More Information on Non-Renewable Energy
Generating nuclear power appears to be an effective way to create dangerous waste garbage that cannot be safely thrown away, though often is. Past operations have resulted in contamination and fatalities throughout almost every step of the mining, refining, and disposal process. Even now we have no idea how to safeguard future generations from radioactive material used to produce today's electricity. Yet we continue to rely on it to provide over 17% of our world's energy.
Uranium is distributed unevenly throughout the world. About 80% is located in six countries with only 9 companies accounting for 82% of uranium production. Canada and Australia supply 34% and over 15%, respectively, of the world's supply. Over 440 reactors worldwide process the uranium for electricity.
The process begins in the mines. To supply an average plant (1000 MWe) with one year's worth of uranium, 45,000-90,000 tons of low-grade uranium ore are dug from surface or underground mines in order to extract a meager 25 tons of enriched uranium to be used in a nuclear reactor core. Uranium usually composes less than 1% of the total material mined, so the rock that encases it winds up littering the landscape in the form of radioactive tailings. In the US , radioactive tailings make up "over 95 percent of the volume of all radioactive waste from all stages of the nuclear weapons and power production" process.
The people who work at these uranium mines and plants live with the constant threat of radioactive contamination in their clothes, on their skin, and in the air they breathe. Even alpha radiation, the least dangerous of the three types (alpha, beta, and gamma), can eventually kill someone if they inhale particles containing it. Improper disposal of radioactive tailings is also an issue that affects nearby communities. Mill tailings have been responsible for most of the radioactive environmental contamination that has occurred in the last few decades. In the US , "nearly one third of all mill tailings from abandoned mill operations are on lands of the Navajo nation alone. Many Native Americans have died of lung cancers linked to their work in uranium mines. Others continue to suffer the effects of land and water contamination due to seepage and spills from tailings piles." This radioactivity will likely affect other people who go near the area for hundreds or thousands of years. Nuclear power therefore concerns everyone, since the poison it leaves behind does not just go away in a few months.
Once rock containing uranium has been whittled down to 25 tons and the tailings discarded, it must be enriched for use in modern reactors. The naturally occurring 0.7% ratio of the isotope uranium-235 must be increased to about 3.5%. First it is converted into a gas. Then the isotope uranium-238 is extracted, wasting 87% of the material in order to retrieve the desired 13% of U-235-enriched uranium. This uranium dioxide is converted into powder and compacted into pellets, which are put into fuel rods and inserted into the reactor.
In the recent past, some of the 87% of the so-called "depleted" uranium "was used by the US military to fabricate armor-piercing conventional weapons and tank armor plating." Armed forces personnel were not informed of their exposure to radioactive material, nor were there procedures for measuring doses.
The enriched 13% that enters the nuclear reactor core undergoes fission and causes a chain reaction. Heat boils water and steam drives a turbine and an electric generator capable of providing about 7 billion kilowatt-hours of electricity annually.
After the enriched uranium is used, 97% of it goes back into the reactor to be reprocessed with fresh uranium. About 200 tons of enriched uranium is needed to keep a plant going but only 25 tons of fresh fuel are added each year. "The remaining 3%, about 700 kg, is high-level radioactive waste which is potentially hazardous and needs to be isolated from the environment for a very long time." While in the reactor, some of the U-238 turns into plutonium and fission products. These are even more dangerous and deadly than the original uranium that went into the reactor. A person would quite literally drop dead by getting too close.
The storage of this high-level waste is a serious concern for the nuclear power industry, governments, and people in general. One option is to heat the waste to the point that it turns into a dry powder that can be immobilized in Pyrex glass and stored in stainless steel canisters. This process is called vitrification. Another storage option was developed in Australia . "SYNROC" is the incorporation of radioactive wastes "in the crystal lattices of the naturally-stable minerals in a synthetic rock. In other words, copying what happens in nature." But neither of these techniques solves the problem of final disposal.
"Final disposal" is the most controversial issue of all because the only solution receiving serious consideration is "deep geological disposal" the burial of radioactive waste in stable rock structures or bentonite clay that inhibits groundwater movement. This is only a temporary answer to the radioactive problem. No material used to encase the waste can withstand the continuous assault of heat, helium, and hydrogen that the spent fuels produce. The nuclear industry frankly admits that such a "solution" carries the risk of contamination to underground water tables. Eventually the unstable material will reenter the ground and poison the groundwater. Consider this the longest any language has continuously been spoken is 4,000 years. This spent fuel will remain lethal for more than 10,000 years. What language will be used to make the signs warning people of the distant future away from the site?
"Some countries believe that the final disposal of high-level radioactive wastes and/or spent fuel should be delayed as long as possible." But in an effort to get this dangerous material out of sight and out of mind, the nuclear industry has identified possible dumpsites. In 1987, Yucca Mountain , Nevada , was selected as a potential repository for the 77,000 tons of nuclear waste awaiting disposal from the US 's 110 nuclear plants. Thousands of researchers and scientists have been testing the region's rock formations, climate, and groundwater flows. According to the Nuclear Waste Policy Act, "if, at any time, Yucca Mountain is found unsuitable, studies will be stopped immediately. If that happens, the site will be restored and DOE will seek new direction from Congress." The entire project from start to finish, that is if it goes, is estimated to cost $18.7 billion.
Apparently the 621 earthquakes of a 2.5 rating or greater that have occurred within a 50 mile radius of Yucca Mountain since 1976 have not proven the site "unsuitable." Hundreds of these earthquakes have happened during DOE's site evaluation. According to Nevada 's Nuclear Waste Project Office (NWPO), Yucca Mountain itself is "a result of millions of years of intense faulting and volcanism. Records of recent events indicate that faulting is an ongoing process in the vicinity of Yucca Mountain that is expected to continue long into the future. Thirty-three faults are known to exist within and adjacent to the Yucca Mountain site." The NWPO as well as two-thirds of Nevadans oppose the project altogether.
Despite the lack of a dependable solution for disposing of the radioactive waste, nuclear power plants are still being constructed. Why? Because of statistics such as this: 2 million tons of coal is burned in order to produce the same amount of electricity that 21 tons of spent uranium fuel produces. That is almost 10,000 times more, not to mention the 5.4 million tons of CO 2 ; 120,000 tons of ash; and 50,000 tons of SO 2 that are emitted in the coal-burning process. But people tend to forget that the radioactive materials discarded in the nuclear fuel process cannot be filtered out of the environment in a blink of geologic time.
Nuclear operations are especially harmful to indigenous people who will be affected by a plant but whose refusals go unheeded. Jabiluka (Djabulukku), Australia is home to one of the biggest and highest-grade uranium deposits in the world an estimated 212,400 tons of uranium oxide. It also happens to be in the middle of a national park in a beautiful floodplain that the Mirrar people call home. Although the Mirrar clan leaders "have clearly stated that they are opposed to any mining operations at the site," the Jabiluka Uranium Mine proposal may become a reality. Sometime in 1999, a tunnel will be dug "toward the uranium orebody, without a clear plan for where the ore will be milled or what will happen to 19 million tonnes of powdered radioactive waste rock produced by the mine. What is clear is that mining, far from providing benefits to the local community, is instead destroying them." The Mirrar fear this mine "will push their culture past the point of cultural exhaustion to genocidal decay."
Fortunately, a more permanent solution for dealing with radioactive waste is in the works. Paul Brown of International Fission Fuels, Inc., recommends the transmutation of spent fuels into "short lived or stable products." This could be done with an accelerator-driven reactor that "may be used to 'burn up' spent fuel from fission reactors." It would speed up electrons directed onto a metal such as tungsten in order to create gamma rays capable of disintegrating radioactive materials. This reaction would require about 1 MW of power and produce about 20 MW of power, so the use of multiple reactors would provide "a relatively cheap and safe source of power at the same time." The fuel to generate this power is obviously abundant; all that needs doing is constructing an experimental prototype.
Until such reactors are made a reality, nuclear power will remain a threat to the global community for thousands of generations. Common sense has been lost somewhere along the line and current regulations in the US only cover the next 1,000 years. Yet we continue to depend on a form of electrical generation that produces many times more radioactive waste and spent fuel than it uses, even though we are not sure how to dispose of the waste products. In fact, the production of nuclear energy would be more aptly called the production of lethal, uncontainable waste whose existence shatters the significance of our present electrical needs.