McNAMARA: What Is Radioactive Waste?
Posted: Thu Sep 20, 2012 9:50 amWhat is Radioactive Waste?
by Pat McNamara September 18, 2012
Radioactive waste is created at every stage of the nuclear fuel cycle and falls into one of three categories; low, medium and high. These "levels" do not refer to the toxicity of the wastes, but rather to their source. High-level waste refers to fission products and spent fuel assemblies from reactors. Medium-level waste comes from decommissioning, reprocessing or fuel fabrication. Low level waste embraces everything else. Low-level waste is a misnomer as it can be as toxic as high-level waste.
Decay Products
Dealing with nuclear material is complicated by the fact that it is constantly decaying. For instance, radium decays into radon gas which in turn decays into radioactive bismuth, lead and polonium. Each of these substances decays into another material with unique properties. The Radium decay chain, starting with uranium 238, consists of 20 different substances until it becomes stable as lead. Heat and radioactivity are given off when decay occurs.
Half Life of Radioactive Material
The term half-life refers to the amount of time required for half of a radioactive substance to decay to the next link in the chain. The half-life of radium is 1602 years. If you start with a kilogram of radium, you will only have half a kilogram after 1602 years. It will be just as radioactive as the day it started decaying, but there will be only half as much of it. As soon as it starts to decay, it creates radon gas which has a half-life of 3.82 days. After 3.82 days, only half of the radon gas remains but polonium, bismuth and lead have been created. Within days of the radium starting to decay, you have five contaminating substances to deal with.
Mine Tailings
The decay process is what causes mine tailings to be so dangerous. Once the uranium is removed from the ore, all of these decay products remain in the tailings which are dumped in lakes and in open pits where they contaminate our water, land and air. All of these substances are naturally occurring. There are over 200 million tones of radioactive tailings in Saskatchewan, Ontario and the Northwest Territories.
Fission Products
Uranium itself decays very slowly and is not as radioactive as most of its decay products. However, once the uranium atom is split in a nuclear reactor or during the detonation of an atomic bomb, over 300 radioactive substances (radionuclides) are created from the fragments of the uranium atom. Most of these do not occur in nature and all have their own decay chain and their associated dangers.
Spent Reactor Fuel
The spent fuel rods that are removed from the reactors contain the 300+ radionuclides mentioned above, each giving off heat and radioactivity. The spent fuel rods are so radioactive when they come out of a reactor that a person would die within minutes if he was within a metre of them. The spent bundles are placed in a giant swimming pool for eight to ten years to allow them to cool down and allow the radioactivity levels to be reduced. The spent rods are then placed in metal and concrete containers and placed on storage pads at the reactor site.
Nuclear Waste Management Organization (NWMO)
The NWMO is comprised of the owners of the nuclear reactors in Canada and its mandate is to find a method of disposing of the spent reactor rods which are piling up at the reactors. They want to bury this waste deep underground in an isolated community; deep geological storage. They will place the spent fuel rods in copper containers, inside steel containers and surround them with bentonite clay 500+ metres underground in the Canadian Shield. They claim the containers will last for 100,000 years without causing any contamination problems. Unfortunately, they didn’t factor in the amount of helium that is given off during the decay process. Dr. Chris Busby from Great Britain has been at the forefront of research showing the buildup of helium in the canisters will cause them to explode after 800-1000 years. No one can predict the effect the explosion of thousands of canisters underground will have on the surrounding area and the northern hemisphere of the planet.
Reprocessing Spent Reactor Fuel
One of the radionuclides contained in the spent fuel rods is plutonium which makes up one per cent of the contents. Plutonium can be used in a nuclear reactor but the most common use for it is in nuclear bombs. The Canadian government and the nuclear industry want to recover the plutonium. The process involves chopping up the highly radioactive spent fuel rods and dissolving them in boiling nitric acid. The process causes the release of radioactive gases and the contamination of the nitric acid which has to be dealt with as high-level radioactive waste. The plutonium and uranium are separated from hundreds of other radioactive products. Contrary to the industry’s assertion, there is more waste at the end of reprocessing than what they started with. Reprocessing spent reactor rods has been a failure in every country that has tried it.
Waste From Other Countries
The Canadian government has been trying to import spent reactor fuel from other countries since PM Harper signed on to George Bush’s Global Nuclear Energy Partnership (GNEP) in 2006. The GNEP stipulated that spent reactor fuel from other countries would be returned to the country that supplied the uranium in the first place. As Canada supplied 40% of the uranium for reactors around the world, we would become home to 40% of the global high-level waste. The GNEP was cancelled by U.S. President Obama in 2009. The Saskatchewan government picked up the ball in 2009 when it included its intention to set up a high-level waste processing facility as part of its Uranium Development Partnership. This proposal was defeated by residents when 88% of respondents opposed the project.
Waste From United States
No country in the world has been able to dispose of their high-level waste. Sweden is the closest to starting disposal but they intend to use the same flawed method described above. There’s an urgency around the world to dispose of this material as it has been piling up for fifty years at reactor sites. Eleven states in the U.S. have placed moratoriums on further reactor construction until the waste issue has been solved. The U.S. Supreme Court recently ordered that no licenses be given to new reactors or life extensions on old ones until a satisfactory method of high-level waste disposal is developed. We must be vigilant in Canada to prevent any of the American high-level waste from coming here. The Free Trade Agreement prevents us from stopping the influx of waste once it gets started.
Pat McNamara
by Pat McNamara September 18, 2012
Radioactive waste is created at every stage of the nuclear fuel cycle and falls into one of three categories; low, medium and high. These "levels" do not refer to the toxicity of the wastes, but rather to their source. High-level waste refers to fission products and spent fuel assemblies from reactors. Medium-level waste comes from decommissioning, reprocessing or fuel fabrication. Low level waste embraces everything else. Low-level waste is a misnomer as it can be as toxic as high-level waste.
Decay Products
Dealing with nuclear material is complicated by the fact that it is constantly decaying. For instance, radium decays into radon gas which in turn decays into radioactive bismuth, lead and polonium. Each of these substances decays into another material with unique properties. The Radium decay chain, starting with uranium 238, consists of 20 different substances until it becomes stable as lead. Heat and radioactivity are given off when decay occurs.
Half Life of Radioactive Material
The term half-life refers to the amount of time required for half of a radioactive substance to decay to the next link in the chain. The half-life of radium is 1602 years. If you start with a kilogram of radium, you will only have half a kilogram after 1602 years. It will be just as radioactive as the day it started decaying, but there will be only half as much of it. As soon as it starts to decay, it creates radon gas which has a half-life of 3.82 days. After 3.82 days, only half of the radon gas remains but polonium, bismuth and lead have been created. Within days of the radium starting to decay, you have five contaminating substances to deal with.
Mine Tailings
The decay process is what causes mine tailings to be so dangerous. Once the uranium is removed from the ore, all of these decay products remain in the tailings which are dumped in lakes and in open pits where they contaminate our water, land and air. All of these substances are naturally occurring. There are over 200 million tones of radioactive tailings in Saskatchewan, Ontario and the Northwest Territories.
Fission Products
Uranium itself decays very slowly and is not as radioactive as most of its decay products. However, once the uranium atom is split in a nuclear reactor or during the detonation of an atomic bomb, over 300 radioactive substances (radionuclides) are created from the fragments of the uranium atom. Most of these do not occur in nature and all have their own decay chain and their associated dangers.
Spent Reactor Fuel
The spent fuel rods that are removed from the reactors contain the 300+ radionuclides mentioned above, each giving off heat and radioactivity. The spent fuel rods are so radioactive when they come out of a reactor that a person would die within minutes if he was within a metre of them. The spent bundles are placed in a giant swimming pool for eight to ten years to allow them to cool down and allow the radioactivity levels to be reduced. The spent rods are then placed in metal and concrete containers and placed on storage pads at the reactor site.
Nuclear Waste Management Organization (NWMO)
The NWMO is comprised of the owners of the nuclear reactors in Canada and its mandate is to find a method of disposing of the spent reactor rods which are piling up at the reactors. They want to bury this waste deep underground in an isolated community; deep geological storage. They will place the spent fuel rods in copper containers, inside steel containers and surround them with bentonite clay 500+ metres underground in the Canadian Shield. They claim the containers will last for 100,000 years without causing any contamination problems. Unfortunately, they didn’t factor in the amount of helium that is given off during the decay process. Dr. Chris Busby from Great Britain has been at the forefront of research showing the buildup of helium in the canisters will cause them to explode after 800-1000 years. No one can predict the effect the explosion of thousands of canisters underground will have on the surrounding area and the northern hemisphere of the planet.
Reprocessing Spent Reactor Fuel
One of the radionuclides contained in the spent fuel rods is plutonium which makes up one per cent of the contents. Plutonium can be used in a nuclear reactor but the most common use for it is in nuclear bombs. The Canadian government and the nuclear industry want to recover the plutonium. The process involves chopping up the highly radioactive spent fuel rods and dissolving them in boiling nitric acid. The process causes the release of radioactive gases and the contamination of the nitric acid which has to be dealt with as high-level radioactive waste. The plutonium and uranium are separated from hundreds of other radioactive products. Contrary to the industry’s assertion, there is more waste at the end of reprocessing than what they started with. Reprocessing spent reactor rods has been a failure in every country that has tried it.
Waste From Other Countries
The Canadian government has been trying to import spent reactor fuel from other countries since PM Harper signed on to George Bush’s Global Nuclear Energy Partnership (GNEP) in 2006. The GNEP stipulated that spent reactor fuel from other countries would be returned to the country that supplied the uranium in the first place. As Canada supplied 40% of the uranium for reactors around the world, we would become home to 40% of the global high-level waste. The GNEP was cancelled by U.S. President Obama in 2009. The Saskatchewan government picked up the ball in 2009 when it included its intention to set up a high-level waste processing facility as part of its Uranium Development Partnership. This proposal was defeated by residents when 88% of respondents opposed the project.
Waste From United States
No country in the world has been able to dispose of their high-level waste. Sweden is the closest to starting disposal but they intend to use the same flawed method described above. There’s an urgency around the world to dispose of this material as it has been piling up for fifty years at reactor sites. Eleven states in the U.S. have placed moratoriums on further reactor construction until the waste issue has been solved. The U.S. Supreme Court recently ordered that no licenses be given to new reactors or life extensions on old ones until a satisfactory method of high-level waste disposal is developed. We must be vigilant in Canada to prevent any of the American high-level waste from coming here. The Free Trade Agreement prevents us from stopping the influx of waste once it gets started.
Pat McNamara