Ceramic Trap Seals Nuclear Waste for Millions of Years
A scientist has developed an inexpensive, room-temperature method to contain radioactive gas.
To say nuclear containment is challenging is a bit of understatement. At the Hanford Site, a mostly decommissioned nuclear complex in the state of Washington, 55 million gallons of radioactive waste have been stored miles underground. Since 2012, reports of leakages started trickling in and according to the U.S. Department of Energy, the government will spend upwards of $150 billion in clean up costs by 2090.
Better containment could prevent future disasters.
Ashutosh Goel, an assistant professor along with his graduate student, Charles Cao, at Rutgers University, has come up with a simple, inexpensive way to immobilize nuclear waste, specifically radioactive iodine, trapping it in ceramic for millions of years.
The radioactive waste, called iodine-129, is a by-product of a containment system expected to be in use at the Hanford Site starting around 2022. As part of that system, nuclear waste will be mixed with boron and silica and treated at very high temperatures to turn it into glass.
Unfortunately, the heating releases radioactive iodine-129 gas. Although the iodine-129 can be captured in a special filter, called a caustic scrubber, no one had figured out an efficient way to contain it.
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Containment it is crucial since radioactive iodine decays very slowly and will linger in the environment for millions of years. It's known for targeting the thyroid gland in people, increasing the risk of cancer. Because it disperses easily through air and water, some countries, like France and the U.K., dispose of it by dumping it into the ocean.
"At the end of the day, it has to end up somewhere," Goel said. "It will end up being in fish, being in aquatic bodies, and then slowly it will enter into the food chain."
Goel, who has spent his career on glass- and ceramics-related projects came up with a method for containing the radioactive gas that doesn't require high-temperatures or vacuum-sealed chambers.
" "We developed a technique where everything is at room temperature. It's just that you have to mix the chemicals in the proper order in water," Goel said. "That is it."
Wait. It's that simple? Yes, said Goel. The iodine-129 gas is captured in the caustic filter and then mixed with other chemicals in a specific order and turned into ceramic.
Goel and his team won second prize in the 2016 Innovations in Fuel Cycle Research Awards sponsored by U.S. Department of Energy for this technological breakthrough.
While iodine-129 is found mainly in "low activity" radioactive waste, meaning the level of radioactivity is low, the team is also working on the challenges of containing waste described as "high activity," too. That may take a little more time.
The good news is the 90 percent of nuclear waste at the Hanford site is made up of low-activity waste and so the impact of this new approach could be huge.
"This is not a trivial problem as we are working on the largest, most expensive environmental remediation project in the U.S. history," Goel said. "I feel honored to be a part of this effort, and hope that our research brings a great promise to safe and efficient immobilization of spent nuclear fuel in United States and a much increased use of nuclear power in the near future."