There are a few reasons why Iran has chosen to work with Russia again. Russia took over the Bushehr project from a German company after the 1979 Islamic Revolution, and even though the project was delayed many times and problematic, it has finally been completed. Russia is also one of the leaders from the anti-Western camp, and Iran values this position. There may be better, cheaper alternatives for cooperation on a nuclear power facility, yet for now Russia is the logical partner.
Personally I am still very worried about nuclear power facilities in Iran. The safety issues are well-documented, yet no one is paying attention to the potential environmental hazards. A whistleblower from the Atomic Energy Organization of Iran provided a document to The Times which stated that:
...Bushehr, which began operating last month after 35 years of intermittent construction, was built by "second-class engineers" who bolted together Russian and German technology from different eras; that it sits in one of the world's most seismically active areas but could not withstand a major earthquake; and that it has "no serious training program" or a contingency plan for accidents.This corroborates other claims about problems including cracks resulting from earthquakes, and a broken cooling pump which forced a shutdown of the plant. The plant is designed to sustain up to a magnitude 8 earthquake without serious damage, yet the several meter long cracks mentioned in the previous sentence were the result of a mere 6.4 earthquake.
Even though there are many problems with Iran's nuclear power plants, the Iranians are continuing to build. I hope that they take steps to address these issues, especially the ones relating to safety. The Iranian ambassador to the UN promised that Iran would be working to join the Convention on Nuclear Safety in January 2013, yet this has not happened yet. The world does not need another nuclear disaster, especially so soon after Fukushima.