高速実験炉「常陽」ナトリウム注入後第2回格納容器全体漏洩率試験 試験報告書(速報)

The second integrated leak rate of the JOYO pressure containment vessel

井上 達也*; 榎本 俊彦*; 平田 豊*; 伊藤 忠弘*; 福田 達*; 朝倉 文雄*; 野本 昭二*

not registered; Enomoto, Toshihiko*; not registered; not registered; not registered; not registered; not registered

高速実験炉「常陽」原子炉格納容器の気密保持機能確認を目的とし,昭和54年12月,原子炉格納容器の全体漏洩率試験を実施した。試験は高速実験炉「常陽」の定期点検の一環とし,昭和53年2月に実施したナトリウム注入後第1回試験に引続き,第2回試験として第1回試験と同一の方法にて実施した。試験の結果,全体漏洩率(みかけの漏洩率)は絶対圧力法にて0.034+-0.021%/day,基準容器法にて0.039+-0.006%/dayであり,第1回試験で測定された漏洩率(それぞれ,0.036+-0.011%/day,0.036+-0.008%/day)とほぼ等しく,誤差並びにナトリウム冷却型炉として特殊な試験状態を採用したことに伴う補正漏洩率を加えた結果も基準値1.90%/day以下であって,原子炉格納容器の気密保持機能は維持されていることが確認された。第1回試験並びに第2回試験の結果により,ナトリウム冷却型炉固有の,冷却材を溶融循環させた状態での試験並びにそれに伴う漏洩率の評価法に問題はなく,以後の試験も,ナトリウム冷却型炉の全体漏洩率試験として支障なく実施出来るものと考えられる。

In December 1979, the integrated leak rate test (ILRT) of the JOYO reactor pressure containment vessel was conducted, as part of the JOYO annual inspection, to confirm the leaktightness of the containment vessel. The test was tbe second ILRT perfomed since initial sodium fill (the first ILRT was carried out in February, 1978). As a result of the test, leak rates of 0.034 0.021 %/day by the absolute pressure method and of 0.0390.006 %/day by the reference chamber method were obtained. These leak rates were almost the same as those obtained in the first test which were 0.0360.011 %/day and 0.036 0.008 %/day, respectively. After combining results from local leak tests and correcting for measuring errors, and the compensated leak rate was found to be well within the leak rate limit of 1.90 %/day which was established by the safety criteria of the containment. These test results demonstrate that the JOYO containment vessel manitains the leaktightness which is required for the functional integrity of the containment in an accidental condition. The successful completion of both the first and second ILRT showed that the test methods and procedures used for leak tests of the JOYO Liquid Metal Fast Reactor are accurate and practical.