The installation of the 12 sections which make up the tier, was completed within four weeks “by domestic experts … despite adverse weather conditions”, the Atomic Energy Organisation of Iran (AEOI) said.
Work is now taking place to connect and weld the sections. The installation of the new tier means the height of the structure has increased by 14 metres to 40 metres.
(Image: AEOI)
The AEOI says that the fourth ring of the building will be installed during 2026.
The first unit at the Bushehr plant, on the Persian Gulf coast, was connected to the grid in 2011. It is a Russian-designed VVER unit with a capacity of 915 MWe. Two further units featuring VVER-1000 units are under construction – unit 2 had first concrete poured in 2019 and the core catcher installed in 2024. At an event at the International Atomic Energy Agency’s General Conference in September 2024, Iran suggested unit 2’s target date for operation was 2029. According to Russia’s Rosatom, unit 3 is also under construction.
In September 2025, Rosatom and the AEOI signed a memorandum of understanding for cooperation in the building of small modular reactors in Iran. The country says it has an ambition for 20 GW of nuclear energy capacity by 2041.
