Part 1 of 2 Parts
The disposal of nuclear waste is an extremely serious problem for the world and an impediment in selling nuclear power to the public and investors. The cooling pools at many U.S. commercial nuclear power reactors are so full of spent nuclear fuel rods that if many of the rods are not removed soon, the reactors will have to be shut down. It is estimated that there are around one hundred and thirty-eight million pounds of nuclear waste accumulating at commercial nuclear power plants around the country.
There was a plan to create a permanent underground repository for spent nuclear fuel under Yucca mountain in Nevada. The development of that repository was suspended in 2009. It is now estimated that there will not be a permanent repository in the U.S. until 2050 at the earliest.
There have been a number of suggestions on ways to handle nuclear waste other than a centralized underground repository. One of those idea is to drill deep holes in the ground and bury the spent fuel rod deep underground. This is not a new idea. Getting rid of nuclear waste by shoving it down deep boreholes drilled into basement rock has been under consideration since the 1950s. There has been research into deep borehole disposal in Denmark, Sweden, Switzerland and the U.S. but so far no one has implemented such a disposal system.
Basement rock is a thick foundation of ancient metamorphic and igneous rock that forms the crust of continents. It lies below sedimentary rock such as sandstone and limestone which are laid down over the basement rock. Generally, sedimentary rock is relatively thin but can be up to three miles think in places. Basement rock can be more than thirty miles thick. It has been geologically stable for tens of millions of years.
In 2016, the Battelle Memorial Institute was selected by the U.S. Department of Energy to drill a sixteen-thousand foot test borehole into a crystalline basement rock formation in North Dakota. This project was carried out as part of a research program to determine whether this could serve as practical and safe way to dispose of spent nuclear fuel. Other plans for deep borehole tests in the U.S. had to be cancelled because of public resistance at the possible test sites.
Also, in 2016, the International Atomic Energy Agency announced that it had successfully carried out “proof of concept” tests for disposal of small amounts of radioactive waste in deep boreholes.
The expert consensus has been that using deep boreholes for disposal of large volumes of spent nuclear fuel would be very expensive compared to a centralized underground repository. One issue of concern with respect to borehole disposal is the fact that it was considered impossible to retrieve nuclear waste from such boreholes should it ever be necessary.
Deep Isolation (DI) is a private company located in Berkeley, California. Last November, DI successfully placed a prototype nuclear waste canister into a borehole two thousand feet deep. DI then retrieved the waste canister and brought it back to the surface. DI has patented technology based on off-the-shelf standard drilling technology developed by the oil and gas industry. The tests were carried out at a commercial test facility for gas and oil drilling.
Please read Part 2