Japan’s Mitsubishi Heavy Industries Ltd (MHI) has delivered three replacement steam generators to Electricite de France (EDF) for unit 1 at its Cruas NPP, a 900MWe pressurised water reactor (PWR). They will be installed later this year during a scheduled maintenance outage.
The replacement steam generators had been certified by France's nuclear authority as compliant with French strict regulatory requirements on 28 April. MHI won the contract to supply the steam generators jointly with Comex Nucleaire, its alliance partner in the French nuclear power market.
The replacement steam generators were ordered in 2010 and manufactured at MHI's Kobe facilities. They are made of low-alloy steel and are approximately 21 metres high and weigh 300 tonnes. 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).
MHI has received orders from EDF for a total of 15 replacement steam generators since 2005, and is delivering the components. MHI has supplied a total of 31 replacement steam generators to several countries, including France, Belgium and the USA.
The Cruas NPP comprises four 900MWe PWRs which began operating between 1984 and 1985. The steam generators of unit 4 were replaced in 2014.
EDF’s fleet of 58 PWRs include 34 with 900MWe reactors which came into operation in the late 1970s and 1980s. To extend the life of the reactors, EDF is sequentially replacing their steam generators. In July 2009 the Autorité de Sûreté Nucléaire (ASN – Nuclear Safety Authority), approved EDF's safety case for 40-year operation of the 900MWe units, based on generic assessments.