高速炉格納容器バウンダリの耐圧強度評価手法の開発,1; 内圧によるベローズの限界圧力試験

Development of evaluation methods of ultimate behavior for fast reactor containment vessel boundary, 1; Burst pressure test of bellows structures subject to internal pressure

安藤 勝訓 ; 矢田 浩基 ; 月森 和之; 一宮 正和*; 安濃田 良成*

Ando, Masanori; Yada, Hiroki; Tsukimori, Kazuyuki; Ichimiya, Masakazu*; Anoda, Yoshinari*

重大事故対策に関して、原子炉格納容器は1次冷却材バウンダリが破損した際に、放射性物質を留める重要な機器であるため事故時の放射性物質の拡散防止の観点から、その適切な機能維持が求められる。本件では、高速炉の原子炉格納容器バウンダリのなかで、相対的に限界圧力が小さいと考えられる原子炉格納容器貫通部配管ベローズおよび、格納容器破損に関する安全性評価の観点から重要となる中間熱交換器のカバーガスバウンダリベローズについて破損様式の検証と限界圧力の評価法の開発を目的とした試験および解析を実施した。

Containment vessel is an important structure to prevent a significant and sudden radioactive release under the severe accidents. In case of the severe accidents, the pressure generated in the containment vessel is supposed to exceed the maximum design pressure. The required function of the containment vessel as radiological confinement should be enhanced, as far as reasonably achievable. To clarify the progress of events under the severe accidents and design the severe accident countermeasure equipment, it is necessary to evaluate the pressure toughness of containment vessel boundary adequately. The containment vessel of fast reactor is composed of the various structures, and the one of the most thin boundary structure is bellows structure to absorb the thermal expansion of the coolant piping penetrating the containment vessel. In addition, the cover gas bellows of the intermediate heat exchanger has important role when the progress of the events under the severe accidents is considered. Therefore, in order to develop the evaluation method of the pressure toughness under the severe accidents, the burst pressure tests of the bellows structure subjected to internal pressure was performed.