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1.3.4 Management of Low-Level, Long-Lived
Waste (LLW-LL)
Low-Level Long-Lived Waste (LLW-LL) comprises two
main categories: graphitewaste resulting fromthe operation
of the Graphite-moderatedGas-Cooled Reactor (UNGG)
nuclear power plants, and radium-bearing waste, from
the radium industry and its offshoots. Other types of
waste fall into this category, such as certain bituminised
effluents, substances containing radium, uranium and
thoriumwith lowspecific activity, aswell as certaindisused
sealed radioactive sources.
The 2013-2015 PNGMDR required the various actors
involved to carry out studies (characterisation andwaste
treatment possibilities, geological investigations on a site
identified by Andra, design studies and preliminary safety
analyses) so that in 2016 the State can specify guidelines
for the management of LLW-LL waste.
The holders of LLW-LLwaste have thus made progress in
the characterisation of their waste and in the processing
possibilities, particularlywith regard to graphitewaste and
some types of bitumen-solidifiedwaste. More specifically,
the radiological inventory for chlorine-36 and iodine-129
has been considerably reduced.
As part of the PNGMDR, Andra submitted a report in
July 2015 containing:
•
proposals of choices of management scenarios for
graphite and bituminous waste, notably with the
possibility of reinitiating the search for a site for an
“intact cover disposal” type repository or not;
•
a feasibility file for the project for a “reworked cover
disposal
5
” type disposal facility, the types of waste to
be placed in it and the schedule for its deployment.
This report is currently being examined by ASN which
will issue an opinion on the management of LLW-LL
waste at the beginning of 2016. ASNwill be particularly
attentive not only to waste characterisation but also to
the characteristics of the prospective site with regard to
the safety requirements (thickness and depth of the clay
layer, position of aquifers, examined intrusion scenarios)
and the inventory of envisaged waste.
5. Reworked cover disposal is disposal at shallow depth achieved by
open-cast excavation of a layer with a clayey or marly component
to reach the storage level. Once filled, the vaults are covered by a
layer of compacted clay followed by a protection layer of planted
vegetation reconstituting the site’s natural level.
1.4 Socodei melting/incineration
facility
The Centraco low-level waste processing facility
(BNI 160), located in Codolet near the Marcoule site
(Gard
département)
, is operated by Socodei, a subsidiary
of EDF.
The purpose of theCentracoplant is to sort, decontaminate,
reuse, treat and package - particularly by reducing their
volume - waste and effluentswith low levels of radioactivity.
The waste is then routed to the Andra CSA repository.
The facility comprises:
•
a melting unit melting a maximum of 3,500 tonnes of
metallic waste per year;
•
an incineration unit incinerating a maximum of
3,000 tonnes of solidwaste and 2,000 tonnes of liquid
waste per year;
•
storage areas for ash and clinkers, liquidwastes, leaching
effluents and metallic waste;
•
a maintenance unit.
At the start of 2015 the incineration unit underwent a
long and complete technical shutdown during which
the refractorymaterial, various internal equipment items
and the quenching tower were replaced.
2015 saw the restarting of the melting unit, shut down
since 2011 following an accident that occurred in the
facility’s melting furnace in September 2011. An ASN
resolution of 27th September 2011 made restarting of
the furnace subject to ASN authorisation on the basis of
a file submitted by the licensee presenting the analysis
and lessons learned from the accident of 12th September
2011, the conclusions of a design and operation review
of the melting unit with regard to the explosion risk, an
assessment of the repair and equipment modification
work necessary for operation of the melting unit and an
assessment of the tests concerning safety.
After examining the restarting application file and in
particular the risks analysis carried out by the CTIF
6
(FrenchMetal Casting Research andDevelopment Centre)
with respect to the explosion risk, ASNauthorised Socodei
to carry out furnace calibration tests on 26th September
2014. After taking into account the results of these tests
in the licensee’s baseline safety requirements (general
operating rules, procedures, etc.), ASNauthorised Socodei
to restart the melting furnace on 9th April 2015.
6.
Centre Technique des Industries de la Fonderie
(French
metal casting research and development centre) is a reference
organisation for the appraisal of metallic material casting and
transformation processes.
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CHAPTER 16:
RADIOACTIVE WASTE AND CONTAMINATED SITES AND SOILS
ASN report on the state of nuclear safety and radiation protection in France in 2015