French nuclear power giant Areva has found a high-carbon anomaly in the steel used for portions of the reactor vessel head and reactor vessel bottom at the Flamanville 3 project in Normandy, France, the French regulator, the Authority of Nuclear Safety (ASN) said Tuesday.
Areva is constructing the Flamanville 3 reactor on behalf of state-controlled utility Electricite de France (EDF). The project has already run into long delays, pushing the original completion date back from 2014 to 2017. Meanwhile, Areva, which is also government-owned, is already reeling from four years of consecutive losses, partly the result of delays at Flamanville and in Olkiluoto, Finland, where a similar reactor build has run into costly delays, and partly due to an abrupt slowdown in the industry after the March 2011 earthquake and tsunami event crippled the Fukushima Daiichi nuclear power plant in Japan.
ASN said the tests conducted on a vessel head similar to the Flamanville EPR components were conducted in late 2014 and “revealed the presence of a zone in which there was a high carbon concentration, leading to lower than expected mechanical toughness values.”
The higher carbon steel is not only less tough than low-carbon steel, but it also has a lower melting point. Areva said it had confirmed the higher-carbon zones were present in the bottom and top vessel heads of the Flamanville 3 reactor.
The company is also designing and implementing new tests to pinpoint the location and the extent of the anomaly. The company will have its testing approved by the regulatory agency, after which it is expected to have results of the new tests available in October.
ASN said it would make test results available to other countries that are building similar EPR units. The project in Finland is one similar project. There are also two EPR units under construction in China – Taishan 1 and 2. Those reactors are expected to start commercial operation in 2016 and 2017, respectively.
The project in Finland is expected to be completed in 2018, according to the World Nuclear Association.