Bushehr was the first civilian nuclear power plant to be commissioned in the Middle East. It cost an estimated $1bn to develop and began commercial operations in late 2013, with a capacity of 1,000MW.
Irans nuclear programme has made stop-start progress since 1975, with construction initially halted by the Islamic revolution. The Bushehr site was also bombed during the Iran-Iraq War.
A contract was signed with Russias Ministry for Atomic Energy in 1995, but construction continued to be delayed due to technical issues and political pressure. Financial problems stopped work again briefly in 2007.
The plant was connected to the electricity grid in late 2011, adding 60MW of capacity. The remaining capacity was brought online in stages. According to the World Nuclear Association, the Bushehr reactor frees up about 11 million barrels of oil a year for sale that would have been used for power generation.
Construction has begun on the second and third reactors; each will have a capacity of 1,000MW. They are being developed by Russias Atomstroyexport under a $9bn contract. The reactors are due to be fully commissioned in 2025 and 2026 respectively.