America Shouldn’t Restart Production of Weapons-Grade Uranium

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This has been a terrible year for arms control. The United States withdrew from the Intermediate-Range Nuclear Forces (INF) Treaty, announced a withdrawal from the Open Skies Treaty, threatened not to renew the New START treaty limiting long-range nuclear weapons, and reportedly explored the resumption of underground nuclear weapons testing that would violate the Comprehensive Test Ban Treaty (which the United States has signed but not ratified).

Now, to make matters worse, the Department of Energy has announced a plan to restart production of nuclear weapons-grade, highly enriched uranium (HEU) for the first time since 1992. Under a new “strategy to assure U.S. National Security,” the department declared in April a “well-defined future defense need” to produce “highly-enriched uranium needed to fuel Navy nuclear reactors in the 2050s,” when the existing stockpile supposedly will run out.



So, while the U.S. government is demanding that Iran and other countries not initiate production of weapons-grade uranium, we would do exactly that ourselves. It is hard to imagine a policy more damaging to U.S. national-security efforts to stop the spread of nuclear weapons.

Fortunately, this policy disaster could be avoided through technological innovation. As Congress has urged for five years, the U.S. Navy should explore designing its next generation of aircraft carriers and submarines with reactors that run on low-enriched uranium (LEU), which is unsuitable for nuclear weapons, instead of the Navy’s traditional weapons-grade fuel. Not only would this avoid the contentious restart of HEU production, it could prevent other countries like Iran from claiming to require weapons-grade uranium for their navies, and it would reduce terrorism risks at Tennessee’s civilian facility that makes Navy fuel. Such safer LEU fuel is already utilized successfully by the navies of France and China.

Powering the Nuclear Navy on Low-Enriched Uranium

The Navy itself has said that LEU fuel might be feasible, but now opponents within the service have dug in against it, on grounds essentially that, “if it ain’t broke, don’t fix it.” These nuclear Navy officials believe nonproliferation is someone else’s job, so they see no reason to go through the trouble, and possible expense, of changing their fuel.

However, that represents a sharp reversal for the Navy under the administration of President Donald Trump. Previously, in a 2014 report to Congress, the U.S. Office of Naval Reactors had said that an “advanced” reactor system could “allow using LEU fuel” to power Navy vessels. Its follow-up report two years later detailed that, “LEU fuel in an aircraft carrier reactor might meet ship performance requirements in the available size envelope,” and “has the potential to satisfy the energy requirements of an aircraft carrier without affecting the number of refuelings.” If so, existing ships could switch to the safer fuel without even altering deployment schedules.

Submarines face additional limits, including on space and noise, so the 2016 report had said these vessels “would not be addressed until experience could be gained during the development of an LEU-fueled aircraft carrier reactor.” Thanks to Congress, the development of Navy LEU fuel is now underway, so the Navy could start redesigning its next generation of subs in one of two ways to accommodate LEU fuel’s lower energy density. Increasing the reactor size would enable the LEU fuel to last for the life of the ship, as HEU fuel does in our latest subs. Alternatively, a refueling hatch could be added as in France’s nuclear subs, which enables them to be refueled in weeks or less.

Under this plan, the United States could avoid ever restarting production of weapons-grade uranium. The 2016 Navy report observed that, “Development of an advanced naval fuel that uses LEU would demonstrate United States leadership toward reducing HEU and achieving nuclear non-proliferation goals.”

If fuel development went well, the Navy could start using newly enriched LEU in fuel for aircraft carriers in the 2030s, thereby freeing up the HEU stockpile to fuel submarines till the 2070s. Fortunately, most submarines should be able to switch to LEU fuel well before then. The Navy is still only drawing up plans for its next-generation attack submarine, which is slated to deploy in the 2040s, so its design could be tweaked to accommodate an LEU-fueled reactor. The final class of ship to convert to LEU fuel would be our handful of ballistic missile submarines, when a new generation is designed and then deployed in the 2070s.

The total cost to develop Navy LEU fuel over 15 years is $1 billion, according to the 2016 report. Additional expenses to deploy the fuel are uncertain and would depend on the outcome of the research and development. Potential savings in security costs from avoiding tons of weapons-grade uranium at a civilian facility are also uncertain. However, any net costs would be marginal in comparison to the price tag of constructing the Navy nuclear fleet, which is around $300 billion, excluding operating expenses.

Congress has backed this plan for five years, appropriating $40 million to start developing Navy LEU fuel. However, the Trump administration has fiercely resisted, apparently believing that nonproliferation is not worth the effort. In 2018, overturning President Barack Obama’s decision of two years earlier, the energy and Navy secretaries wrote to Congress that, “we have jointly determined that the United States should not pursue Research and Development (R&D) of an advanced naval nuclear fuel system based on Low-Enriched Uranium (LEU).” The administration also refused for several years to initiate the Congressionally funded research, failing to produce its first study until this February and even then claiming that the research and development was not for aircraft carriers and submarines but for obscure purposes like desalination plants.

Follow the Budget

This year’s defense and spending bills, currently being crafted on Capitol Hill, may prove decisive. If Congress increases funding for the Navy LEU program, the administration will have little choice but to accelerate development of that fuel, potentially averting any future need to produce HEU. But if the Republican-controlled Senate Armed Services Committee gets its way by killing the program, the United States inevitably will need to restart production of nuclear weapons-grade uranium, undermining nonproliferation and thereby increasing the risk of nuclear war.



Alan J. Kuperman is Associate Professor, and Coordinator of the Nuclear Proliferation Prevention Project (, at the LBJ School of Public Affairs, University of Texas at Austin.

Image: U.S. Navy (Photo by Mass Communication Specialist 1st Class Ashley Berumen)