Predictive analysis of the radiation exposure for the primary cooling system of the rated power operation of MONJU

Matsuo, Yoichiro; Hasegawa, Masanori; Maegawa, Yoshiharu; Miyahara, Shinya  

Radioactive corrosion products (CP) are main source of personal radiation exposure during maintenance without fuel-failure accident in the liquid-metal fast breeder reactor (LMFBR) plants. In order to establish the techniques of radiation dose estimation for personnel, program system DORE has been developed. The DORE system is constructed by PSYCHE code and QAD code system. The density of each deposited CP of primary coolant system in MONJU was estimated by using the PSYCHE. Moreover, the QAD-CGGP2R code is applied to dose rate calculations for the primary coolant system in MONJU. The predicted values were estimated to be saturated at 2-3 mSv/h in twenty years after the start of operation, and the dose rate reaches 4 mSv/h in domains near the IHX and the cold-leg piping.