The development of fast reactor steam generators

Steam generators perform an essential function, making it possible to transfer thermal energy extracted from the reactor and to render it usable by the turbo-generator. In the case of fast neutron reactors using a sodium coolant, this function is particularly delicate owing to the risk of violent reaction between the two heat-transfer fluids. Considerable attention has therefore been given to the design, development and construction of the Superphenix 1 steam generators. The authors discuss the programme for the reference solution adopted (steam generators with helicoidal tubes made of alloy 800), which has been running for more than 15 years in France. The Superphenix 1 steam generators were constructed by Novatome with the support and co-operation of the CEA and EDF in the areas of testing, research and development. Experience acquired during the construction of Superphenix 1 forms a very important basis for the study of the steam generators in Superphenix 2 which is at present being made by Novatome. For this reason, these components are of the same type as those used in Superphenix 1. The authors report on the additional development studies now in progress for the adaptation of the steam generators to the planned conditions and the optimization of their design so as to further increase their reliability and reduce their cost. Also presented are the studies conducted in parallel with the reference solution to develop an alternative steam generator solution. The solution, studied by Novatome, is based on a modular straight-tube design. An R and D programme, together with an engineering study, has been commended and will have to be continued if there is a need in due course for a level of knowledge comparable to that provided by the reference solution. (author)