Decommissioning of Candu protoype moves forward
The NPD, a 20 MWe pressurised heavy water reactor in Rolphton, Ontario - about 225 kilometres northwest of Ottawa - generated its first electricity in 1962. The reactor was the prototype and proving ground for research and development that led to commercial application of the Candu system for generating electric power from a nuclear plant using natural uranium fuel, heavy water moderator and coolant in a pressure tube configuration with on-power refuelling.
The reactor operated for 25 years, generating electricity and providing a training centre for nuclear operators and engineers from Canada and around the world. The first stages of decommissioning, including the removal of all nuclear fuel from the site and the draining of the systems, were completed after its final closure in 1987, and the site has been in a safe shutdown state for the last 30 years.
The structures that currently remain onsite include the main reactor building, a diesel generator, a ventilation stack, a pressure relief duct, a guardhouse, foundations from previously removed structures, two landfills, buried utilities and drainage systems, and temporary structures, such as sea containers and portable washrooms.
CNL's NPD Closure Project aims to safely carry out the decommissioning of the NPD facility and complete the closure of the site, using an in-situ approach. This would see the reactor systems and facility structure entombed in place using specially formulated grouts. The structure would then be capped with a reinforced concrete cap and covered with an engineered barrier. The decommissioned facility would be considered to be a licensed disposal facility under Canada's Nuclear Safety and Control Act.
The CNSC is currently accepting public comments on CNL's draft EIS for the project, which provides an analysis of potential environmental effects and measures to mitigate those impacts. The public comment period opened on 15 November and had originally been due to end on 29 January.
Subject to regulatory approvals, CNL's timeline for the project envisages final decommissioning work starting in 2019, with site closure completed in early 2020.