Nuclear power is presently one of the few non-fossil fuel energy sources capable of providing baseload electrical supplies. It emits virtually no greenhouse gases and, unlike oil, is more secure because the United States has large uranium reserves.
Unlike many non-fossil fuel energy sources, nuclear power has a decades-long track record of success in Europe, Japan, the U.S. and many other nations around the planet. While many people unfortunately associate nuclear power with nuclear weapons and glowing waste, the fact is that the United States gets nearly 20 percent of its electrical power from 104 nuclear reactors that, since 1979, have operated accident free. Nuclear power is a tremendously important resource today and is an even more valuable component to our energy future.
| ||Making Nuclear Power || |
Electricity is generated in nuclear reactors when uranium atoms split in a process called nuclear fission, releasing heat and a variety of smaller atoms. The heat is captured as steam and drives turbines where the electricity is produced. Today, 20% of U.S. and 17% of global electricity is produced by nuclear reactors. Nuclear power has proven to be clean, efficient, and cost effective and promises to be a major contributor to resolving America’s and the world’s energy security concerns in the future.
A major challenge for U.S. industry and consumers is to acquire affordable and reliable sources of energy. Increasing global demand is placing stress on all production sources, resulting in shortfalls and price increases. In addition, the use of fossil fuels is resulting in increasing emission of greenhouse gases, which could be a factor in global climate change.
The question today is not whether one source of energy is better than another. We must utilize all sources of energy but do so in an environmentally acceptable fashion. This makes nuclear energy a prime candidate for significant expansion, not only in the United States but throughout the world.
Indeed, a number of noted environmentalists have come to endorse nuclear power as the only realistic solution that balances environmental and economic concerns.
“Nuclear power is the only non-greenhouse gas emitting power source that can effectively replace fossil fuels and satisfy global demand” stated Greenpeace Founder Patrick Moore. Dr. James Lovelock, noted Green Party chemist and author of the Gaia hypothesis, recently stated, “Opposition to nuclear power is based on irrational fear fed by Hollywood-style fiction, the green lobbies, and the media. These fears are unjustified and nuclear energy has proved to be the safest of all energy sources.”
| ||CARE's POSITION || |
Nuclear Power is an environmentally responsible pathway to achieve global economic sustainability, environmental quality, and energy security. Its role in a diversified energy portfolio should increase, and, coupled with energy efficiency will provide improved quality of life worldwide.
Fossil fuels are a finite resource whose value transcends the energy sector, and therefore should be managed to the greater good of society. Using fossil fuels for electricity production is less efficient and a different energy future should be planned for.
Greater reliance on nuclear energy for electricity reduces demand for natural gas, freeing up this valuable resource for competing industrial use. It also reduces demand for oil, thereby reducing pressure on the transportation sector. This will extend the inventory of world oil and natural gas, providing time to transition to advanced transportation technologies which do not strictly rely on liquid fossil fuels.
| ||Making Nuclear Fuel || |
- Uranium is a naturally occurring element in ore, found worldwide.
- Uranium ore is mined and purified into uranium oxide, called “yellowcake”.
- Uranium exists in two isotopic forms (235U and 238U) which can be separated in a process referred to as “enrichment” where the 235U is preferentially concentrated.
- The enriched uranium, containing as much as 6% 235U (94% 238U), is formed into fuel pellets which are assembled into fuel rods for insertion into the reactor core.
| ||Making Nuclear Power || |
- Bundles of fuel rods are lowered into a water-cooled pressure vessel located within a concrete “containment vessel” that is designed to survive disasters such as earthquakes, tornadoes and airliner crashes.
- Control rods made of neutron absorbing boron are included in the fuel bundle in order to control and manage the nuclear reactions.
- Control rods are withdrawn allowing fission to begin, releasing large amounts of heat.
- This heat boils water, turning it into steam which drives electric turbines.
| ||Facts || |
- Uranium is a naturally occurring element in the earth’s crust.
- In its natural form,uranium is mostly a mixtture of 2 primary “isotopes”, 238U (~99.3%) and 235U (~0.7%)
- The first, 238U, undergoes neutron capture and slowly decays naturally
- The second, 235U, undergoes neutron capture and then fissions, releasing energy as heat, neutrons, and gamma radiation.
- To be used in U.S. power reactors, the 235U level must be enriched to a level of 3-5%.
- A one-pound chunk of 235U is smaller than a baseball, but has as much energy as one million gallons of gasoline!
- Uranium is a very dense metal, commercially used in armor, armor piercing munitions, and ballast in racing sloops, among other things.
- Countries with large uranium deposits include Australia, Canada, and United States.
- Currently, about 20% of America’s electricity comes from 104 nuclear reactors
- Only about 3-5% of the energy value in a nuclear fuel bundle is actually recovered in any single refueling cycle, meaning that 95-97% of the energy value remains in the spent nuclear fuel.
| ||Pros || |
- Nuclear power is ideal for electricity generation.
- Highly reliable and cost effective as a base load energy source.
- Nuclear power has zero greenhouse gas emissions.
- Uranium is available as a domestic fuel, improving our nation’s energy security.
- Implementation of spent fuel reprocessing and “breeder reactors,” along with the traditional water reactors would result in a very high efficiency fuel consumption scenario, achieving long term electrical energy sustainability.
- Researchers are developing next generation reactors and fuel cycles that will greatly improve safety and efficiency.
| ||Cons || |
- Without reprocessing, spent nuclear fuel remains radioactive for centuries and is difficult to dispose of safely (the waste challenge).
- Enriched uranium and elements from spent fuel reprocessing, such as plutonium, can be used to make nuclear weapons (the proliferation challenge).
- Nuclear facilities represent terrorist targets thereby requiring new security measures (the security challenge).
| ||The Future || |
Researchers at the DOE National Laboratories are working on a variety of advanced reactor concepts to include a family of reactors called fast reactors (FR). FRs differ from today’s reactors in that they can fission (or consume) over 99% of their fuel, while today’s reactors fission only 3-5 percent of their fuel and the other 95-97 percent is declared “spent,” destined for disposal. The waste left behind by FRs is a mixture of fission products that will be harmless within 300 years. In comparison, today’s high-level waste (a signifcant fraction of which is actually usable fuel) will be toxic for thousands of years.
FRs are cooled by liquid metals such as sodium or lead alloys, and are designed so that the fuel elements expand if the reactor overheats. The nuclear reactions stop without the need for human intervention and would prevent accidents like those that occurred at Three Mile Island and Chernobyl.
Researchers are also developing an advanced, passively safe high-temperature reactor known as the pebble bed modular reactor (PBMR). PBMRs fuel comes in the form of tennis sized graphite balls that encase 9 grams of uranium. A 120-megawatt reactor, which could power 56,000 homes for a year, uses 380,000 of these balls. The graphite acts as a neutron moderator and the reactor is cooled by an inert helium gas, which then directly drives an electrical turbine. This eliminates mechanical loops in the reactor and enhances safety. German scientists conducted tests in 1986 in which they tried to melt down a PBMR. As one of the scientists put it afterwards, “the reactor politely refused (to melt down).”
Publicizing these test results and bringing such new and safe reactor designs to market could greatly alleviate public concerns about building new nuclear power plants.
Researchers at the DOE National Laboratories are also working on closed fuel cycle technology wherein spent nuclear fuel is reprocessed to recover the useable fuel fractions and to recycle them into new reactor fuels. The waste resulting from the closed fuel cycle processing represents only a few percent of the initial feed stock, making the eventual waste management issue modest indeed. Performing this level of processing will make the deep geologic repository at Yucca Mountain in Nevada, the only repository the nation will ever need.
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