Steel supplied by Kitakyushu manufacturer Japan Casting & Forging Corp. to nuclear facilities in France has been named in an investigation that found it had a high level of impurity, the nuclear watchdog said.
The Nuclear Regulation Authority said the standard for carbon content in metals — a gauge of impurity — is below 0.22 percent in France, while the figure is below 0.25 percent in Japan.
But in some products provided by Japan Casting & Forging Corp. for some nuclear facilities, carbon content in steel was over 0.3 percent.
The NRA said it had recently been briefed by French regulators and needed to carry out its own tests to determine the quality of the steel.
The higher the concentration of impurity in steel, the weaker the product.
French regulators said in June they found steel containing larger-than-expected amounts of impure substances in facilities such as reactor pressure vessels at 18 reactors operating in France and are investigating the matter.
The steel products in question were made by Japan Casting & Forging and Creusot Forge, a subsidiary of France’s Areva SA.
In August, the NRA ordered local utilities hosting nuclear power plants in Japan to examine reactors and other major parts at the plants. The utilities have been asked to report the results to the NRA by the end of October.
Japan Casting & Forging is also under scrutiny in Japan as it is responsible for the construction of reactor pressure vessels in 13 Japanese nuclear reactors including the Sendai Nos. 1 and 2 reactors operated by Kyushu Electric Power Co. in Kagoshima Prefecture.
Currently, the two Sendai reactors are operating in Japan after passing stricter safety checks in the wake of the 2011 nuclear crisis that crippled the Fukushima No. 1 nuclear power plant in Fukushima Prefecture.
Japan Casting & Forging had said earlier it has removed the impurities from its steel as instructed by its clients.