Atomstroyexport JSC (a company of ROSATOM) has completed a visual inspection and flushing of the reactor internals and main circulation circuit at Bushehr NPP. On April 8, 2011 the plant started loading the fuel assemblies again in the core. Thus, the plant first criticality program continues.
Shortly, the reactor will be assembled, primary and secondary equipment will be tested and the reactor will be brought to the minimum controlled power.
The fuel unloading from the Bushehr reactor was a necessary precaution after the Russian specialists had found damages of internals of a cooldown pump. The assumption was that metal particles (predominantly chips of less than 3 mm in size) could have entered the reactor pressure vessel with water. To avoid potential consequences of the particles getting on the fuel assemblies, the latter were unloaded and washed, while the reactor pressure vessel was cleaned.
The pump failure was due to its design features. As a result of the inspection, similar deficiencies were eliminated at other pumps. These pumps are part of the equipment supplied to Bushehr NPP site in the 1970's of the past century. According to the contract, the Russian side was obliged to integrate them in the project.
During construction of nuclear facilities, safety issues always remain of primary importance; therefore, all procedures and tests before power unit commissioning are carried out thoroughly with all necessary requirements been met.
Construction of Bushehr nuclear power plant is fully compliant with the existing international norms, legislation, nonproliferation regime, and is carried out under the IAEA control.