The problem was first reported on Friday in the latest quarterly report on Iran’s nuclear programme by the International Atomic Energy Agency (downloadable here courtesy of the Institute for Science and International Security, ISIS)
In the ‘Other Matters’ section towards the end, it briefly notes:
On 23 February 2011, Iran informed the Agency that it would have to unload fuel assemblies from the core, and the Agency and Iran have agreed on the necessary safeguards measures.
The Iranians have been on record as saying that the Bushehr plant was affected by the Stuxnet computer worm, which is widely believed to have been a joint venture in cyber warfare by the US and Israel. But the initial signs are that Stuxnet has not played a part in this setback. Before Soltanieh spoke, ISIS provided an instant analysis of the IAEA report, saying it had learned that:
the unloading may be motivated by concerns about the possible sabotage of the fuel assemblies or defective fuel assemblies.
David Albright, who runs ISIS, told the New York Times:
It raises questions of whether Iran can operate a modern nuclear reactor safely…The stakes are very high. You can have a Chernobyl-style accident with this kind of reactor, and there’s lots of questions about that possibility in the region.
The other interesting line from the IAEA report comes in the “Possible Military Dimensions” section, which is quite toughly worded and suggests th… >>>