2009 Volume 44 Issue 2 Pages 184-190
Japan Nuclear Fuel Limited has carried out environmental monitoring in order to ascertain that the dose of radiation to which the public is exposed around the Rokkasho Reprocessing Plant (RRP) is much lower than the annual dose limit. This report presents the point of view of selection of the monitoring items for dose estimation and the point of view of the dose estimation from the monitoring results. As measurement items of the monitoring for dose estimation, the objects and nuclides are selected in consideration of main exposure pathways. Estimation of the public dose is based on these monitoring data. However, when it is difficult to make such estimation, it is calculated by the dose estimation model, using discharge data from the RRP and meteorological data around the site, etc. In the monitoring items for dose estimation, in 85Kr, although frequency of appearance was very few, a transitory variation considered to be effect of the facilities accompanied by the active testing was observed. Except the monitoring items for dose estimation, the results considered to be effect by the discharge from the facilities were obtained in the samples from rain water and lake water. The effective dose from April, 2007 to March, 2008 by RRP was estimated about 0.0013 mSv/year from the measurement results of discharge, etc.
