Super-critical water nuclear reactor status update

The Gen IV international forum had an updated presentation on super-critical water nuclear reactors in 2017 by Laurence Leung.

* Potential for cost reduction
• Fuel cost is lower, but capital cost is higher, for nuclear than coal-fired power plants
• Increase in steam temperature could simplify the nuclear system
* Advancement in boiler technology
• Leverage development in the fossil-power industry reducing cost and risk
• Net efficiency could reach ~50% at steam temperature of 700°C

SCWR Concept Development Status as of 2017

* Canada, EU and Japan have completed the development of their concepts
• International peers reviewed the concept and assessed viability
• R&D to improve confidence on the developed concepts
* China and Russian Federation are working on completing of their concepts
• China plans to host the review of their concept with international peers
* Preparation of a fuel irradiation test
• Acquire design and licensing experience of in-reactor supercritical water system
• Obtain in-reactor data on fuel, cladding material and thermal-hydraulics at supercritical pressures to improve understanding and for code validation
* Development of small SCWR concepts
• Other than Japan’s Super Fast Reactor, all SCWR concepts have been developed to generate electric powers at or greater than 1000 MW
• Small remote communities require much less power
• Adjustment of SCWR core size to meet local deployment needs (e.g., 10 to 300 MWe)

SCWR Design Challenges: Materials

* In-core (except cladding) and out-of-core components
• No single alloy with sufficient information to confirm its performance
• Based on materials used in current fleet of reactors and fossil – fired power plants
• Different acceptance requirements on corrosion for nuclear power plants
• Need thermal and corrosion -resistant barrier
* Cladding
• Zirconium
-based alloys are not viable material
• Stainless steel or nickel
-based alloys are potential candidates
• Demonstrate performance in key areas: Corrosion and stress corrosion cracking; strength, embrittlement and creep resistance; and dimensional and microstructural stability
• Quantify irradiation effect
* Challenges
• Testing at high pressures and high temperatures
• Irradiation effect