Complementary-safety-assessments-french-nuclear-safety

- 326 - 6.2.3. Facilities of the nuclear fuel cycle Tricastin site The licensee has presented the measures implemented on the Tricastin site in its CSA report. These measures are presented in the preceding sub-chapter. La Hague site The feared situations identified by the licensee for the La Hague site are:  With regard to the risks due to releases of heat from radioactive material: o loss of cooling of the spent fuel pools of units NPH, C, D and E; o stopping of rotation of the pendulum-type centrifugal decanters (DPC) of units R1 and T1; o loss of cooling of the concentrated fission product storage tanks in units R2, T2, T2C, T2D, SPF5, SPF6, R7 and T7; o loss of cooling of the fission product concentration evaporator condensers of units R2 and T2; o loss of cooling of the plutonium oxide (PuO2) container storage areas in units BSI and BST1;  With regard to the risk of explosion of hydrogen from radiolysis: o loss of the supply of air sweeping the storage tanks of concentrated fines solutions and alkali rinsing solutions from units R1, T1, T2, R7 and T7;  With regard to the loss of containment risks o loss of tightness of the HAO and 130 waste storage silos, and of unit STE2-A. Identification of the factors potentially hindering accident management and of the resulting constraints The dimensions of the site can hinder severe accident management, resulting in long delays in the implementation of consequence-mitigation actions. The limited robustness of certain support buildings (FLS, infirmary, administration building and building 148) is also a factor that could hinder accident management by creating material disorders or loss of human life. In an earthquake-induced fire situation, the build-up of fumes in the premises could hinder the emergency intervention actions in addition to the possible disruptions caused by the earthquake. A failure in the civil engineering of the pools (breach) or serious disorders around the pools further to an earthquake are factors that could hinder accident management, and notably the implementation of the planned means to mitigate consequences. Existing severe accident management measures In addition to the means presented in the preceding paragraph, the licensee has specific means for each feared severe accident. Loss of cooling: According to the licensee, the site currently has water supply sources it considers robust to an earthquake and providing sufficient autonomy to restore the cooling systems:  the West pond with a capacity of between 30,000 and 55,000 m3;  the Moulinets dam, holding between 250,000 and 410,000 m3;  the Froide Fontaine dam holding a maximum of 5,000 m3 of water. The licensee plans deploying the following means to manage a cooling loss:  supplying water to the equipment (pools, FP tanks, etc.) using motor-driven pumps and a network of fire-fighting-type pipes installed in the emergency management process and supplied from the sources presented above;

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