28-2-02 0.24 ? 0.07 0.26 ? 0.02 < MDA 0.129 ? 0.014 0.0015 ? 0.0006 0.0049 ? 0.0009 0.16 ? 0.02 24-6-03 0.24 ? 0.01 0.22 ? 0.01 < MDA 0.062 ? 0.007 0.0017 ? 0.0004 0.0083 ? 0.0001 0.15 ? 0.02 BUND C 28-2-02 0.40 ? 0.08 0.30 ? 0.02 0.0010 ? 0.0004 0.025 ? 0.006 0.060 ? 0.006 0.0046 ? 0.0008 0.06 ? 0.01 24-6-03 0.23 ? 0.01 0.20 ? 0.01 0.0010 ? 0.0003 0.028 ? 0.004 0.018 ? 0.002 0.0044 ? 0.0007 0.08 ? 0.01 Notes: 1. See Figur e 2 for the locations of the stor mwater bunds. 2. Radioactivity units ar e becquer els per gram (dr y weight) of sample. 3. < MDA: indicates that the r esult was below the minimum detectable activity , calculated with 95% confidence. Indicative (medi an) MDA values for various radionuclides and envir onmental media ar e listed in T able 1. T able 31. RADIOACTIVITY IN SEDIMENT , LHSTC STORMW A TER BUNDS, Januar y 2002 to June 2003 66 ANSTO E-752 Date of Survey Location (1,2) Dose-rate ( ? Sv/hour) 13 December 2002 Backgr ound r eading (at LFBG gate ) 0.08 ? 0.15 T r enches 1-51 0.10 ? 0.15 T r enches 52-77 0.08 ? 0.15 T r enches S1 and S2 0.10 ? 0.15 Dose-rate ( ? Sv/hour) Background Date Location (1,2) Ground Below Dose-rate Joint Pipe Joint ( ? Sv/hour) 27/28-2-02 Joints #1-22 0.07 ? 0.13 0.07 ? 0.13 0.07 ? 0.13 9-10-02 Joints #1-22 0.07 ? 0.12 0.06 ? 0.13 0.06 ? 0.12 25-3-03 Joints #1-22 0.06 ? 0.11 0.06 ? 0.11 0.05 ? 0.16 T able 32. GAMMA DOSE-RA TE SUR VEY , LFBG TRENCHES, December 2002 Notes 1. See Figur e 4 for the location of the waste burial tr enches and sampling points. 2. The survey was per for med using a calibrated Eberline PRM-7 gamma dose-rate meter , held at gr ound level. T able 33. GAMMA DOSE-RA TE SUR VEYS, LIQUID EFFLUENT PIPELINE, LHSTC, Januar y 2002 to June 2003 Notes: 1. Survey of exposed por tions of pipeline between LHSTC and the Sydney W ater sewer connection, using a calibrated Eberline PRM-7 gamma dose-rate meter . 2. The survey excluded joints number ed 18 & 19 which ar e inaccessible. ANSTO E-752 67 Sampling Date Gamma-emitters in Blackfish (2) Location Sampled (1) Bq/kg FW (3) Be-7 (4,5) K -40 Am-241 Co-60 Cs-137 I-131 POT TER 7-5-02 < MDA 155 ? 1 5 < MDA < MDA < MDA < MDA POINT 11-6-03 < MDA 150 ? 2 0 < MDA < MDA < MDA < MDA Ocean Outfall 11-6-03 < MDA 140 ? 1 5 < MDA < MDA < MDA < MDA The Royal 21-11-02 < MDA 150 ? 1 5 < MDA < MDA < MDA < MDA National P ark Reference 21-11-02 < MDA 110 ? 1 5 < MDA < MDA < MDA < MDA Site Notes for T ables 34, 35 and 36: 1. Samples wer e split to for m duplicates, wher e possible. See Figur e 5 for sampling locations at the Potter Point ocean outfall and the r efer ence site. 2. The whole, unwashed samples of algae (Ulva sp.) and bar nacle (T esser opera r osea) wer e dried and gr ound prior to gamma spectr ometr y analysis. The fish, Luderick (Gir ella sp.), wer e cut into flesh fillets. 3. Radioactivity is in units of becquer els per kilogram of fr esh (wet) sample. 4. U &Th Series, Be-7 and K-40 ar e of natural origin. The U & Th Series column indicates the unquantified pr esence of decay pr o ducts fr om the natural uranium-238 or thorium-232 series. 5. < MDA indicates that the r esult was below the minimum detectable activity , calculated with 95% confidence. Indicative (media n) MDA values for various radionuclides and envir onmental media ar e listed in T able 1. T able 34. RADIOACTIVITY IN FISH, POTTER POINT AND THE ROY AL NA TIONAL P ARK, Januar y 2002 to June 2003 68 ANSTO E-752 Sampling Date Gamma-emitters in Algae (2) Location Sampled (1) Bq/kg FW (3) U&Th Series (4) Be-7 (5) K -40 Am-241 Co-60 Cs-137 I-131 POT TER 6-5-02 Th-234 < MDA 195 ? 2 0 < MDA < MDA < MDA 31.5 ? 3.0 POINT 6-5-02 Th-234 < MDA 195 ? 2 0 < MDA < MDA < MDA 31.3 ? 3.0 Ocean Outfall 8-5-03 Th-234 < MDA 110? 1 0 < MDA < MDA < MDA 7.2 ? 0.7 The Royal 21-11-02 Th-234 < MDA 250 ? 2 5 < MDA < MDA < MDA < MDA National P ark 21-11-02 Th-234 < MDA 250 ? 2 5 < MDA < MDA < MDA < MDA Reference 13-6-03 Th-234 2.8 ? 0.7 125 ? 1 5 < MDA < MDA < MDA < MDA Site 13-6-03 Th-234 3.0 ? 0.8 135 ? 1 5 < MDA < MDA < MDA < MDA T able 35. RADIOACTIVITY IN ALGAE, POTTER POINT AND THE ROY AL NA TIONAL P ARK, Januar y 2002 to June 2003 Sampling Date Gamma-emitters in Barnacles (2) Location Sampled (1) Bq/kg FW (3) Be-7 (4,5) K -40 Am-241 Co-60 Cs-137 I-131 POT TER 6-5-02 < MDA 35 ? 5 < MDA < MDA < MDA < MDA POINT 6-5-02 < MDA 45 ? 5 < MDA < MDA < MDA < MDA Ocean Outfall 8-5-03 < MDA 35 ? 6 < MDA < MDA < MDA < MDA The Royal 21-11-02 < MDA 25 ? 1 0 < MDA < MDA < MDA < MDA National P ark 21-11-02 < MDA 20 ? 1 0 < MDA < MDA < MDA < MDA Reference 13-6-03 < MDA 30 ? 5 < MDA < MDA < MDA < MDA Site 13-6-03 < MDA 24 ? 5 < MDA < MDA < MDA < MDA T able 36. RADIOACTIVITY IN BARNACLES, POTTER POINT AND THE ROY AL NA TIONAL P ARK, Januar y 2002 to June 2003 ANSTO E-752 69 Receptor 2001-2 2002-3 Location Estimated Effective Dose Estimated Effective Dose mSv/yr mSv/yr Near est r esident 0.00263 0.00191 LHSTC Librar y 0.00325 0.00268 LHSTC Building 9 0.00464 0.00310 LHSTC Main gate 0.00219 0.00180 Stevens Hall Motel 0.00617 0.00503 W aste Services Centr e 0.00099 0.00075 BMX track 0.00054 0.00047 W o r onora V alley 0.00059 0.00045 At 1.6 kilometr e radius fr om HIF AR NOR TH 0.00401 0.00378 NNE 0.00297 0.00308 NE 0.00319 0.00249 ENE 0.00334 0.00254 EAST 0.00285 0.00207 ESE 0.00141 0.00115 SE 0.00133 0.00124 SSE 0.00142 0.00121 SOUTH 0.00104 0.00089 SSW 0.00101 0.00100 SW 0.00168 0.00185 WSW 0.00155 0.00156 WEST 0.00074 0.00071 WNW 0.00068 0.00059 NW 0.00123 0.00093 NNW 0.00216 0.00189 At 4.8 kilometr e radius fr om HIF A R NOR TH 0.00097 0.00103 NNE 0.00059 0.00053 NE 0.00074 0.00057 ENE 0.00076 0.00057 EAST 0.00062 0.00045 ESE 0.00030 0.00024 SE 0.00027 0.00025 SSE 0.00031 0.00027 SOUTH 0.00021 0.00017 SSW 0.00021 0.00022 SW 0.00039 0.00043 WSW 0.00034 0.00033 WEST 0.00016 0.00016 WNW 0.00015 0.00013 NW 0.00028 0.00022 NNW 0.00050 0.00049 Notes: 1. The annual ef fective dose is estimated using actual stack discharge data as input to the computer model, PC-Cr eam. 2. The annual dose limit for members of the public is 1 mSv/year (NH&MRC, 1995). T able 37. ESTIMA TED EFFECTIVE DOSES FROM LHSTC AIRBORNE DISCHARGES, 2001-2002 and 2002-2003 70 ANSTO E-752 Appendix A ? Quality Assurance and Control APPENDIX A ? QUALITY ASSURANCE AND CONTROL The ANSTO program of environmental and effluent monitoring operates within a quality system that complies with the Australian and New Zealand standard AS/NZS ISO 9001:2000 series for Quality Management Systems. This includes a commitment to continual improvement, put into practice through internal audits, client surveys and other management tools. ANSTO?s environmental management system includes the external verification of analytical results from the environmental and effluent monitoring program, as agreed with ARPANSA. ANSTO?s environmental monitoring includes a variety of radioanalytical techniques applied to a range of environmental media and with determination of many different radionuclides. Some basic statistics and simple decision rules have been applied in order to summarise this multi-factorial comparison. Method of comparing analytical results Comparative statistics are based on the difference between paired analyses (as absolute % of the ANSTO value) and presented as the median ? IQR. Data below the various detection limits ("less than" data) were replaced with a value of half the detection limit for the individual analysis. Where more than half the data were ?less thans?, no comparison was attempted. The quality of comparison is broadly categorized, based on the median difference, as follows: a difference of 10% or less represents a ?good? agreement between the ANSTO data and those of the independent laboratory; 30% or less difference is considered a ?fair? agreement, and anything greater than a median difference of 30% is considered a ?poor? agreement. It should be noted that many of the radionuclides, particularly those determined by gamma spectrometry of environmental samples, were being measured close to the detection limits where the comparative statistics used (ie percentage differences) are sensitive to small variations. The problem of dealing with data less than the detection limits also contributes to variation in the comparative statistics. Airborne discharges At least twenty samples of airborne effluent were submitted to ARPANSA (Environmental Radiation and Health Branch) for measurement of either tritium (trapped in water) or iodine-131 (trapped on charcoal). Both tritium and iodine measurements were in fair agreement for 2002- 2003, with median differences of 26 ? 50% for tritium and 23 ? 10% for iodine. Liquid effluent discharges Six samples (monthly pipeline composites) of liquid effluent were submitted to ARPANSA (Environmental Radiation and Health Branch) for measurement of gross alpha and beta activity, tritium activities and various radionuclides determined via gamma spectrometry. More than half of the gross alpha measurements returned ?less than? values, so no comparison of statistics was made. Gross beta measurements were in fair agreement for 2002-2003, with a median difference of 11 ? 11%. Tritium data were in good agreement for 2002-2003, with a median difference of 6 ? 6% ? this comparison is based on few data. However, of the eleven radionuclides reported from gamma spectrometry by at least one of the two laboratories, only two (cesium-137 and cobalt- 60) were commonly detected. Cesium-137 analyses were in poor agreement, differing by 51 ? 148%. Cobalt-60 analyses were in fair agreement, with a median difference of 24 ? 10%. Environmental sampling and analysis In 2002-2003, more than 20 environmental samples (ground- and surface-waters and biota) were submitted to ARPANSA (Environmental Radiation and Health Branch) for parallel determination of radioactivity including gross alpha and beta activity, tritium activity and various radionuclides determined via gamma spectrometry (americium-241, cesium-137, beryllium-7, cobalt-60 and potassium-40). Most gross alpha measurements of waters returned ?less than? values, so no comparison of statistics was made. Gross beta measurements of waters were in fair agreement, with a median difference of 12 ? 11%. A median difference of 14 ? 11% also indicated fair ANSTO E-752 71 agreement for tritium measurements of waters. The repeatability of these measurements was also tested using multiple aliquots from two samples of varying tritium activity ? the median difference between laboratories (0.4 ? 2%) showed that there was good agreement. Cesium-137 measurements of waters were in fair agreement, with a median difference of 15 ? 25%. Beryllium- 7 measurements of waters were in poor agreement, differing by 45 ? 60%. Americium-241, cobalt-60 and potassium-40 were detected in too few samples for comparative analysis. External gamma radiation ARPANSA-supplied personal thermoluminescent dosimeters (TLDs) were placed at the 19 locations where ANSTO environmental TLDs were situated in 2001-2002 and 2002-2003. Three locations were in nearby suburbs and one set of TLDs was placed at the Cronulla STP. The ARPANSA personal TLDs systematically underestimate the effective dose by around 20% compared with ANSTO?s environmental TLDs (20 ? 9% for 2001-2 and 18 ? 13% for 2002-2003), as a result of their different design and purpose. Accounting for this, the two sets of TLDs were in good agreement for both 2001-2 and 2002-2003, with median differences of 6 ? 5% and 9 ? 11%, respectively. Conclusion In conclusion, external verification of ANSTO?s environmental monitoring measurements indicates acceptable agreement between ANSTO analytical results and independent analyses. This applies across the range of analytical techniques, environmental media and for most radionuclides determined. 72 ANSTO E-752 SI* units Note: For a fuller explanation of the terms used in this table, refer to the Glossary. *SI stands for Syst?me International Multiples And Submultiples Of SI Units SI Unit and Quantity Abbreviation Absorbed Dose Gray (Gy) Dose Equivalent Sievert (Sv) Radioactivity Becquerel (Bq) 10 3 kilo (k) 10 - 3 milli (m) 10 6 mega (M) 10 - 6 micro (?) 10 9 giga (G) 10 - 9 nano (n) 10 12 tera (T) 10 - 12 pico (p)