his report is a summary of a joint symposium held on June 8-10, 2011, by the National Research Council (NRC) of the U. S. National Acad­emies and the Russian Academy of Sciences (RAS) on progress, chal­lenges, and opportunities for converting United States and Russian Federation (R. F.) research reactors1 from highly enriched uranium (HEU) to low enriched uranium (LEU) fuel.2,3 This symposium was organized in response to a 2010 request from the U. S. Department of Energy (DOE), National Nuclear Secu­rity Administration’s (NNSA) Office of Defense Nuclear Nonproliferation.

NNSA requested that a symposium be organized and a subsequent summary document be produced to address:

• Recent progress on conversion of research reactors, with a focus on U. S.- and R. F.-origin[3] [4] [5] [6] reactors;

• Lessons learned for overcoming conversion challenges, increasing the effectiveness of research reactor use, and enabling new reactor missions;

• Future research reactor conversion plans, challenges, and opportu­nities; and

• Actions that could be taken by U. S. and Russian organizations to promote conversion.

The statement of task for the project is included as Appendix C.

The preparation of the symposium agenda and the production of this summary report were carried out by a committee of U. S. experts appointed by the National Academies and a committee of Russian experts appointed by the Russian Academy of Sciences. Biographical sketches of the commit­tee members are provided in Appendix B. These organizing committees met jointly three times over the course of the project: First, in November 2010 to plan the symposium; second, in June 2011 to hold the symposium; and third, in September 2011 to finalize the symposium report. The agenda for the symposium is provided in Appendix A, along with a list of briefings presented at the November 2010 meeting.

NNSA and the NRC agreed that the symposium would not produce consensus findings or conclusions but would instead be used to encourage discussion among U. S. and Russian participants. For this reason, this sym­posium summary does not contain findings, conclusions, or recommenda­tions and does not represent a consensus of symposium participants.[7] This report represents a summary record of the briefings and discussions that occurred during the symposium. Although the U. S. and Russian organiz­ing committees are responsible for the content of this report, any views contained in the report are not necessarily those of these committees, the National Academies, or the Russian Academy of Sciences.

The remainder of the chapter provides background information on pro­liferation risks associated with civilian use of HEU; basic operating principles and terminology associated with research reactors; and potential impacts of reducing HEU use in research reactors. Much of the content of this discus­sion is drawn from symposium briefings (Adelfang, 2011; Arkhangelsky, 2011; D’Agostino, 2011; Dragunov, 2011; Matos, 2011; Roglans, 2011a). Additionally, some basic concepts and definitions were added for the benefit of non-expert readers.