Mitsubishi Heavy Industries, Ltd. (MHI) has delivered three replacement steam generators to Électricité de France S.A. (EDF) for the Cruas Nuclear Power Plant Unit 1 Reactor. The replacement steam generators have been certified by France's nuclear authority as compliant with the country's strict regulatory requirements on April 28, 2017.
The replacement steam generators for the 900 MWe pressurized water reactor (PWR) nuclear power plant were ordered in 2010. They are approximately 21 meters in height and 300 tons in weight, and were manufactured at MHI's Kobe facilities. The steam generators are made of low-alloy steel.
Low-alloy steel includes no more than 5 percent alloying element. Steam generators are pressure resistant vessels made with strong low-alloy steel (manganese, molybdenum, and nickel steel).
Each steam generator contains more than 4,000 heat transfer tubes made from state-of-the-art TT690 alloy material, a nickel, chromium, and iron alloy, specially heat-treated for enhanced corrosion resistance. It is the main material in the steam generator's heat transfer tubes. According to MHI, it offers superior corrosion resistance under high temperatures and pressures.
Steam generators play a central role in transferring the thermal energy generated in the reactor vessel from the primary (reactor) cooling system to the secondary (turbine) cooling system, using steam to drive the turbine.
Headquartered in Paris, EDF operates 58 PWRs in France. As part of its component renewal program, the company is currently replacing the existing steam generators at its PWR plants that started operations in the 1980s.
Since 2005, MHI has received orders from EDF for a total of 15 replacement steam generators and is currently filling those orders and delivering the components. MHI has been working to expand the business of nuclear equipment in nuclear power markets worldwide, and has supplied a total of 31 replacement steam generators to several countries, including France, Belgium and the U.S.
EDF selected the supplier for the steam generators through an international bidding process, with MHI receiving the order jointly with Comex Nucleaire (CXN), its alliance partner in the French nuclear power market.
CXN, is subsidiary of ONET Technologies, provides specialized after-sales service and maintenance for nuclear power plant facilities.