A comparison exercise performed by the Commission of the European Communities on fission product source term within a licensing framework

In 1982 the Commission of the European Communities appointed a Task Force on Safety Objectives (T.F.S.O), one of whose tasks was to examine the degree of coherence in developments of safety objectives for nuclear power plants. In a status report /1/ published in 1983 it was pointed out that there appeared to be a considerable degree of coherence between the dose-frequency targets used in different Member States for application to design basis accidents. However, it was recognized that the coherence might be more apparent than real for a variety of reasons, including: - differences in the status of these dose-frequency targets in the regulatory framework of different countries, - differences in the models and assumptions adopted in various countries to estimate doses from design basis accidents within a regulatory framework, - differences in classification of accidents, and in the estimation of source terms of radionuclides released to the environment. To identify similarities and possible differences and enable a comprehensive intercomparison, the Task Force has initiated a general programme of work which includes two benchmark exercises. The contents and structure of the two benchmark exercises were devised with the aim of facilitating the understanding of the origins of, and reasons for, possible differences in regulatory dose calculations. Such differences should not, however, be interpreted as representing differences in nuclear safety standards. The latter can only be assessed when all aspects of the regulatory approach are taken into account