1990 年 25 巻 2 号 p. 135-145
According to the concept of ICRP Pub. 26, the actual procedure to estimate the effective dose equivalent at Japanese nuclear power stations was studied.
The study included: (1) the development of the specific instrument designed to determine the dose equivalent at a depth of 10mm of the ICRU sphere, (2) specification tests about the energy dependence, accuracy etc. on the instrument, (3) the radiation survey at standard Japanese BWR and PWR comparing the developed instrument and the standard gamma radiation exposure (rate) meter, (4) the confirmation of gamma spectra at the power stations by a spherical 3″ NaI(T1) gamma radiation monitor.
It was confirmed that the ratio of the dose equivalent rate at 10mm depth and the gamma radiation exposure rate, in mSv·h-1/mR·h-1, was nearly 1/100 under the conditions of the normal operations and the outages of BWR and PWR. Therefore, it was clear that the gamma radiation exposure (rate) meters were satisfactory to determine the dose equivalent at 10mm depth of the ICRU sphere in the nuclear power stations.