When the Yucca Mountain idea for disposing of nuclear waste was torpedoed by Harry Reid, senator from Nevada, the problem of disposing of 70,000 metric tons of spent nuclear fuel remained unsolved – a sort of “sword of Damocles” hanging over the nuclear power industry and the United States. But Europe is ahead of us in this area as countries like France, Belgium and Switzerland, as well as Canada, have for some time been looking at shale rock as a safe medium for storing nuclear waste- possibly for as long as a million years(!) as an article in the April 7th issue of Chemical Engineering News recently pointed out. Original concerns about leakage in shale formations have now been abated as more studies were carried out. Modelling, including computational chemistry is being used in further work, such as at the Ecole des Mines de Nantes, in France.
Shale has some good features, including absorptive clays, which act as filters. Work being done in actual shale beds involve studying the movement of water and pressure patterns in the rocks. It has been found that there is essentially no movement of water, a very positive finding.
A shale repository would be created half to one kilometer below the earth’s surface, consisting of a tunnel of galleries excavated outward like veins in a leaf. Nuclear waste containers could be stored “for hundreds of millenia”.
Clearly, our nuclear scientists and the DOE will be following these studies closely. According to the article, the Canadian Nuclear Waste Management Organization is planning an underground storage facility that “will be capped with shale”.