FACTBOX-Tehran Research Reactor

Feb 15 (Reuters) - Iran said on Wednesday it will load domestically made nuclear fuel rods into its Tehran Research Reactor on Wednesday for the first time to keep it running.

Here are some details about the reactor:


* Iranian President Mahmoud Ahmadinejad said in late 2011 Tehran would stop producing 20 percent enriched uranium if it were guaranteed fuel for the Tehran Research Reactor, seeking to revive a fuel swap deal that fell apart in 2009.

- The fuel swap plan, envisioned by the West as a way to reduce mistrust and help pave the way for broader talks on Tehran’s nuclear programme, entailed an exchange of Iranian low-enriched uranium (LEU) for higher-refined fuel from abroad.

* Iran recently began shifting enrichment centrifuges to an underground bunker near the holy city of Qom as part of a push to triple output capacity of higher-grade enriched uranium, a development Washington called “troubling.”

- Western analysts have said that Iran’s camopaign to stockpile 20 percent enriched material puts it closer to the 90 percent threshold suitable for atom bombs.

- Iran said it needed the material to fuel the Tehran Research Reactor (TRR) as imported Argentinian fuel used by the complex was running out. Iran asked the International Atomic Energy Agency for assistance in resupplying the reactor so it could produce medical isotopes for the treatment of an estimated 850,000 cancer patients in Iran.


- Iran operates five research reactors and has another under construction. The TRR is the largest in operation.

- The TRR is a 5 megawatt-thermal (MWth), pool-type light water research reactor. The United States supplied the TRR to Iran in 1967 and uranium fuel for the reactor.

- After the 1979 revolution, Iran was no longer able to procure replacement nuclear fuel from the United States or Europe. In 1987, the Atomic Energy Organisation of Iran paid Argentina’s Applied Research Institute $5.5 million to convert fuel for the reactor from 93 percent enriched uranium - which is weapons-grade - to slightly less than 20 percent enriched.

- Of the original U.S.-supplied fuel, about 7 kg (15 pounds) of irradiated highly enriched uranium remains stored at the reactor site.

- In 1993, the reactor was converted to use 19.75 pct enriched fuel, 115 kg (253 pounds) of which was provided by Argentina with tacit U.S. agreement, because the lower-enriched material is a lesser proliferation concern.

- In the late 1980s and early 1990s, the TRR was used to irradiate uranium oxide (UO2) fuel targets for unreported, laboratory-scale plutonium-reprocessing experiments.

These were among the nuclear safeguards failures by Iran reported by the IAEA in 2003. Iran also acknowledged that it had used the TRR to produce small amounts of polonium-210 - a well-known radioactive material used in a neutron initiator that starts the chain reaction in a nuclear weapon.

- Iran has maintained that the polonium was produced as part of a study of the production of neutron sources for use in radio-isotope thermoelectric generators and not for use in a neutron initiator.

- The reactor core consists of 27 uranium-oxide, aluminium-alloy fuel plates, representing a total of about 30 kg (66 pounds) of uranium.

Reporting by David Cutler, London Editorial Reference Unit, and Fredrik Dahl in Vienna; Editing by mark Heinrich