Occupational radiation exposure at PWRs: international comparison of some exposure indicators between 1975 and 1976

This report presents occupational radiation exposures at PWRs for 1986. It updates the CEPN report no 103 which covered the 1975-1985 period. Data have been collected for Belgium, Federal Republic of Germany, Finland (this country was not included in the previous report), France, Japan, Sweden, Switzerland, United-States. Only reactors in commercial operation since July 1974 have been considered in the analysis. Figures related to 1986, do not change significantly previous results for average annual doses over all operating years in the various countries. Differences between average annual collective doses remain important: from 0.95 to 4.68 expressed in terms of man-Sv/reactor, and from 1.4 to 8.3 expressed in terms of man-Sv/GW-y. As far as average annual individual doses are concerned, values are ranging between 1.6 and 4.8 mSv. The data up to the end of 1986 show however a general increase of collective doses in the various countries apart for the United-States. The average collective dose per reactor for all PWRs out of the United-States raised from 2.07 man-Sv in 1985 to 2.37 man-Sv in 1986. This general increase is mainly due to special or unscheduled maintenance works which tend to raise with plant age. In the United-States the dose reduction is reflecting the 5 new reactors that came on stream in 1986 with relatively lower doses in the first operating year. Excluding these 5 new reactors from the analysis, figures show a stability in the average annual collective dose. Generally it can be concluded that collective exposures in the various countries are coming closer. This probably shows a tendency towards an uniformization of practices and mode of operations in the different countries