- 239 - The examination showed that the implementation of these measures should be put into perspective with the forthcoming shutdown of this reactor. The licensee has also undertaken to assess the robustness of the pile block to earthquake intensities exceeding the design-basis earthquake. For the Osiris reactor, ASN will require the performance of work to improve the seismic behaviour of the metallic structure and the installation of seismic-qualified systems to maintain or supplement the water inventory. Jules Horowitz Reactor (JHR) Design of the facilities The JHR facility was designed considering a design-basis earthquake (DBE) that is defined as being the envelope of the SSE spectra for Cadarache and the paleo-earthquake established in application of RFS 200101. Measures to protect the facility The JHR facility is covered by an earthquake monitoring system that monitors the CEA Cadarache Centre as a whole, and not just the JHR (networks monitoring the local and regional microseismicity, accelerometric instrumentation), as well as measuring accelerometers and seismic triggers specific to the JHR BNI. In the event of an earthquake, the licensee is immediately informed so that it can apply the instructions given in the operating documents for such a situation. The following provisions have been adopted with respect to the seismic risk for the civil engineering structures: the presence of reinforced elastomeric paraseismic supports mounted on reinforced concrete blocks below the upper basemat that supports the reactor unit building (BUR) and the auxiliary units building (BUA) to filter the horizontal component of the seismic excitation; the seismic design of the internal and civil engineering structures of the nuclear unit (UN) made up by the BUR and the BUA, guaranteeing the integrity and stability of these structures, the supporting and protection of the reactor containment and the equipment important for safety (EIS) within these structures and which must withstand the earthquake, the resistance of the containment walls and leak-tightness of the water block, its penetrations and the containment connections, the integrity of the penetrations and civil engineering structures of the nuclear unit, thereby ensuring radiological protection; the seismic design of the other safety-classified buildings (safeguard buildings (BAS) containing the diesel generators, protected galleries (BAG) and nuclear unit exhaust stack), the resistance of the premises housing the systems necessary to place and maintain the reactor in safe condition. Measures have been taken to protect the containment and its penetrations against earthquakes, and more particularly the seismic design of the civil engineering structures of the nuclear unit (UN) guaranteeing the integrity of the third containment barrier, the seismic design of the penetrations (fluids and electrical) associated with the containment guaranteeing integrity during the earthquake of the mechanical parts of the penetrations (sleeve, etc.) and the integrity during the earthquake and post-quake operability of the containment isolation valves. The electric utilities and the instrumentation and control associated with the control of the containment isolation electric valves and isolation monitoring are designed to withstand an earthquake. These systems are energized by the backup electrical power supply. The following measures have been taken for reactor earthquake protection: the reactor emergency shutdown system and the associated equipment for controlling reactivity and sub-criticality have been designed to be operational during and after an earthquake. Furthermore, the equipment for the containment of the radioactive substances and for the removal of residual power has been designed to withstand earthquakes.
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