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Fire
Following these inspections and with regard to the fire
risk, ASNnotes that the relations between the sites and the
departmental fire-fighting and emergency response services
are on the whole satisfactory and that the organisation of
the response is not generally an issue in themanagement
of actual fires. However, the findings made in previous
years are still valid and concern a majority of the sites
inspected:
•
the sectoring of premises could be improved in order to
prevent the spread of fire (in particular poor closure of
the doors contributing to fire sectoring and lack of risk
assessment with respect to certain sectoring anomalies);
•
deviations linked to the management of fire detection
inhibitions;
•
deviations in the management of stores of equipment
representing significant heat potential, in particular
during reactor outage phases;
•
deviations in the use of fire permits.
Problemswith the accessibility of fire-fighting equipment
were once again observed.
The number of outbreaks of fire recorded for 2015 exceeds
that of 2014. On 2nd July 2015, the lack of identification
of the titanium fire risk prior to cutting operations led
to a fire which concerned a part of the condenser of the
Paluel NPP reactor 2.
Explosion
During its inspections, ASNalso assessed the organisation
of the sites for dealing with the explosion risk, including
nuclear safety and worker protection aspects in the
management of this risk.
ASN found that the expertise of the personnel regarding
this question is gradually improving, but considers that
EDF must ramp-up its efforts concerning training and
exercises for the response crews.
Some of the maintenance measures required by the EDF
internal doctrine for pipes carrying hydrogenated fluids
are not always taken (nitrogen tightness test of the double
envelope on certain pipes, daily average estimate of leaks
from the alternator, etc.).
ASN also considers that on all the reactors in operation,
insufficientconsiderationisgiventotheoperatingexperience
feedback concerning events which occurred in 2014 on
theDampierre, Tricastin and Le Blayais sites; it found that
certain compensatorymeasures defined in2014 following
these events have still not been implemented.
Finally, an event of interest in terms of operating experience
feedback occurred on 16th September 2015 in Civaux:
when cutting a pipe, a flame appeared and persisted for
approximately fifteenminutes. The risk of hydrogen leaks
linked to the cutting of this pipe had not been identified
prior to the activity.
Maintenance activities
Concerning the performance of maintenance work, ASN
observes that the number of quality defects found is on the
whole stable. Theworkers still have to deal with constraints
linked to work organisation, insufficient preparation
for certain activities, scheduling changes and problems
withworksite coordination, leading to activity delays or
postponements. EDF has implemented a specific multi-
year action plan designed to reinforce themanagement of
activities scheduled and carried out duringmaintenance
outages of nuclear power generating reactors. Even if
this action plan allows unhurried management of the
preparation and performance phase by the licensee, ASN
considers that EDFmust continue with long-termefforts,
in particular with a view to the operating life extension
of the reactors, the “major overhaul” programme and the
lessons learned from the Fukushima-Daiichi accident,
leading to an increased volume of maintenance activities,
as well as extensive personnel turnover.
With regard to the procurement of spares and equipment
repairs, ASN observed that the shortcomings in the
satisfactory control of these activities, identified inprevious
years, are fewer in number but nonetheless persist.
Delays in the inspections or in incorporating new
maintenance programmes into the documents mean
that deviations or equipment deterioration are detected
belatedly.
ASN also observes differences among the sites in how
the qualification of the equipment for accident operating
conditions is maintained and in the requalification
operations for this equipment.
Finally, ASN considers that the NPPs could improve the
way in which they implement the AP-913 maintenance
method (see point 2.7.1).
Equipment condition
The equipmentmaintenance and replacement programmes,
the periodic safety reviewapproach and the correction of
conformitydeviations shouldmake it possible to check and
ensure the continued ability of the equipment important
for safety in an NPP to perform the functions assigned
to it for protection of the interests mentioned in Article
L.593-1 of the Environment Code.
During the course of its inspections, while still observing
shortcomings in the NPPs’ implementation of and
compliance with the rules issued by the head office
departments for handling conformity deviations, ASN
did see significant progress this year on this subject, with
regard to organisation and in-house training of the persons
involved in this conformitydeviations remediationprocess.
ASNconsiders that the sitesmust continue their efforts, in
particularwith regard to the identification and traceability
of the deviations detected. The potential seriousness of
certaingeneric conformitydeviationsdemonstrates that EDF
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CHAPTER 12:
EDF NUCLEAR POWER PLANTS (NPPs)
ASN report on the state of nuclear safety and radiation protection in France in 2015