A1 nuclear power plant damaged fuel and radioactive waste management. Annex III

The A1 nuclear power plant (NPP) was the first NPP in the former Czechoslovak Socialist Republic. It was a gas cooled (CO2) and heavy water moderated reactor (Fig. III−1), and operated from 25 December 1972 to 22 February 1977. The A1 NPP's average power output was approximately 150 MW(e). There were 148 fuel assemblies and 40 control rods in the core. The fuel assemblies had diameters of 102 mm or 114 mm and were made up of fuel elements of natural uranium with magnesium/beryllium cladding. The length of their active part (in the core) was 4 m. The reactor vessel has a diameter of 5.1 m and a height of 20.1 m. The primary circuit consists of six loops, each with a turbo compressor and a steam generator. The moderator circuit consists of three loops, each with a circulation pump and a cooler. At the end of February 1977, an operational accident occurred. As a result of the accident, fuel cladding fractured and fuel damage occurred in the upper part of fuel elements ranging from 30 cm to 100 cm in length. The primary circuit (coolant) was contaminated by fission products. Some auxiliary circuits and facilities were also contaminated.