Nuclear Expansion: Iran and Russia Move Forward With Sirik Plant

Iran has approved a $25 billion agreement to build a new nuclear power plant in its southern Hormozgan Province.

The project, known as Sirik, sits near the Strait of Hormuz and involves Russian construction. The deal was signed in September 2025. According to Iranian state news agency IRNA, the facility will have a combined capacity of approximately 5 gigawatts. This output would exceed the total capacity of the existing Bushehr complex, which stands at under 3 gigawatts.

The expansion follows a timeline of increasing cooperation between Moscow and Tehran. The Comprehensive Strategic Partnership Treaty entered into force in October 2025. This legal framework builds upon an intergovernmental Cooperation Plan for 2024 and 2026 that was approved in September 2024. The two nations have deepened economic and military ties in recent years, a trend accelerated by Western sanctions on both countries.

Work continues at the Bushehr station on Iran's southern coast, the first operating nuclear plant in the country. A contract to complete the first reactor was signed in 1995, but full commercial electricity generation did not begin until 2013. Construction on a second reactor unit has passed the 60 percent completion mark. Rosatom targets a start of operations for that unit in 2029. Work is also underway on a third unit.

Rosatom resumed on-site activities after a period of evacuation. Following the start of the US-Iran war in February 2026, the Russian state nuclear corporation pulled most of its staff out of the country. By October 11, 135 engineering and technical specialists had returned to Bushehr to continue their work.

Analysts suggest the partnership serves distinct needs for both governments. Nikita Smagin of the Carnegie Endowment for International Peace wrote in November 2025 that the balance of the relationship is shifting in Russia's favor. He noted that Russia remains one of the few available sources of investment for Iran. Researchers Dmitry Kovchegin and Arkady Mil-Man at Israel's Institute for National Security Studies described Moscow's approach as a calculated balancing strategy in a June analysis.

The expansion occurs while the International Atomic Energy Agency faces obstacles in monitoring Iranian sites. A report published on June 4, 2026, stated that inspectors conducted an inspection at Bushehr from June 1 to June 3. The agency reported that it could not carry out inspections at other declared nuclear sites during that period. These sites include four uranium enrichment facilities. The IAEA said it could not verify the status of nuclear material there or confirm whether Iran had suspended enrichment and reprocessing activities as required by UN Security Council resolutions.

The Arms Control Association noted in a June 2025 analysis that Iran's accumulation of uranium enriched to 60 percent has no civil justification. Enrichment at that level can be increased to 90 percent, the threshold generally associated with nuclear weapons. The new Sirik plant will tie Iran's civilian nuclear sector to Russian technology and fuel supplies for decades if completed.