CNL reactor decommissioning process continues
CHALK RIVER - Canadian Nuclear Laboratories is hard at work getting its plan to decommission Canada's first generating reactor approved by the Canadian Nuclear Safety Commission.
While the CNSC hearing on the matter is tentatively scheduled for the end of 2018, a lot of groundwork is still needed to prepare for that. Once CNL gets its ducks in a row, it is confident they can get approval to proceed with the plan, which will see the reactor site near Rolphton sealed up by 2020.
During a public information session held in December at Chalk River's fire hall, Meggan Vickerd, operations manager of the Nuclear Power Demonstration Facility and CNL Licensing Activities, said they have been working on the plan for some time, and have decided sealing off the reactor site is the safest way to deal with it.
She said trying to dig it up would release materials into the environment and expose the workers to potential risks, so it is better to deal with it where it lies.
“This has been a painstaking process,” Vickerd said, resulting in 600 pages of research and engineering work describing the containment plan and all associated and potential risks, wrapped up in a draft Environmental Impact Statement. That statement is now being offered to the public to comment on throughout 2018.
“There are no predicted adverse environmental effects because of this project,” she said, but all public concerns will be collected and included in the final draft of the EIS, which would be the subject of public hearings in the fall of 2018.
“We did all of our homework, and submitted it to the regulator (the CNSC), and now the regulator is gathering input to be used as part of the approvals process,” Vickerd said.
Closing the Nuclear Power Demonstration (NPD) site marks the last chapter in the history of Canada’s first practical nuclear power reactor. When it went online in 1962, it served as an important training facility for future reactor engineers and operators, then working for Ontario Hydro. Nuclear Power Demonstration was the first Canadian nuclear power reactor, and the prototype for the CANDU reactor design.
The site has been subject to a three-phase decommissioning, which started in 1988 with the permanent shutdown of the reactor and the removal of the fuel and power generating equipment from the site. The fuel itself remains stored at Chalk River Labs. This lasted until 1993, a period during which the outer buildings like the training centre were demolished, leaving behind the main reactor building.
The second part of this has been a long term monitoring period, scheduled to last until 2018, in order to allow radiation levels to drop within the structure, to help reduce the risks to staff who are working on the closure project.
Once the CNSC gives its approval, again following a thorough environmental assessment, the main building will be collapsed into the below ground portions of the structure, which dip below ground nearly 80 feet, with the whole thing sealed up in a specially tailored grout – which is like a flowable concrete – made on site.
Once filled, the structure will be buried under a concrete cap topped with liners, geotextiles and grass to divert the flow of groundwater away from it. The water itself will be held by other engineered structures so as to not flow off site.
The decommissioned site will be monitored over the next 100 years or so to ensure it remains intact as part of long-term care and maintenance activities.
One structure which will be spared from demolition is the tall ventilation stack, which has become the roosting place of 2,500 chimney swifts.
Vickerd said the birds use the upper half of the stack from May to September before migrating south. Because the stack plays such an important role for the birds, and as it is structurally sound, it has been decided it will remain in place.
The tentative hearing date for final approval of the project is Dec. 12, 2018, at the end of the public review period. This is not connected to the public hearings set for the end of January for CNL's licensing renewal, nor the Near Surface Disposal Facility, whose hearing date has not yet been set.
All three matters are being dealt with separately by the CNSC.