Supercritical Water Reactor (SCWR) - Survey of Materials Research and Development Needs to Assess Viability [report]

Philip E. MacDonald
2003 unpublished
Executive Summary Supercritical water-cooled reactors (SCWRs) are among the most promising advanced nuclear systems because of their high thermal efficiency [i.e., about 45% vs. 33% of current light water reactors (LWRs)] and considerable plant simplification. SCWRs achieve this with superior thermodynamic conditions (i.e., high operating pressure and temperature), and by reducing the containment volume and eliminating the need for recirculation and jet pumps, pressurizer, steam generators,
more » ... eam generators, steam separators and dryers. The reference SCWR design in the U.S. is a direct cycle, thermal spectrum, light-water-cooled and moderated reactor with an operating pressure of 25 MPa and inlet/outlet coolant temperature of 280/500 C. The inlet flow splits, partly to a down-comer and partly to a plenum at the top of the reactor pressure vessel to flow downward through the core in special water rods to the inlet plenum. This strategy is employed to provide good moderation at the top of the core, where the coolant density is only about 15-20% that of liquid water. The SCWR uses a power conversion cycle similar to that used in supercritical fossil-fired plants: high-intermediate-and low-pressure turbines are employed with one moisture-separator re-heater and up to eight feedwater heaters. The reference power is 3575 MWt, the net electric power is 1600 MWe and the thermal efficiency is 44.8%. The fuel is low-enriched uranium oxide fuel and the plant is designed primarily for base load operation. 5 The needed materials development tasks, schedules, and costs to assess the feasibility of the SCWR are presented in Section 4 of the report. The costs for the needed work for the SCWR are summarized below: Component Costs ( millions) Reactor pressure vessel 21. Reactor pressure vessel internal components 150. Pumps and piping 32. Power conversion system 15. Total Costs $218. The total cost estimate for development of the needed materials for the SCWR is about $218 million dollars. These costs will be lower if (1) existing university facilities are used, (2) the costs are shared with our international GIF partners, and/or (3) the costs are shared with other Generation IV reactor development programs. Note that these costs are for "viability" research and development as defined in the Generation IV Roadmap (GIF 2002). Viability research and development examines the feasibility of key technologies and is that R&D necessary for proof of the basic concepts, technologies, and relevant conditions. Potential showstoppers are identified and resolved. The information generated at this stage of the R&D is sufficient for the conceptual design of a prototype. It is not sufficient for the final design of the plant. We conclude that there are significant materials development and qualification needs for the SCWR, but existing materials have been identified that could meet the requirements of all the SCWR components and subsystems. 6 ACKNOWLEDGEMENTS
doi:10.2172/910721 fatcat:lzn5u7buuzetjbtod74r7p6nsi