Windscale Fire

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Akasha Purohit and Kelly Meehan

THE WINDSCALE FIRE


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HISTORY

The Windscale Fire took place at the Windscale nuclear processing plant in Cumberland,

which is known as Cumbria today.

The project was started to compete with America and the Soviet Union in the arms race.

After the Windscale fire was put out, Harold Macmil lan covered up the incident, saying

that it was the Windscale employees who were in error. This cover-up was used to stop

the United States from finding out that England was trying to make an atomic bomb.

Cumberland Cumbria


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SAFETY CONCERN

The British were not experienced with nuclear processing, Windscale was their first

nuclear reactor.

They did not account for the Wigner Effect on graphite cores, which was the underlying

cause of the incident.

Eugene WIgner


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THE WIGNER EFFECT

Displacement of atoms caused by neutron radiation.

Neutrons hit the crystal lattice structure of Graphite and displace carbon atoms.

These displaced atoms either find other vacancies within the structure, or become

interstitials.

Build up of interstitials causes a build up of potential energy, which eventually releases asheat.


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ANNEALING

Way to combat the Wigner Effect

Core is heated to 250C

Displaced carbon atoms slip back into the crystal lattice structure

Allows for a gradual release of heat

This process was difficult to do and required higher temperatures each consecutive time.

Required uranium

This process wasnt kept in mind during the initial design of the plant, monitoring devices

for the process werent working properly.


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IGNITION

Britain began focusing on the production of tritium

Required heating the graphite core to higher temperatures

This decreased the safety level of the plant, but was overlooked due to the high quantities

of tritium being produced

Annealing process was started, but somewhere during the process it is speculated that acan of uranium had ruptured and oxidized, which added to the fire.


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TWO UNSUCCESSFUL ATTEMPTS AT

ELIMINATING THE FIRE

Oxygen

Since the fans were turned off due to the fact that certain parts of the atomic bomb had

to be made at high temperatures, a decision was made to turn the blowers in the nuclear

plant back on to cool down the fire and potentially put it out. However, this only caused

an increase in temperature.

Carbon Dioxide

Since oxygen was not useful, workers decided that carbon dioxide had the potential to

extinguish the flame. The plant had just received 25 tons of carbon dioxide, however,

workers were unable to properly haul the carbon dioxide to the fire, and there was an

insufficient amount that could be used at once.


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THE DEBATE

With both attempts of carbon dioxide and oxygen failing to work, a new contention arose.

Options for how to put the fire out were running low, and Tom Hughes, who was one of the

employees and key figures in putting the fire out, decided that it was between dousing the

fire with water or waiting for it to go out on its own.

There were several problems with both aspects. If the fire was allowed to remain, not only

would it progressively get worse, it would also cause large amounts of radiation to spreadmiles from the site. This would risk the lives of people of countless people.

If the employees tried to put the fire out with the use of water, the nuclear plant had the

potential to explode. As water is added to molten metal, the metal can oxidize and will

release hydrogen gas. This hydrogen gas is extremely explosive when introduced to

outside air. The emission of this hydrogen gas could cause a nuclear explosion, killing all

of the people left in the plant.


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SUCCESS IN ELIMINATING THE FIRE

Tom Hughes decided that it would be best to subject the fire to water, instead of risking

the lives of thousands through radiation poisoning. Unable to tell whether the water was

working in decreasing the temperature when added to the molten metal, and with poor

knowledge of how much hydrogen gas was being emitted, Tom Hughes got rid of his

radiation recording badge and climbed the Windscale pile 1 to monitor the inspection

holes that contained the fire.

Upon several inspection, Tom Hughes saw that the fire was dying down and also that the

hydrogen gas was not building up. With the constant amount of water being poured on the

fire, the potential disaster was able to be averted.


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AFTERMATH OF THE WINDSCALE FIRE

Overall, the design of modern nuclear reactors are different today than when the

Windscale fire occurred, preventing an incident like this from happening again.

After the fire was stopped, the production and use of air-cooled reactors in nuclear power

plants stopped. The Windscale piles have not been used since.

The amount of radiation that leaked out from the fire at the Windscale piles resulted in

approximately 240 cases of cancer.


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Windscale Sellafield


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REFERENCES

Arnold, L. Windscale 1957: Anatomy of a Nuclear Accident; Palgrave Macmillan:

Basingstoke, 2007.

Crick, M.J.; Linsley, G.S. An Assessment of the Radiological Impact of the Windscale

Reactor Fire, October 1957. Int J Radiat Biol Relat Stud Phys Chem Med[Online] 1984.

46, (5) 479-506. http://informahealthcare.com/doi/abs/10.1080/09553008414551711

(accessed April 10, 2011).

Glasstone, S.; Sesonske, A. Nuclear Reactor Engineering: Reactor Systems Engineering;

Chapman & Hall: London, 1994.
http://informahealthcare.com/doi/abs/10.1080/09553008414551711http://informahealthcare.com/doi/abs/10.1080/09553008414551711

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