NRX reactor

The NRX reactor at Chalk River Laboratories , Ontario , Canada is a light water cooled and heavy water moderated research and test reactor.

Building grounds

The ZEEP reactor at Chalk River Laboratories was built to outline the design of the NRX reactor; Scientists needed a better understanding of how a reactor core works. The NRX was under construction when ZEEP was completed. NRX was originally the abbreviation for National Research X-metal . During the Second World War , the Allies designated uranium as "X-metal" to keep it secret. The name later stood for National Research eXperimental . When the reactor was completed in 1947, it was a scientific marvel for its time. With 25 megawatts, it was the most powerful nuclear reactor in the world, equipped with facilities for a variety of research purposes. Scientists came to Chalk River from all over the world to discover the new possibilities that such a facility would bring. The NRX reactor produced plutonium for export to the USA. Canada did not pursue any military use of nuclear energy, but it was one of only a few countries that became so heavily involved with the technology at the end of World War II. NRX was powerful enough to produce radioactive isotopes, some for important medical applications. The NRX reactor made the Chalk River Labs famous in science.

Construction started in 1944 and operations started on July 22, 1947.

Reactor accident

The first major accident occurred in the reactor on December 12, 1952: During a test, incorrect operation, misunderstandings between the operator and the operating staff, incorrect status displays in the control room, incorrect assessments by the operator and hesitant action destroyed the reactor core in the event of a partial core meltdown . An oxyhydrogen explosion in the reactor core threw the dome of a four-tonne helium gas container 1.2 m high, where it got stuck in the structure. The explosion released at least 100 TBq of fission products into the atmosphere . Up to four million liters of radioactively contaminated water with around 400 TBq long-lasting fission products were pumped from the basement of the reactor containment into a sandy septic tank in order to prevent contamination of the not far away Ottawa River . The damaged reactor core was buried. The future US President Jimmy Carter , then a nuclear technician in the Navy , helped with the several months of clean-up work. The reactor did not go back into operation until two years later.

See also

• Chalk River Laboratories
• List of accidents in nuclear facilities
• List of nuclear reactors in Canada

Web links

• Danny Kringiel: Historic reactor disaster . Almost disaster in Canada's wasteland. In: one day on Spiegel Online from December 11, 2012

Individual evidence

1. ↑ The NRU Reactor - 1947: NRX (English) ( Memento from March 8, 2012 in the Internet Archive )
2. ^ The American Experience: Meltdown at Three Mile Island . PBS. Retrieved December 17, 2012.

Coordinates: 46 ° 1 ′ 0 ″  N , 77 ° 27 ′ 0 ″  W.