Nuclear PowerMost of the world’s electricity is generated by either thermal orhydroelectric power plants. Thermal power plants use fuel to boil water whichmakes steam. The steam turns turbines that generate electricity. Hydroelectricpower plants use the great force of rushing water from a dam or a waterfall toturn the turbines.
The majority of thermal power plants burn fossil fuelsbecause thermal power plants are cheaper to maintain and have to meet less ofthe governments requirements compared to nuclear power plants. Fossil fuels arecoal and oil. The downfall of using fossil fuels is that they are limited.Fossil fuels are developed from the remains of plants and animals that diedmillions of years ago. Burning fossil fuels has other downfalls, too. All theburning that is required to turn the turbines releases much sulfur, nitrogengases, and other pollutants into the atmosphere. The cleanest, cheapest, andleast polluting power plant of the two types is the hydroelectric power plant.
The main reason most countries use thermal versus the hydroelectric is becausetheir countries don’t have enough concentrated water to create enough energy togenerate electricity. (World Book vol. 14, 586) Nuclear power plants generateonly about eleven percent of the world’s electricity.
There are around 316nuclear power plants in the world that create 213,000 megawatts of electricity.(INFOPEDIA) Radioactive, or nuclear, waste is the by-product of nuclear fission.Fission occurs when atoms’ nucleus’ split and cause a nuclear reaction.
(GeneralInformation) When a free neutron splits a nucleus, energy is released alongwith free neutrons, fission fragments that give off beta rays, and gamma rays.A free neutron from the nucleus that just split splits another nucleus. Thisprocess continues on and is called a chain reaction. (World Book vol.
14, 588)The fission process is used to create heat, which boils water inside the nuclearreactor. The steam that boiling the water makes is used to turn turbines, whichin turn, generate electricity. Fission happens inside a carefully monitorednuclear reactor, when being used in a nuclear power plant. The fission processthat nuclear power plants use spends approximately 30,000 tons of highlyradioactive waste a year.
(General Information)In a nuclear power plant, Uranium is used as fuel to boil the water forthe steam that makes the turbines turn. So, uranium is, in a sense, the coal ofa coal-fired power plant.When fueling nuclear power plants, the uranium arrives as uranium-enriched pellets. These pellets are an equivalent to one ton of coal. Thepellets are sealed in tubes that are made of a strong heat- and corrosion-resistant metal alloy. This metal alloy will protect people and the environmentfrom the high levels of radiation that the uranium is giving off.
The tubes arebundled together to make a fuel assembly. The assemblies are put inside thereactor to create heat that will boil the water. The fuel assemblies are useduntil they are depleted. A fuel assembly is depleted when it no longer givesoff enough energy to turn the turbines.
Once every year, one third of thenuclear fuel in a reactor is replaced with fresh fuel. The used-up fuel iscalled spent fuel. Spent fuel is highly radioactive and is the primary form ofhigh-level nuclear waste. (General Information)High-level radioactive waste is the by-product of commercial nuclearpower plants generating electricity, and from nuclear materials production atdefense facilities.
This high-level waste must be isolated in a safe place forthousands of years so its radioactivity can die down and not be harmful topeople and the environment. The name of the “safe place” that the Department ofEnergy is trying to make is called a repository. But until a repository is made,spent fuel and high-level waste is being stored in temporary storage facilitiescalled dry casks and cooling pools. By the end of the year 2000, there will bemore than 40,000 metric tons of high-level waste in casks and storage pools.There will also be more than 8,000 metric tons of high-level waste from defenseprograms.
The high-level waste from defense programs is currently being storedin Idaho, South Carolina, and Washington. (General Information)Reprocessing is the chemical process by which uranium and plutonium arerecovered from spent fuel. This means that it is the recycling process of high-level waste.
The reason private industries aren’t reprocessing their high-levelwaste is because reprocessing costs more than mining and making new fuel.Several countries that actually care about their environment reprocess theirhigh-level waste. (General Information)Dry casks and cooling pools are being used to store spent fuel in powerplants everywhere. (Shulman, 14) Dry casks and cooling pools are only meant tobe temporary storage facilities until a permanent repository is made.
The needfor a permanent disposal for high-level radioactive waste is becoming moreurgent every year because the dry casks and cooling pools at nuclear powerplants are filling up. A dry cask is a concrete of steel container that protectsthe outside world from its radioactive innards. A cooling pools is a pools ofwater that the spent fuel is put into. The water is a radioactive shield andcoolant. (General Information) The cooling pools were supposed to contain nomore than 400 fuel assemblies, approximately 80,000 rods. The pools containover four times as much of the spent fuel that they’re supposed to.
Nearly allof the nations older power plants are in this state of overload. In the late1980’s, government industry researchers became concerned that if the rods weretoo closely stored in the pools, a nuclear reaction would occur. Whenresearched further, the chain reaction theory became very remote. News of thisresulted in even more densely packed cooling pools. (Shulman, 14) The coolingpools are a type of concrete warehouse.
Inside the warehouses are steel casketscontaining the spent fuel rods and cooling pools. Scientists say that thecooling pool prevents the spent fuel to explode, but the extreme weight of thefuel inside the warehouses might cause the structures to rupture, especially inthe case of an earthquake. (Shulman, 15)A repository is a storage facility that stores high-level nuclear wastedeep underground so the waste can not harm or effect people or the environment.(DOE’s Yucca Mountain Studies) With the technology that we humankind havetoady.
Scientists believe it to be possible to make a repository somewhere.The guidelines of a repository are mainly if the geologic location will work out(i.e. will an earthquake be able to rupture it, will water be able to corrodethe repositories outer wall.).To make sure that the repository would be able to stay unscathed forthousands of years, scientists in all areas of science are making predictions ofwhat could happen over the time period. According to U.
S. EnvironmentalProtection Agency (EPA) standards, a repository may pose no greater threat thanunmined uranium from which the high-level waste was produced.The repository the DOE is wanting to make has to be proven that it willstill be isolated underground in 10,000. After this extensive time, the high-level waste should no longer be radioactive enough to harm the public health.(General Information)A rem is a unit scientist use to measure radiation exposure. Over apersons lifetime, they usually receive 7-14 rems of natural sources of radiation,such as cosmic rays and ultraviolet rays from the sun. On a single exposure of5-75 rems, there are few to no noticeable symptoms.
For someone to receive 75-200 rems of exposure, vomiting, fatigue, and loss of appetite would occur.Recovery would take a few weeks. If someone were to be exposed to more than 300rems, severe changes in blood cells and hemorrhage takes place. If someone wereto receive more than 600 rems, symptoms would be hairloss, loss in your bodiesability to fight infection and usually results in death.
(World Book vol. 16,79)As you can see, the effects of radiation sickness is not too pleasant.The main reason for building a repository is to keep people and the environmentsafe from deadly radiation.Bibliography”DOE’s Yucca Mountain Studies.” A repository is an enormous challenge. URL:http://www.ymp.
gov/faq/facts/geninfo/y0343p.htm (4 Feb. 1997)”General Information.
” What is nuclear fuel and waste? URL:http://www.ymp.gov/faq/facts/geninfo/Y338P.HTM (4 Feb. 1997)INFOPEDIA. Vers. 1.
5. Computer software. Future Vision Multimedia, 1995. IBMWindows 3.1, 30KB, CD-ROM.
Shulman, Seth. “Waiting Game for Nuclear Waste.” Technology Review Aug. – Sept.1992: 14-15.World Book.
22 Volumes. Vol.14 and 16. Chicago: World Book, Inc., 1988 Business