Summary and conclusions: capabilities and challenges.
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Decision Support Systems, Management↗
Biomedical subjects
M J Crick
Publications and source records attributed to M J Crick.
Models for the transfer of radionuclides in cattle for use in radiological assessments.
In performing assessments of the radiological impact of releases of radioactive materials to the environment, mathematical models are required to enable the transfer through various parts of the environment and hence the dose to man to be predicted. The nature of the models and their degree of complexity depend largely upon the particular applications in which they are to be used. Two types of model of differing degrees of complexity for predicting the transfer of strontium, caesium and iodine in cattle have been developed at NRPB . They form part of a general model for the transfer of radionuclides through terrestrial foodchains . The first is a relatively simple model based on the use of equilibrium transfer factors, while the second is an improved but more complex model which incorporates the extra features necessary to provide a reasonable representation of the time dependence of transfer to milk and to meat. Comparisons of the results using the two types of model in some situations of radiological interest have been performed. From these comparisons conclusions have been drawn about the adequacy and pertinence of the use of each model type in different situations.
Animals↗
An assessment of the radiological impact of the Windscale reactor fire, October 1957.
On the 10th and 11 October 1957 a fire in the No 1 Pile at the Windscale establishment in Cumbria led to an uncontrolled release of activity to the atmosphere. The resultant cloud subsequently dispersed and radionuclides could be detected over England, Wales and parts of northern Europe. The extensive environmental measurements which were made during and after the release enabled a fairly accurate estimate to be made of the radiation doses to the most exposed individuals in the local population. Until recently, no estimates of the population dose resulting from the release had been published. This paper describes assessments which have been made by the NRPB of the population or collective dose from the release and of the possible associated health impact. In addition to the fission products that escaped, radionuclides were released from materials undergoing irradiation in the pile at the time of the fire. The assessment has included the results of a review of previously unpublished data which established the quantity of these nuclides released and considers their impact on both individual and population doses. The collective effective dose equivalent commitment from the release is estimated to have been 2.0 x 10(3) man Sv. The route of exposure which contributed the most to the collective dose was the inhalation pathway. Iodine-131 was the most important radionuclide, contributing nearly all of the collective dose to the thyroid and a large part of the collective effective dose. Polonium-210 and caesium-137 also made significant contributions; that from caesium-137 came in the longer term via external irradiation from ground deposits and the ingestion of contaminated foodstuffs. The methodology used in the study has been validated to a certain degree by comparing the predicted levels of individual thyroid activity and those measured directly in the weeks following the accident in London, Leeds and Cumbria.
Adult↗