The dangers, according to a technical assessment prepared by the Defense Nuclear Facilities Safety Board, include leaking, corroded and sometimes cracked containers, and the ongoing release of gases that indicate the radioactive material continues to degrade.
The report – dated Jan. 3 but made public this week – focuses on the site’s L-Area, where about 15,000 spent fuel assemblies are kept in underwater storage basins. The board’s concern was directed at the older material that accounts for about 10 percent of the L-Area’s inventory.
“Nearly all the inner cans containing metal fuel are approximately 50 years old, and DOE is considering the possibility of extended storage of these cans for an additional 50 years,” inspectors wrote in an analysis sent by board chairman Peter Winokur to David Huizenga, the Department of Energy’s senior adviser for environmental management.
Although spent nuclear fuel from commercial power plants – such as Plant Vogtle – is stored at those plants, a different kind of spent nuclear fuel has been gathered and stockpiled at Savannah River Site for many decades.
The submerged containers include the widely varied fuels from Cold War activities and from “research reactors” in the U.S. and dozens of foreign countries, whose programs once required highly enriched uranium fuel that today’s terrorists might want.
Two years ago, the safety board singled out one batch of corroded fuel – from the Sodium Reactor Experiment launched in California in the 1950s – as being particularly dangerous and most in need of attention.
The reactor, which made history in 1957 by powering homes in nearby Moorpark, was damaged during a coolant blockage two years later and was shut down for good in 1964.
As a result of the board’s concerns, work began in September to process the 36 cans of sodium reactor fuel at nearby H Canyon – the nation’s sole remaining facility where certain types of plutonium, highly enriched uranium and aluminum-clad spent fuels can be processed for disposal.
Other than the sodium reactor fuel, the board wrote, the rest of the spent fuel inventory in L Basin “lacks a disposition pathway” and needs attention.
“The limited inspection data indicate that many of the cans have significant corrosion and that some have failed leading to fuel degradation,” the report said, noting that the release of gas from several of the cans indicates the metal fuel is continuing to degrade.
“As the fuel degrades it becomes more difficult to handle, repackage, and/or process in the future, the report said.
In addition to the corroded fuels mentioned in the board report, L-Area also stores spent fuels – all containing weapons-grade material – recovered from other countries under the National Nuclear Security Administration’s Global Threat Reduction Initiative.
So far, material has been moved to SRS from Turkey, Israel, Japan, Indonesia, Taiwan, Australia, Canada, Germany, Romania, Portugal, Sweden, Brazil, Argentina, South Korea, the Netherlands, Greece, Austria, Denmark, Chile, Italy, United Kingdom, Venezuela, Thailand, Spain, Uruguay, Colombia and the Philippines.
According to a DOE fact sheet, the L-Area basin has concrete walls three feet thick and holds 3.5 million gallons of water with pool depths of 17 to 30 feet.