D.F. Torgerson Award: Methology for the removal of the first NRX calandria
Alan Taylor, Peter Reid, Stephane Charbonneau, Chris Recoskie, Andrew Toomey, Natalie Sachar, Christian Surette, Austin Hrynyk, David Yuke, Nicholas Simpson, Sean Green, Bradley Banville, Daniel Cadieux, Bradley Kuehl, Jonathan Wishart, Dwane Killeen, Andrew Toomey
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.