Emergency monitoring procedures at Central Electricity Generating Board nuclear power stations: Developments since the Three Mile Island accident

Following a brief review of Central Electricity Generating Board emergency arrangements prior to the 1979 Three Mile Island accident, the paper discusses the technical bases of subsequent developments in monitoring procedures. Some of these result from experience gained from the Three Mile Island accident, while others arise from the ongoing review of emergency arrangements in order to take account of advances in knowledge and improved equipment. In particular, continuously recording gamma monitoring systems have been installed at power station sites in order to assist in the estimation of the temporal pattern of any release of radioactivity. Further, passive thermoluminescent detector systems have been deployed around power stations in order to improve estimates of external radiation doses from the plume, while methods of assessing potential doses due to consumption of contaminated foodstuffs have also been improved. The range of emergency survey data available during an accident is described and their interpretation to provide early estimates and ongoing summaries of both individual and population doses is discussed. (author)