French nuclear regulator approves review of 10-year lifespan extension for 900 MW fleet

London — French nuclear regulator ASN has completed a generic review to extend the lifespan of 32 reactors of the 900 MW fleet for 10 years beyond the initially planned 40 years, it said Feb. 25.

EDF's thirty-two 900 MW reactors are the oldest reactors in operation in France and were initially designed for 40 years of operation.

"ASN considers that the measures planned by EDF combined with those prescribed by ASN open the prospect of continued operation of these reactors for a further 10 years following their fourth periodic safety review," it said.

Continued operation required updating of design studies or equipment replacements, ASN said.

The resolution sets out improvements and measures to be applied during the reactors' fourth 10-year overhauls (VD4).

Two have already been completed at Tricastin 1 and Bugey 2. The full program is scheduled to run until 2031.

EDF's Grand Carenage program to extend the lifespan of the 900 MW fleet is estimated to cost Eur49.4 billion ($60.4 billion) for the period to 2025, according to EDF's annual report.

The review and measures planned by EDF were subject to a public consultation under HCTISN (French High Committee for Transparency and Information on Nuclear Security), ASN said.

French nuclear output fell 2020 to a record-low 335 TWh mainly due to coronavirus related maintenance adjustments, but also closure of the two 900 MW reactors at Fessenheim and extended outages at Flamanville, Paluel and Bugey.

France in 2017 postponed plans to reduce the share of nuclear in its power mix to 50% by 10 years to 2035 allowing for extended operation and lifespan extension of the 900 MW fleet.

Under a new PPE energy roadmap four to six reactors would close by 2028 and 14 by 2035. EDF named seven sites where it would shut units (Blayais, Bugey, Chinon, Cruas, Dampierre, Gravelines, Tricastin).