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With a view to the shutdown of the Osiris reactor, CEA
updated the decommissioning plan, proposed extensive
decommissioning preparationwork, which is to begin in
2016, andundertook to submit the decommissioning file
by the end of 2016. ASNaskedCEA to provide additional
substantiation information inorder to assesswhether these
preparation operations are indeed in conformitywith the
ASNGuide onBNI final shutdown anddecommissioning
(Guide No. 6) (see chapter 15) and recalled that any
significantmodification to the facilitymust be substantiated.
Jules Horowitz Reactor (RJH) (Cadarache)
With the support of several foreign partners, CEA is
building a new research reactor owing to the ageing of the
European irradiation reactors currently in service, which
are scheduled for shutdown in the short tomediumterm.
The RJH(BNI 172)will be able to carry out work similar to
that done by theOsiris reactor. It does however comprise
a number of significant changes with regard to both the
possible experiments and the level of safety.
The constructionworkon the facility,which started in2009,
continued in 2015. According toCEA, commissioning of
the RJHwill be significantly behind schedule, in factmore
than four years late.
The civil engineering work on the reactor building
was completed with pre-stressing of the building. The
operations involved in the lining of the reactor cavity
continuedwith the installation of the anchors and of the
first stainless steel liners. The nuclear auxiliaries building
is still under construction, in particular the installation
of the shielded experimentation cells. Installation of the
lining on the storage channel andpools also continued. The
manufacture of the first elements of the reactor itself also
began in 2015. ASN considers that CEA is demonstrating
sufficient rigour and efficiency with regard to the risks
and drawbacks of the project.
The inspections in2015mainly concerned thepre-stressing
work on the reactor building and the organisation of the
construction site, with regard to both procedures and
follow-up of anomalies. ASN is also continuing regular
discussions with CEA in order to check the measures
requested following analysis of the preliminary safety
report and in preparation for the review of the future
commissioning authorisation application.
Neutron source reactors
Orphée reactor (Saclay)
The Orphée reactor (BNI 101) is a pool-type research
reactor with an authorised power of 14 MWth, using
heavy water as the moderator. It was authorised by the
Decree of 8th March 1978 and its first divergence dates
from1980. It is equippedwith nine horizontal channels,
tangential to the core, enabling nineteen neutron beams to
be used. These beams are used to conduct experiments in
fields such as physics, biology and physical chemistry. The
reactor also has ten vertical channels for the introduction of
samples to be irradiated in order to produce radioisotopes
or special materials and to carry out analysis by activation.
The neutron radiography installation is used for non-
destructive testing of certain components.
ASN considers that the level of safety of the Orphée
reactor is on the whole satisfactory. During an inspection
in 2015, ASN in particular noted compliance with the
plannedmeasures and restart conditions following the two
significant fuel handling events which occurred at the end
of 2014. However, improvements are necessarywith regard
to radioactive wastemanagement, especially concerning
themanagement of waste zoning in the installation and the
formal definition of storage area operating instructions.
The licensee must also reinforce its organisation for
planning and following up the performance of periodic
checks and tests.
The causes of the significant events notified in 2015 are
split equally between hardware failures and organisational
shortcomings. The analysis of one of these events has
shown that the licensee needs to be vigilant in the analysis
and traceability of deviations from the safety requirements
with regard to the supply of equipment important for
the protection of interests.
Shutdown of the Osiris reactor (Saclay)
While the ASN resolution of 2008 duly noted CEA’s undertaking
to cease all activities at Osiris by the end of 2015, CEA has
since 2011 repeatedly expressed its desire to continue
operations, given that reactor core melt is a design basis
scenario for the various intervention and response plans for
the Saclay plateau, where urban development is accelerating.
In its opinion of 25th July 2014, ASN restated that that
“it was not in favour of continued operation of the Osiris facility
beyond 2015 owing to the current level of safety of this
reactor”.
However, considering the fact that the CEA application
was based on the possible risk of a shortage of medical
radionuclides, ASN could have
“for the period 2016-2018,
examined an approach which would minimise operation of the
Osiris reactor, reserving it solely for the purpose of countering
the shortage of 99Mo”.
The shutdown of the reactor in late
2015 was confirmed by the Government in August 2014
and CEA carried out this shutdown In December 2015.
The latest assessments by the Nuclear Energy Agency, which
take account of the Osiris shutdown, show no major risks linked
to the production of 99Mo by irradiation in European research
reactors.
CEA transmitted the updated decommissioning plan for
the facility at the end of 2014 and should then submit
a decommissioning authorisation application file. ASN
will be attentive to the definition and monitoring of the
decommissioning preparation operations, which can involve
risks In terms of radiation protection and dispersal of materials.
TO BE NOTED
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CHAPTER 14:
NUCLEAR RESEARCH AND MISCELLANEOUS INDUSTRIAL FACILITIES
ASN report on the state of nuclear safety and radiation protection in France in 2015