Corrected below

The White House announced last week that the U.S. inventory of highly enriched uranium (HEU) as of September 2013 has been declassified.

“The newly declassified information shows that, from 1996 to 2013, U.S. HEU inventories decreased from 740.7 metric tons to 585.6 metric tons.  This reflects a reduction of over 20 percent,” according to a March 31 White House fact sheet.

The White House added that “This announcement marks the first time in fifteen years that the United States has declassified and released information of this kind.”

But that assertion is in error.

In 2006, the Department of Energy declassified and released data on US HEU inventories dating from 2004. See Highly Enriched Uranium Inventory: Amounts of Highly Enriched Uranium in the United States, Department of Energy, January 2006.

Moreover, the DOE report from a decade ago shows that almost all of the 20% reduction in HEU inventories cited by the White House last week had already been accomplished by 2004, when the HEU total was 590.5 metric tons. Thereafter, in the period between 2004 and 2013, the total HEU inventory evidently declined by only about 5 additional metric tons (less than 1%) to 585.6 metric tons. [See correction below.]

But the White House added that “further reductions in the inventory are ongoing; the U.S. Department of Energy’s material disposition program has down-blended 7.1 metric tons of HEU since September 30, 2013, and continues to make progress in this area.”

The latest disclosure was made to enhance nuclear transparency so as to encourage reciprocal disclosures by other nuclear weapons states.

“The U.S. commitment to sharing appropriate nuclear security-related information has also been demonstrated by recent actions such as the declassification of information on the U.S. nuclear weapons stockpile and transparency visits by officials from non-nuclear weapons states to Los Alamos and Sandia National Laboratories,” the White House said. “These actions show that countries can increase transparency without revealing sensitive information.”

Correction I mistakenly wrote that the inventory of HEU in 2004 was 590.5 Metric Tons. But that number was the amount of U-235. (I read the 2006 DOE report wrong.) The actual inventory of HEU at the time was 686.6 Metric Tons.

Therefore, between 2004 and 2013 there was a reduction in the U.S. HEU inventory of 101 Metric Tons. Thanks to Prof. Alan Kuperman for pointing out the error.

The United States and other countries with nuclear navies have benefited from having nuclear-powered warships. But do the continued benefits depend on indefinite use of highly enriched uranium (HEU)—which can be made into nuclear weapons—as naval nuclear fuel? With budgetary constraints bearing down on the U.S. Department of Defense, the Naval Nuclear Propulsion Program is finding it difficult to address many competing needs including upgrading aging training facilities, handling spent nuclear fuel, and designing the next generation submarines to replace the Virginia-class attack submarines.

FAS convened an independent, nonpartisan task force of experts from the national security, nuclear engineering, nonproliferation and nuclear security fields to examine effective ways to monitor and safeguard HEU and LEU in the naval sector, and consider alternatives to HEU for naval propulsion so as to improve nuclear security and nonproliferation.

The results of the year-long task force study are compiled in the report, Naval Nuclear Propulsion: Assessing Benefits and Risks. The task force concluded that the U.S. Navy has strong incentives to maintain the continuing use of highly enriched uranium and would be reluctant, or even opposed, to shift to use of low enriched uranium unless the naval nuclear enterprise is fully funded and the Naval Nuclear Propulsion Program has adequate financial resources to try to develop a life-of-ship reactor fueled with LEU that would meet the Navy’s performance requirements. The task force endorses having the Obama administration and Congress allocate adequate funding for R&D on advanced LEU fuels no later than 2017 in time for development of the next generation nuclear attack submarine. “The United States should demonstrate leadership in working urgently to reduce the use in naval fuels of highly enriched uranium–that can power nuclear weapons–while addressing the national security needs of the nuclear navy to ensure that the navy can meet its performance requirements with lifetime reactors fueled with low enriched uranium,” said Dr. Charles D. Ferguson, Chair of the Independent Task Force and President of FAS.

Four companion papers written by task force members are also available:

• Investigation into the Unintended Consequences of Converting the U.S. Nuclear Naval Fleet from Highly Enriched Uranium (HEU) to Low Enriched Uranium (LEU) by Dr. Alireza Haghighat, Professor, Virginia Tech Transport Theory Group (VT³G), Nuclear Science and Engineering Laboratory (NSEL) Nuclear Engineering Program, Jack Bell, Graduate Research Assistant and Nathan Roskoff, Graduate Research Assistant.
• Phasing Out Highly Enriched Uranium Fuel in Naval Propulsion: Why It’s Necessary, and How to Achieve It by Dr. Alan J. Kuperman, Coordinator, Nuclear Proliferation Prevention Project and Associate Professor , LBJ School of Public Affairs, University of Texas at Austin.
• The UK Naval Nuclear Propulsion Programme and Highly Enriched Uranium by Dr. Nick Ritchie, University of York, UK.
• A Novel Framework for Safeguarding Naval Nuclear Material by Naomi Egel, Dr. Bethany L. Goldblum, & Erika Suzuki, University of California, Berkeley.

Naval Nuclear Propulsion: Assessing Benefits and Risks can be read and downloaded here (PDF).

The task force members thank the John D. and Catherine T. MacArthur Foundation for its generous support of this project.