Iran's Bushehr nuclear plant, its only power-producing reactor, has been damaged by the recent successive earthquakes that struck the country in April and May.

According to unidentified sources quoted and described by AP as diplomats, cracks of several metres long have reportedly surfaced in one section of the plant. The good news, according to the diplomats who come from different from countries monitoring Iran's nuclear program, was that they didn't see cracks around the highly-radioactive reactor core.

Although not considered a threat, nations and nuclear experts are concerned just how safe and sound the Bushehr nuclear plant. Built in the 1970s and opened in 2011, Iran had consistently insisted the plant is safe and was built to withstand earthquakes up to magnitude 8.

Tehran officials continued to convince the international community the facility remains unscathed and undamaged, following the April and May earthquakes, the biggest of which was a 7.7-magnitude quake which gave off much damage in neighbouring Pakistan as well as leaving 40 dead and wounding hundreds.

The diplomats, who came from member-countries of the International Atomic Energy Agency, said they gathered their material based from restricted information gathered from the site.

Although the reactor core bore no cracks or damage, still, the diplomats did not totally rule out that more damage could be found elsewhere.

The diplomats went to check the facility after Tehran informed the IAEA that they were shutting down the facility, but didn't offer explanations.

The cracks reportedly developed after the April 9 and April 16 earthquakes.

Iran remains the sole country operating a nuclear power plant but refused to sign to the 75-nation nuclear safety convention. The treaty was created after the 1986 Chornobyl nuclear disaster.

Located in a zone of tectonic compression, the Arabian plate frequently moves into the Eurasian plate, Iran has been rocked by hundreds of killer quakes over past centuries. More than 90 per cent of it is crisscrossed by seismic fault lines.