1971 年 6 巻 4 号 p. 177-181
The Fuel Reprocessing Test Plant at JAERI was operated during the period of 1968-1969 to gain experiences of the fuel reprocessing.
Fuel elements reprocessed were irradiated in the JRR-3 reactor up to about 700MWD/ton and cooled for 87-300 days. Therefore, krypton-85 is the most dominant radionuclide in the long lived gaseous fission products and the major part of krypton-85 in the fuel is discharged from the stack to atmosphere in the process of uranium dissolution.
The purpouse of the paper is to describe the measured results of gaseous krypton-85 released in each chemical processing and also to discuss the performance of krypton-85 gas monitor, in particular the relationship of counting rate and the inner pressure of the krypton-85 sampler. The measured activity of krypton-85 released was in fairly good agreement with the calculated inventory.