Two communities must work together to convert a research reactor, but they often have conflicting goals: researchers and operators of the facilities and those supporting the nonproliferation conversion programs. Two of the recommendations provided, if implemented, could offer a way for these two communities to advance each of their respective goals. Developing a 50-year strategy for neutron research in the United States (Recommendation 1) is connected to the committee-proposed stepwise conversion (Recommendation 4) of the U.S. high performance research reactors (USHPRRs). Negotiation with reactor operators on stepwise conversion—when there is also a clear long-term strategy in place for continued neutron research capabilities in the United States—would allow for wider consideration of conversion options including discussions about shutting down aging reactors or reducing reactor performance while ensuring the continued ability to meet U.S. mission needs with new neutron facilities that utilize low enriched uranium (LEU).
The importance of eliminating highly enriched uranium (HEU) from civilian research reactors is clear. Throughout its work the committee was impressed by the progress made since 1978 in the reduction of HEU in civilian research reactors around the world. More than 90 reactors have been verified as converted or shut down since 1978, with more than 26 of those conversions or shutdowns occurring since 2009. The 90-reactor estimate is incomplete because reactor shutdowns were not counted by the earliest conversion program, the Reduced Enrichment for Research and Test Reactors (RERTR) Program, which led the research reactor conversion effort from
1978 to 2004. This is an accomplishment in which the Department of Energy/National Nuclear Security Administration should take satisfaction.
Seventy-four civilian research reactors continue to use HEU fuel, have HEU on site, or, in the case of one new reactor, have plans to start using HEU in the coming years. Elimination of HEU from these facilities will be significantly more challenging than what has already been accomplished. Success will depend on several developments:
- Qualification of manufacturable, affordable high-density LEU fuels that can be used in high performance research reactors (HPRRs) without significant loss of performance, followed by conversion of these research reactors to LEU fuel.
- Positive engagement with the countries that still have HEU-fueled civilian research reactors, possibly with the additional engagement of international bodies, to incentivize conversion to LEU fuel. Engagement with Russia is particularly important because it operates greater than 40 percent of the remaining HEU-fueled civilian research reactors.
- Demonstration of continued U.S. commitment to the goal of HEU minimization, and ultimately elimination, by taking intermediate steps to limit the use of weapon-usable HEU fuel in U.S.-based reactors en route to full conversion to LEU.
The challenges associated with achieving conversion goals have resulted in dramatically expanded time lines for LEU conversions and HEU elimination relative to what was projected 5 years ago. A number of issues have come to light since the previous Academies report on conversion and medical isotope production (NRC, 2009). In particular, the USHPPRs will be 65 years old on average at the time they are scheduled to be converted; therefore, one can no longer consider LEU conversion without also thinking about plans for a new generation of research reactors. At the same time, no government-wide strategy exists for how the United States will meet its needs for research reactors later in this century. Research reactors are vital components of the U.S. and worldwide science and technology infrastructure. Other countries, especially in Europe, are planning, constructing, and commissioning new reactors to replace aging research reactors and even provide new capabilities, but there is no such activity in the United States. A long-term government-wide strategy for neutron sources, including research reactors, must be developed.
The M3 Office of Conversion needs stable and effective management and long-term political support to be successful. This holds true even after conversion—fuel costs will likely increase, and it will probably require a
national commitment to maintain reactor operations. To be successful, the Office of Conversion needs to
- Take a systems-level view of the program, including research, fuel qualification and manufacturing, and reactor conversion and back-end processes. This view needs to include rigorous risk management.
- Provide regular, truly independent technical reviews of all technical aspects of the program.
- Explicitly recognize those aspects of the program that are within the control of the M3 Office of Conversion and those that are not, such as nontechnical obstacles identified in Chapter 5, and develop plans accordingly.
The committee saw indications that the Office of Conversion is recognizing and acting on these needs, which is laudable. The committee hopes that this report will help the M3 Office of Conversion be successful in its most important mission.
