Radioactivity from burning coal.

Worry about the release and accumulation of radioactive materials in the environment has led to much hand wringing over the risks of accidents at nuclear power plants and weapons facilities.

But what about radioactivity released from burning coal?

W. Alex Gabbard, a nuclear physicist at the Oak Ridge (Tenn.) National Laboratory, did a little calculating. According to Environmental Protection Agency figures, an average ton of coal contains 1.3 parts per million of uranium and 3.2 parts per million of thorium. Both naturally occurring trace metals are radioactive. Of the uranium, roughly 0.71 percent is U-235, the fissionable variety used by nuclear power plants.

Thus in 1982, he estimates, U.S. coal-burning power plants, which collectively consumed 616 million tons of coal, released 801 tons of uranium and 1,971 tons of thorium into the environment -- virtually unnoticed.

Roughly 11,371 pounds of the uranium was U-235.

Moreover, global combustion of 2,800 million tons of coal that year released 8,960 tons of thorium and 3,640 tons of uranium, of which 51,700 pounds was U-235.

Ironically, in 1982, 111 U.S. nuclear power plants used 540 tons of nuclear fuel to generate electricity. Thus, "the release of nuclear components from coal combustion far exceeds the entire U.S. consumption of nuclear fuels," Gabbard notes in the fall issue of the OAK RIDGE NATIONAL LABORATORY REVIEW.

Gabbard then calculated the energy value of the lost radioactive materials. He found that the nuclear fuel released by burning coal has one and a half times more energy than the coal itself.

Because electric utilities are not perceived to be as hazardous as nuclear power plants, "large quantities of uranium and thorium and other radioactive species in coal ash are not being treated as radioactive waste," Gabbard says.

"These products emit low-level radiation. But because of regulatory differences, coal-fired power plants are allowed to release quantities of radioactive material that would provoke enormous public outcry if such amounts were released from nuclear facilities," he adds.

"Nuclear waste products from coal combustion are allowed to be dispersed throughout the biosphere in an unregulated manner," Gabbard concludes. Such wastes accumulate on electric utility sites and are "not protected from weathering, thus exposing people to increasing quantities of radioactive isotopes through air and water movement and the food chain."