Could low-enriched uranium be used in naval reactors? Don’t ask the Navy

Naval propulsion reactors account for the largest non-weapons use of highly enriched uranium (HEU) in the world. The largest stores of naval propulsion fuel are in the United States, the Russian Federation, and the United Kingdom. Using low-enriched uranium (LEU) for naval propulsion reactors would allow a significant reduction in non-weapons stocks of HEU and would have significant positive impacts on global nonproliferation and counterterrorism efforts. The US Navy holds the largest declared stock of HEU for propulsion purposes, and HEU-fueled reactors power all US submarines and aircraft carriers. In 1995 and again in 2014, the Navy reported to Congress on the potential for using reactors fueled with LEU instead of HEU. The Navy’s reports to Congress in both years are lacking in substantive analysis and transparency and arguably do not provide the straightforward assessment that Congress requested. The 1995 report provided Congress with a very negative assessment of the use of LEU and offered little hope that the Navy would consider LEU-fueled reactors. In 2013, Congress asked the Navy to provide an update to its 1995 report; in response, the Navy produced only a very brief analysis in 2014. Because the congressional mandate was for an update of the 1995 report, both reports need to be examined to determine the Navy’s current position on LEU use. Sadly, that position appears to have changed little over almost 20 years, despite advances in LEU use by other navies. However, the 2014 report does indicate that the Navy might be willing to support further studies of LEU use. While an optimist might see that as a change to the Navy’s adamant desire to continue to use HEU in naval reactors, a pessimist would view the Navy’s statements as a reflection of the desire to disingenuously use LEU studies to maintain the health of the service’s research and development programs. Congress should commission qualified experts to conduct an impartial review, at classified and unclassified levels, of naval LEU use.