NRU Reactor

The NRU reactor at Chalk River Laboratories has operated since 1957, and has been the birthplace of many scientific achievements. Canadian physicist Bert Brockhouse won the Nobel Prize in Physics for his seminal work at NRU using neutron scattering to explore materials.Using the same scientific approach that Brockhouse pioneered, NRC scientists today apply neutron scattering techniques in a wide range of research into materials.

In addition to five decades of neutron scattering research, NRU is the source of the majority of the world's supply of medical isotopes. These materials are used in the diagnosis and treatment of cancer and other diseases. Isotopes from NRU benefit more than 5 million people internationally each year: a huge contribution to world health.

Moreover, NRU is the source of the fundamental knowledge that was required to develop Canada's fleet of nuclear power stations. Fuel and structural material needed to build a CANDU reactor are tested and proved in NRU. Domestic nuclear power generation prevents millions of tonnes of greenhouse gas emissions each year, by reducing Canada's use of fossil fuels, and is a $5 billion industry.

Key Features

The NRU reactor at AECL's Chalk River Laboratories has provided intense beams of neutrons since it began operation in 1957. The reactor uses heavy water as both moderator and coolant and operates at 125 MW. Presently it uses 20% enriched fuel. It has a large core contained in a vessel that is 12 ft. in diameter and 10 ft. high. The core contains ninety fuel sites and has eight reactor loops and thirty isotope irradiation sites. It has seven beam tubes dedicated for neutron scattering instruments. The on-line fueling capability of NRU means the reactor does not operate on a fixed fueling cycle. Rather, shut-downs are scheduled by the scientific, engineering or maintenance needs.

The peak thermal flux in NRU, 3×10¹⁴ cm^-2 sec^-1, remains one of the highest in the world. The beam tubes are large, 22 cm high by 7.5 cm wide, to give beam optics that produce a high flux on the specimen. The floor plan of the reactor experimental hall is shown schematically on another page, with the neutron scattering spectrometers outlined and identified by the beam hole designations.

AECL has recently applied to operate NRU beyond 2005. However, for the long-term future of neutron science in Canada, NRC in partnership with AECL, universities and industry, is proposing a new Canadian Neutron Facility for Materials Research (CNF) to support next-generation neutron-based materials research and innovation in Canada.