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4. ASSESSMENTS
4.1 Assessments of the overall
performance of the NPPs in service
4.1.1 Nuclear safety assessment
Reactor operations
Management of reactor operations is on the whole
satisfactory. However, in 2015, a number of activities
governed by prescriptive documents, such as the
performance of periodic tests, were nonetheless the
cause of significant events. The root causes of these events
are numerous and can sometimes be cumulative. These
include inadequate preparation for activities, meaning
that the personnel concerned are not sufficiently aware
of the risks involved or of the documentation needed
to carry them out. It is also necessary to minimise the
possible interpretations of these documents and take
account of the differing levels of know-how and expertise
among the personnel concerned.
This situation is indicative of the insufficient involvement
by the head office departments in monitoring the
assimilation of the prescriptive documents by the NPPs.
It is also indicative of external Operating Experience
Feedback (OEF) management that is not yet robust
enough, both between the sites and with respect to
EDF head office departments. It in particular highlights
the need to reinforce the national OEF loop in order
to improve the documentary production process. ASN
drew the attention of the licensee to these weak points.
EDF’s in-house Independent Safety Organisation (FIS)
plays its role of verifying the actions and decisions
taken by the departments in charge of operating the
installations. However, there is a need for improved
traceability of the points justifying the need for these
verifications and of the resulting positions adopted.
The inspections carried out by ASN on the FIS in 2013
and 2014 led EDF to propose an action plan, currently
being evaluated by ASN.
With regard to the periodic tests and despite the
improvements observed on the sites compared to
2014, efforts are still needed with regard to the
scheduling, preparation and performance of these tests.
Furthermore, both the prior analysis of the operation
and the interpretation of the results obtained need to be
strengthened. The process used for a subsequent ruling
on the validity of the tests also needs to be reinforced
in order to promote a questioning attitude.
ASN inspection on the topic of water intake and measurement of samples of effluents discharged from the Flamanville NPP, November 2011.
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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