照射後試験における渦電流探傷技術の開発 - 探傷技術の開発(その2 FCCI 測定技術)-

Development of eddy current techniques at PIE facility; phase II testing for FCCI measurement

菊地 晋  ; 北澤 健夫; 永峯 剛; 松元 愼一郎

Kikuchi, Shin; Kitazawa, Takeo; not registered; Matsumoto, Shinichiro

渦電流探傷技術の照射後試験への適用を目指し、ホットセル外(以下、セル外)において性能試験を実施してきた。その結果、被覆管材料等の欠陥検査への適用性を確認でき、照射材への適用の見とおしを得た。このうち、前報では燃料-被覆管化学的相互作用(Fuel Cladding Chemical Interaction:FCCI)測定試験(減肉測定)を除いた、セル外での外面、内面、貫通孔の探傷性能について述べた。本報告では、セル外における模擬FCCI測定試験の結果について述べると共に、外面欠陥、内面欠陥、貫通孔、FCCIのそれぞれの標準欠陥ピンを用いた渦電流探傷装置のセル内導入後の校正試験の結果について報告する。模擬FCCI測定試験では試験結果を基に測定条件や模擬FCCI量と渦電流信号値の相関関係を確認し、渦電流試験によるFCCI測定の見通しについて検討した。模擬FCCI測定試験の結果、測定の最適条件はそれぞれ1)ピンの搬送速度:20mm/sec、2)試験周波数:32kHz、3)位相: 0DEG、4)利得:-10dB、5)フィルター:0であった。また、模擬FCCI量と渦電流信号値の間に相関関係があり、300mオーダーの肉厚量をもつ被覆管に対して、50m以上の減肉変化が認められる場合、FCCIを検出できる見通しを得た。また、セル内導入後の校正試験を実施した結果、セル外における性能試験とほぼ同等の性能があることを確認した。

Eddy current techniques have been tested for future Post irradiated Experiment ;PIE applications outside hot cell(the following, cell outside). As the result, applicability to the defects inspection such as the cladding tube material was able to be confirmed, and an outlook to the application to the irradiation material was obtained. The last time, report described results of the external surface defects, inside defects, and open holes outside hot cell except for Fuel-Cladding Chemical Interaction (FCCI) measurement testing This paper mainly describes the results of the trial FCCI measurement testing outside hot cell. Other tests include the results of external surface defects, inside defects, and open holes in the proofreading tests. The proofreading tests used a standard defect pin inside hot cell. In the trial FCCI measurement testing outside hot cell, the correlation between reduction in thickness and eddy current signal value was comfirmed, and the prospect of FCCI measurement by the eddy current testing was examined. As the result, the optimum conditions for measuring the FCCI quantity are respectively (1)carrier speed of the pin :20mm/sec, (2) test frequency : 32kHz, (3)phase : ODEG, (4) gain :-10dB, (5)filter : 0. The correlation between trial FCCI quantity and eddy current signal value was found on the basis of the test result, and the prospect which could detect FCCI was obtained when there is reduction in thickness of over 50 m for the cladding tube with wall thickness quantity of the 300 m order. And, the proofreading test inside hot cell on eddy current measurements were confirmed to be equivalent to the performance test outside hot cell.