Study of the reduction method of the helium gas leakage from bolted gasket flanged connection for HTGRs

高温ガス炉におけるボルト締結フランジからのヘリウム漏えいの低減技術の研究

濱本 真平  ; 高田 昌二

Hamamoto, Shimpei; Takada, Shoji

High temperature gas-cooled reactors (HTGRs) use helium as coolant. Because helium tends to leak, welding is often used for joints of pipes and containers. However, the bolt fastening flange is useful for enhancing the maintainability of the industrial plant. If the helium leak characteristic of the bolt fastening flange is clarified and the factor that reduces the leakage of helium can be controlled, it can lead to the reduction of the leak rate of helium. In this study, it was clarified that the temperature difference between the flange surfaces strongly influences the helium leak rate from the flange by experiment using Helium Gas Circulator installed in High Temperature engineering Test Reactor. We also demonstrated that helium leak can be reduced by using this correlation by controlling the flange temperature.