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2. SITUATION OF NUCLEAR
INSTALLATIONS UNDERGOING
DECOMMISSIONING IN 2015
Somethirtyinstallationsarecurrentlybeingdecommissioned
in France (see map opposite).
2.1 EDF nuclear installations
2.1.1 The decommissioning strategy of EDF
The decommissioning strategy of EDF, the first version
of which was submitted to ASN at its request in 2001,
presents the decommissioning programme for the first-
generation Nuclear Power Plants (NPP) and the state
of reflections on the decommissioning strategy for the
fleet currently in operation.
As requested by ASN, EDF submitted an update of
the decommissioning strategy for its reactors in
October 2013. This file was examined by the advisory
committee of experts in 2015. ASN had asked EDF
beforehand to include a study of the alternative solutions
for graphite waste management in order to avoidmaking
decommissioning of the gas-cooled reactor vessels more
dependent on the commissioning of the Low-Level Long-
LivedWaste (LLW-LL) disposal facility. It nevertheless
notes that where decommissioning of gas-cooled reactors
is concerned, the question of the disposal route for
graphite waste can complicate correct implementation
of this immediate dismantling strategy.
The examinations of the safety of the installations, the
review of EDF’s decommissioning strategy and waste
management, and the Andra report on the technical
feasibility of a LLW-LL repository were communicated
in 2015.
On the basis of these new elements, the ASNCommission
will again hear EDF on the decommissioning strategy
for the gas-cooled reactors in March 2016. It will adopt
a position on the need to prescribe firstly the date for
opening the gas-cooled reactor vessels and secondly a
feasibility study for the creation of storage facilities for
managing the LLW-LL graphite waste.
2.1.2 Internal authorisations
The system of internal authorisations is governed by the
Decree of 2nd November 2007 (see chapter 3) and the
resolution of 11th July 2008. The aim of implementing
a system of internal authorisations in basic nuclear
installations is to consolidate the prime responsibility of
the operator with regard to nuclear safety and radiation
protection, one of the fundamental principles of the
safety of activities involving risks being that the person
or entity carrying them out is responsible for them. For
operations of minor importance it introduces flexibility
in the updating of the baseline safety requirements
of the facilities, whose state changes rapidly during
decommissioning. ASN, having authorised the EDF
system of internal authorisations relating essentially
to reactors undergoing decommissioning through a
resolution of 15th April 2014, conducted an inspection on
the subject in 2015 to check application of the resolution.
2.1.3 The Brennilis NPP
The Brennilis NPP on the Monts d’Arrée site, called
EL4-D, is an industrial prototype heavy water moderator
nuclear power reactor cooled with carbon dioxide
which was definitively shut down in 1985. The nuclear
operator since 2010 is EDF. Partial decommissioning
operations were carried out from 1997 to mid-2007
(plugging systems, dismantling certain heavy water
and carbon dioxide systems and electromechanical
components, demolition of non-nuclear buildings,
etc.). A Decree of 27th July 2011 authorised part of
the decommissioning operations with the exception
of decommissioning of the reactor unit. In 2015,
decommissioning of the installation continued under
this Decree (cleaning up of the soil situated around the
Effluent Treatment Station (STE), decommissioning
of the STE, decommissioning of the heat exchangers.
EDF must submit a complete decommissioning file
for this installation without delay.
During 2015, the licensee encountered several difficulties
in the decommissioning operations:
•
the heat exchanger decommissioning worksite was
interrupted on 23rd September 2015 when in the
clearing up and equipment removal phase, due to
a fire and triggering of the on-site emergency plan;
•
the clean-up and demolition worksite of the effluent
treatment stationwas interrupted several times, notably
by the incident involving the fall of a screeningmachine
which damaged the worksite containment.
ASN’s inspections further to these incidents revealed
deficiencies in the preparation of operations and in the
risk analyses, particularly with regard to consideration
of the fire risk.
ASN has asked EDF to review all the organisational
and human measures implemented to control the risks
associated with hot work on the decommissioning work
sites as soon as possible.
These difficulties led EDF to ask for an extension of
the deadline for performing the operations authorised
by the decree to that it can complete STE clean-out.
Clean-out of the STE and the subjacent soils should
continue in 2016.
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CHAPTER 15:
SAFE DECOMMISSIONING OF BASIC NUCLEAR INSTALLATIONS
ASN report on the state of nuclear safety and radiation protection in France in 2015