Iran
Graphite Sub-Critical Reactor (ENTC GSCR)
About
The Graphite Sub-Critical Reactor (GSCR) is a zero power light-water reactor (with graphite reflector) operating on uranium metal fuel. 1 China constructed the reactor in 1991, and it first became operational in 1992. The reactor is used for training and, according to the IAEA, operates for two hours a day, five days per week. 2
This facility was attacked in June of 2025 as part of an Israeli airstrike operation targeting Iranian nuclear and missile infrastructure. While the facility was attacked, there was no reported damage to the GSCR at this time.3
Glossary
- Light-water reactor
- Light-water reactor: A term used to describe reactors using ordinary water, where the hydrogen is hydrogen-1, as a coolant and moderator, including boiling water reactors (BWRs) and pressurized water reactors (PWRs), the most common types used in the United States.
- Uranium
- Uranium is a metal with the atomic number 92. See entries for enriched uranium, low enriched uranium, and highly enriched uranium.
- International Atomic Energy Agency (IAEA)
- IAEA: Founded in 1957 and based in Vienna, Austria, the IAEA is an autonomous international organization in the United Nations system. The Agency’s mandate is the promotion of peaceful uses of nuclear energy, technical assistance in this area, and verification that nuclear materials and technology stay in peaceful use. Article III of the Nuclear Non-Proliferation Treaty (NPT) requires non-nuclear weapon states party to the NPT to accept safeguards administered by the IAEA. The IAEA consists of three principal organs: the General Conference (of member states); the Board of Governors; and the Secretariat. For additional information, see the IAEA.
Sources
- “Nuclear Research Reactors in the World, Research Reactor Details - ENTC GSCR,” International Atomic Energy Agency, www.iaea.org.
- “Nuclear Research Reactors in the World, Research Reactor Details - ENTC GSCR,” International Atomic Energy Agency, www.iaea.org.
- According to satellite analysis by Sam Lair at the James Martin Center for Nonproliferation Studies, 18 June 2025.