Conceptual design study of Cu bonded steam generator; Pressurized crack propagation experiments at the room temperature

Chikazawa, Yoshitaka  ; Aizawa, Kosuke ; Konomura, Mamoru

In the feasibility study of commercialized fast reactor cycle systems of JAEA, we make a concept of a sodium cooled reactor without secondary sodium circuits. And a sodium cooled reactor with Cu bonded steam generator is one of promising concept has been investigated. In the FY2004 study, pressurized tube experiments using the 33 array specimen imitated the reference tube geometry are carried out aiming to clarify crack propagation behavior in the reference steam generator. Compared with the results of the bend experiments in the FY2003, it is understood that the crack initiation and the crack propagation are greatly obstructed by the effect of the specimen shape. The reference tube geometry was optimized to pursue the economic. As a result of optimization, the construction cost of reactor cooling system with Cu bonded steam generators is 0.7 times as much as that of an ordinary sodium cooled reactor with secondary sodium circuits. Condition for crack propagation in the reference tube geometry is analyzed by using the result of the bend experiments in the FY2003. From the results of the bend experiments and the analysis, it was understood that there was a possibility that the crack reaches the Cu layer. But, when the crack reaches the Cu layer, it was shown that the crack propagation stopped.