Nuclear+Waste


 * Nuclear Waste Disposal**

http://maps.grida.no/library/files/existing_radioactive_waste_disposal_and_proposal_alternatives_for_storage_001.jpg

Radioactive Isotopes: The major radioactive elements associated with nuclear waste are Uranium, Plutonium, Radium, and other radioactive elements.

Half-Life: The half-lives of these elements depend on if the element is a low or high level of nuclear waste.

Nuclear waste can be generally classified as either "low level" radioactive waste or “high level" radioactive waste:

-Low Level Nuclear Waste: The level of radioactivity and half-life of the radioactive isotopes in low level waste is relatively small. Storing the waste for a period of ten to fifty years will allow most of the radioactive isotopes to decay in a relatively short amount of time. Low level waste usually includes materials used to handle high radioactive parts of nuclear reactors such as cooling water pipes and radiation suits. It is usually involved in medical procedures with treatments or x-rays, also materials used to handle the highly radioactive parts of nuclear reactors.

-High Level Nuclear Waste: High level waste is generally material from the core of the nuclear reactors or nuclear weapons. This waste includes uranium, plutonium, and other highly radioactive elements produced during fission. This waste includes high level nuclear waste, which has extremely long half-lives. This makes it very hard to dispose of this type of waste because it takes approximately 100,000 or more years to decay. This is a big problem for those who have to store this hazardous material because it must be kept underground for so long.

Transmutation: To dispose of the high level of waste, physicists transmute the long half live elements into less radioactive elements with shorter half-lives. There are two main methods for transmutation of high-level nuclear waste:

-Fast Nuclear Reactors: This method takes elements created by nuclear reactors as byproduct or as their fuel for nuclear weapons and consumes it, leaving less dangerous elements. Isotopes of the elements created as byproducts generally have shorter lives than the original highly radioactive waste used as fuel.

-Hybrid Nuclear Reactor: For the high level radioactive waste, this method produces a sub critical nuclear reactor and bombards the reactor fuel with neutrons. The neutrons then break apart the large elements in the waste, releasing energy used to power neutron source to start fission reaction.

http://www.greenpeace.org.uk/files/images/migrated/MultimediaFiles/Live/Image/7547.jpg

Claus Rolf: A group of physicists believe they have discovered a technique that would cut down the decay time for nuclear waste. Professors Claus Rolfs and his team are examining Radium-226 which has a half-life of 1600 years, and they calculate that the technique could reduce the half life to 100 years or maybe as little as 2 years. Rolf believes that if cooling nuclei in metal enhances fusion then it could enhance the opposite reaction and speed up the rate at which the radioactive particles decay. Thus lowering the half-life and this would affect the needed space to store high-level waste for long periods of time. The process to dispose of waste would take less time and be less hazardous than keeping the harmful radioactive elements underground for thousands of years.

The Yucca Mountain: Yucca Mountain is used to manage and dispose high-level radioactive waste and spent nuclear fuel. Spent nuclear fuel is the radioactive product of electric power generation at commercial nuclear power plants, and high-level radioactive waste is the by-product from production of fissile material at defense facilities. This is done so that it protects health, safety, and the environment. It also improves the national and energy security. The mountain is composed of volcanic material ejected from a now-extinct caldera-forming supervolcano. It is located in a desert on federal land near the Nevada Test Site in Nye County, Nevada. The U.S. Department of Energy began studying Yucca Mountain in 1978 to determine whether it would be good for the nation's first long-term geologic repository for over 144,331,200 pounds of spent nuclear fuel and high-level radioactive waste currently stored at 126 sites around the nation. In October, 2007, the Department of Energy announced it was looking to double the size of the Yucca Mountain repository to a capacity of 288,662,400 pounds. On September 8, 2006 Ward Edward Sproat, a nuclear industry executive, was nominated by President Bush to lead the Yucca Mountain Project. The Department of Energy was to begin accepting spent fuel at the Yucca Mountain Repository by January 31, 1998. However, there have been many delays, and the earliest feasible opening date is now in 2021.

Nuclear Waste Policy Act: In 1982, the United States Congress established a national policy so that they could solve the problem of nuclear waste disposal. This policy is a federal law called the Nuclear Waste Policy Act. Congress based the policy on what most scientists worldwide agreed was the best way to dispose nuclear wastes.

The Nuclear Waste Policy Act: This act made the U.S. Department of Energy responsible for finding a site, building, and operating an underground disposal facility called a geologic repository. The geologic repository was recommended by the National Academy of Sciences in 1957 because they wanted to protect the environment and public health. Disposing the waste in rock deep underground would also provide safety.

http://www.yuccamountain.org/usamap1.gif

The Pro’s and Con’s of Yucca Mountain:

-The Pro’s of Yucca Mountain:
 * Placement of the storage facility will not affect the environment harmfully.
 * The construction of the site will not have a huge impact upon the environment of the Yucca Mountains
 * Air quality will not be decreased.
 * Soil erosion will be sprayed with a soil stabilizer.
 * Wildlife will not be affected by the radiation.
 * The only endangered species near the Yucca Mountains is the desert tortoise and their natural habitat wont be affected.

-The Con’s of Yucca Mountain:
 * Billions of dollars spent on research
 * Transportation related pollution, calculated from the current routes that have been proposed about 185 million gallons of gas will be consumed in the 25 years of transportation. Routes pass or cross vital habitats for species such as wild horses or big game.
 * From calculated equations approximately 209 million pounds of CO2 will be released a year.
 * Yucca Mountain was a poor decision by the United States. Maximum capacity for the storage of 77 000 tons of waste was not made for 80 000 tons of highly hazardous nuclear waste to be stored.

http://www-cmls.llnl.gov/data/assets/images/science_and_technology/materials/yucca_mountain/yucca_2.jpg

The Pro’s and Con’s of Waste Disposal:

-The Pro's of Waste Disposal:
 * Nuclear Waste Disposal keeps radioactive waste contained, which helps make living organism shielded from the radioactivity.

-The Con's of Waste Disposal:
 * Building disposable sites takes careful planning and months to prepare. It needs to be placed somewhere that won't be dug up in the future. A place that is highly stable. Free of earthquakes and other geologic activity.
 * If containers aren't dry they could contaminate water supplies underground.
 * Waste can be radioactive for 250,000 years.
 * The general public most fear aspects of the nuclear fuel cycle.

Bibliography: "Nuclear Reactor." Encyclopædia Britannica. 2008. Encyclopædia Britannica Online. 24 Jan. 2008 Davis, Raymond E. Modern Chemistry. Austin, Texas: Holt, Rinehart, and Winston, 2002. 715-719. "Nuclear Waste Disposal." NMC. 24 Jan. 2008 <[|http://www.nmcco.com/education/facts/waste/yucca.htm>.] "Yucca Mountain." CBS. 24 Jan. 2008.] World Book