National Research Universal reactor

National Research Universal Reactor (NRU) was a Canadian research reactor located at the Chalk River Laboratories in Ontario. It was a multipurpose science facility that served as a source of neutrons for research in physics, chemistry, biology, and materials science. Additionally, the NRU reactor played a critical role in the production of medical isotopes, which are used worldwide for diagnostic and therapeutic purposes in medicine.

History

The NRU reactor was officially opened in 1957, succeeding its predecessor, the National Research Experimental Reactor (NRX), which was one of the world's first nuclear reactors when it became operational in 1947. Over its operational lifespan, the NRU reactor underwent several upgrades to enhance its capabilities and safety features. It was a pivotal facility in the development of Canada's nuclear industry and nuclear science research globally.

Design and Function

The NRU reactor was a tank-type reactor that used heavy water (D2O) as both a moderator and coolant. This design allowed it to produce a high flux of neutrons, making it highly effective for various types of nuclear research and for the production of isotopes. The reactor was versatile, supporting a wide range of scientific experiments and industrial applications, including the testing of materials and fuel for power reactors.

Contribution to Medicine

One of the most significant contributions of the NRU reactor was its role in the production of medical isotopes, particularly molybdenum-99 (Mo-99), which decays to technetium-99m (Tc-99m), a critical isotope used in nuclear medicine. Tc-99m is utilized in over 30 million diagnostic procedures annually, ranging from cancer detection to heart disease diagnostics. The NRU reactor's ability to produce large quantities of Mo-99 made it a key player in the global supply chain of medical isotopes.

Decommissioning

After nearly 60 years of service, the NRU reactor was permanently shut down on March 31, 2018. The decision to decommission the reactor was made due to its age, the cost of ongoing maintenance, and the development of new technologies for isotope production that do not require a nuclear reactor. The decommissioning process is expected to take several decades and involves the safe removal and disposal of radioactive materials and the decontamination and dismantling of the reactor facilities.

Legacy

The legacy of the NRU reactor extends beyond its scientific achievements. It played a crucial role in the training of nuclear scientists and engineers and contributed significantly to the advancement of nuclear safety and technology. The reactor also highlighted the importance of international collaboration in science and technology, as it served researchers from around the world and helped to establish Canada as a leader in nuclear research and isotope production.

See Also

• Chalk River Laboratories
• Nuclear reactor
• Nuclear medicine
• Radioisotope production