On December 12, 1952, the world experienced its first nuclear reactor accident in Chalk River Laboratories here in Ontario. Chalk River was around 180 kilometers northwest of Ottawa and was a latest nuclear research facility.
The incident that occurred with the national reactor for experimental research experimental (NRX) was caused by a combination of mechanical problems and operator errors, which led to overheating fuel bars and considerable damage to the reactor.
On this fateful date, around 3 p.m., the last experiment of the day before the start was. The cooling system has been modified and the water flow to the reactor has been reduced for the test, which should probably only require very low performance.
First public photo of the NRX reactor. Photo: Toronto Star Archives.
However, the modifications led to unforeseen consequences. The reactor experienced an overheating that had damaged the reactor core, and a series of hydrogen gas (or steam) explosions followed, which caused the four-month gas holder dome to be thrown four foot through the air, where it was disturbed in the superstructure. This brought thousands of gap products into the atmosphere.
After the incident, about one million gallons had to be pumped from the basement of radioactive contaminated water and not far from the Ottawa river, according to the Canadian coalition for nuclear responsibility. At that time, the contaminated water was seven times radioactive than the entire worldwide radium production.
Specialists of the Royal Canadian Engineers in 1952. Photo: National Ministry of Defense.
The clean -up work included over 800 Atomic Energy of Canada Ltd. (AECL), Canadian and US soldiers, including one that you may have heard of -the former US President Jimmy Carter. At that time, Carter was served as a lieutenant of the US Marine in an atom -u boat project in Schenectady, New York.
During the clean -up process, the reactor was switched off, the dismantling was dismantled and the damaged parts were replaced. A precise replica of the reactor was even built nearby for training purposes, in which Carter and his team practiced the necessary procedures.
Due to the high levels of radiation, the men were only able to work in layers of 90 seconds. Carter later remembered the after -effects of the exposure, including radioactive urine for weeks and concerns that he may not have children. Nevertheless, Carter had four children.
Official reports from AECL emphasized that only a few of the employees involved were overexposed, and most of the doses recorded were at this time within permissible limits for nuclear workers. However, no medical follow-up studies were carried out to determine whether those who were involved in cleaning later had normal cancer or other health problems.
Chalk River in 1958. Photo: Toronto Star Archives.
This accident was not the only one who occurred at the Chalk River. In 1958, another serious accident occurred in the NRU reactor than several metallic uranium burners in overheated and roared. One of the poles caught fire and was torn into two parts when it was removed from the reactor core.
When a remote-controlled crane went above them, a three-foot part of the pole fuel broke off and fell into a maintenance pit. A team of scientists and technicians was able to extinguish the fire by wearing protective equipment and putting buckets out of wet sand on the pit.
The incidents of the chalk flow were decisive in the history of nuclear energy, and these early accidents drawn attention to the need for strict security protocols, including effective risk -based communication. Today Chalk Nuclear Laboratories is a leader in the development of nuclear technology for peaceful and innovative applications.