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Downblending Highly Enriched Uranium Just Makes Sense

USS Michigan Submarine

The USS Michigan, a nuclear-powered guided missile submarine.

The Department of Energy currently holds the key to eliminating one of the biggest threats to homeland security—highly enriched uranium (HEU) stored here in the United States in massive quantities. The U.S. Navy has long required HEU to fuel the reactors in some of its fleet’s vessels, but new designs could mean the end of the Navy’s reliance on this dangerous material. And reducing the HEU stockpile would not only significantly increase our security, but also allow dramatic cost savings through the consolidation of the nuclear weapons complex.

Why is our homeland security currently at risk? With just 100 pounds of HEU (an amount that would fit in a shoebox) a potential terrorist could create an improvised nuclear device in minutes right here on U.S. soil. This device could produce the same kind of devastating effect as the bomb dropped on Hiroshima.

The U.S. stockpile of HEU, estimated to be approximately 300-400 metric tons—the equivalent of approximately nine hundred thousand pounds—is stored in one building at the Y-12 nuclear weapons production facility in eastern Tennessee.

Unfortunately, the Y-12 complex has not proven its ability to keep the HEU stockpile safe. In 2012 an 82-year-old nun and two other protestors broke into the complex and protested outside the building storing the United States’ entire stockpile of HEU for over 20 minutes before security found them. If the intruders had been intent on sabotage, this security failure would have ended in disaster.

Fortunately, there is a proven method for rendering HEU unusable by terrorists. By mixing HEU with low enriched uranium (LEU), a process called downblending, the material is rendered useless as a weapon and so would no longer pose a threat.

There’s another plus: It can still be used as fuel for commercial and military nuclear reactors.

POGO has previously encouraged the DOE to increase the rate of downblending, but one major impediment has stood in the way: the U.S. Navy’s reliance on HEU for the propulsion systems in attack submarines, ballistic missile submarines, and aircraft carriers. At least 100 metric tons of the U.S. stockpile of HEU has been set aside for the Navy’s use (although the exact amount is classified). The Department of Energy, which manages the Y-12 facility, has argued that the Navy may require more HEU in the future and has used that as an excuse to slow its pace of downblending to a glacial crawl, despite promises to Congress of a swifter schedule.

But new analysis confirms that in fact, naval reactors can run on LEU, and now is the time for the Navy to make the switch. Both France and China are using LEU to propel their submarines; the U.S., Britain, Russia, and India still use HEU naval reactors. Nuclear non-proliferation experts Alan Kuperman and Frank Von Hippel have suggested that if the U.S. would convert to LEU, Britain would follow suit, as they depend on U.S. reactor designs. Russia has already designed an LEU reactor for its next nuclear-powered ship.

The Department of Energy has twice studied the feasibility of using LEU in naval reactors. In a 1995 report, the Department concluded that using LEU was too expensive and dismissed the notion without acknowledging significant security or non-proliferation advantages. But in 2012, the House Armed Services Committee requested a second review. The report, released in 2014, arrives at a much more favorable conclusion. The DOE determined that LEU fuel could be used “with less impact on reactor lifetime, size, and ship costs.” But DOE also stated that development of an LEU reactor could take 10-15 years and cost around $2 billion.

The Federation of American Scientists is releasing a study they commissioned that confirms that now is the time for the Obama Administration and Congress to allocate funding for researching and developing LEU naval reactors.

The Navy will soon begin replacing its aging fleet of ballistic missile submarines with the Ohio-Class Replacement Program (SSBN-X), one of the most expensive Pentagon programs in history with an estimated total cost of $139 billion for 12 subs. Which is why it is absolutely critical for the Navy to begin work on LEU conversion now.

Construction will begin on the first SSBN-X submarine in FY 2021 and is expected to cost about $14.5 billion. Once the testing phase is complete and procurement begins en-bloc, it will become much more difficult to alter the fundamental features of the program. Adding $2 billion now to make LEU fueled reactors at this juncture is a relative drop in the bucket for a common-sense improvement that will ultimately save money and increase security.

If the Navy makes the change from HEU to LEU, the Energy Department can focus on downblending the remaining HEU stockpile, making the country significantly safer and potentially even turning a profit while doing so. POGO has found that the sale of LEU to private nuclear power companies could generate millions (if not billions, depending on the market) for the U.S. Treasury.

The vulnerability of HEU, and the U.S. commitment not to build any new nuclear weapons, makes now an excellent time to consolidate the entire nuclear weapons complex. There are several opportunities for consolidation that would make the country far safer and more secure, beginning with the Y-12 complex.

But first the Energy Department and the Navy must work together to eliminate the need for this dangerous material once and for all. LEU is the future and it makes sense to make the change now.

Image from the U.S. Pacific Fleet.

By: Peter Stockton
Sr. Investigator, POGO

Peter Stockton, Sr. Investigator At the time of publication Peter Stockton was a senior investigator for the Project On Government Oversight. Peter's investigations include security and safety issues at the U.S. nuclear weapons complex and nuclear power plants.

By: Lydia Dennett
Investigator, POGO

lydia dennett Lydia Dennett is an investigator for the Project On Government Oversight. Lydia works on safety and security of nuclear weapons and power facilities, foreign lobbying and influence, and works with Department of Veterans Affairs whistleblowers.

Topics: National Security

Related Content: Nuclear Power, Nuclear Weapons Complex Oversight, Submarines, Y-12 /Oak Ridge National Lab, Nuclear Security, Waste

Authors: Lydia Dennett, Peter Stockton

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