France's nuclear safety regulator has set the conditions for the continued operation of EDF's 900 MWe reactors beyond 40 years. The regulator said it considers the measures planned by EDF combined with those prescribed by ASN will ensure the safety of the units for a further 10 years of operation.
The French electric utility company Électricité de France (EDF) operates three pressurised water reactor designs, known as the 900 MWe, the 1300 MWe and the 1450 MWe N4. Its 32 operating 900 MWe reactors came into commercial operation between 1977 and 1988, and are in operation at EDF's Blayais, Bugey, Chinon, Cruas-Meysse, Dampierre, Gravelines, Saint-Laurent and Tricastin nuclear power plants.
France has a total of 58 nuclear reactors in operation
The French nuclear safety regulator Autorité de Sûreté Nucléaire (ASN) reviews all french reactors on a 10-yearly basis. These reviews are performed in two steps:
- The generic review phase, which covers subjects common to all 900 MWe reactors.
- The specific review phase, which relates to each reactor individually.
ASN noted that the fourth periodic safety review of the 900 MWe reactors is "of particular importance because the service life hypothesis adopted at the design stage was 40 years. Continuing operation beyond 40 years necessitates the updating of the design studies or equipment replacements."
Continuing operation beyond 40 years necessitates the updating of the design studies or equipment replacements
On 23 February, ASN issued a resolution closing the generic phase of the safety review, which concerns the studies and modifications of the installations common to all the 900 MWe reactors, as they all have a similar design model,” ASN noted.
The safety of the 900 MWe reactors will be greatly improved due to a number of measures, ASN said. These include verifying the conformity of the reactors with their reference system, as well as improving their ability to withstand more severe attacks “of internal or external origin”. Modifications will also limit the radiological consequences of accidents without core meltdown. Additionally, improvements will be made in the arrangements for managing accidental or aggressive situations affecting the used fuel storage pools at the units.
The safety of the 900 MWe reactors will be improved due to a number of measures
ASN said the improvements and measures will be applied to each reactor individually during their fourth periodic safety reviews, scheduled to run until 2031. These reviews will take the particularities of each facility into account, it said. The measures planned by EDF for each reactor will be subject to a public inquiry.
The improvements and measures will be applied to each reactor individually
"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," ASN said.
The regulator requires EDF to report annually on the actions implemented to meet the requirements and their deadlines, and also on the industrial capacity of both EDF and its outside contractors to complete the modifications of the facilities within the set timeframes. ASN requires that this information be made public.
Source: World Nuclear News