SRR-1

This page is part of the Facilities Collection.

The SRR-1 is a 30KW miniature neutron source reactor (MNSR), supplied by China and modeled after the Canadian Slowpoke reactor. ^{1 2 3}[3] The MNSR is a pool-type reactor that uses highly enriched uranium (HEU) as fuel (90 percent U-235), light water as a coolant and moderator, and a beryllium reflector. ⁴[4] China provided Syria with an initial fuel supply of 980.4 grams, intended to ensure the reactor’s operation for 2,000 hours per year for ten years. ⁵[5] The SRR-1 is the smallest research reactor on the world market, and is not capable of producing sufficient fissile material for nuclear weapons production. ⁶[6] According to the IAEA, research reactors smaller than 25MW thermal cannot produce a significant quantity of plutonium (8 kg). ⁷[7]

In November 1991, China agreed to supply Syria with the MNSR. ⁸[8] Despite the reactor’s small size, the deal raised proliferation concerns in Israel and the United States. ⁹[9] The sale, however, was not made directly between China and Syria, but rather through the IAEA. The IAEA initially did not agree to the deal, but approved the sale in March 1992 after Syria concluded a formal safeguards agreement with the Agency. ¹⁰[10] The reactor subsequently went critical on 4 March 1996 and became fully operational in 1998. ¹¹[11] The reactor’s primary uses include neutron activation analysis, small-scale radioisotope production, education, and training. ¹²[12] The facility has a staff of 13 people and a limited operation schedule of only two hours per day, restricting further training opportunities. ¹³[13]

Of proliferation concern, the MNSR operates on weapons-grade highly enriched uranium. However, the initial fuel load containing 980.4 grams of 90% U-235 is not considered a “Significant Quantity” of weapons-grade material. Under IAEA guidelines, a first-generation nuclear weapon requires approximately 25kg of 90% enriched uranium metal. ¹⁴[14] Additionally, the production of plutonium in the SRR-1 is minimal because of the limited quantity of U-238-the uranium isotope capable of breeding plutonium-in the fuel. The IAEA considers 8kg of plutonium sufficient for a first-generation nuclear weapon, but it would take approximately 30.6 kg of 93% U-235 enriched uranium to create just 0.08 kg of plutonium. ¹⁵[15] Furthermore, the agreement between the IAEA, Syria, and China on the MNSR transfer stipulates that the SRR-1 would be subject to IAEA safeguards, and must not be used for military purposes. ¹⁶[16]

On 5 June 2009, the IAEA reported that inspections in 2008 had revealed the presence of undeclared anthropogenic uranium particles from a hot cell facility at the MNSR. ¹⁷[17] The presence of the undeclared particles in the hot cell facility could imply that Syria was experimenting with techniques to isolate plutonium from spent reactor fuel. In July 2009 the IAEA performed a physical inventory verification at the MNSR, and took environmental samples that also showed traces of anthropogenic natural uranium. ¹⁸[18] In its defense, Syria stated that the natural uranium particles had resulted from the accumulation of sample and reference materials used in neutron activation analysis. ¹⁹[19] However, the agency did not accept this explanation because it did not find matching anthropogenic uranium particles on the equipment that Syria had identified. ²⁰[20]

In a subsequent meeting with the IAEA, Syria identified other possible sources, including yellowcake produced at the phosphoric acid purification plant in Homs, and small quantities of imported, but previously undeclared, depleted uranyl nitrate. ²¹[21] The IAEA conducted another inspection at the MNSR on 31 March 2010, in which Syria provided more details on these undeclared activities, as well as samples and documentation. ²²[22] According to AECS officials, in 2004 the MNSR had converted tens of grams of yellowcake from Homs into uranyl nitrate, and then irradiated this domestically produced uranyl nitrate alongside the imported depleted uranyl nitrate for comparison. ²³[23] Syria amended its inventory reports to the IAEA based on this new information.

However, some inconsistencies remained concerning the amounts and types of nuclear materials used at the SRR-1 based on the results of the March 2010 physical inventory verification and open source publications. ²⁴[24] Following a plan of action agreed to in September 2010, the IAEA visited the Homs facility on 1 April and conducted another visit to the SRR-1 on 19 April 2011. ²⁵[25] In its report on 24 May 2011, the Agency finally “concluded that Syria’s statements concerning the origin of the anthropogenic uranium particles found at the MNSR are not inconsistent with the Agency’s findings” and reverted to the “routine implementation of safeguards” at the SRR-1. ²⁶[26]