

By Allyson Versprille
The Navy should consider phasing out its use of highly enriched uranium as fuel for nuclear-powered vessels in favor of a low enriched alternative, which is not as easily converted into nuclear weapons, a new study recommends.
The Federation of American Scientists study said there is enough highly enriched uranium stockpiled for naval purposes to last at least 50 years. When that finite amount is depleted, the U.S. will have to spend money to produce more. This would undercut the United States' goal of ending the worldwide production of highly enriched uranium, members of the task force that complied the report said at a press briefing.
The report released March 19 — "Naval Nuclear Propulsion: Assessing Benefits and Risks" — said creating a new HEU stockpile would be an expensive endeavor that could cost hundreds of millions of dollars. 
"There are potentially large savings once you have switched over entirely from HEU to LEU," or low enriched uranium said Alan J. Kuperman, an associate professor at the LBJ School of Public Affairs at the University of Texas at Austin and coordinator of the Nuclear Proliferation Prevention Project. "You would not have to pay for the extremely high security costs that are currently applied to facilities that produce HEU, fabricate HEU fuel [and] store HEU fuel." 
Additionally, replacing highly enriched uranium would save millions of dollars per year based on estimates he has seen regarding the increase in security costs at similar facilities following 9/11. 
The task force recommended that the Obama administration allocate $2 billion for research and development of advanced low enrichment uranium fuels no later than fiscal year 2017 because it could take 10 to 15 years to fully assess the benefits and risks. That would synchronize with the construction of the first Virginia-class submarine replacement, scheduled to begin in 2032. 
It also recommended that the National Nuclear Security Administration, which is responsible for supplying the Navy with fuel and reactors, come up with a cost-benefit analysis for converting from HEU to LEU. When asked about their own estimates, the authors said it wasn't yet clear that total savings would outweigh costs.
Over three-quarters of the total global amount of highly enriched uranium that is not used for nuclear weapons is used to fuel naval propulsion reactors, said Kuperman. Less than 1 percent of that would be enough to make a nuclear weapon.
The other advantage, according to the study, is that switching from highly enriched to low enriched uranium would eliminate the need for the NNSA to build a new facility that enhances uranium to levels above 90 percent — the amount currently used in U.S. naval reactors.
There are some drawbacks to using low enriched uranium according to the report. Low enriched uranium-reactors produce plutonium, which increases radiation levels and the costs associated with waste disposal. Low-grade uranium also requires larger reactors, expanding the volume of the ship and potentially restricting the Navy's ability to carry out missions, according to the report.
It is unlikely that the Navy will agree to replace its current reactors unless adequate resources are provided and the design meets the service's performance requirements, said the study.
Replacing highly enriched uranium has political and nonproliferation implications as well, said Kuperman. If the U.S. continues to use nuclear-grade uranium, certain non-nuclear states such as Iran could use a naval propulsion program as a back door to obtain nuclear weapons. 
"Under the nuclear non-proliferation treaty, if a country says that it wants to have a naval nuclear propulsion program, it can produce HEU and then remove it from safeguards, remove it from international inspection, for the entire time that it ostensibly is in the naval sector," said Kuperman. That period of secrecy could last 20 to 50 years. Iran has said explicitly that it wants to produce HEU for its navy, he added.
Photo: The USS California, a Virginia-class attack submarine, underway during sea trials (Navy)

Topics: Shipbuilding, Submarines

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