- 225 - 1.2.3 Other facilities The ATPu (plutonium technology unit) The ATPu entered service in 1964 for the manufacture of experimental reactor fuels, and notably the Phénix and Superphénix fast-neutron reactors. It entered the phase of definitive ceasing of operation in 2003, with the stoppage of fuel rod production. Its shutdown and decommissioning were authorised by a decree of 6 March 2009. The current decommissioning phase concerns the equipment in which the radioactive material was placed (glove boxes and their internal equipment, effluent tanks and associated conduits, overhead transfer tunnels between glove boxes). It should be finished in mid-2013. Depending on their function when in operation, the equipment items can contain residues of uranium or plutonium oxide powder, green or sintered fuel pellets, and ground manufacturing discards (mixed oxides or mixtures of oxides). Chemical products and inflammable liquids are used to decontaminate the equipment or to fix the contamination. The main risks presented by this facility are the risk of disseminating radioactive material, external exposure to radiation, the criticality risk and the chemical or explosion risks associated with the use of decontamination or contamination-fixing products. The Masurca reactor The Masurca reactor, whose creation was authorised by a decree of 14 December 1966, is dedicated to determining the neutron characteristics used for the sodium-cooled fast-neutron reactors. In its current configuration, the reactor core has been unloaded since 2007 further to the last periodic safety review, to allow work to bring it into conformity with a view to its continuing use for the experimental programmes associated with the future generation IV reactors. This is a low-power reactor (5 kW). The facility comprises: the reactor building (BR) consisting of a metal containment chamber kept at negative pressure. The core is made up with fuel assemblies when the experimental programmes are run; the storage and handling building (BSM) housing all the neutron simulation elements, whether fissile, fertile or inert (sodium and others) that enter into the composition of the core; the instrumentation and control building (BCC) which contains all the reactor control, monitoring and measurement components; the auxiliary building (BA) which contains the auxiliary systems for the reactor (ventilation, cooling, utilities). Given the current configuration of the facility, the reactor building only contains nine sealed sources. The BSM houses the fissile materials, the sodium, the fertile and inert materials stored in separate storerooms, and the materials of the active laboratory and the radioactive sources stored in the source room safe. The BCC and the BA contain no nuclear or hazardous substances. The reactor is not due to resume operation until 2017. The complementary safety assessment was carried out taking account of the state of the facility on 30 June 2011, in accordance with the specifications. The main risk inherent to the facility results from the storage of substances in the BSM. Consequently, for the purpose of the CSA, this facility is examined as a material storage facility and not as an experimental reactor. These two facilities are installed on the Cadarache site described earlier (§ 1.2.1 / JHR). 1.3 An approach adapted to the diversity of the facilities 1.3.1 Particularities of the approach for nuclear facilities other than power reactors The complementary safety assessment approach undertaken by ASN is common to all the facilities. This complementary assessment consists in a targeted re-assessment of the safety margins of the nuclear facilities in the light of the events that occurred at Fukushima, namely extreme natural phenomena taxing the safety functions of facilities that could lead to a severe accident.
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