NRU Mock-up
AECL has constructed a full-height mock-up (first image) of the NRU reactor at Chalk River Laboratories to be used for training and qualifying welders and technicians on the proper use of the cleaning and repair tools. The second image is taken from the top of the reactor mock-up, 30 feet above the repair site and highlights the narrow openings (5 cm in diameter) through which workers must lower and then operate the cleaning and repair tools.
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Cleaning Tools
Prior to conducting weld repairs, AECL developed cleaning tools to remove debris and corrosive build-up on the interior and exterior walls of the reactor vessel. Here technicians practice using a new brush tool designed and developed by AECL, on the NRU mock-up facility. Today all cleaning and vacuuming of the actual NRU reactor is complete.
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Welding Tools
Working in partnership with Liburdi Automation Inc. of Dundas, Ontario, AECL designed and developed the repair tools to conduct the horizontal and vertical repair welds. The design allows technicians to lower the tool into the reactor vessel through the narrow access point. Once the tool is anchored to the bottom of the reactor vessel, technicians extend an ‘arm’ of the tool to reach the repair site and begin welding. With testing of the tool completed at the vendor’s facility, the tools arrive at Chalk River Laboratories for final testing and qualification at the NRU reactor mock-up.
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Repair Training
AECL’s repair team conducts test welds on the NRU reactor mock-up, allowing technicians to perfect the welding equipment and closely inspect the quality and accuracy of the welds. When performing the welds on the actual NRU reactor vessel, this accessibility isn’t possible. Instead, welding specialists rely on visuals displayed on computer monitors to guide the tools and perform the work.
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Non-destructive Examination
Atomic Energy of Canada Limited (AECL) continues inspections of the National Research Universal (NRU) reactor at Chalk River Laboratories to determine the extent of repairs required to return the reactor safely to service. AECL’s Operations and Radiation Protection technicians lower remote cameras into the reactor to inspect the exterior of the reactor vessel. The NRU reactor has three main purposes: to be a supplier of industrial and medical radioisotopes used for the diagnosis and treatment of life-threatening diseases; to be a major Canadian facility for neutron physics research; and to provide engineering research and development support for CANDU® power reactors.