Articles from 2013
Can Shale Safely Host Nuclear Waste?
- Written by Nick Grealy
- Published: 25 July 2013
Interesting research from scientists at the US Geophysical Union, raises a number of issues for shale in general.
About 70,000 metric tons of SNF (Spent Nuclear Fuel are now in pool or dry cask storage at 75 sites across the United States [Government Accountability Office, 2012], and uncertainty about its fate is hobbling future development of nuclear power, increasing costs for utilities, and creating a liability for American taxpayers
Let’s remember, the fear, especially in France, is that chemicals, such as they are, in shale gas fluid miles underground can eventually migrate towards the water aquifers, which are never more than a few hundred feet below the surface.
The source rock for shale gas is separated by several thousand feet, and impermeable cap rock from aquifers, but questions have been asked about whether or not shale drilling opens up pathways to the surface. Even the fact that fractures are not wide avenues or underground caverns, but the width of grains of sand, doesn’t convince those who insist on arguing with the laws of physics.
Let’s remember that shale formations are widespread worldwide and include many formations not prospective (at current technology) for oil and gas extraction. Despite the fears of the Captain Kirks of the more paranoid shale opponents, geophysicists themselves are now studying shale for storage of SNF.
Flowing groundwater transports dissolved material and is thought to be the most likely means by which nuclear waste in an underground repository could escape and contaminate the biosphere, posing a risk for future generations. Clay-rich geologic media are millions to tens of billions of times less permeable than productive aquifers and hydrocarbon reservoirs [e.g., Ingebritsen et al., 2006].
Their exceptionally low permeability suggests that argillaceous formations could be effective geologic barriers to the migration of SNF and HLW constituents from a repository. What’s more, argillaceous media are the most common and voluminous of sedimentary materials and often are found in relatively old and stable geologic settings. Thus, tectonically quiet sedimentary terrains with thick clay-rich sequences may have a number of desirable qualities for hosting America’s substantial and growing inventory of nuclear waste.
So, there we have it. If shales can be stable enough to contain nuclear waste, why the concern they won't contain frack water? Which of course also contains, in some formations, naturally occurring nuclear material of far lower concentrations of spent fuel or HLW (High Level Waste).
Apart from it’s incredible cost, the disposal of spent fuel has been a major issue preventing the emergence of nuclear power, which as some greens, or at least those like Bryony Worthington or Mark Lynas, appear to feel provides a much more realistic carbon free future than natural gas. I edited the orignial version of this, but can't help pointing to Mark Lynas that the bravery and open mindedness he's shown about both nuclear and GMO's would be welcome in the shale gas debate. It may be he simply lacks time or thinks he has more on this plate already.
Another voice is that of George Monbiot, grudgingly accepting of nuclear even as he is rabidly anti gas. This was him in 2011 on shale:
Both the fracking fluids and the flowback fluids can contaminate water either through the cracks forced open in the rocks by the fracking process, or through drilling bores through aquifers. In the US this has happened repeatedly. The Tyndall Centre found that water supplies have been contaminated not only by the fracking chemicals and dissolved pollutants from the rocks, but also by gas bubbling out through the cracks.
Again: Repeatedly contaminate? Or even once? This is him this year on nuclear, highlighting the very issue that shale rocks can solve:
Germany also decided to shut down its nuclear power plants after the Fukushima crisis, due to the imminent risk of tsunamis in Bavaria. Last year, as a result, its burning of "clean coal" – otherwise known as coal – rose by 5%. That was despite a massive cut in its exports of electricity to other European countries. One estimate suggests that by 2020, Germany will have produced an extra 300 million tonnes of CO2 as a result of its nuclear closure: equivalent to almost all the savings that will be made in the 27 member states as a result of the EU's energy efficiency directive.
If the UK fails to replace its nuclear plants, which generate 22% of our electricity, the same thing will happen. Replacing fossil fuels with renewable energy – which is essential if we're to have any chance of meeting our climate change targets – is hard enough. Replacing fossil fuels and nuclear power with renewables is harder still. As thermal power plants perversely attract less opposition than wind turbines, the temptation to replace nuclear power with fossil fuels will be overwhelming. Abandoning a proven and reliable low-carbon technology as climate breakdown accelerates is a special form of madness.
I put that spending huge sums of money to reduce CO2 by 100% via either nuclear or renewables, when CO2 can be reduced by 60% by replacing coal worldwide is putting purism against pragmatism. When going gas also creates wealth and gives power to energy consumers to have their own energy sourced responsibly, rejecting gas is even madder.
But, all good things come to an end, and there will be some who insist that there will be a point when the nuclear waste will somehow end up on the surface. But is that something we can afford to worry about?
Ensuring geologic isolation of nuclear waste over tens of millennia or longer poses questions that Earth scientists continue to study.
If shales can contain nuclear waste for tens of millenia, they can also contain frack water. Especiallly true considering the half life of common frack fluids measured in days not millenia
I’ve always said that shale gas and renewables are companion fuels that enable each other. What if the research that enabled shale production can enable nuclear too?