ASN Report 2017

431 ASN report on the state of nuclear safety and radiation protection in France in 2017 Chapter 15  - Decommissioning of Basic Nuclear Installations BNI 47, further characterisations are necessary before starting decommissioning; they will be available in 2018. ASN does note however that Areva NC is endeavouring to define action plans to control drifts in the schedule. 2.3.3 BNI 105 at Tricastin Operated by Areva NC, BNI 105 mainly produced uranium hexafluoride (UF 6 ) for the fabrication of nuclear fuel. Alongside this main activity, BNI 105 produced various fluorinated products such as chlorine trifluoride. The fabrication of UF 6 from natural uranium was carried out in a part the plant governed by the ICPE regulations, while the fabrication of UF 6 from reprocessed uranium was carried out in a part of the plant classified as a BNI. This latter part, BNI 105, which was definitively shut down in 2009, essentially comprises two units: ཛྷ ཛྷ the 2000 unit, which transformed reprocessed uranyl nitrate UO 2 (NO 3 ) 2 into uranium tetrafluoride (UF 4 ) or uranium sesquioxide (U 3 O 8 ); ཛྷ ཛྷ the 2450 unit, which transformed the UF 4 from the 2000 unit into UF 6 . This UF 6 was intended to enrich the reprocessed uranium for the manufacture of fuel. Areva NC filed a decommissioning decree application in February  2014. The expert technical assessment of the file was completed in May 2016 and the Environmental Authority of the CGEDD issued its opinion on the file in September 2016. The examination continued in 2017 with the public inquiry and drafting of the draft decree which will be made available for consultation in 2018. The licensee submitted the first periodic safety review file for its facility at the end of 2017; examination of this review which start in 2018. Three events rated level 1 on the INES scale were reported by the licensee in 2017. These events concerned environmental dispersion of potassium contaminated with uranium and anomalies in the packaging of nuclear waste and materials present in the storage areas. In 2018, ASN will check the effectiveness of the measures implemented by the licensee further to these events. 2.3.4 Eurodif plant at Tricastin The Eurodif facility (BNI 93), licensed in 1977, consisted primarily of a plant for separating the isotopes of uranium using the gaseous diffusion process, with a nominal annual capacity of 10.8 million separative work units. Following stoppage of its production in May 2012, the licensee – Eurodif Production – was authorised inMay 2013 to implement the operations of the Eurodif project for intensive rinsing followed by “air-filling” (operation “Prisme”), which consisted in repeatedly rinsing the gaseous diffusion circuits with chlorine trifluoride (ClF 3 ), a toxic and hazardous substance which allowed the extraction of virtually all the residual uranium deposited in the diffusion barriers 1 . 1 . The Eurodif plant used the process of gaseous diffusion through a cascade of diffusers. Further to the production stoppage in 2012, decommissioning preparation operations have been undertaken: these operations (baptised “Prisme”) consist firstly in intensive rinsing with ClF 3 to extract the large majority of the residual uranium from the equipment and secondly in injecting moist air to cause a hydrolysis chemical reaction in order to extract the gaseous effluents. In accordance with the Decree of 24th May 2013, the licensee filed its final shutdown and decommissioning application for the installation in March 2015. The initial examination by ASN revealed that further information was required before the examination could proceed. This additional information concerned general aspects in the decommissioning strategy adopted by Eurodif Production, more particularly in the management of radioactive waste and the description of the initial and final states of the installation. On 31st March, the Prefect coordinating the public inquiry issued a favourable opinion on the final shutdown and decommissioning application for the Eurodif plant. The decommissioning challenges concern the volume of very low-level (VLL) waste produced (including 180,000 tonnes of metallic VLL waste) and the reduction in the decommissioning time frame which must be as short as possible (currently estimated at 30 years). Operations to prepare for final shutdown and decommissioning of the Eurodif plant were started in 2017. Once they are completed, ASN will authorise the shut down installations to enter a surveillance phase pending starting of the first decommissioning operations. Before delivering its authorisation, ASN will ascertain that the installations in are in a safe state compliant with that described in the application file submitted by the licensee, particularly regarding the removal of operational waste and the addressing of the events that led to pollution in the past. Examination of the final shutdown and decommissioning file will continue in 2018 with the preparation of the draft decree governing decommissioning. 2.3.5 SICN plant in Veurey-Voroize The former nuclear fuel fabrication plant of Veurey-Voroize, operated by the Société Industrielle de Combustible Nucléaire (SICN, Areva Group) consists of two nuclear facilities, BNIs 65 and 90. Fuel fabrication activities were definitively stopped in the early 2000’s. The Decrees authorising the decommissioning operations date from 15th February 2006 and the decommissioning work has now been completed. The site nevertheless displays residual contamination of the soil and groundwater, the impact of which is compatible with its envisaged future use (industrial). ASN has therefore asked the licensee to submit, as a prerequisite to delicensing, an application for the implementation of active institutional controls designed to restrict the use of the soil and groundwater and to guarantee that the land usage remains compatible with the state of the site. SICN submitted this file to the Isère département Prefecture in March 2014, and the delicensing application file for the two BNIs to ASN. Delicensing will not be able to be declared until these active institutional controls have been effectively put in place by the Prefect of the Isère département , at the end of the examination procedure which includes a public inquiry. Initiated at the end of 2017, this procedure will continue in 2018.