Preliminary study of the criticality monitoring method based on the simulation for the activity ratio of short half-life noble-gas fission products from fuel debris

Riyana, E. S.   ; 奥村 啓介 ; 坂本 雅洋 ; 松村 太伊知 ; 寺島 顕一  ; 神野 郁夫

Riyana, E. S.; Okumura, Keisuke; Sakamoto, Masahiro; Matsumura, Taichi; Terashima, Kenichi; Kanno, Ikuo

We investigated the possibility of estimating the effective neutron multiplication factor () of the fuel debris inside the canister and primary containment vessel (PCV) of Unit 2 of the Fukushima Daiichi Nuclear Power Station (1F) using remote gas-radioactivity measurement via simulation-based calculations. Our results demonstrate an almost linear correlation between and the Kr-to-Xe activity ratio with respect to various fuel debris compositions. This correlation is maintained regardless of geometries such as the fuel debris canister and the PCV.