418 / 536
in the operation and maintenance of these plants. This
latter point must also be considered in the context of the
ongoing staff turnover, which is a subject of particular
attention for ASN, in particular in the light of the start-up
of new plants in the coming years.
With regard to the environmental aspects, the discharge
resolutions for BNI 105 were revised in 2015. ASN
also notes repeated events entailing hydrofluoric acid
discharge limits being exceeded at the 200 structure stack.
With a view to the continued operation of the plants,
ASN prescribed automatic shutdown of the electrolysis
process when an exceedance is detected, as well as an
additional discharge counting system. ASN also observed
an unsatisfactory situation in the management of the
conventional waste areas in BNI 105. The licensee reacted
rapidly and implemented a conformity action plan.
Finally, ASN is calling on the licensee to remain vigilant
with regard to the stringency required in themanagement
of anomalies detected by the periodic checks and tests
and in the management of modifications.
ASN considers that the facilities located within the
perimeter of BNI 105 are operated with a level of safety
that is on the whole satisfactory.
The Eurodif gaseous diffusion
enrichment plant – BNI 93
This installation is dealt with in section 15.
The Georges Besse II gas centrifuge
enrichment plant – BNI 168
BNI 168, called Georges Besse II (GB II), licensed in
2007 and operated by the Société d’enrichissement du
Tricastin (SET), is a plant enriching uraniumby means of
gas centrifugation. The principle of this process involves
injecting UF
6
into a cylindrical vessel rotating at very high
speed. The centrifugal force concentrates the heavier
molecules (containing uranium-238) on the periphery,
while the lighter ones (containing uranium-235) are
recovered in the centre. By combining several centrifuges,
creating what is known as a cascade, it is then possible to
recover a stream enriched with fissile U-235 isotope and
a depleted stream. This process has two key advantages
THE INSTALLATIONS
of the fuel cycle in operation or undergoing decommissioning
La Hague plant
UP3
UP2-800
STE3
UP2-400
HAO
ELAN II B
STE2
Areva NP plants in
Romans-sur-Isère
FBFC
CERCA
Tricastin site
Comurhex
Eurodif
GB II
TU5/W
Socatri
Marcoule site
Mélox
Malvési site
Comurhex
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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