Local researchers are designing a product that could change the nuclear industry. Like many good ideas, it started on a napkin.
Executives from Tokyo-based Sakae Casting visited Idaho Falls in 2016 to determine where to open their first U.S. office. They brought a sample of their proprietary product: a thin aluminum plate embedded with a U-shaped cooling tube.
In a meeting with local economic development representatives and researchers, Sakae CEO Takashi Suzuki posed a simple question: can this be used in the nuclear industry?
University of Idaho Nuclear Engineering Director Richard Christensen sketched a design that incorporated the plates. On the napkin: a new nuclear fuel storage cask.
The cask would allow a new type of temporary dry storage. The casks would be used after fuel cools in expensive and spatially limited on-site reactor storage pools, and before fuel is sealed in permanent concrete cask storage.
Sakae executives liked the idea and opened an Idaho Falls office in April. Cask design work is underway at the Center for Advanced Energy Studies, which is a research consortium between local universities and Idaho National Laboratory.
The project is funded largely by a $237,898 grant through the Idaho Department of Commerce.
Christensen thinks the new cask design has the potential to change nuclear fuel management as well as establish a new model for Gem State economic development.
“It’s not just this little research project we’ll have great fun with, it’s something that holds some real import for the state of Idaho and Idaho Falls in particular,” he said. “During a previous meeting, the Sakae CEO stood up in front of the commerce board and said ‘I have business contacts in Japan, and if this works they will come and do the same thing we are.’”
Currently, used fuel rods spend 15 to 20 years cooling in on-site storage pools before they are safe for transport to permanent concrete storage casks.
Storage pools — complete with circulation pumps and temperature control instrumentation — are expensive to build, and they contain only so many rods before a new pool must be built.
“Companies running out of space is a credible problem that’s growing,” said UI Nuclear Engineering Assistant Professor R. A. Borrelli, who is working on the cask project. “And it’s closer to dire in places like Korea or Japan.”
The new cask would be composed of composite plates made from aluminum and boron. The neutron- and gamma-absorbing plates would contain Sakae’s cooling tubes, which would improve temperature cooling properties.
If they work as envisioned, the aluminum casks will contain fuel rods for 10 to 15 years after they’ve already spent five to eight years in storage pools. After cooling in the aluminum casks, fuel would be moved to permanent concrete storage.
Casks would be applicable to fuel used by most types of reactors, including the test facilities at INL, or commercial generators used all over the world.
Researchers don’t believe the aluminum casks will require special storage conditions, therefore they are intended to provide reactor operators a cheaper alternative to building additional storage pools.
“The pools are filling up, so operators can either build a completely new pool or something else. We’re trying to provide the something else,” Christensen said. “We’re creating a middle ground that should save utilities time and money.”
Christensen said the principles behind the design are sound; the main work is in figuring out how long fuel rods must be stored in pools before they can be transferred to the aluminum casks. There also hasn’t been much research regarding aluminum and boron composites used in a nuclear context, Borrelli said.
They both agreed the Center for Advanced Energy Studies provides ample opportunity to collaboratively research such issues. The building contains offices for both individuals, as well as for Boise State University and INL researchers also working on the project.
“It’s easy to walk 100 feet and say ‘Hey, I need to talk to you about something,’” Borrelli said. “It’s harder to do that when someone works on the other side of the state.”
The Department of Commerce grant, administered through the Idaho Global Entrepreneurial Mission, encompasses a one-year design timeline.
In March, Sakae will build a small-scale cask prototype for testing purposes, Sakae Sales Manager Takayuki Kitazumi said. Company representatives also will approach energy companies to gauge commercial interest in the product.
“We want to make sure there are customers out there willing to say ‘If you can make this work the way you claim you can, then we’re very interested in seeing that process go forward,’” Christensen said.
If the cask’s design is effective and its cost viable at the end of the yearlong research period, Sakae likely will build a factory in Idaho roughly five years from now to manufacture the containers, Kitazumi said.
The casks built here could warrant global interest, Borrelli said.
“There’s a larger context at work than just building something neat. Nuclear reactors are very similar pretty much everywhere. If it works, Sakae can export these to lots of other countries — they can effectively start a whole new industry,” he said.
Kitazumi said executives from one of Sakae’s sister companies, automated manufacturing firm Atom Co., visited Idaho last week, and are considering their own Gem State facilities in order to develop technology for the agriculture industry.
The cask project could further raise the international economic profile of eastern Idaho and its unique mix of research and development infrastructure and personnel, Borrelli said.
“This is a big deal for us because it’ll open the door for a lot more companies to come to Idaho and put down some offices and see what kind of business they can do. According to Sakae’s CEO, that was part of their whole intent,” he said.
“That’s what we’re working toward,” Christensen added. “Being able to successfully complete this because we know there’s a lot hanging on it.”
Reporter Kevin Trevellyan can be reached at 208-542-6762.