By Greg Staskiewicz, Reporter
The United States currently has no prospects for permanent storage of high-level radioactive waste.
The federal government in 2011 ceased funding of the Yucca Mountain Nuclear Waste Repository project due to political opposition in Nevada, the host state, and in Congress. If completed, the repository would have received dangerous radioactive waste from around the country, to be stored permanently and far underground, for up to 10,000 years, when the radioactivity would largely have dissipated.
Because of this lack of permanent waste storage, the over 50 operating plants in the US have been forced to resort to on-site dry cask storage, said assistant professor of civil and environmental engineering at the University of Nebraska Lincoln, Dr. Jongwan Eun.
This exposes the public to potential risks over time as the casks are exposed to the environment – the safest way to dispose of the waste is deep underground storage.
Eun’s and his colleagues received a grant from the Department of Energy (DOE) to research ways to reinforce the permanent containment systems to be used in a future permanent repository. These systems would normally use metal canisters, encased in bentonite clay, and capped with concrete, Eun said.
But the high temperatures from the decaying waste, up to 200 degrees Celsius, cause cracking in the bentonite over time, compromising the safety of storage. Accordingly, the team proposed the addition of fibers from glass or basalt in order to reinforce the clay, potentially increasing the durability of the container and reducing their size.
Even though the nuclear plants lack a permanent waste storage facility, many experts agree that on-site intermediate storage is a safe solution for now, though there is still disagreement and much research to be done, Eun said. Scientists need to keep looking at permanent and intermediate storage solutions, so that the necessary technology is available in the future.
“I would say to not stop within three years, five years. It’s too hurried and hasty,” Eun said. “But if we’re looking at the long term, like twenty years or thirty years, we need to have some kind of convincing, or some possible solutions.”
Fort Calhoun Nuclear Generating Station, which ceased operation in 2016, is currently undergoing decommissioning. The radioactive spent fuel is being transferred to the on-site ISFSI, or Independent Spent Fuel Storage Installation, where it will be housed until 2058, when OPPD will transfer the fuel to DOE for permanent storage elsewhere, according to the Nuclear Regulatory Commission. The ISFSI will be monitored, maintained, and staffed for the next several decades to ensure safe containment of the radioactive waste.
Danielle Cram, project manager at OPPD, said she is confident that the dry casks at Fort Calhoun station will withstand the test of time and the unknown, as they are designed to be durable and withstand natural disasters, and have also been tested to withstand floods.
“So we’re very proud of the work that we do here at OPPD, especially on the decommissioning project,” Cram said. “Safety is first and foremost in everything that we do. So that goes to the health and safety of the public, and the health and safety of our employees. So with that, it’s been a tremendously good year for us.”
