- 283 - 4.3.2. La Hague site With regard to the risks associated with snow and wind, the licensee indicates in its complementary safety assessment that the facilities were designed on the basis of estimated envelope values for the loads induced by snow and wind. It considers that projectiles picked up by a tornado would be unlikely to damage the reinforced concrete structures housing functions important for safety, as these structures are designed to withstand the impact of a projectile such as a light aircraft engine. It also indicates that the chimney stacks and their anchoring systems are designed to withstand extreme winds. ASN considers that the licensee must supplement its analysis of extreme meteorological phenomena for the La Hague facilities on the basis of experience feedback, taking into consideration a tornado and evaluating all the associated effects (negative pressure, resistance of chimney stacks, impact of any projectiles on the metal structures and external utilities, etc.). ASN will issue requests in this respect. 4.3.3. Other facilities in the fuel cycle (Mélox, FBFC) Mélox Stronger than design-basis winds and tornadoes were considered in the complementary safety assessment. Extreme winds can cause chimney stacks to collapse, which would not affect the third containment barrier (designed to withstand the impact of a light aircraft engine), but would lead to loss of control of discharges. By engineering judgement, the licensee estimates that a tornado would progress along the Rhône valley and bypass the Mélox building. ASN has no particular remarks concerning the licensee's analysis of the Mélox facility in this respect. FBFC With the exception of the risk of flooding by rainfall, the licensee considered that no climatic event capable of generating an accident situation needed to be analysed. ASN has no particular remarks concerning the licensee's analysis of the FBFC facility in this respect. 4.4 Other facilities (ATPu and Masurca) 4.4.1. ATPu In view of the measures taken in the design (application of the snow and wind rules in effect on the date of construction, lightning protection) and operation of the facility (monitoring and intervention in the event of flooding), the licensee considers that there is no risk of a cliff-edge effect being caused by meteorological conditions. ASN has no particular remarks concerning the licensee's analysis of the ATPu facility in this respect. 4.4.2. Masurca The CEA assessed the risk of localised blockage of the water drainage system induced by debris carried by a very strong wind, or hail, associated with a rainfall event. The CEA also considered lightning strike, highlighting the presence of a mesh cage on the roof, the external walls of the storage and handling building BSM and a protection system against electric power grid overvoltages. The CEA concludes that the extreme meteorological conditions associated with flooding do not risk causing a cliff-edge effect. In view of the planned measures to reinforce the robustness of the Masurca facility, ASN has no particular remarks concerning this complementary analysis.
RkJQdWJsaXNoZXIy NjQ0NzU=