393 / 536
ten-yearly outage and on the assessment of the reactor
review report submitted by EDF.
In 2015, 4 reactors incorporated the improvements
resulting from the periodic safety review on the occasion
of their third ten-yearly outages, thus raising to 27 the
number of the 900 MWe plant series reactors (out of
34) which had carried out their third ten-yearly outage
inspection.
In 2015, ASN also sent the Minister responsible for
Nuclear Safety its analysis of the review conclusions
reports for the Tricastin 2 and 3 reactors. On the basis
of this analysis, ASN has not identified any element that
would compromise EDF’s ability to satisfactorily control
the safety of these two 900 MWe reactors until the next
periodic safety review. Pursuant to Article L.593-19 of
the Environment Code, ASN took this opportunity to
issue additional prescriptions designed to reinforce the
safety of these reactors.
The periodic safety review associated
with the fourth ten-yearly outage inspections
The continued operation of the nuclear reactors beyond
their fourth ten-yearly outage inspection is of particular
importance in a number of respects:
•
The period of forty years of operation corresponds to
the initial design hypotheses for a certain number of
equipment items, in particular with regard to their
ability to function in accident operating conditions
(qualification). The studies concerning the conformity
of the installations and the management of equipment
ageing therefore need to be reviewed to take account
of the degradation mechanisms actually observed and
the maintenance and replacement strategies adopted
by the licensee.
•
This periodic safety review is then an opportunity to
complete the integrationon the 900 MWe reactors of the
modifications specified following the stress tests carried
out in thewake of the Fukushima-Daiichi accident. This
concerns thephase3work (seepoint 3.1onFukushima).
•
Finally, thewishexpressedbyEDF in2010 to significantly
extend the operating life of the reactors beyond40 years
was examinedbyASN. By this time frame, the 900 MWe
series of reactors will be operating alongside EPR or
equivalent type reactors, which are designed to meet
significantly reinforced safety standards. Their safetymust
therefore be reassessed in the light of these new safety
requirements, the state of the art nuclear technologies
and the operating life targeted by EDF.
After familiarising itself with ASN’s requests of June
2013 concerning the orientations of the generic studies
programme carried out by EDF in order to extend the
operating life of the reactors beyond40 years, EDFdrafted
and, inOctober 2013, submitted its orientation file for the
periodic safety reviewassociatedwith the fourth ten-yearly
outage inspections for the 900 MWe reactors (DORVD4-
900). Further to ASN’s requests for additional data in
March 2014, EDF updated its file.
ASN examined this file with the assistance of IRSN.
In April 2015, it asked the GPR for its opinion on the
orientations of the generic studies being envisaged
by EDF on the various topics contained in the
DOR VD4 900 file.
Following the GPRmeeting, EDF completed its generic
studies programme in June 2015with a certain number of
measures and clarified a certain number of its proposals.
In 2016, ASN will issue a position statement on the
orientation of the generic studies to be carried out in
preparation for the fourth periodic safety reviews on
the nuclear reactors, after consulting the public on the
draft requests for additional information to be sent to
EDF concerning its study and verification programme.
The reactors of the 1,300 MWe plant series
The periodic safety review associated
with the second ten-yearly outage inspections
In 2006, ASN gave a favourable opinion to the generic
aspects of continued operation of the 1,300 MWe reactors
up to their third ten-yearly outage inspections, provided
that the modifications decided on during this review
were effectively implemented.
The twenty 1,300 MWe reactors have now all undergone
their second ten-yearly outage inspections and have
incorporated the improvements identified by the periodic
safety review.
Pursuant to Article L.593-19 of the Environment Code,
ASN sent its position statement on the two Saint-Alban
reactors, Cattenom reactors 2 and 3, the two Nogent
reactors and Penly reactor 1 and took this opportunity
to issue additional prescriptions designed to reinforce
the safety of these reactors. It is currently preparing its
position regarding the continued operation of the other
1,300 MWe reactors.
The periodic safety review associated
with the third ten-yearly outage inspections
In early 2015, ASN ruled on the generic aspects of the
continued operation of the 1,300 MWe reactors beyond
thirty years. ASN considers that the steps taken or
being envisaged by EDF to assess the condition of its
1,300 MWe reactors and manage their ageing up until
the periodic safety review associated with their fourth
ten-yearly outage inspections are acceptable. ASN also
considers that the modifications identified by EDF
during this study phase will help to significantly improve
the safety of these installations. These improvements
in particular concern reinforcing protection of the
facilities against hazards, reducing releases of radioactive
substances in the event of an accident, with or without
core melt, and preventing the risk of uncovering of
the fuel assemblies stored in the spent fuel pit or
during handling.
393
CHAPTER 12:
EDF NUCLEAR POWER PLANTS (NPPs)
ASN report on the state of nuclear safety and radiation protection in France in 2015