by Sandia National Laboratories
Deep Isolation, a company founded in 2016 and headquartered in California, launched a “Deep Borehole Demonstration Center” on February 27. most contemporary designs for nuclear waste storage facilities.
But while the launch named its first board members and published a high-level plan, the startup does not yet have a permanent location, nor does it have the resources to complete its planned drilling and testing program.
While the idea of using deep boreholes for nuclear waste storage is not new, no one has yet demonstrated that it works. The Deep Borehole Demonstration Center aims to be an end-to-end, full-scale demonstration, testing everything: safe handling of waste containers at the surface, disposal, potential recovery, and ultimately permanent sealing deep underground. It will also rehearse techniques to ensure that any underground leaks do not contaminate the surface environment, even many millennia after salvage.
But it will do all that without any actual nuclear waste: “This site, to be clear, will never be used for radioactive waste storage,” said Liz Muller, CEO of Deep Isolation and chairman of the board of the Deep Borehole Demonstration Center .
“What this needs to do is really bring people together to understand what are the key issues that need to be addressed before we move forward,” said Ted Garrish, the center’s executive director. “There’s nothing really new here in terms of the actual technologies; it’s just they get married together and do it in a nuclear environment.
Universal bus
At the time of this announcement, the center’s first exercise to “marry” standard oil drilling and nuclear technology had already begun. In February, there was a technology demo at a downhole testing site near Cameron, Texas. “We need to have an attachment mechanism for this nuclear-designed bus to attach to standard oil and gas rigs,” explains Muller.
They used a newly designed canister large enough to enclose a Pressurized Water Reactor (PWR) fuel assembly of 13 feet. They locked it down with standard oilfield equipment, lowered it through the rig floor and unlocked it there. Later they tied him up again and fished him out again.
With funding from the U.S. Department of Energy’s ARPA-E program, Deep Isolation is designing a new universal bus that fits down a borehole and captures waste generated by a variety of reactor designs, not just PWRs: “We’re talking to a number of different advanced reactor companies , what will their waste form look like, can we design it to fit in this universal jerry can?” said Muller, who thinks they should all fit in a canister the same size as their PWR fuel canister used in February’s test.
Decentralized Removal
A universal bushing should make deep boreholes suitable for a variety of nuclear waste, while the depth of the boreholes should make them suitable for different locations.
At the depths where repositories for mined nuclear waste have been built – about 400 meters deep – there is usually quite a lot of flowing groundwater that can bring contaminants to the surface. Mined nuclear waste repositories must therefore find unusual locations, where the rock is dense and the water static, so that leaks in the repository will not go far, even after millennia. But by going much deeper, Muller argues, the waste can be placed at depths where groundwater flow is typically minimal, so there are far fewer restrictions on suitable locations. “The geology is much more flexible than if you look at a mine dump,” Muller said. “If you go much deeper, if you go one kilometer, two kilometers deep, there are many more locations that are suitable.”
That means there may be deep borehole storage facilities in most places where nuclear waste is generated, reducing the need to ship nuclear waste to a centralized facility, such as Nevada’s failed Yucca Mountain site. “We expect the first iterations of Deep Isolation technology to be at existing waste facilities,” Muller said.
“I think if we’ve learned anything from the efforts to… have consolidated locations and relocate [nuclear waste] in all states I think the big lesson, the big, big lesson to take home is don’t do it! Muller said. The transportation of nuclear waste is still cited to this day as one of the Nevada State’s objections to the Yucca Mountain disposal site.
