Irradiation test and post irradiation examination of the high burnup HTGR fuel

高燃焼度高温ガス炉燃料の照射試験および照射後試験

植田 祥平   ; 相原 純 ; Shaimerdenov, A.*; Dyussambayev, D.*; Gizatulin, S.*; Chakrov, P.*; 坂場 成昭 

Ueta, Shohei; Aihara, Jun; Shaimerdenov, A.*; Dyussambayev, D.*; Gizatulin, S.*; Chakrov, P.*; Sakaba, Nariaki

燃焼度100GWd/t付近で使用する高温ガス炉の新型TRISO燃料の照射性能を調べるため、カザフスタン共和国核物理研究所(INP)のWWR-K照射炉においてキャプセル照射試験が実施された。照射されたTRISO燃料試料は、原子力機構が新たに設計し、HTTR燃料製造技術に基づいて製造されたものである。燃焼度100GWd/tまでの照射により当初予想量を超える核分裂生成物ガスの放出は起こらなかったものと考えられる。加えて、照射済みTRISO燃料の健全性評価と将来のさらなる高燃焼度化に向けた温ガス炉燃料設計の高度化を目的とした照射後試験を計画している。

In order to examine irradiation performance of the new Tri-structural Isotropic (TRISO) fuel for the High Temperature Gas-cooled Reactor (HTGR) at the burnup around 100 GWd/t, a capsule irradiation test was conducted by WWR-K research reactor in the Institute of Nuclear Physics (INP) of Kazakhstan. The irradiated TRISO fuel was designed by Japan Atomic Energy Agency (JAEA) and fabricated in basis of the HTTR fuel technology in Japan. The fractional release of fission gas from the fuel during the irradiation shows good agreement with the predicted one released from as-fabricated failed TRISO fuel. It was suggested that unexpected additional fuel failure would not occur during the irradiation up to 100 GWd/t. In addition, the post-irradiation examination (PIE) with the irradiated fuel is planned to qualify TRISO fuel integrity and upgrade HTGR fuel design for further burnup extension.