Читать книгу Industrial and Medical Nuclear Accidents - Jean-Claude Amiard - Страница 41

Serious incidents of level 3 on the INES occurring at nuclear power plants are relatively numerous. Among these incidents were the discovery in 2002 at the Davis–Besse power plant reactor (United States) of a cavity in the tank cover as a result of corrosion of the metal by boric acid; the loss of power supply in 1993 to Unit 1 of the Narora nuclear power plant (India) caused by a fire in the turbine hall; the emergency shutdown of reactor 1 at the Kola nuclear power plant (Russia) resulting from network disruptions following a tornado; and, in 1991, the exceeding of operating limits during restart tests following a maintenance shutdown of reactor 2 at the Smolensk nuclear power plant (Russia). The same applies to the incident that occurred on April 10, 2003 in reactor no. 2 at the Paks nuclear power plant. This power plant is located in the central region of Hungary, 5 km from Paks and 100 km south of the capital Budapest, on the banks of the Danube. On that day, the reactor was shut down for its annual refueling, and the fuel elements were unloaded and stored temporarily in a cleaning tank located next to the fuel pool. Some of these underwater fuel assemblies were damaged and leaking. The incident initially classified as level 2 was reclassified as level 3 by the authorities because with fuel leaks, there was a risk of reaching the critical mass at the bottom of the cleaning tank.