Nuclear waste - types, storage, disposal

NUCLEAR WASTE : TYPES , STORAGE , DISPOSAL

Nuclear Waste : Types , Storage , and Disposal

NUCLEAR WASTE : TYPES , STORAGE , DISPOSAL PAGE 1 of 6

Nuclear reactors operate by containing a self-sustaining chain reaction of a few kilograms of fissionable material , either Uranium 235 or Plutonium 239 . The reaction emits fast moving neutrons , which are slowed down by a moderator , normally either water or deuterium . The reaction is controlled by a series of control rods , made of good neutron absorbers like boron or cadmium . Water or liquid sodium is ran through the core , absorbs heat , and

moves to a heat exchanger where clean water is heated to make steam . This steam turns a series of turbines that generate electricity (Giancoli 2005 ,

.868-869

One of the major concerns with nuclear power is the contaminated waste that is produced . This waste consists of fission fragments from the reaction , the reactor core , control rods , and the water used as a moderator . The release of radioactive waste into the environment is a major health concern . Nuclear power accidents in the United States (Three Mile Island ) and the Soviet Union (Chernobyl ) demonstrate the danger and havoc a nuclear event would cause (Giancoli 2005 ,

br 869-870 . Safe storage and disposal of the waste is essential if nuclear power is to be viable . This will investigate the types storage , and disposal of nuclear waste

Nuclear waste is generally divided into three general types . High level waste includes the spent reactor fuel and the chemical solutions that are used during the reprocessing of that fuel (Andryszewski 1995 br

. 22 Gephart 2003 ,

. 5 .9 . The fission fragments from the reaction are included in this solution (Giancoli 2005 ,

. 868 . A one million kilowatt nuclear reactor will produce about one ton of these fission fragments each year (Connolly 1985 ,

. 10

Transuranic waste contains radioisotopes that are heavier than uranium This would include plutonium . These elements do not occur in nature and are the products of breeder reactors (Giancoli 2005 ,

. 870 . In to be considered transuranic waste , the half life of the

NUCLEAR WASTE : TYPES , STORAGE , DISPOSAL PAGE 2 of 6

element must be grater than 20 years (Gephart 2003 ,

. 5 .9 . The half life of plutonium is 24 ,000 years (Giancoli 2005 ,

870

Low level waste consists of items such as contaminated clothing and equipment . The half lives of the component radio isotopes are either very short or very long . Compared to high level or transuranic waste the level of radioactivity that emits from low level waste is small , but still dangerous to unshielded organisms (Andryszewski 1995 ,

. 22

Low level waste is further classified into three subcategories . Class A waste has the lowest level of radiation and is the easiest to dispose of . Class B waste has a higher concentration of radioisotopes . The half life of these isotopes is still relatively short . Class C waste is the most dangerous and difficult to handle low level waste . Class C waste must be disposed of at a site...