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Q&A on Plutonium/MOX | Safety issues around MOX fuel | MOX makes nuclear bombs | Plutonium Shipments |

Questions and Answers on Plutonium/MOX

What is plutonium?
Why is plutonium dangerous?
Why is plutonium used in nuclear weapons?
How do they get plutonium out of the nuclear reactor?
What is nuclear reprocessing?
What is plutonium MOX fuel?
What's the problem with MOX fuel?
Is transporting MOX fuel safe?
Is MOX fuel economic?
Why is this upcoming plutonium shipment from Charleston to Cherbourg said to be important for the US, and why is it important to stop this particular shipment from taking place?
Why does Japan want MOX fuel?

What is plutonium?

When uranium is put into a nuclear reactor as a fuel, the resulting nuclear reactions create a large number of radioactive substances of which plutonium is one. Other radioactive substances created include caesium, ruthenium, iodine, krypton and strontium. Since plutonium requires a sustained nuclear reaction to create it, plutonium does not occur naturally in the environment. The only background environmental sources of plutonium are from nuclear power production, nuclear weapons production and nuclear weapons testing.

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Why is plutonium dangerous?

Plutonium has only existed in the environment since the first atomic bomb was detonated in the US in 1945. As a result very little is known about how plutonium behaves in the environment and in the human body. What is known is that plutonium is a very toxic and radioactive substance that has no safe levels of exposure to the human body. There is no safe dose.

Plutonium is known to cause cancer in people exposed. It is recognised that even inhalation of one thousandth of one gram of plutonium can lead to cancer. Plutonium once inside the human body will remain there for a very long period of time - longer than the average life of a person. Plutonium therefore stays within the body exposing very sensitive parts of the body to damaging radiation which can lead to genetic damage that can cause cancer or other health effects such as birth defects in offspring.

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Why is plutonium used in nuclear weapons?

The only reason governments researched nuclear energy during the 1940s and 1950s was to develop nuclear bombs. Although nuclear bombs can be made from highly enriched uranium, most of the nuclear weapons countries have decided to use plutonium. This is because plutonium is more 'reactive' in its normal state. In other words it takes less extra radiation to be bombarded at the plutonium to cause a supercritical mass which leads to a runaway nuclear chain reaction that explodes into a nuclear fireball. This means that a nuclear bomb can be made much smaller and fit into a missile, for example, than the bulkier uranium.

Plutonium can be made very pure for nuclear weapons. As the level of impurities in the plutonium decreases the explosive force can be increased. This pure form of plutonium is called 'weapons grade'. However even plutonium that has relatively high levels of impurities, such as that used in nuclear power stations, can be used as a nuclear explosive. Such a 'reactor grade' plutonium bomb has been successfully tested in the US nuclear weapons testing program.

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How do they get plutonium out of the nuclear reactor?

Once the uranium fuel rods in a nuclear reactor reach the end of their useful life (usually around three years) the fuel is unloaded and treated as highly radioactive nuclear waste. The waste nuclear fuel is so radioactive that it generates a large amount of heat and needs constant cooling - this is usually done by submerging the waste fuel rods in huge ponds of water at a nuclear power station.

Some countries with nuclear power have decided to use a nuclear process to extract the plutonium from the waste fuel rods. This process is called nuclear reprocessing. Nuclear reprocessing is crucial to produce plutonium for nuclear weapons - all the countries with plutonium based nuclear weapons have reprocessing facilities.

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What is nuclear reprocessing?

Reprocessing is carried out at very large facilities. Once the waste nuclear fuel rods have cooled a little, after about one to three years, the rods are cut into pieces - this releases all the radioactive gases stored inside the metal fuel rods and most of these gases are discharged into the atmosphere.

The pieces of waste fuel rods are then tipped into a large steel vat of boiling nitric acid. Here the nitric acid dissolves the nuclear fuel, but leaves the metal pieces of the rods intact. This mixture is then sieved to take out the metal pieces of rods and this is stored as intermediate nuclear waste. This waste is still extremely radioactive and requires looking after for thousands of years.

The remaining liquid nuclear waste is then pumped through a large number of chemical processes that use solvents. This slowly extracts out the plutonium and uranium from the mixture. The remaining liquid waste is still very radioactive and gives off huge amounts of heat and requires constant cooling.

Nuclear reprocessing creates a great deal of waste from all the machinery, buildings, liquids and chemicals used, filters, clothing of the nuclear workers, etc. As a result reprocessing creates up to 180 times the volume of nuclear waste compared to the volume of the original waste nuclear fuel.

The resulting high-level liquid waste that requires constant cooling still contains as much radioactivity as the original waste fuel - reprocessing does not reduce the radioactivity of the waste

At most nuclear reprocessing facilities the resulting low level liquid wastes are discharged into rivers or the sea via pipelines. The two largest reprocessing facilities in Europe, Sellafield in northern Britain and La Hague in northern France have some of the world's highest radioactive liquid waste discharges into the sea - accounting for over 97 per cent of all the radioactive discharges from all nuclear facilities in Europe.

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What is plutonium MOX fuel?

MOX fuel stands for Mixed Oxide fuel. This means that both plutonium and uranium are mixed in the nuclear fuel. The plutonium used is usually from the reprocessing operations. However the uranium used is usually freshly mined uranium and not the uranium recovered by reprocessing. This is because the reprocessed uranium still contains small amounts of radioactive waste and therefore many nuclear power companies do not want to use it in their reactors.

The uranium and plutonium are mixed together as a powder and then turned into a ceramic fuel pellet measuring about 2cm high by 1cm wide. These MOX pellets are then loaded one on top of the other into long fuel 'pins'. These fuel pins are made of metal and are hollow and can be up to 3 metres long.

Usually there are some 300 pellets in each fuel pin. Each MOX fuel pin is then placed with others in a fuel 'assembly' that has around 289 pins in total (17 pins high and 17 pins wide). This finished MOX fuel assembly is what is finally loaded into the nuclear reactor.

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What's the problem with MOX fuel?

Most nuclear power stations were designed and built to take only uranium fuel. When plutonium MOX fuel is placed in the reactor instead, the whole safety of the reactor is reduced. This is because plutonium is more 'reactive' - which is why nuclear bomb makers like it.

This increase in 'reactivity' inside the nuclear reactor is more than the original reactor design allows for. This means that additional measures and modifications are required to the reactor, increasing the risk of accidents.

Plutonium MOX fuel becomes hotter and more radioactive than the normal uranium fuel and this can lead to the reactor safety margins being reduced. Therefore in any type of loss of coolant accident, (one of the worst types of reactor accident and similar to the 1979 Three Mile Island Accident in the USA), the hotter, more radioactive MOX fuel can cause increased localised melting of the fuel in the reactor.

This melting in the reactor's core can spread to other fuel in the reactor and start the catastrophic 'meltdown' accident, as at Three Mile Island nuclear power station.

Recent scandals in Japan surrounding the deliberate falsification of crucial safety data in British-made MOX fuel that was delivered to Japan in October 1999, has exposed even further safety concerns about using MOX. The falsification related to measurements made of the diameter of the MOX fuel pellets. This data is crucial because any pellets that are too large or too small should be rejected and not put into the fuel assemblies. This is because once inside the reactor, the wrong sized pellets can vibrate or expand and rupture the metal fuel pins, releasing radioactivity into the reactor and increasing the risk of a meltdown accident.

As well as causing safety problems in the reactor, plutonium MOX fuel leads to increased hazards for the workers involved in making the fuel. The plutonium gives off more radiation than the uranium and therefore increases the radiation exposure to workers. Also, once the MOX fuel is finished in a nuclear reactor, it is much more radioactive and hot - this greatly exacerbates the already severe problems of dealing with highly radioactive waste nuclear fuel.

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Is transporting MOX fuel safe?

The release of even a small amount of the plutonium in MOX fuel as a result of an accident during transport could lead to widespread environmental, health and economic impacts for the surrounding area.

The containers used for transporting the plutonium MOX fuel to Japan are only tested to a fire of 800 degrees centigrade for 30 minutes. According to worldwide statistics the average fire on ships burn for 23 hours at higher temperatures.

Tests on plutonium MOX fuel exposed to air has shown that it can start to be broken down within 15 minutes in temperatures of only 430 degrees centigrade. Once the plutonium fuel starts to break up, breathable particles of plutonium can escape into the air and be blown far from the scene of the accident depending upon the weather conditions. Such plutonium particles would be a very serious health hazard to anyone who breathed them in.

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Is MOX fuel economic?

No. The average cost of manufacturing MOX fuel is between three and eight times more expensive than normal uranium fuel. This is because the radiation exposure to the workers making the fuel has to be reduced and this leads to many cost increases.

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Why is this upcoming plutonium shipment from Charleston to Cherbourg said to be important for the US, and why is it important to stop this particular shipment from taking place?

The U.S. Government claims that it needs to proceed with this shipment as it essential to plans to make experimental nuclear fuel out of "surplus" military plutonium. The U.S. does not have a factory to make MOX fuel from plutonium, so has contracted the job to Areva/Cogema in France. The pure plutonium, in a highly-dispersible power form, would be placed on board the Pacific Teal and Pacific Pintail at a Navy facility in Charleston, South Carolina and shipped to Cherbourg, France. It would then be transported 1000 km. overland in lightly-guarded trucks to MOX fabrication facilities.

The fabricated MOX would be shipped back in late 2004 or early 2005 and then by truck to Duke Energy's Catawba reactor, located about 250 km away from Charleston, for testing. The U.S. MOX program could cost a whooping $5 billion or more. These plans are thankfully facing growing legal, technical, and funding problems.

Shipment of plutonium around the globe and associated fabrication into nuclear fuel presents all sorts of environmental and proliferation risks which can be avoided. This transport flies in the face of sensible non-proliferation policy and underscores the double-standard which the U.S. is perpetrating in respect to nuclear weapons material and nuclear weapons. Also, use of MOX in a nuclear reactor makes operation of trhe reactor even more unsafe.

Rather than maximize the amount of handling and transport, which increases the possibility of accident, attack, or theft, the plutonium should be secured in the U.S. and managed as nuclear waste, which the U.S. has admitted is cheaper than MOX. This could entail mixing it, or "immobilizing" it, with the millions of litres of high-level nuclear waste which is being stored near Charleston at the Department of Energy's Savannah River Site, the facility where much of the plutonium was created in nuclear reactors.

Citizen opposition to this and other plutonium transports is essential if we are to stop commerce in nuclear weapons materials. Likewise, support of management of plutonium as nuclear waste - which also presents risks - is necessary if we are to bring the global threat of these materials under control.

The following U.S. Senators, who sit on the committee which fund the MOX program, are key to what happens with plutonium. Let them know that you oppose the MOX program and are in favor of managing plutonium in the U.S. and other countries as nuclear waste.

Senator Robert Byrd
http://byrd.senate.gov/byrd_email.html

Senator Ted Stevens
http://stevens.senate.gov/contact_form.htm

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Why does Japan want MOX fuel?

The Japanese government and its nuclear industry did not originally want plutonium MOX fuel. In the 1970s Japan started to realise that its increasing number of nuclear reactors did not have any way of dealing with the large amounts of waste nuclear fuel that was starting to be unloaded from the reactors. As in most other countries with nuclear power, public opinion and support for the industry has always dropped when the unsolved issue of nuclear waste needs to be addressed.

The Japanese industry and government wanted to find a way to reduce the opposition to the unsolved nuclear waste problem. Sending nearly all of Japan's nuclear waste fuel to the reprocessing facilities at Sellafield in Britain and la Hague in France, became the easiest way to deal with the problem.

The contracts signed in the 1970s with Britain and France required that the plutonium and some of the resulting wastes from reprocessing should be taken back to Japan. To date Japan has some 30 tonnes of plutonium that has been separated out of its waste nuclear fuel in European reprocessing plants. A further 15 tonnes will become separated within the next 10 years.

The Japanese nuclear industry and government decided to try and use any returned plutonium in a new type of nuclear reactor, called a Fast Breeder Reactor. This reactor uses mainly plutonium instead of uranium as a fuel. However, Fast Breeder Reactors have been a technological failure around the world, with countries such as Britain, USA, France and Germany abandoning their Fast Breeder Reactor programs due to technical and economic problems.

Japan's own Fast Breeder Reactor called Monju, was opened in 1994 and only operated for 18 months before suffering a major coolant leak of liquid sodium. The reactor has remained closed ever since.

With no credible use for the plutonium planned to be shipped back from Europe and increasing opposition from the countries along the transport routes, the Japanese nuclear industry and government tried to find a replacement use. It was in 1997 that the Japanese government announced that plutonium in Europe would be made into plutonium MOX fuel for use in normal Japanese nuclear reactors.

So far only two large shipments of plutonium have been made from Europe to Japan. The first in 1992 transported 1.7 tonnes of plutonium in the form of plutonium powder. Due to the large amount of opposition from up to 60 countries along the shipment route, no further plutonium shipments were made in this form. In 1999 the first shipment of plutonium in the MOX fuel form took place.

To date only 2 tonnes of plutonium have been returned from Europe. None of the plutonium returned has ever been used in a nuclear reactor. Most of it remains stockpiled in Japan. With some 45 tonnes of plutonium to be returned from Europe, up to 80 shipments will be required in the next ten years.

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