The recent shutdown of Iran’s 1.0gw Bushehr nuclear power plant has been attributed to the discovery of a fragment broken off a large bolt on the plant’s main circulation pump. The International Atomic Energy Agency (IAEA) revealed in a report circulated among members in mid-November that fuel assemblies had been transferred from the core to the spent fuel pond in late October. Iran claimed that the shutdown was “a very normal technical procedure” during the handover of the plant from its Russian builders to Iranian operators. However, the lack of concrete information about the shutdown raised concerns about plant safety (MEES, 23 November).
Russia’s RIA Novosti news agency on 4 December quoted an unnamed official from Atomstroyexport, the Russian state firm that built the Bushehr plant, as saying that noises were heard near the bottom of the reactor when the plant was operating at full capacity. “After dismantling the reactor,” said the official, “a fragment of a part (an M20 [20mm diameter] bolt) of the main circulation pump was found between the reactor hull and the internal chamber, which also serves to protect fuel assemblies in the event of foreign objects getting into the primary circuit.” The official added that the fuel assemblies had since been fully re-loaded into the reactor and IAEA inspectors had installed seals on the lock of the cooling pond. (CONTINUED - 275 WORDS)