Development of mechanical seal structure for reuse of re-instrumentation device used in fuel irradiation test

Inoue, Shuichi ; Yamaura, Takayuki ; Saito, Takashi; Ishikawa, Kazuyoshi; Kikuchi, Taiji; Sozawa, Shizuo; Tsuchiya, Kunihiko 

In Japan Material Testing Reactor (JMTR), a lot of experiments of fuel irradiation with the power ramping tests have been performed by using the shroud irradiation facility and the Boiling Water Capsule (BOCA). The fuel samples used in these tests were welded to re-instrumentation devices such as thermocouples and FP gas pressures. In this development, the mechanical connection method as "mechanical seal structure", that enables the re-use of re-instrumentation devices, was adopted in order to improve the utilization efficiency of the device. The test samples with mechanical seal structure were fabricated and the confirmatory tests such as He leakage test, thermal cycle test, autoclave test, etc. were carried out. The test samples with the mechanical seal structure showed an excellent result in various confirmatory tests, and the prospect are bright for the re-use of re-instrumentation devices with the mechanical seal structure.