Improvement of the NSRR simulator

Murao, Hiroyuki ; Yachi, Shigeyasu; Ota, Kazunori  ; Muramatsu, Yasuyuki; Nakamura, Takehiko ; Terakado, Yoshibumi

Prior to actual runs in the shaped pulse and in the combined pulse operations, the online simulation and the offline simulation must be performed to examine safety and appropriation. Actual reactor power of the NSRR can be simulated practically, but a slight difference canbe observed between the present simulation results and the actual operation during the NSRR start-up phase and power controled operation. Regulating rod worth and fuel temperature feedback reactivity were re-evaluated and installed into the simulators. As a result, the accuracy of the simulator was remarkably improved. So that the application and safety of the shaped pulse and combined pulse operation were improved.