Security & Safety

ASN Will Allow Flamanville-3 EPR To Begin Operation With Existing RPV

By David Dalton
29 June 2017

29 Jun (NucNet): France’s nuclear regulator, the Autorité de Sûreté Nucléaire (ASN), will allow EDF's 1,600-MW Flamanville-3 EPR unit to start commercial operation – scheduled for 2018 – with the existing reactor pressure vessel (RPV) despite high carbon levels, but will require the RPV head to be replaced by the end of 2024, ASN said in a statement on 28 June 2017. In April 2015, ASN, EDF and reactor manufacturer Areva revealed that tests had shown higher-than-expected carbon segregation in RPV material samples, indicating a possible manufacturing flaw and potentially affecting the RPV’s ability to withstand the propagation of cracks. The tests followed earlier chemical and mechanical examinations on forged steel parts representative of the RPV, which showed the carbon segregation phenomenon was higher than expected in a certain area. ASN’s draft position on the matter was announced in a statement yesterday. ASN’s position is based on analysis that indicates margins are sufficient to authorise the vessel to be used when the unit starts operation next year. But safety margins are reduced, which is why ASN will order periodic inspections of the RPV bottom head. These inspections will ensure the component can perform its function, but such inspections may not be possible on the RPV head, ASN said. The safety of the RPV head, however, is not at stake for some years so it could be allowed to be used for the seven years it is estimated to take to order and manufacture a replacement head, ASN said. ASN’s draft decision will be available for public comment and the final decision of ASN will be made around October, said ASN in yesterday’s statement.

Pen Use this content

Related