Two presentations on the challenges posed by research reactors that cannot be converted were given by Panel 2.2 speakers: Jeffrey Chamberlin (U. S. Department of Energy, National Nuclear Security Administration) provided a U. S. viewpoint (Chamberlin, 2011), and G. Pshakin (Institute for Physics and Power Engineering in Obninsk) provided a Russian view­point (Zrodnikov et al., 2011).

U. S. Viewpoint on Challenges

Jeffrey Chamberlin

GTRI is the key program within the U. S. government for implementing the U. S. policy to minimize the civilian use of HEU. GTRI’s mission is to reduce and protect vulnerable nuclear and radiological materials located at civilian sites worldwide. Its specific goals are to: (1) convert research reactors and isotope production facilities from HEU to LEU; (2) remove and dispose of excess nuclear and radiological materials; and (3) protect high-priority nuclear and radiological materials from theft and sabotage.

GTRI’s Reactor Conversion Program is focused on converting civilian research reactors worldwide to operate on LEU fuel. Its goal is to convert or verify the shutdown of 200 civilian research reactors and HEU facilities by 2020.[47] However, GTRI does not specifically encourage the shutdown of

research reactors; such decisions are made by facility operators. A research reactor does not have to be considered to be vulnerable to be a candidate for conversion. GTRI is focused on converting civilian reactors and HEU facili­ties that use HEU fuel because it provides for permanent threat reduction.

Since the inception of GTRI in 2004, 23 HEU-fueled research reactors have been converted as part of the program, including 7 research reactors in the United States and 16 research reactors in other countries.[48] The most recent conversions were the Kyoto University Research Reactor in Japan (March 2010) and the Rez Reactor in the Czech Republic (April 2011).

As noted in Chapter 1, nearly all U. S. HEU-fueled reactors that can convert with existing LEU fuels have successfully been converted (see also Footnote 3 in this chapter). As noted in previous presentations, there are six HEU-fueled U. S. research reactors (ATR and its critical assembly, HFIR, MITR, MURR, and NBSR) that cannot be converted until a new LEU fuel is developed. Additionally, in December 2010, DOE and Rosatom signed an Implementing Agreement to perform feasibility studies for the possible conversion of six HEU-fueled research reactors in the Russian Federation.

The reduction of HEU use in civilian applications is supported at the highest levels in the U. S. and Russian governments. In a joint statement issued on July 6, 2009, Russian Federation President Dmitry Medvedev and U. S. President Barack Obama issued a joint statement expressing their strong support for HEU minimization:

We declare an intent to broaden and deepen long-term cooperation to further increase the level of security of nuclear facilities around the world, including through minimization of the use of highly enriched uranium in civilian applications and through consolidation and conversion of nuclear materials.

This call for minimization was echoed in UN Security Council Joint Reso­lution 1887, which was issued in September 2009, and in the April 2010 Nuclear Security Summit.

GTRI works in cooperation with reactor owners/operators to convert reactors to LEU fuel. This cooperation involves:

• Performance of feasibility studies to determine if reactors can be converted and still achieve their missions without major changes in reactor structures or equipment.

• Ensuring that required fuel assembly criteria for LEU conversion are satisfied; LEU fuel provides a similar service lifetime as the HEU fuel; there is no significant penalty in reactor performance; and safety criteria are satisfied.

• Development of a schedule for conversion based on operational requirements, capabilities, and regulatory processes.

• Demonstrating that conversion and subsequent reactor operations can be accomplished safely.

• Determining, to the extent possible, that overall costs associated with conversion do not significantly increase the annual operating expen­ditures for reactor owners/operators.

• Obtaining/verifying that agreements and authorities are in place to proceed with conversion.

GTRI’s starting assumption for reactor conversions is that “anything is possible.” The experience gained from previous conversions demonstrates that there are many ways to overcome technical barriers. Indeed, many of the recent successful conversions of U. S. reactors were not thought to be possible 20-30 years ago.

Although GTRI policy is to take all reasonable steps to convert facilities and reduce the use of HEU, there may be some facilities that are not feasible to convert. For example, a feasibility study for a particular reactor might indicate that conversion is not feasible because LEU fuel assembly criteria are not satisfied and a unique fuel development effort is not technically or economically feasible. This might be the case for fast reactors, fast critical assemblies, or HEU reactors with very small core volumes.

In such cases, there are four options for addressing HEU minimization at such facilities: [49]

GTRI considers each of these options to be “last resort” and does not en­dorse them as a matter of policy. These options must be considered on a case-by-case basis by the facility and the host government.