Tuesday, December 11, 2007

Learn About Uranium

Reprint from the Danville Register and Bee

A large deposit of uranium - possibly one of the largest in the country - is in Pittsylvania County, and a powerful group of investors wants to mine it. The mining of uranium may have serious implications, not only for Pittsylvania County, but most of eastern Virginia.

Here are some basics.Uranium is ubiquitous in nature. You can find it in anything and anywhere, but usually in only trace amounts that have insignificant environmental implications. In nature, uranium exists as three main isotopes (Uranium 238, Uranium 235 and Uranium 234).Uranium 235 is the isotope used in most fission processes, such as energy production in nuclear power plants and nuclear weapons.

The property that makes these elements useful is their instability. Uranium deteriorates by emitting particles (alpha particles and beta particles) and energy (gamma radiation), converting the uranium into other elements such as thorium, eventually leading to lead, which is stable and does not undergo any further degradation. These emissions are ionizing energy, and cause the most trouble. When living cells are exposed to this ionizing radiation, it can cause either cell death or disrupt DNA sequences, increasing the risk for cancer. Uranium 238 is the most prevalent isotope in nature and generally poses little risk unless it is either inhaled or ingested. But it does cause problems - an example being lung cancer - when inhaled.

Uranium is mined in areas where the concentrations of uranium are higher, but needs to be removed from the rocks and surrounding materials by some process. One method is to obtain the ore by removing material from open pit mines and then extracting the uranium from this material by dissolving the uranium with acid and then extracting the uranium in the form of uranium oxide, which is called yellow cake. The material left over is called mill tailings.

Mill tailings have relatively low radioactivity, but they can cause environmental contamination due to the large amount left over by the mining and extracting processes. The principle radioactive components of mill tailings are Thorium 230 (with a half life of 75,000 years) and Radium 226 (half life 1,600 years). Mill tailings also contain heavy metals such as manganese and molybdenum, which can leach into the groundwater causing contamination. Near existing mill tailing sites, groundwater has concentrations of heavy metals that are hundreds of times greater than government standards.

Another method of extracting uranium is called in situ leaching. This process is performed by injecting a solution into the uranium deposits and then removing the uranium oxide from the solution collected from the surrounding aquifer. ISL depends on the ore body being permeable to the solution - and being away from areas in which contamination of groundwater is likely or will be a problem.

This method is preferable in many areas because there is no leftover mill tailings. It is used in Australia, America and Ukraine. ISL is generally used in areas where the water supplies are already contaminated and there is no concern over the quality of the groundwater. But this method utilizes the underground aquifer to recover the uranium and is not an acceptable method for this area where so many (both here and in the eastern part of our state) depend on the water that moves through our area.

So, I guess the questions are: Do we trust the mining of this uranium ore to the people who are preparing to mine it? Who are they? What processes are they going to use to mine uranium? Is our state/national government capable of overseeing these operations? What regulations are in place to protect our environment, and are they going to be enforced? Who is going to be responsible for the uranium mill tailings and other byproducts that are going to be around for thousands of years - Virginia or Pittsylvania County?

The implications of the slightest mistake in mining this ore will result in a contamination of our environment that will not go away in our lifetime or our great-grandchildren’s lifetime. Think about it, ask the questions and educate yourself. But do it quickly.

STEPHEN C. THOMPSON, M.D.
Chatham

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