検索対象:     
報告書番号:
※ 半角英数字
 年 ~ 
 年

Failure mechanism of Nb$$_{2}$$O$$_{5}$$ doped PWR fuels under power transient

出力過渡化を受けたNb$$_{2}$$O$$_{5}$$添加PWR燃料の破損メカニズム

柳澤 和章

Yanagisawa, Kazuaki

(1)ニオブ(Nb$$_{2}$$O$$_{5}$$)添加の非加圧PWR燃料は安全審査で使われる破損しきい値の260cal/g以下では破損しなかった。(2)燃料破損はニオブ添加の有無とは無関係に被覆管の溶融脆化メカニズムで起こった。(3)炉内過渡ふるまいとして、供試燃料は大きな軸方向PCMI(最大18%)を示したが、その径方向PCMIは相対的に小さかった。(4)発熱量276cal/gを超えた領域、すなわち、被覆表面最高温度が1467$$^{circ}$$Cを超えた領域で、ニオブ添加PWR燃料はボンディング、径方向微細割れ、金属凝集物、金属介在物の生成といった組織変化を起こした。

(1) The niobia doped PWR fuel (test specimen) did not fail below 260 cal/g defined as the failure threshold for RIA. (2) The fuel failure occurred by the cladding melt-brittle mechanism irrespective to the doping. (3) The test specimen caused a significant axial PCMI to the magnitude of 18%. (4)Above 276 cal/g, the test specimen restructured and formed the bonding, the small radial cracks, the metallic agglomeration and inclusion at the very narrow ring area. The grain size of the test specimen at the ring was reduced from original 31 to 10-21 microns. Meanwhile, undoped fuel grew the grain size from original 9 to 60 microns at the similar ring because of the recrystallization.

Access

:

- Accesses

InCites™

:

Altmetrics

:

[CLARIVATE ANALYTICS], [WEB OF SCIENCE], [HIGHLY CITED PAPER & CUP LOGO] and [HOT PAPER & FIRE LOGO] are trademarks of Clarivate Analytics, and/or its affiliated company or companies, and used herein by permission and/or license.