Alexander Glaser and Pavel Podvig
The Forschungsreaktor München II (FRM-II) has been using Russian-origin highly enriched uranium (HEU) for many years. It has now become clear that since 2012 Russia has used its role as a supplier for FRM-II to justify production of fresh weapon-grade HEU. This poses a major problem for German policy on HEU purchase and is not consistent with international and German nuclear nonproliferation policy.
The FRM-II is one of the very few reactors that have been designed for the use of highly enriched uranium (HEU) since in the late 1970s when the efforts to eliminate this directly weapon-usable material from the civilian nuclear fuel cycle were launched. The choice of HEU as fuel led the United States to make clear that it would not supply this material for the reactor. While the FRM-II was under construction, the German Federal Government and the reactor operators in Munich therefore began to seek an alternative supply of HEU and, in 1998, the German Government entered into a first HEU supply agreement with Russia. Combined with some legacy material the operators were able to secure in Europe, the FRM-II was able to operate up until 2016-2017 with this original stock of HEU. To extend reactor operations beyond that date, a new agreement was negotiated with Russia to supply the HEU needed for FRM-II fuel fabrication in France.
The German Government and the reactor operators argue that since Russia has large amounts of HEU from the Cold-War era, the Russian uranium supplied for FRM-II come from existing stocks. TUM makes this statement directly on its website:
It is important to state that it comes from military disarmament stocks.
Similarly, the Federal Government in a response to a question submitted by Sylvia Kotting-Uhl stated (see "Antwort der Staatsministerin Dr. Maria Böhmer vom 17. Oktober 2017," No. 14 in "Schriftliche Fragen mit den in der Woche vom 16. Oktober 2017 eingegangenen Antworten der Bundesregierung") that
according to the Russian producer TVEL (Annual Report 2015, p. 78), ... metallic uranium [was produced] from already highly-enriched source material for later use in FRM-II
Neither of these two statements is correct. In fact, Russia has resumed production of HEU in 2012, and FRM-II played a role in that decision.
Existing stocks versus new production of HEU in Russia
Neither TVEL, a subsidiary of Russia's State Atomic Energy Corporation ROSATOM, nor any Russian government body ever stated that the material supplied to the FRM-II reactor under the current agreement is taken from existing HEU stocks or that it is a disarmament material. In fact, the information provided by TVEL makes is clear that the HEU provided to Germany is the new material produced by an enrichment cascade that was opened in 2012 with the specific purpose of resuming production of HEU, including weapon-grade HEU, i.e., material with a uranium-235 content of 90% and higher. FRM-II is the only customer of this production cascade that requires HEU of that enrichment level.
The Electrochemical Plant in Zelenogorsk, a subsidiary of TVEL, reported opening of the HEU production cascade in its 2012 Annual Report. It was described as part of a program to produce fuel for research and fast neutron reactors. According to TVEL's 2015 Annual Report, the Electrochemical Plant then worked on producing "highly enriched raw material to produce metallic uranium for Munich-II reactor." The Federal Government response from 17 October 2017 refers to this statement (included on p. 78 of the English edition of the report), but quotes it incorrectly. The statement does not say that this metallic uranium "was produced from already highly-enriched source material," as the Federal Government response suggests. The "highly-enriched raw material" referred to in the annual report is uranium hexafluoride with highly enriched uranium that was produced from natural uranium or equivalent feed through the enrichment process.
The original Russian text of this annual report is very clear and unambiguous on this point. It states that one of the key events of 2015 was "new production at the Electrochemical Plant of highly-enriched raw material to be used to produce metallic uranium for the Munich-II reactor."
The term that is used in the Russian text--наработка/narabotka--means new production from scratch, which in this context means enrichment of natural uranium to produce HEU. Had the production of HEU involved any other process, a different term and a different description of the process would have been used. It is also important to note that enrichment is the only production process that can be carried out at the Electrochemical Plant. Conversion of uranium hexafluoride produced there to metal is done at a different TVEL facility, the Novosibirsk Chemical Concentrates Plant.
Why is Russia not using existing (excess) HEU stocks for FRM-II?
If Russia still has an enormous stockpile of weapon-grade uranium today, why is it not using existing stocks? There are no official explanations provided by the Russian suppliers. It could be logistically just more straightforward to make new HEU instead of processing existing stocks given that Russia has so much extra enrichment capacity. It is also possible that Russia recognizes that, since the United States is pushing to limit the use of HEU in civilian applications, there is now an opportunity to establish itself as a new international supplier of research reactor fuel. In addition to FRM-II, the new HEU line is currently used to produce material for CEFR in China (64%-enriched) and probably also for Jules Horowitz in France (27%-enriched). Once Russia built the capability to produce this kind of material, it can cover all markets, potentially replacing the United States, which is currently supplying fuel for older HEU-fueled reactors in Europe and elsewhere. FRM-II created an opportunity to build that capability.
Finally, existing HEU stocks may simply not meet the preferred or required isotopic requirements for uranium. As most weapon states, Russia originally optimized fissile material production for weapon purposes by using natural uranium first in plutonium production reactors, separating the irradiated uranium along with the plutonium, and then using this slightly depleted uranium for further enrichment. This strategy effectively doubles the amount of weapons materials that can be produced for a given amount of mined uranium. It also means, however, that most existing HEU stocks not only contain naturally occurring isotopes (U-234, U-235, and U-238), but also unwanted ones only produced in reactors (U-232 and U-236). U.S. uranium suppliers point out that "reprocessed material is usually less suitable due to the minor uranium isotope concentrations and the processing required to remove the impurities." They also note that the use of reprocessed uranium is not acceptable to some of the fuel fabricators and reactor users. To be a successful supplier, Russia should be able to provide "clean" HEU, not contaminated by reactor isotopes.
Whatever Russia's considerations are, it is clear that the opportunity to supply HEU to FRM-II played an important and perhaps critical role in the decision to re-start production.