36 / 536
The fuel cycle concerns all the steps
involved in the fabrication of the fuel
and then its reprocessing once it has
been used in nuclear reactors.
Themainplantsinthecycle–ArevaNC
Tricastin (Comurhex and TU5/W),
Eurodif, GB II, ArevaNPRomans-sur-
Isère (ex-FBFCand ex-Cerca),Mélox,
Areva NC La Hague and Areva NC
Malvési – are part of theAreva group.
These plants include facilities which
have BNI status.
Significant events
Withregardtotheuraniumconversion
installations,theproductiontoolinthe
ArevaNCComurhexplant(BNI105)is
tobemodernisedwiththeconstruction
thencommissioningoftheComurhexII
installations initially scheduled for
2015 and today planned for 2018,
while the current plant, Comurhex I,
will close by the end of 2017. Delays
in the new plant led Areva NC to
ask ASN for an operating extension
for the former ICPE (Installation
ClassifiedonEnvironmentalProtection
grounds) plants. This operationof life
extension of the Comurhex I plants
from July 2015 to the end of 2017
was accepted in 2015 provided that
work was done to reinforce them.
This work in particular concerns the
implementation of mitigationmeans
to limit the consequences of a major
hazardous gas leak in the Procédé
buildings.
With regard to the back-end cycle,
the most significant point concerns
the status of the evaporation capacity
in the UP2-800 plant at La Hague.
In 2011, Areva NC brought to light
several perforations of the shell of an
evaporator used to concentrate fission
product solutions in the R7unit. This
evaporator could not be returned to
service and needs to be replaced. In
mid-2012, the licensee sent ASN a
file presenting the safety options it
had selected for the designof the new
evaporator, to replace the old one.
Examination of this file continued
in 2014, with installation of this
new evaporator currently being
envisaged for 2017. Furthermore,
in October 2014 in the R2 unit,
high corrosion rates were observed
on the fission product solutions
concentration evaporators. These
rates are higher than the equipment
design-basis and higher than those
observed on the same equipment in
the T2 unit. ASN asked the licensee
to explain this difference between the
R2 and T2 units and to analyse the
impact of this accelerated corrosion
mechanism on the safety of the
plant’s evaporator capacity for the
coming years. In addition, given the
safety issues associated with these
evaporators, ASN prescribed an
annual inspection of the condition
of this equipment inorder toprevent a
possible accident. The situationof this
equipment demands particularlyhigh
vigilance by ASN, which considers
that this is a priority issue for 2016
in terms of safety on this site.
Concerning the integration of
experience feedback from the
Fukushima Daiichi accident, work
is continuing on the fuel cycle
installations. The ASNresolutions of
9th January2015prescribe thehazard
levels and associated requirements
for the “hardened safety core” and
the deadlines for deployment of this
“hardened safety core” in all fuel cycle
installations.
Assessment and outlook
Cross-disciplinary aspects
With regard to the Areva group, ASN
will beparticularlyvigilant inensuring
that the BNI licensees to be created
as a result of the ongoing split-up
of the group, are in full possession
of the capabilities needed to meet
their responsibilities. In particular,
the engineering capability of the two
groups resulting from the split-up
of Areva as it currently stands shall
be credible enough to make any
modifications to the installations
concerned and manage any internal
crises.
Fuel cycle consistency
In2016, ASNwill start anexamination
of thenew“Cycle impact” file covering
the period 2016-2030 and aimed at
anticipating the various emerging
needs in order tomanage the nuclear
fuel cycle in France. ASN will in
particular focus on monitoring the
level of occupancy of the spent fuel
underwater storage facilities (Areva
andEDF). It askedEDF toexamine the
impact on the anticipated saturation
dates for these storage facilities
of the shutdown of a reactor, of a
possible modification in the spent
fuel reprocessing traffic, as well as
the solutions envisaged for delaying
this saturation. ASN considers that
the saturation of the storage facilities
must be anticipated (pools at LaHague
and fuel building pools for the EDF
reactors) and thatAreva andEDFmust
very rapidly define a management
strategy going beyond 2030.
Tricastin site
ASN will continue to monitor the
reorganisation of the Tricastin
platform to ensure that these major
organisational changes within the
grouphave no impact on the safety of
the various BNIs on the site. Itwill also
13
Nuclear fuel cycle installations
36
ASN Report on the state of nuclear safety and radiation protection in France in 2015
SIGNIFICANT EVENTS IN 2015