Iran will have to remove nuclear fuel from its forthcoming Bushehr power plant, which was scheduled to generate power within weeks.
While official Iranian news reports say all is progressing well, the admission of a commissioning setback came in the International Atomic Energy Agency's 25 February report to its board of governors.
"On 23 February," said the report, "Iran notified the agency that it would have to unload fuel assemblies from the core."
Russia's state nuclear power firm Rosatom, building the plant for the Iranian government, said that internal components of a coolant pumps were damaged and 'the hypothesis was that metal particles (mostly chips smaller than 3mm)' could 'pass through the reactor internals and get on the fuel assemblies.' The pump was one supplied by Siemens KWU the 1970s when the plant was begun and its reuse was among the terms of the 1994 contract for Russia to complete the project.
Normally a new reactor coolant system is flushed very thoroughly and any debris easily removed from the bottom of the reactor vessel before the reactor internals are put in place and the fuel is loaded. This was carried out at Bushehr in late October to early December last year. While it is unusual to find particles at this stage, it is not unheard of as final assembly checks are made. Rosatom said it would flush clean all the fuel assemblies and again clear the reactor vessel before reloading the fuel.
A report by Nuclear.Ru said that Iran had hoped to bring Bushehr to minimum controlled power levels on 20 February ahead of first power generation on 9 April. The procedure to remove fuel may delay these milestones by up to three weeks.
Power generation at Bushehr is entirely peaceful but some elements of Iran's program, including the Arak heavy water research reactor and uranium enrichment at Natanz, are the subject of suspicion by other governments and monitored closely by the IAEA.
Bushehr's nuclear fuel was sealed by IAEA inspectors in Russia before delivery. The agency said in its report it had agreed the necessary safeguards measures with Iranian officials for the period the fuel is unloaded.
Researched and written
by World Nuclear News