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Browsing Scientific and Technical Reports by Subject "Accidents"

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    Modelling of biota dose effects. Report of working group 6 biota dose effects modelling of EMRAS II topical heading reference approaches for biota dose assessment. Environmental modelling for radiation safety (EMRAS II) programme
    (International Atomic Energy Agency, 2014) Johansen, MP
    Radiological protection of the environment is advancing from the old paradigm which stated that if humans are protected then by default all other components of the environment are protected as well [1]. Indeed, humans are among the most sensitive organisms to radiation and their protection does ensure protection of much of the environment. However, a more satisfying approach for many stakeholders, and one that is in-line with protection strategies implemented for other types of environmental contaminants, is to explicitly show that the environment is protected. Therefore, the International Commission on Radiological Protection (ICRP) now recommends explicit consideration of the environment and new approaches are being developed to demonstrate such protection. Appropriately, the new developments strive to protect populations or higher organizational levels (e.g. communities, ecosystems [2]), rather than focusing on the protection of individuals. The protection of higher levels of biological organization was not originally addressed [3], but is now being considered further [4]. During the last 10 years, considerable progress has been made in deriving screening ecological benchmarks and in developing a tiered Ecological Risk Assessment (ERA) approach for radioecology [5–7]. While the ERA-type approach is a substantial advancement in radioecology, a lack of sufficient data prevents current ERA analyses from fully accounting for the realistic environmental conditions to which organisms are exposed. Data are insufficient to predict effects from chronic, low doses; variable dose rate regimes; multicontaminant scenarios or multi-generational exposures; ecosystem level effects; or the influence of variable life-history traits [8]. Additionally, most measurements of effects are assayed on individuals within a population. Extrapolation is required to estimate population level effects from the individual-based measurements, or to account for the knowledge gaps mentioned above. The extrapolation uses assessment factors (or safety factors) that add conservatism and substantially increase uncertainties in risk assessments. Large uncertainties do little to promote confidence with the stakeholders of radioecology. Improvements are therefore needed.
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    Report of the committee of inquiry into a fire which occurred on 18 March 1987 in a radioisotope processing cell, Building 54 at the Lucas Heights Research Laboratories
    (Australian Atomic Energy Commission Research Establishment Lucas Heights, 1987-03-25) Australian Atomic Energy Commission Research Establishment Lucas Heights
    l. At about 1745 hours on Wednesday, l8 March 1987 a fire occurred in a small charcoal filter inside a processing cell (hot cell) in Building 54 at the Lucas Heights Research Laboratories (LHRL). This cell was being used to process irradiated uranium to separate the radioactive isotope molybdenum—99. 2. The fire was not related to either of the two research reactors at the LHRL site. It was confined to the charcoal filter in the above mentioned cell, which is about 500 metres from the nuclear reactor HIFAR. 3. Some radioactive contamination escaped from the hot cell into the operating area and three AAEC officers were found to have minor radioactive contamination on their skin/hair. A fourth AAEC officer had a spot of contamination on his trousers. The contamination was short-lived and was quickly and easily removed by washing with soap and water. 4. The majority of the radioactive material released from the fire was trapped by the main filters outside the cell. The total amounts of radioactive noble gas and of radioiodine released to the environment during the week in which the fire occurred were within the normal range of discharge and were 53% and 2.1%, respectively, of the weekly limit authorised by the NSW Department of Health. 5. Early advice on the accident was provided to the Minister for Resources and Energy and to relevant State and Local Government Authorities. A representative of the NSW Department of Health was present at the Lucas Heights Research Laboratories on the evening of 18 March. 6. The Committee noted that the response to the accident by personnel of the AAEC and of NSW emergency organisations was prompt and effective. 7. A number of recommendations have been made by the Committee to avoid a similar occurrence and to make further improvements in the effectiveness of the emergency response. 8. On the evidence available to it, the Committee: . concludes that the fire was caused by spontaneous combustion in the charcoal filter used to trap radioactive gases released by the operations in the hot cell, . concludes that the mechanism causing the fire cannot be clearly established at this stage and some further research and investigation is necessary to clarify the mechanism, . believes that no member of AAEC staff, NSW emergency services personnel or the general public suffered, or will suffer, any adverse health effects from radioactivity as a result of the accident.
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    Risks to individuals in NSW and in Australia as a whole
    (Australian Nuclear Science and Technology Organisation, 1989-07) Higson, DJ
    Objective, quantitative estimates are made of some risks to which individual members of the general public are exposed in NSW and in Australia as a whole, in their private lives and ordinary activities. The risks are given as averages for the group of people exposed to each risk. In many cases, this is the whole population. Occupational risks and unusual risk-taking are excluded as far as possible from the study. Some of the estimates are based upon statistics on the causes of death. Others are based upon mathematical models, because specific evidence relating causes and effects is lacking. The results of the study show that by far the highest risks of fatality are either voluntarily incurred or could be greatly reduced as a matter of choice by the risk-takers. Risks which come into these catagories include smoking, some other causes of cancer, drinking alcohol and motor vehicle traffic accidents. Risks to the general public from industrial accidents are comparatively low. These latter risks can be (and usually are) controlled to levels which, in a purely quantitative context, would generally not be perceived as significant.