ASN Report 2018

NORMANDIE REGIONAL OVERVIEWOF NUCLEAR SAFETY AND RADIATION PROTECTION ASN authorised the first phase of work to retrieve the sludges from STE2 in 2015. During 2017, Orano Cycle submitted additional information relating to the first phase of the work and an authorisation application concerning the process for retrieving the sludges from STE2 and transferring them to STE3. This file is currently being examined. The creation authorisation decree for the STE3 effluents treatment station was modified by the Decree of 29 January 2016 to allow the installation of the STE2 sludges treatment process. Orano Cycle, however, has informed ASN that the process adopted for treating the sludges in STE3 could lead to difficulties in equipment operation and maintenance. It has also presented the alternative centrifuge treatment scenario that it intends implementing, which will lead to the production of drums for interim storage in the existing dedicated facility. Orano Cycle plans submitting a safety options file in 2019. The currently prescribed regulatory deadline for starting retrieval of the sludges will not be met. Silo 130 Silo 130 is a reinforced concrete underground storage facility, with carbon steel liner, used for dry storage of solid waste from the reprocessing of Gas-Cooled Reactor (GCR) fuels, and the storage of technological waste and contaminated soils and rubble. The silo received waste of this type as from 1973, until the 1981 fire which forced the licensee to flood the waste. The leak-tightness of the silo thus filled with water is today only ensured by a single containment barrier consisting of a steel “skin”. Silo 130 is monitored by a network of piezometers situated nearby. The scenario for retrieving and packaging this waste comprises four stages: •  retrieval and packaging of the solid GCR waste; •  retrieval of the liquid effluents; •  retrieval and packaging of the residual GCR waste and the sludges from the bottom of the silo; •  retrieval and packaging of the soils and rubble. Schematic diagram of retrieval and packaging of the waste from Silo 130 ASN report on the state of nuclear safety and radiation protection in France in 2018  69