Application of the system based code concept to the ASME code for liquid metal reactors

ASME液体金属炉規格へのシステム化規格概念の適用

浅山 泰 ; 高屋 茂  ; 森下 正樹 

Asayama, Tai; Takaya, Shigeru; Morishita, Masaki

システム化規格概念は、我が国における高速炉向け規格体系構築の基本概念となっている。本概念は現在米国機械学会(ASME)でも、Section IIIとSection XIを統合し、より柔軟な設計やメンテナンスを実現するうえで必須の概念として大きく期待され技術的議論が盛んに行われている。本論文はASMEボイラー及び圧力容器規格へ本概念を適用し、規格案を作成するための構想について、その中で用いられるコア技術である構造信頼性評価と破損規模限定解析の概要を含めて述べたものである。ASMEでは、近い将来にシステム化規格概念に基づく規格案作成作業が開始されると思われる。

The System Based Code (SBC) which was initially proposed by Asada forms the basis of the development of a set of codes and standards in Japan that fully take advantage of the potential of liquid metal reactors (LMRs). The concept is also being elaborated within the American Society of Mechanical Engineers (ASME) as a promising way to improve current codes and standards which would allow significantly wider technical options with various advantages both in Sections III and XI by bridging them. This paper illustrates an envisioned scheme for code rules for new reactors based on the SBC concept that could be also implemented in ASME Boiler and Pressure Vessel Codes. The outline of technologies needed to materialize the concept such as "Break Size Limitation Analysis (BSLA)" and structural reliability evaluation are also mentioned. Recent discussions in ASME indicate that efforts on drafting code rules based on the SBC concept will soon take place in the ASME.