Decommissioning of the Fort Calhoun Station (FCS) nuclear plant has accelerated and become nearly $200 million cheaper since the Omaha Public Power District (OPPD) board shifted its decommissioning method last fall.
In about a year or soon after, all of around 1,000 bundles of spent fuel at FCS will be stored in two-dozen on-site bunkers made of concrete and steel, OPPD spokesman Cris Averett said. Other waste material and plant components will be decontaminated and removed from the property by 2025.
OPPD switched from the SAFSTOR to the DECON decommissioning method in October. DECON's timeline can take up to 10 years, as opposed to SAFSTOR's, which requires the maintenance of a nuclear site for about 60 years until material radioactivity decays. DECON, however, allows dismantling and transfer of radioactive materials once they've reached an acceptable level, according to the United States Nuclear Regulatory Commission (NRC).
FCS' decommissioning is being completed by about 270 OPPD employees with FCS experience and EnergySolutions, a nuclear services company from Salt Lake City, Utah. About 50 OPPD employees will remain on the site after decommissioning for maintenance and security.
"This is an OPPD-led project, with our seasoned workforce performing much of the decommissioning work," Averett said. "(EnergySolution's) experience and our expertise will combine to meet project goals."
As decommissioning continues over the next several years, a reduction in the number of employees at the site will occur. Averett said some employees may retire, resign or find other positions in the company, or severance packages may be offered by OPPD. About 700 employees were at the site when it closed in 2016.
"When the time comes, we will work with impacted employees as we have in the past," he said.
OPPD estimates the cost of the DECON process will be about $621 million. The total cost of the project, however, could be around $1 billion.
The additional cost after the decommissioning process is due to the concrete and steel spent-fuel storage bunkers that will remain on site. After decommissioning is complete, OPPD has budgeted 50 years for the maintenance and security of the bunkers.
It's possible, however, the bunkers could remain on site more than five decades, since no longterm federal storage options currently exist for nuclear fuel. As such, all commercial nuclear power plants in the country must store their spent fuel on-site.
All other radioactive materials from FCS, such as pumps or pipes, will be stored at a EnergySolutions facility in Clive, Utah. OPPD officials hope to see a similar longterm solution for fuel sooner rather than later.
"We look forward to the Department of Energy fulfilling their mandated obligation to safely remove the spent fuel from site," Averett said.
He added that the safety of residents in Washington County and surrounding areas is important. He said the storage system for spent fuel will ensure radioactive material remains isolated from the public.
The fuel will be stored in welded, dry-shielded steel canisters, that, once filled, will be welded shut. The canisters, holding up to 40 tons, are then inserted into the concrete and steel bunkers. The bunkers are about 20 feet high, 10 feet wide, and 20 feet deep, with walls and roofs up to five feet thick.
"The technology and materials used to safely store spent fuel is incredibly robust, and the process is tightly regulated, as it should be," Averett said.
Without a longterm federal storage solution, the type of spent fuel storage OPPD is completing, called dry-cask storage, is recommended to reduce malfunction or terrorist attack risks, according to the Union of Concerned Scientists (UCS).
"While dry casks are still vulnerable to safety and security hazards, those risks are reduced," compared to other storage methods, a UCS article states, adding that many casks would have to fail before they could release as much radioactivity as other storage method failures.
Aside from the fuel storage area, much of the site's 660 acres will be released by the NRC for redevelopment after decommissioning finishes. About 120 acres have already been released, but, Averett said, OPPD is still considering options for what to do with the land.
"Our saying at the site is, 'Honor yesterday, perform today, define tomorrow,'" he said. "OPPD is proud of its people, past and present, and we are working to preserve the legacy of safety and trust we have with our communities."