Tuesday, March 16, 2010

Radon as harbinger of a cornucopia

Map of Natural Radioactivity in the United States
Joe Romm recently offered an interesting post on growing concerns about the environmental impact of fracking as a natural gas production method. I have been calling Joe's attention to the problem created by radioactive radon in the natural gas produced by fracking (hydrolic fracturing) of gas containing shale. There are dozens of radioactive waste cleanup sites in Texas, associated with the natural gas industry. The natural gas industry has largely kept the Texas radon problem largely hushed up. But elsewhere the problems are becoming increasingly well known.

A November 2009 story in Pro-Publica, titled Is New York’s Marcellus Shale Too Hot to Handle states,
The information comes from New York's Department of Environmental Conservation, which analyzed 13 samples of wastewater brought thousands of feet to the surface from drilling and found that they contain levels of radium-226, a derivative of uranium, as high as 267 times the limit safe for discharge into the environment and thousands of times the limit safe for people to drink.

Not only is unsafe levels of radon coming up with water used in the fracking process, but it is also coming up with natural gas, and flowing into peoples homes through natural gas pipelines.According to the physics department of Idaho State University, Natural gas in the home is believed to produce an annual exposure of 9 mrem per year, while average home exposure to radiation from nuclear power plants is almost 100 times less dangerous. Amazingly, environmentalist who claim to be concerned about radiation problems related to nuclear power have ignored the radiation problems caused by natural gas, even though they are potentially far more deadly. Anti-nuclear organizations like the Sierra Club and Greenpeace advocate putting more, rather than less highly radioactive natural gas into peoples homes, while opposing nuclear power which has been shown to pose far less radiation dangers than natural gas does, the New York state evidence suggests that natural gas produced by fraking may be much more dangerous than ordinary natural gas.

So where does the radon that seems to appear every time shalr rock formations are farked for natural gas, come from? According to a report from Commonwealth of Kentucky Geological Survey,
radioactive minreals uranium, radon, and thorium . . . occur in the black shale, which crops out in a horseshoe shape around central Kentucky, and in the phosphate deposits in the Lexington Limestone in central Kentucky.

The black shale is a marine, organic shale that contains many different kinds of minerals, including phosphates. The outcrop of the shale is extensive, and the high organic content makes the shale a good host for radioactive minerals. Uranium and thorium occur in the shale, and radon is a daughter product of the uranium in phosphates within the shale. The black shale also occurs in the subsurface in eastern and western Kentucky where it comes into contact with groundwater. In some areas of the state where there has been significant oil drilling, casing and pipes have become radioactively contaminated, which could cause secondary health hazards when humans come into contact with this drilling equipment.
So it is clear that the presence of radon indicates the presence of uranium and/or thorium, and since radon has no other natural source, finding a lot of radon, enough to be dangerous means that a lot of uranium and/or thorium must be around.

In situ mining is a very old technology. Copper has been mined in situ for at least 1000 years and quite possibly for 2000 years in China. In order to mine in situ. a leaching solution is pumped through resource baring permeable rocks. The resource mineral or minerals are dissolved in the leach solution and then pumped to the surface. Many uranium mines now use in situ leaching technologies as a means of uranium recovery.

From the viewpoint of energy investment, in situ mining has a big advantage over the pick and shovel type traditional mining. Yes I know, they don't use picks and shovels any more, but they still dig, and pull large amounts of material out of the earth. Digging and pulling material out of the ground, and then milling it, and disposing of the waste is energy intensive, especially when you are dealing with low grade ore. In situ mining, however, is not energy intense. Thus so called low grade ores can be mined by in situ mining without huge energy costs. There are of course challenges with approach. A major limitation to the in situ approach would seem to be that while there is a whole lot of uranium and thorium locked up in shale rock, shale is not permeable, and thus not currently seen as a candidate for in situ mining. That is where frarking comes in.

What a fracking does is to fracture shale and other rocks, that is to make them permeable. So it is possible to frake uranium/thorium baring shale, and then mine them in situ? Why not? We are not looking for a technological break through, just the wedding of two proven technologies. That looks like a slame dunk.

There is no reason why granite could not be also mined for minerals in sutu, and fracking has been used to mine granite already. Still, I suspect that a whole lot more research would be required on fracking granite before the fracking/in situ technology would be used, but the research hardly need take a long time, and fracking/in situ mining of granite can yield enormous amounts of Uranium and thorium plus many valuable metals and other minerals.

Among the common elements often found in shale in recoverable amounts are , vnadium, magnesium, copper, chromium, zinc, nickel, iron, aluminum and phosphorus.

if you would like to confirm the presence of Uranium and/or thorium an granite, there is a simple experiment that you could perform. Take a Geiger counter to a cemetery, and start checking granite tombstones for radiation. Some, although not all will show up as radioactive. The same thing will be true for granite in public building and countertops. In addition to thorium and uranium many granites contain recoverable amounts of Tantalum, Niobium. Titanium, Zirconium, Hafnium. and Yttrium, beryllium, and other rare earths. Clearly then the in situ mining of granites for actinides would yield a wealth of other mineral riches.

Let us now take a look at the big picture. The world Thorium and Uranium is for all practical purposes a sustainable energy resource. They can be mined from shale with very favorable energy return on energy Invested (EROEI). In addition to uranium and thorium a number of valuable minerals can be recovered in the same mining process with little to no further energy investment. Uranium and thorium recovery is also possible through in situ mining of some granite with a favorable EROEI. Many valuable minerals could also be recovered from the granite along with uranium and thorium with little to no further energy investment,

These findings are inconsistent with the neo-Malthusian view that we will soon run out of mineral resources. Indeed my conclusion is that the world can continue to supply abundant energy and material resources that will not be exhausted for as long as people live on it.


Robert Hargraves said...

Radon has a half-life of 3.8 days, so most will have decayed by the time the natural gas reaches the consumer.

Bill Hannahan said...

Nice analysis Charles. I would just add that fracking might unzip a fault line in some locations resulting in one or more earthquakes.

Charles Barton said...

Robert, A lot of radon from Barnett shale under Fort Worth flows to North Texas homes the same day it leaves the ground. That means that gas is more radioactive that it would be after several days in the pipeline.

Bill you are right and geologists need to be consulted. However any significant earthquake would probably be an earthquake waiting to happen.

LarryD said...

Shale is soft, brittle rock. So tectonic stress can't build up like it can in harder rock. It's the surrounding rock that needs to be checked for stress.

It occurs to be that this is an opportunity for the Natural Gas Industry, which is going to be trying to develop the shale fields anyway. After the Natural Gas is extracted, follow on with in situ mining of Phosporus, Uranium, Thorium, etc. And if there isn't any Natural Gas, then the field may still still be minable. It would give the Industry a financial incentive to be pro-nuclear.

Nick Palmer said...

Interesting idea. I don't think there are too many "Malthusian" people saying that we are going to actually run out of certain minerals, just that they will be getting steadily harder to find and extract with a reasonable return.

There are other considerations that suggest that a high energy supply/high consumption world is ultimately not sustainable


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