High Performance Light Water Reactor - where nuclear meets coal technologies
| Supercritical water is the state-of-the-art coolant for modern coal fired power plants. By increasing the system pressure from subcritical to supercritical conditions, sizes of components can be reduced and higher plant efficiencies can be obtained. Thus, the construction costs of fossil power plants have been reduced significantly within the last years leading to economic, compatible electricity generation costs for the European electricity market. |
| The High Performance Light Water Reactor Phase 2 (HPLWR Phase 2) project explores the particular advantages of supercritical water technologies to be applied to newest Light Water Reactors. As for the coal fired power plants, similar cost reductions are envisaged for a High Performance Light Water Reactor using supercritical water as a coolant. |
HPLWR Phase 2 Project | ||
HPLWR Phase 2 is focused to assess the critical scientific issues and the technical feasibility of a High Performance Light Water Reactor operating under supercritical pressure. It is expected that the HPLWR will be more economical than conventional light water reactors, it will have a higher efficiency and thus a better fuel utilization, which also produces less waste per kWh, but it still fulfills the high safety standards of 3rd generation nuclear plants (e.g. EPR, SWR1000). HPLWR Phase 2 utilizes the results from the "HPLWR" project being carried out within the 5th Framework Programme. The consortium comprises ten partners from eight European countries: Seven research centers, two universities and one industrial company. Members of the HPLWR Advisory Board, who are not partners within the project to guarantee their independency, are representatives from a Finish utility, from a Swedish nuclear safety authority and from two universities from the UK and Japan. Close links to R&D are maintained mainly through the Generation IV International Forum (GIF). Links to International Science & Technology Center (ISTC), OECD Nuclear Energy Agency (NEA), International Atomic Energy Agency (IAEA), and to 6th Framework Programme projects of EU, e.g. ExtreMAT on materials, are currently being established. |
 Design Sketch of the HPLWR Reactor Pressure Vessel by Fischer (2006) |
Evolutionary Step in Light Water Reactor Technologies |
The plant characteristics of the High Performance Light Water Reactor include a supercritical coolant pressure of around 25 MPa and a coolant heat up from 280°C to more than 500°C. At these conditions, water changes its phase continuously from liquid to steam without boiling, so that a boiling crisis in the core can be physically excluded. As in a boiling water reactor, the high temperature steam is fed directly to the high pressure turbine, so that a closed primary cycle like in a pressurized water reactor can be omitted. Steam separators or primary pumps, which are needed in boiling water reactors, are not required either. The high steam enthalpy increases the power density of the steam cycle by more than 40%. The envisaged net efficiency of 44% exceeds by far those of conventional light water reactor. Most components of the steam cycle can be taken from fossil fired power plants, where they are successfully in operation for several years, knowing that the assessment for a life time of 60 years will be based on this experience and some additional experiments on e.g. materials. Therefore, the project is focused first to assess the reactor design and its nuclear core behavior in case of normal or accidental conditions. Primary interest is on a thermal reactor. An alternative study of a fast core option is carried out accompanying the project. Safety systems shall be assessed and analyzed to check if they fulfill the European Utility Requirements (EUR), and a concept for the balance-of-plant shall be worked out for final assessment of feasibility and economics of this reactor concept. The project will be supported by corrosion, creep and stress corrosion tests of candidate cladding alloys at the expected pressures and temperatures. Numerical studies of heat transfer of supercritical water will help to gain confidence in predicted peak cladding temperatures. A later in-pile experiment about radiolysis and water chemistry of supercritical water will also be prepared. Finally, a training and educational program will be carried out in the course of this project. HPLWR Phase 2 is one of the most suited to keep the competence in light water reactor technologies in Europe which is needed by vendors and utilities to operate their Light Water Reactors now and in the future. |
Contribution to GIF - Worldwide Interest |
HPLWR Phase 2 is cooperating in the Generation IV International Forum (GIF) R&D Programme on Supercritical Water Reactors (SCWR) and constitutes the Euratom contribution to GIF in this area. Key research areas addressed by HPLWR Phase 2 are integrated within three GIF SCWR Sub-Programs: "Design & Integration", "Safety, Codes and Methods", and "Materials and Water Chemistry". Japan and Canada play a v ery active role in GIF; the same is true for Korea and Europe. China and Russia have a strong interest to join GIF for a common research on SCWR. |