抄録
Studies have been made to obtain the release limits of radioactive gas from a stack in normal operation of a BWR plant. These included observation of the behavior of radio-nuclides in the plant system and determination of significant nuclides, referring to the data gained by the operation of the JPDR (JAERI), and also the evaluation of exposures at ground surface around the plant site due to the released noble gas cloud.
It was found that the gamma exposure from a fission noble-gas cloud is a determining factor for the release limit from a BWR plant. The release limit of fission noble gases (diffusion mixture) from the JPDR with a 55-meter high stack is calculated as 47Ci/h for the dose limit of 0.04rem per 3 months under the meteorological stability D and a yearly average wind-speed of 3.6m/sec.
