November 01 2013
By Mark Hibbs
Because neither side has disclosed details, we don’t know for sure whether the roadmap Iran proposed to the P5+1 powers in Geneva in mid-October includes the future of the IR-40 reactor project. Iran’s counterparts have good reason to make sure that the unfinished heavy water reactor is on a short list of must-resolve issues. Once it is completed, Iran will have an installation which can generate annually in its irradiated fuel between 5 and 10 kilograms of weapon-grade plutonium. That’s enough for one nuclear weapon a year.
The powers don’t want the IR-40 to make plutonium which Iran then separates. Iran wants a versatile and safe research reactor. These issues could be reconciled by diplomacy. The P5+1 could help Iran finish the reactor if Iran provides credible assurances it won’t access the plutonium.
Since 2006 the powers have served notice to Iran in United Nations Security Council resolutions that both the IR-40 project and Iran’s uranium enrichment program are proliferation threats. The resolutions ordered Iran to suspend both endeavors. Iran has ignored the resolutions on both counts. It continues to enrich uranium and to build the IR-40.
Unlike Iran’s enrichment plants, which are operating routinely, once the IR-40 is completed, operation of the reactor will pose safety concerns. Some of these are related to a raft of technical challenges which Iran must overcome in manufacturing the nuclear fuel for the reactor.
In part because of these issues, the IR-40 will not be finished and operated for awhile, most likely not before 2015, and possibly not for as long as Iran remains under international sanctions.
This project has been delayed at least four times since it got underway during the 1990s. The most recent delay was revealed to the IAEA in August during a physical inventory verification. A number of items were still not in place, including cooling pumps, instrumentation and control systems, and sufficient uranium fuel.
Iran is behind on this project because it is under sanctions enforced by global export controls on knowhow, materials, and equipment. Without these measures the reactor would probably be operating today. Nearly everywhere else worldwide, research reactor projects like the IR-40 have access to off-the-shelf nuclear-grade items which conform to international safety and quality specifications. Iran is cut off from these sources.
FUEL FABRICATION AND TESTING
As of September Iran had made about 1/5 of the amount of fuel it had predicted in June it would make by then.
Iran faces two main challenges here: fabrication of fuel to quality standards, and testing of the fabricated fuel to make sure it will perform safely and as expected.
Fuel fabrication is difficult for several reasons. Iran chose zirconium for cladding material instead of much softer and more malleable aluminum. This will permit Iran to operate the reactor at higher temperatures and with higher fuel burnup–but only if Iran masters the difficulties of extruding less-ductile zirconium tubes. Add to this the difficulties in making the fuel itself. The natural uranium fuel pellets are produced in Iran in batch mode using mixers which must be precisely controlled to ensure homogeneity, as well sintering ovens which must be carefully operated to guarantee a constant temperature prolife and other technical parameters. Precise control is essential to make sure that the thousands of fuel pellets loaded into the IR-40s core are identical. If they are not, or if tubing is not precisely machined and welded, slight irregularities in geometry can result in deformation and loss of fuel integrity, possibly leading to a serious core accident.
In virtually all nuclear programs today, national regulators would not permit a reactor to operate using specially-designed fuel, produced by people with relatively little experience, without first carrying out a comprehensive fuel testing program. Tests would measure the behavior of fuel under irradiation, focusing on such factors as high temperature, chemical interactions, and both thermal and mechanical stresses. The cladding would be tested for irradiation growth, bowing, swelling, and resistance to fission gas pressure.
The fuel assemblies for IR-40 are uniquely-designed long tube bundles which do not fit into any other reactors in Iran and represent a modification of a Russian fuel design. Iran currently has no access to Russian experts to assist it in making and testing the fuel. So far, Iran has conducted limited irradiation tests of fuel assembly components only, not complete assemblies. Because of sanctions Iran can’t test the fuel abroad.
WHAT TO DO?
In theory, Iran could rely on testing individual segments of the fuel in Iran. Given Iran’s current lack of access to foreign expertise, this would not be ideal, but Iran could obtain considerable data which would be useful in determining whether the fuel made in Iran would be safe and perform as calculations would expect.
In May, the IAEA reported to its Board of Governors that Iran disclosed its intention to begin hot fuel testing in Q1 of 2014 but provided no details.
Iran currently has no management system to carry out such tests, little competency and experience, and insufficient infrastructure. The IAEA is aware of these deficits because its personnel have been to the IR-40 project on numerous occasions, including in 2010 when the IAEA carried out a formal review of Iran’s resources for performing experiments and tests which would be relevant for this project. Iran has not disclosed to the IAEA or other outsiders where it plans to carry out testing of the IR-40 fuel.
A decision by the Iran Atomic Energy Organization (AEOI), which is in charge of the IR-40 project, to operate the reactor without prior comprehensive fuel testing would challenge the authority of the Iran Nuclear Regulatory Authority (INRA). Its mission includes “regulatory review and assessment… prior to authorization… to determine whether the operating organization’s submissions demonstrate that the facility complies with the safety objectives, principles, criteria, and regulations approved by INRA.” Presumably that would include preparations for commissioning a reactor of unique design loaded with fuel that was produced by a fabricator without a demonstrated performance track record.
Were Iran to systematically carry out comprehensive quality assurance tests for all the hand-made fuel it is producing for IR-40, detection of any irregularities should delay commissioning of this project further since Iran must first identify and rectify any quality control problems. Should Iran instead assume the risk of commissioning and operating the IR-40 without taking such care, that course of action should prompt objections–both in Iran and elsewhere–that the AEOI is proceeding without heeding advice from the IAEA which is based on international good practices.
What should Iran and the P5+1 do? The best course of action would be to include IR-40 commissioning in the basket of issues subject to a negotiated settlement. The powers don’t want Iran operating a reactor to accumulate weapons-grade plutonium in spent fuel which it could reprocess. Iran needs a research reactor that it can use for a variety of civilian applications and that Iran can be confident will be safe to operate.
As part of a negotiated comprehensive settlement with the P5+1, Iran could get access to foreign expertise to realize its ambitions to have a versatile research reactor. The P5+1 might agree to help Iran replace the IR-40 with a light water reactor better suited to produce the medical isotopes Iran says it wants to produce. Should Iran–like a number of other countries–want instead to have a heavy water reactor to maximize production of neutrons for research (and given Iran’s investment in heavy water production infrastructure Iran may well insist on this), the P5+1 might consent to help Iran finish the IR-40 project–provided that Iran agree that IAEA safeguards would apply in perpetuity on both the IR-40 and its inventory of nuclear material, and that the irradiated fuel will not be reprocessed.
Hibbs is a Berlin-based senior associate in Carnegie’s Nuclear Policy Program.
