The second integrated leak rate of the JOYO pressure containment vessel

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

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.