THE D.F. TORGERSON DISCOVERY AWARD IS AWARDED TO:

For the methodology to evaluate and plan the removal of the first NRX calandria from CRL’s Waste Management Area.   

CNL’s Reactor Segmentation team has a mandate to characterize and plan the removal of nine AECL legacy reactors. Included in this scope is the first NRX calandria which was removed from NRX in 1953 and buried in CRL’s Waste Management “A” facility. This object had been left untouched within its mound since it’s burial and its condition had not been clearly defined. The reactor segmentation team undertook a characterization campaign to better understand its condition, exact location and the radionuclidic profile of its material and contents which will lead to the development of future segmentation strategies and waste planning for this legacy object.

The waste characterization of the first NRX calandria (project WMAX) saw the installation of three standpipes above the buried calandria. These standpipes allowed in-house developed tools to cut into and access the calandria internals. Samples and videos were gathered from within the calandria which were analyzed and summarized in a waste characterization report. The project was successful in taking detailed photos showing damage to the calandria tubes, along with verifying the presence of fuel material left behind as the result of the 1952 NRX accident. The calandria characterization work was completed in May 2023.Building on the characterization work, the team also developed a fullscale mock-up of the NRX reactor calandria to prepare for future planned segmentation work. This design was completed by the Mechanical Equipment Development branch and fabricated by the on-site manufacturing team. The mock-up helped to successfully prove the segmentation methods, define tooling requirements, and define requirements for soil management. The successful mock-up work verified the highly effective segmentation approach, resulting in an economical solution to safely remove the damaged reactor calandria which will be completed in the next few years.

THE D.F. TORGERSON DISCOVERY AWARD IS AWARDED TO:

For the small-specimen fabrication testing capability development for irradiated materials.                                          

Since 2016, CNL has significantly advanced its capabilities in fabricating and testing small-scale mechanical specimens to cater to both domestic and international commercial clients, thereby enhancing its commercial revenue. Small-scale mechanical tests involve the fabrication and testing of specimens that range from millimetre to sub-millimetre sizes.

CNL has multiple advanced fabrication capabilities, namely focused ion beam (FIB) mill, laser ablation system, which are customized to produce high-quality miniature specimens from irradiated reactor components. CNL researchers have developed a FIB-based workflow to fabricate, and test micron-sized tensile specimens of specific microstructural features of interest, to directly observe deformation within ex-service materials. The results from these experiments have provided critical information for life prediction modelling of spacers, and the fracture toughness of irradiated pressure tubes.

The CNL team utilized this technique on Accident Tolerant Fuel (ATF) claddings in a project funded by Global Nuclear Fuel (GNF)-Americas, a GE-Hitachi venture. The aim was to mechanically characterize a ceramic protective coating, only a few microns thick, and its interface with zirconiumalloy- based cladding. The results from this study were shared with the US Nuclear Regulatory Commission (US-NRC) by the customer as part of the material qualification process.Experiments on shear testing of pressure tube rolled joints have been developed to address a need of Ontario Power Generation (OPG) to assess the effect of hydrogen pick-up on the mechanical integrity of the pressure tube at the ribs of the rolled joints. CNL’s team designed a small shear specimen geometry suitable for testing sub-mm sized specimens of pressure tubes. The specimen was fabricated using precision metallography and laser ablation. CNL researchers worked closely with an international meso-scale mechanical test system supplier to customize shear testing grips for miniaturized shear test specimens. Initial OPG funded developmental work has been performed on unirradiated pressure tube material in year 2023, and irradiated material testing has been planned for years 2024-25.

THE DISTINGUISHED MERIT AWARD IS AWARDED TO:

For the development of multi-physics multi-scaled coupled code suite for modelling SMRs.

THE DISTINGUISHED MERIT AWARD IS AWARDED TO:

Luke Lebel, Kyle Barlow, Julian Atfield, Normand Lair, Luke Yaraskavitch, David Grand-Maitre, Toban Verdun, Carl Neggers

For the revitalization of CNL’s Travelling Flux Detector System for Neutron Flux Mapping in CANDU Stations.                                    

The traveling flux detector (TFD) system is a tool that AECL/CNL has used for CANDU 6 flux mapping since the 1980s. With the closure of Gentilly-2, however, and after the completion of a large measurement campaign in 2012 during the Point Lepreau refurbishment, it was originally determined to have limited customers for new scan campaigns. With the system’s components ageing, and key experienced staff retiring, the sustainability of the system was in question in the late 2010s.

In 2021, OPG and Bruce Power both contacted CNL to perform flux scanning for their newly refurbished units, starting with Darlington Unit 3. OPG had attempted to perform similar flux mapping manually with their own instruments during the Unit 2 restart, but encountered many challenges. The renewed interest and prospect of new customers brought the TFD capability back as a CNL priority. However, it was necessary for CNL to rebuild the capability to be ready for the measurement campaigns for new include period after customers.This team was tasked with rebuilding the CNL TFD capability and conducting the measurement campaigns for the new customers. This involved a tremendous amount of work to grow the team of TFD operating staff, train them on the use of the systems, and refurbish the ageing components of the TFD equipment. In addition, the core team had to design support systems for coupling the TFD with the reactors and make the system ready for service at the sites, including the development of work plans and test procedures, and carrying out system tests. A project began to update the electronics systems and operating software. The team worked diligently and cooperated to complete this extensive effort and bring the TFD capability back into full service for CNL customers.

This culminated in TFD flux scan campaigns occurring in May/June 2023 for Darlington Unit 3 and August 2023 for Bruce Unit 6 during their post-refurbishment restarts. Moreover, additional scan campaigns are occurring at Point Lepreau (beginning in 2024 March and throughout the rest of the year around their current outage schedule), and at OPG Darlington to conduct post-refurbishment scans for Darlington Unit 1 in September. Customers are also engaging CNL to conduct flux scanning campaigns for the remaining Darlington, Bruce, and Pickering units upon their refurbishment. Additional avenues of TFD business and new capabilities are also being explored by the team given their understanding of the TFD capabilities and operational experience with the recent campaigns.

THE DISTINGUISHED MERIT AWARD IS AWARDED TO:

For the reduction of bioassay sampling with Facilities Decommissioning.

THE DISTINGUISHED MERIT AWARD IS AWARDED TO:

For the Computational Fluid Dynamics (CFD) Study and Calculations to Support Decision-Making for Decommissioning Strategies for Nuclear Facilities.

THE DISTINGUISHED MERIT AWARD IS AWARDED TO:

For the implementation of a new safety standard for the management of Perchlorate hazard.

THE DISTINGUISHED MERIT AWARD IS AWARDED TO:

The team displayed dedication, innovation and problem solving skills in a tight schedule with limited budget to develop a unique internal pressure fatigue test rig to assess the impact of a coating on the fatigue behaviour of fuel cladding. This unqiue apparatus used state-of-the-art technologies that when combined, enabled control of the test environment to measure strain in the specimen, cycles to fatigue failure and detection of fatigue failure. The test required heating specimens to high temperature (350°C), pressurizing internally with an oil to a maximum pressure of 50 MPa and cycling the internal pressure at a 1 Hz frequency. With the fatigue test rig built upon the biaxial burst apparatus (BBA), two key challenges needed to be overcome: the ability to cycle the pressure at a rapid rate (1 Hz) and acheiving a sufficiently uniform temperature on the test section. The high cycling rate of the pressure required significant design and testing activities to ensure that the cycling rate could be acheived, as well as ensuring that the cycling could be maintained reliably over the long duration of typical testing. Similarly, obtaining a sufficiently uniform temperature on the test section required novel design and testing efforts, especially ensuring uniformity at the high temperature of 350°C. In addition to the novel design challenges, the team had to ensure that testing could be performed safely and that the operator would be protected from the temperature and the sudden burst of the test specimens when fatigue failure occurred.

THE DISTINGUISHED MERIT AWARD IS AWARDED TO:

For the HEPro installation at Bruce Power

THE DISTINGUISHED MERIT AWARD IS AWARDED TO:Mitch MacKay, Gabrielle Gracey, Jeff Miller, Leslie Wilson