Impurities in steel supplied by Japan Casting & Forging Corp (JCFC) to nuclear facilities in France exceeded French standards, Japan’s Nuclear Regulation Authority (NRA) said on 14 September. NRA is looking into allegations regarding the products provided by Kitakyushu-based JCFC, at the behest of French regulators. NRA said it needs to carry out tests to evaluate whether the steel has been weakened by the impurities. France’s Autorité de Sûreté Nucléaire (ASN) said in June they had found steel containing impure substances in facilities such as reactor pressure vessels at 18 reactors operating in France.

In August, the NRA ordered Japanese utilities operating NPPs in Japan examine reactors and other major parts at the plants and to report the results to the NRA by the end of October. JCFC is already under scrutiny in Japan as it is responsible for the construction of reactor pressure vessels in 13 reactors including units 1 and 2 at Sendai NPP which ae currently in operation. 

NRA said the standard for carbon content in metals (a gauge of impurity) is below 0.22% in France, and below 0.25% in Japan. But in some products provided by the Japanese firm in some nuclear facilities, carbon content in steel was over 0.3%.