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Chalk River Nuclear Accident

The Chalk River Laboratories Chalk River Labs and formerly called Chalk River Nuclear Laboratories is a facility located near Chalk River, Ontario (Canada) population engaged in the research of nuclear reactions.

The installation was born in 1942 as a result of the collaboration between the British and Canadian nuclear research. In 1944 Chalk River Laboratories were inaugurated in September 1945 and the installation put into operation the first nuclear reactor outside the United States.

The NRX is a research nuclear reactor moderated by heavy water, cooled by light water. It was built in wartime in order to use it for military purposes, although designers watched many other civilian applications. Today the Chalk River Laboratories are of great importance in medical applications of nuclear energy.

The Chalk River nuclear plant suffered a nuclear accident Chalk River facilities suffered two nuclear accidents in 1952 and 1958. This is the first civil nuclear accident in history of nuclear energy.

First nuclear accident at Chalk River

The first nuclear accident occurred on 12 December 1952. The NRX reactor suffered a failure that shut down along with several bad decisions facility operators, caused a chain reaction which increased by more than double the nuclear power reactor .

Operators opened the 4 valves containment pressure in the cooling system, triggering an explosion that destroyed the nuclear reactor core, causing a spill of nuclear fuel.

Inexplicably, the closure of the control rods not fully descended into the reactor core. A series of explosions of hydrogen gas (or steam explosions) pitched a four-ton dome into the air. Thousands of nuclear fission particles were released into the atmosphere along with a million liters of radioactively contaminated water. The contaminated water had to be pumped out of the basement and poured into shallow trenches near the Ottawa River.

The NRX reactor core could not be decontaminated, but had to be buried as radioactive waste. In its place a new, even more powerful to continue functioning nuclear reactor was placed.

Curiously, a young Jimmy Carter (a nuclear engineer at the US Navy) was one of the hundreds of Canadian and American soldiers who were ordered to participate in cleaning NRX as a result of this nuclear accident. Then he would be US president.

At the time it is not yet and had created the INES scale (International Nuclear Event Scale), but now, due to the characteristics of the accident would be placed at level 5 (accident with off-site risk).

Second nuclear accident at Chalk River

Five years later, in 1958, several metal rods uranium nuclear fuel NRU reactor overheated and broken inside the reactor core. One of the damaged rods caught fire and broke in two while being removed from the base by a robotic crane. It fell into a shallow well maintenance.

The burning of nuclear fuel was there, lying deadly products of nuclear fission and the emission of alpha particles throughout the building of the Chalk River reactor. The ventilation system was stuck in the "open" position, which areas were contaminated access areas of the building, and an important downwind on the site of the reactor area.

A relay team of scientists and technicians finally extinguished the fire. More than a thousand men were involved in cleanup operations after these two accidents in Chalk River.

Impact of the Chalk River nuclear accidents

More than 600 men were needed just to clean the NRU. Official reports from AECL (Atomic Energy of Canada Limited) note that very few of these men were exposed to excessive radiation, ie, most of the radiation dose recorded did not exceed the levels considered acceptable for workers in nuclear installations at the time. Reports also indicated that no adverse health effects caused by radiation exposures received.

However, no doctor has been no follow up to see if the population of men involved in accidents in the future Chalk River showed a higher than normal incidence of cancer.

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References

Last review: August 24, 2015