Implications of Nuclear Waste
May 4th, 2007Nuclear waste has led to some of the most common concerns for personal safety in our country. With numerous nuclear power plants spread throughout the country and each producing waste from plutonium and uranium, there must be locations to house these radioactive byproducts. While typically dealing with wastes is not an intricate problem, nuclear waste takes thousands, if not millions, of years to become stable enough to not emit radioactivity. These high quantities of waste emit alpha, beta, and gamma rays making it difficult for legislation to be passed to allow storage facilities anywhere near populated areas. There are also high concerns for countries with nuclear programs much poorer than the United States, and international regulations try to insure all nations meet basic requirements.
The history of nuclear energy begins as a dark one. The major attempts to obtain results from fission were due in part to World War II and the race to build the atomic bomb. Albert Einstein and Robert Oppenheimer were the most knowledgeable physicists on the topic of atomic understanding. The Manhattan Project created the first successful division of an atom by fission. This top secret assignment was located at Hanford in New Mexico and resulted in the creation of the first two atomic bombs used at Hiroshima and Nagasaki. Once the atomic bomb was created and used, people began to speculate on a peaceful use of this amazing technology. In 1956, the first nuclear reactor was created to provide energy with virtually no form of pollution. This led to nearly 50 years of constant development of nuclear reactors.
Robert Oppenheimer was one of the most influential men in the development of atomic energy. Having worked with Nils Bohr in Europe he returned to the United States in the early thirties to begin work that would end with the first atomic bombs. He directed the Manhattan Project and even began work on the hydrogen bomb. However, during his work with the more in-depth aspects of atomic energy a government investigation determined that Oppenheimer was too much of a left-wing activist. They accused him of associating with communists and revoked his security clearances, leaving him with no means to continue his research. Although he was eventually forgiven for his political views Oppenheimer never returned to the research field, and there is no telling how greatly his works could have furthered our knowledge.
The chief element used to produce nuclear energy by fission is uranium. Fission is the splitting of a potentially unstable element’s nucleus. Fission, unlike fusion, creates radioactive products after the principal element is split to produce energy. Such a splitting could be shown by.
The process can best be described by using marbles in a circle. To represent the nucleus, a large number of marbles would be placed next to one another in a tightly packed circle. Each of these marbles would represent the core components of the nucleus: protons and neutrons. This element would be inside a controlled reactor where an electron would be fired at the nucleus, represented by another marble which could be a neutron. When this marble struck the circle of marbles each would go spinning off, this is how a nuclear chain reaction begins and huge sums of energy are released from each split nucleus. These marbles, which were divided, can create numerous elements which are the actual by-products producing radioactivity, and are mainly cesium 137 and strontium 90.
The most common form of radiation from nuclear material is the alpha particle. Alpha rays are given off as an element decomposes and releases a helium atom. When this helium atom is released it changes the atomic number and mass of the previous element allowing it to slowly become a more stable element. Alpha particles are typically easy to contain, being able to be deflected by materials as simple as paper or even skin. While the particles may be stopped by the skin, they will cause cancer if inhaled or ingested repeatedly. Elements which mostly emit alpha particles and an atomic number over 92 are known as transuranic, allowing for the distinction of transuranic wastes which are sometimes referred to as “TRU waste”. These transuranic elements are also defined by the speed at which they decay, which is over 100 nanocuries per gram of waste. A curie is defined as 37 billion disintegrations per second of an atom, and was discovered by the Curie couple who studied the decaying of radium. These transuranic properties are typically found in plutonium 238, 239, 240, 241, and 242 as well as americium 241 and curium 244. Each decays for hundred of thousands of years, requiring the storage facility used to be extremely secure.
The three most common forms of radiation from wastes are alpha, beta, and gamma particles. Alpha particles are characterized by how they emit a helium atom during decay although it is also very slow and fails to penetrate into most objects.
Shown here is the element of Radium broken down into a helium atom and a Radon atom. Beta radiation moves much more quickly and can also be more dangerous as it has substantial penetrating power. Although two atoms aren’t released from the radiation an electron is released, resulting in the quicker movement.
Shown here is the element of Radium broken down into a helium atom and a Radon atom. Beta radiation moves much more quickly and can also be more dangerous as it has substantial penetrating power. Although two atoms aren’t released from the radiation an electron is released, resulting in the quicker movement.
This equation shows how Carbon is broken down into an atom of Nitrogen and one electron. This electron can be very dangerous and can only be blocked by more serious measures such as aluminum or wood. The last major form of radiation found in nuclear decay is the gamma ray. Gamma rays are a form of electromagnetic radiation and affect us every time we step outside. It is because of gamma rays that people get sunburn. Our atmosphere is the major insulating force, although concrete and lead can also stop the rays. Gamma rays are found on the same spectrum as x-rays and radio waves, although they have the highest frequency of any electromagnetic wave.
This equation shows how Carbon is broken down into an atom of Nitrogen and one electron. This electron can be very dangerous and can only be blocked by more serious measures such as aluminum or wood. The last major form of radiation found in nuclear decay is the gamma ray. Gamma rays are a form of electromagnetic radiation and affect us every time we step outside. It is because of gamma rays that people get sunburn. Our atmosphere is the major insulating force, although concrete and lead can also stop the rays. Gamma rays are found on the same spectrum as x-rays and radio waves, although they have the highest frequency of any electromagnetic wave.The storage areas for radioactive elements are extremely limited. At the moment there is only one permanent facility in the continental United States. It is run by the military to hold decaying material used by the government or for weapon purposes. A permanent storage facility to be used by civilians is under construction in the Yucca Mountains 100 miles north of Las Vegas. In the mean time, nuclear waste has been held at locations which are little better than warehouses in many cases. These storage areas are scattered throughout the country and pose serious risks of exposure to the populations near them if something were to go wrong. To make matters worse, there is no real safe method to transporting nuclear waste. While it is never transported by plane the only other method is to have the waste move by train and truck across the hundreds of miles in this country. Trains don’t always lead to storage facilities however, requiring trucks to be used frequently. Precautions are taken to make sure the trucks only travel on highways and that back roads aren’t used. There is still always the possibility of a truck being involved in an accident, in which case the results could be disastrous.
The facility being constructed in the Yucca Mountains rivals its military installation counterpart in both precautions and storage capacity. It is located in an area with a stable and dry geological bed which dissipates the risk of an earthquake or moving plates causing contaminants to be released. The facility itself is 600 meters underground, with only entry shafts between itself and the surface. These entry shafts lead into a main chamber which contains hundreds of burial vaults. Each burial vault is capable of housing hundreds of tons of radioactive material which will then be filled with material able of absorbing the alpha, beta, and gamma particles emitted. Allowing for the most protective and secure housing facility aside from possible storage in space.
The most pressing concern of populations near the vicinity of a nuclear waste disposal site is the risk of exposure to the radioactive elements. The most common and most easily released element is radon. It is a byproduct of radium which is found in nearly all radioactively decaying substances, and can escape as a gas which is fatal upon exposure. Radon is one of several TRU wastes which transmit an alpha ray. The government has set a standard for civilian exposure to radioactivity which is limited to 1 mSv or millisievert. A millisievert is the average amount of radioactivity a person is exposed to over the course of a year. If this limit is exceeded, the chance of the individual to contract cancer is increased dozens of times.
The ultimate nuclear disaster would be a repeat of the Chernobyl incident. During the duration of the Cold War the Soviet Union had created multiple nuclear reactors for both energy and material for weapons. Under trained personnel were unable to deal with a failure in the steam system of the reactor. The ensuing explosion caused five percent of the radioactive material to be released into the environment. Fallout from the facility has covered the Ukraine and Southeastern Europe to varying degrees. Over fifty deaths have been attributed to the accident and have led to only a handful of new reactors being built since.
One common instance where radiation is used is during carbon dating. This technique measures the amount of half lives that a particular object has gone through to discover its age. Radiation can also be used by doctors to treat cancer or measure metabolisms of individuals. Smoke detectors are also examples of a common usage for radioactivity. They use Americium 241 which ionizes the air around it. When smoke hits the ionized air it changes the current and sounds the alarm. Even Gamma rays can be used in small quantities to sterilize food even after it has been packaged or to clean hospital utilities.
Nuclear energy has to compete with other alternate forms of energy. Solar and wind energy is widely used in Europe as it has no by-products. However, these alternate energy sources can not match nuclear energy in many instances. Reliability is one major downfall to these alternate methods, as there is not always a gust of wind, and there is not light 24 hours a day. These facilities also require a large amount of space for a relatively small yield in energy. While nuclear energy is in no means a perfect source of power, it does allow for the smallest amount of waste with the greatest yield of energy.
Although there are several dangers involved in the transportation and storage of radioactive waste, the advantages are certainly worth the risks. With proper precautions taken, nuclear energy can be a safe and effective means to provide power without negative drawbacks such as global warning. It would also greatly reduce our country’s dependence on foreign sources of energy, while allowing us to spend that money in other endeavors. It is evident that with the increase in energy demands nuclear power has the potential to provide the world with clean and effective sources of power, whether it is fission or fusion.
