Design and requirements for the SNR pipework

A review on the design and the relevant considerations of the SNR pipework for the primary and secondary main sodium loops is given. It is pointed out that the design is governed by thermal stresses and less by mechanical forces. The requirements for materials to be used for the main sodium piping are identified. The reasons for the materials selection are summarized. The integrity of the pipework is confirmed by fracture mechanics investigations. The results show that unstable fractures can be excluded as a failure mechanism; the critical crack lengths are so large relative to the wall thickness that failures will manifest themselves by leaking rather than fracture. (auth)