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to its obsolescence and the cost involved in upgrading
it. This is why, in a resolution of 8th January 2015,
ASN required that work be carried out to ensure the
conformity of these facilities or, failing which, that all
radioactive materials be removed. Areva stated that at
the end of 2015 it had taken the decision to construct
an extension to the building meeting current safety
standards.
On 25th August 2015, ASN also issued a resolution to
upgrade the regulatory oversight of the activities carried
out in the facility and of the scope of its operations. As
this installation is ageing and has not undergone any
substantial modifications, the technical prescriptions
issued concerning it were contained in widely scattered
and sometimes obsolete texts, which were complex and
hard to interpret. ASN’s resolution lists the activities
authorised in the facility and the types and quantities
of radioactive substances used in it. It also specifies
a number of provisions, in particular linked to the
prevention of accident risks, the control of detrimental
effects and environmental impact, to informing ASN and
tomanaging emergency situations, along with particular
provisions concerning the possession and utilisation
of radioactive sources.
The report on the periodic safety review of this facility,
submitted by Areva NP on 31st December 2015, is
currently being examined. This review comprises an
assessment of the conformity of this facility with its
initial authorisation and the safety reassessment with
respect to current safety standards.
1.2 The back-end fuel cycle –
reprocessing
1.2.1 Areva NC reprocessing plants
in operation at La Hague
The La Hague plants, intended for reprocessing of spent
fuel assemblies fromnuclear power reactors, are operated
by Areva NC.
The various facilities of the UP3-A and UP2-800
plants and of the STE3 effluent treatment station were
commissioned from 1986 (reception and storage of
spent fuel assemblies) to 1994 (vitrification facility),
with most of the process facilities entering service in
1989-1990.
The Decrees of 10th January 2003 set the individual
reprocessing capacity of each of the two plants at
1,000 tonnes per year, in terms of the quantities of
uranium and plutonium contained in the fuel assemblies
before burn-up (in the reactor), and limit the total capacity
of the two plants to 1,700 tonnes per year.
The limits and conditions for discharges and for water
intake by the site are defined by two ASN resolutions
of 22nd December 2015. A new update is planned.
Operations carried out in the plant
The reprocessing plants comprise several industrial units,
each of which performs a specific operation. There are
thus the reception and storage installations for spent
fuel, facilities for shearing and dissolving it, for chemical
separation of fission products, uranium and plutonium,
for purification of the uranium and plutonium and for
treatment of effluents and conditioning of waste.
When they arrive in the plants, the spent fuel assemblies
in their transport casks are unloaded either under water
in the spent fuel pool, or in a dry, leaktight, shielded
cell. The assemblies are then stored in pools for cooling.
Afterwards, the assemblies are sheared and dissolved in
nitric acid to separate the pieces of metal cladding from
the spent fuel itself. The pieces of cladding, which are
insoluble in nitric acid, are removed from the dissolver,
rinsed in acid and then water, and transferred to a
compacting and drumming unit.
The nitric acid solution comprising the dissolved
radioactive substances is then processed in order to
separate the uranium and plutonium from the fission
products and other transuranic elements (in other words
the chemical elements heavier than uranium).
After purification, the uranium is concentrated and
stored in the form of uranyl nitrate UO
2
(NO
3
)
2
. It is
intended for conversion into a solid compound (U
3
O
8
)
in the Tricastin TU5 facility, referred to as Reprocessed
Uranium (URT).
After purification and concentration, the plutonium
is precipitated by oxalic acid, dried, calcined into
plutonium oxide, packaged in sealed containers and
placed in storage. The plutonium is then intended for
the fabrication of MOX fuels in the Areva NC plant in
Marcoule (Mélox).
The effluents and waste generated
by the operation of the plants
The fission products and other transuranic elements
resulting from reprocessing are concentrated, vitrified
and packaged in Standard Vitrified Waste Packages
(CSD-V). The pieces of assembly cladding are compacted
and packaged in Standard Compacted Waste Packages
(CSD-C).
The reprocessing operations described in the previous
paragraph also use chemical andmechanical processes,
the operation of which generates gases and liquid effluents
as well as solid waste.
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CHAPTER 13:
NUCLEAR FUEL CYCLE INSTALLATIONS
ASN report on the state of nuclear safety and radiation protection in France in 2015