Replacing Highly Enriched Uranium in Naval Reactors

George M. Moore

Scientist-in-Residence, Adjunct Professor, The James Martin Center for Nonproliferation Studies

Cervando A. Banuelos
Thomas T. Gray

Citing a major gap in the global effort to minimize and eliminate stockpiles of highly enriched uranium (HEU), a new paper funded by the Nuclear Threat Initiative (NTI) notes that the use of HEU in naval reactors continues in the United States, the United Kingdom, India and Russia despite successful transitions to low-enriched uranium (LEU) for similar purposes in other countries. The authors call on Congress to take steps that could lead to HEU conversion and on the Navy to be more transparent about its own investigations into LEU use.

Naval reactor conversion has long been controversial—and converting to LEU is a complex undertaking. In many cases, it requires the development of new reactors and new fuels for future generations of naval vessels. In addition, the use of HEU for naval propulsion has long been perceived as having significant advantages.

However, other countries have successfully made, or plan to make, the transition to LEU. The French Navy converted in 2008, and China is believed to use LEU in its submarines. Russia also has designed a LEU-fueled reactor for its future nuclear-powered icebreakers.

In previous reports to Congress on the subject, the Navy concluded that LEU use offered no advantages and would have adverse economic and environmental consequences. The Navy’s reports, however, lack supporting data according to the new paper. 

In a set of recommendations intended to spur further examination of the issue, the paper calls on Congress to:

  • Request a new report on conversion from the Navy that includes the cost of converting to LEU
  • Request briefings on supporting details of the Navy’s previous reports (1995 and 2014) on the issue
  • Support a study by non-Navy experts on the issues around LEU conversion
  • Consider how information could be exchanged with the French on their experiences switching to LEU
  • Ask the Navy for an expanded assessment of the tactical implications of a switch to LEU
  • Evaluate future funding needs, particularly if LEU design and use were undertaken.

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