高速増殖大型炉の設計主要目に関する研究(II); 中間熱交換器の浮動支持による一次主冷却配管短縮化の検討

Study on the main design parameters of large scale fast breeder reactor (II); Investigation on reduction of piping length by application of IHX floating support piping to primary main heat transport system piping of LMFBR.

田村 政昭*; 竹内 則彦*; 中西 征二; 谷山 洋*

not registered; not registered; Nakanishi, Seiji; not registered

高速増殖炉(LMFBR)の開発においては、実用化の観点から軽水炉並みの安全性を確保しつつ、如何にしてフラント建設コストを低減するかが重要な課題となっている。現在、建設コストの低減のため多大の努力が傾注されているが、熱輸送系配管の短縮化もその有効な方策の一つと考えられている。配管短縮化方策としては種々提案されているが、ここでは軽水炉で採用されて充分な実績を有する機器浮動支持方式を対象に、中間熱交換器を浮動支持した一次主冷却系について、LMFBRの特徴を考慮した設計手法を取り入れてその成立性を評価した。配管については自重、定格運転時および熱過渡時の熱膨張並びに地震に対して、ノズルについては内圧、自重、地震応力、熱膨張応力および熱過渡に対して評価した。その結果、すべての項目について許容値におさまり、また配管支持装置も実現の高いものであることが明らかとなり、その成立性が十分あることが確認できた。

Current emphasis in the development of liquid-metal cooled fast breeder reactors (LMFBRs) is placed on the reduction of the plant construction cost without spoiling the safety in view of its practical application. So much effort is paid for the cost reduction. The reduction of piping length of heat transport system piping is considered as an effective measure for the cost reduction. An application of component floating support piping which brings good results in LWR leads to reduction of piping length and it is an effective measure as well as bellows expansion joint piping and high-chrome-steel piping in LMFBR. A design study for the application of the IHX floating support piping system to primary main heat transport system piping of LMFBR was conducted to demonstrate the adequacy of the piping system by using the improved structural design method considering the characteristics of LMFBR. The stress analysis of piping due to dead weight, thermal expansion at steady and transient conditions, and earthquake was performed, while the nozzles stress due to internal pressure, dead weight, earthquake and thermal expansion reaction force, and thermal transients was analyzed. It was confirmed that the analytical results were satisfied the allowable values and the piping support equipments were highly put into practical use. Therefore it was concluded that the adequacy of the IHX floating support piping system was demonstrated.