UK regulator advised on Areva-supplied forgings

Paperwork related to the manufacture of components for use in UK nuclear power plants by Areva's Le Creusot forge may contain "inconsistencies, modifications or omissions", the French nuclear regulator has advised its British counterpart. The Sizewell B reactor is the only UK reactor to feature such parts.  

The Office for Nuclear Regulation announced on 13 May that it is "engaged" with the ASN (Autorité de Sûreté Nucléaire) and EDF "concerning the reports of anomalies and inconsistencies in quality documentation".

Earlier this month, the ASN said an ongoing quality audit at the Le Creusot forge - which Areva bought in 2006 - had identified "irregularities" in paperwork on some 400 plant components produced there since 1965. The issues "comprise inconsistencies, modifications or omissions in the production files, concerning manufacturing parameters and test results". About 50 of these parts are thought to be in service at French nuclear power plants, according to Areva.

The ASN asked Areva to provide a list of the parts concerned as soon as possible, "along with its assessment of the consequences for the safety of the facilities, jointly with the licensees concerned". Areva said in early May, "At this preliminary stage, no information has come to light that would jeopardize the mechanical integrity of the parts."

The ONR said, "Areva is in the process of completing the characterization of these historical irregularities and their consequences, and has committed to contact affected foreign customers by 31 May".

The British regulator added, "We will await the conclusion of the Areva review before deciding whether there is a need for any specific intervention in the UK."

The ONR said it believes the irregulaties in paperwork occurred before any procurement of forged parts for the two EPR reactors planned for Hinkley Point C.

However, it noted that the Sizewell B reactor is the only one in the UK that has a small number of reactor components supplied by the Areva facility. The 1198 MWe plant, which started up in 1995, is currently the UK's only operating pressurized water reactor.

"This reactor is currently shut down for its scheduled outage and we will be seeking the necessary assurances for the reactor components before we permission the restart of the Sizewell B reactor," the ONR said.

Areva's Creusot Forge and Creusot Mécanique subsidiaries are specialized in the supply of big forgings and castings destined mainly for the nuclear industry. Creusot Forge is one of a few facilities that can produce the heavy nuclear-grade forgings required for large components such as steam generators, reactor pressure vessels and primary pumps. Creusot Mécanique, meanwhile, carries out precision finish machining on large components.

The upper and bottom heads of the reactor pressure vessel for the EPR under construction as Flamanville 3 EPR were manufactured at the Le Creusot facility in September 2006 and January 2007, respectively. A high carbon content in those parts prompted Areva to review the company's quality process in 2015.

Researched and written
by World Nuclear News