* Pump broke up, pieces in primary cooling system
* Will delay start of power generation by nuclear plant
VIENNA, Feb 28 (Reuters) - Iran is believed to have told the U.N. atomic watchdog that a broken pump had made it necessary to remove fuel from its first nuclear power reactor, independent experts familiar with the issue said on Monday.
The experts, who declined to be named due to the sensitivity of the issue, said it was a potentially serious problem likely to cause more delays for the Russian-built Bushehr plant, which has yet to start injecting power into Iran’s national grid.
“I think what happened is that the pump failed but it didn’t just fail, it broke up, so that ... there are pieces of metal that are now circulated throughout the primary cooling system,” one of them said.
The International Atomic Energy Agency (IAEA) said in a report obtained by Reuters on Friday that Iran had told it Iranian experts would unload fuel assemblies from the core of the Bushehr reactor, just a few months after they were loaded.
The confidential IAEA document did not give a reason for the unusual action.
Iranian officials have previously said the reactor on Iran’s Gulf coast, the first in a planned network of nuclear power plants, would start generating electricity early this year.
They say the plant shows Iran’s nuclear programme is peaceful, rejecting Western accusations the Islamic state may also be trying to develop a nuclear weapons capability. (Reporting by Fredrik Dahl; editing by Tim Pearce)