Screening assessment of dose rates to local wildlife from ANSTO's radiological effluent releases

No Thumbnail Available
Date
2018-11-06
Journal Title
Journal ISSN
Volume Title
Publisher
South Pacific Environmental Radioactivity Association
Abstract
A screening assessment was undertaken to investigate the potential dose rates received by local wildlife from radiological effluent releases associated with operations at the Australian Nuclear Science and Technology Organisation (ANSTO) Lucas Heights site in Sydney, NSW. The expected releases from the planned ANSTO Nuclear Medicine Mo-99 production facility were also considered. The assessment applied the methodology laid out in ARPANSA Guide: Radiation Protection of the Environment, which is consistent with current best practice approaches set forth by the international Commission on Radiological Protection and the International Atomic Energy Agency. A range of terrestrial organisms that occur in the bushland perimeter surrounding the Lucas Heights site were selected for assessment because of their potential exposure to ANSTO’s stack emissions - considered the air pathway. A range of marine organisms known to reside close to the outlet (where tertiary-treated sewage from the Sutherland Shire, including ANSTO, is discharged to the ocean) were assessed because of their potential exposure to liquid effluent discharges - considered the water pathway. Dose assessments were performed using the ERlCA tool using radioactivity concentrations for air and water determined from data collected during routine monitoring of ANSTO stack emissions and liquid effluent releases to sewer. Concentration values along the air and water pathways were overestimated, consistent with the decision to use conservative assumptions for this screening assessment. The analysis was unusual in that it considered dose from noble gas isotopes. For the air pathway, the largest predicted dose contribution was from xenon isotopes, followed by tritium. For the water pathway, it was found that the proportion of potential dose from ANSTO discharges was very small compared with those from local medical facilities. Even using a very conservative approach, the potential risk quotients for all organisms were below standard benchmark levels (Garnier-Laplace, J. et al., issues and practices in the use of effects data from FREDERICA in the ERICA integrated Approach; J. Environ. Radioact. 2008, 99 (9), 1474-1483). Dose rates to all organisms were below the lowest benchmark for potential harmful effects (10 uGy hr1). These results were consistent with previous studies that concluded no significant impacts to wildlife from ANSTO’s operations. Therefore, potential radioactivity releases from the planned ANM facility are unlikely to impact local wildlife.
Description
Keywords
Dose rates, Wild animals, ANSTO, ARPANSA, New South Wales, Radioactive effluents, Seas
Citation
Corry, M., Johansen, M., & Loosz, T. (2018). Screening assessment of dose rates to local wildlife from ANSTO's radiological effluent releases. Paper presented to the SPERA Conference 2018, "Bringing environmental radioactivity research to Western Australia", Perth, Western Australia, 6 - 9 November 2018. (pp. 43-44).