NRX

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

Building sites

The reactor ZEEP in the Chalk River Laboratories was built to design the design of the NRX reactor; Scientists need a better understanding of how a reactor core works. The NRX was under construction when ZEEP was completed. NRX was originally an acronym for National Research X -metal. During the Second World War, the Allies described the uranium to secrecy as "X - metal". Later, the name for the National Research eXperimental stood. When the reactor was completed in 1947, he was a scientific marvel for its time. With 25 megawatts, he was the most powerful nuclear reactor in the world, equipped with facilities for a variety of research purposes. The scientists came from everywhere to Chalk River to the new opportunities that resulted from such a system to discover. The NRX reactor produced plutonium for export to the United States. Canada did not pursue military use of nuclear energy, but it was one of only a few countries that dealt with this technology so strong at the end of the Second World War. NRX was strong enough, partly for important medical applications to produce radioactive isotopes. The NRX reactor made ​​the Chalk River Labs famous in science.

The start of construction is given as 1944, and the operation beginning with July 22, 1947.

Reactor accident

On December 12, 1952, the first major accident occurred in the reactor: During a test, was destroyed by operating errors, misunderstandings between the operator and operating personnel, incorrect status displays in the control room, misperceptions of the operator and tentative action of the reactor core at a partial meltdown. The dome of a four -ton helium gas tank threw a oxyhydrogen explosion 1.2 m high in the reactor core, where it remained stuck in the building. By the explosion of at least 100 TBq were released on cleavage products into the atmosphere. Up to four million liters to about 400 TBq long-lived fission products radioactively contaminated water was pumped out of the basement of the reactor containment in a sandy septic tank to prevent contamination of the Ottawa River not far away. The damaged reactor core was buried. The later U.S. President Jimmy Carter, then a nuclear engineer in the Navy, helped permanent cleanups in several months. The reactor was not until two years later returned to service.