Evaluation of insertion property of control rod of JRR-3 at earthquake by time history response analysis method

Kawamura, Sho; Kikuchi, Masanobu; Hosoya, Toshiaki

JAEA-Technology 2021-041, 103 Pages, 2023/02

JAEA-Technology-2021-041.pdf:8.7MB

In response to new regulatory standard for research and test reactor which is enforced December 2013, JRR-3 got license in November 2018 by formulate new design basis ground motion. After that we evaluated for insertion property of control rod using that new design basis ground motion, and that evaluation results were accepted as approval of the design and construction method by Nuclear Regulation Authority. Now, we re-evaluated to insertion property of control rod about neutron absorber and follower fuel element by time history response analysis method. In this report, it shows that new results have sufficiency of margin compared with the past results that are accepted as approval of the design and construction method.

Estimation of I-131 concentration using time history of pulse height distribution at monitoring post and detector response for radionuclide in plume

Hirayama, Hideo*; Kawasaki, Masatsugu; Matsumura, Hiroshi*; Okura, Takehisa; Namito, Yoshihito*; Sanami, Toshiya*; Taki, Mitsumasa; Oishi, Tetsuya; Yoshizawa, Michio

Nihon Genshiryoku Gakkai Wabun Rombunshi, 13(3), p.119 - 126, 2014/09

https://doi.org/10.3327/taesj.J14.006

A method of deducing the I-131 concentration in a radioactive plume from the time history of peak count rates determined from pulse height spectra obtained from an NaI(Tl)scintillation detector employed as a detector of a monitoring post was presented. The concentrations of I-131 in the plumes were estimated from the count rates using the calculated response of the NaI(Tl) detector with egs5 for a model of a plume uniformly containing I-131. This method was applied to the data from the monitoring posts at Nuclear Science Research Institutes of Japan Atomic Energy Agency (JAEA). The estimated time history variation of I-131 concentrations in plumes was in fair agreement with those measured directly by an air sampling method. The difference was less than a factor of 4 for plumes that arrived on March 15 and March 21, indicating relatively high I-131 concentrations among the plumes studied in this work.