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High Performance Light Water Reactor - Phase 2

Final Report Summary - HPLWR PHASE 2 (High Performance light water reactor - Phase 2)

Supercritical water is the state of the art coolant for modern coal fired power plants. By increasing the system pressure to supercritical conditions, the size of key components is reduced and higher plant efficiencies are obtained. This, in turn, reduces significantly the construction cost of fossil-fuel power plants, leading to lower electricity generation costs for the European market.

The HPLWR PHASE 2 project explored the particular advantages of supercritical water concepts and applied them to the latest light water nuclear reactor technology. The project aimed to assess the feasibility of a light water reactor using supercritical water as a coolant and determine its future potential. The project implemented research needs and critical scientific issues defined in the roadmap which had been derived by a previous European Union project, and also took into account another existing roadmap for the development of a supercritical water reactor.

During the first project year the reactor core was designed. The mechanical design, which was frozen after the first year, was subsequently analysed. This research structure had the advantage that results that could lead to a change of the mechanical design did not enter the project randomly and did not force the analysts to change their input deck continuously. The HPLWR concept was further refined and analysed, in order to improve the proposal. The project outcome was then assessed with respect to the goals of the Generation IV international forum (GIF).

The HPLWR PHASE 2 project was the European contribution to the research programme on supercritical water reactors within GIF. During its course, a conceptual design for a light reactor operated at supercritical pressure and temperatures was derived for the first time, to serve as a basis for future investigations. This proposal comprised the mechanical design of the core, reactor pressure vessels and internals, steam cycle and components such as turbines, pre-heaters and pumps, a pressure suppression containment with safety systems including active and passive components and reactor and turbine building. Therefore, its impact on the ongoing research was significant, even though the concept was not yet ready to be built, but rather formed a theoretical approach on critical scientific issues.