Nuclear Power Demonstration Closure Project

In selecting disposal for the NPD reactor, CNL has considered several alternatives, including continued storage with surveillance, partial dismantling and removal, and full dismantling and removal of the reactor and components. Through its various engagements, CNL was asked to provide more detail in the EIS on how it chose the in-situ disposal method for the NPD Closure Project. CNL has added quantitative assessments of the options considered to the EIS, and also updated the scenarios to include a new disposal facility becoming available during the institutional control period. Overall, the in-situ disposal method is still considered the safest and preferred option.

The NPD reactor structure will be filled with custom grout formulations to help contain and isolate contaminants, ensure stability, and reduce corrosion rates of the reactor components. CNL started with a specially-formulated grout used in other in-situ disposal projects and adapted it to the unique requirements of the NPD facility. Extensive research was conducted on the use of grout in similar circumstances. We have also conducted a test program using locally-sourced materials to verify that the grout formula requirements can be met. The test included fresh properties, such as determining the ability of the grout to flow around piping and tanks, and cured properties, such as strength and hydraulic conductivity. Combined with the existing robust construction of the underground facility, the proposed grouting process will enhance protection of people and the environment. CNL has added details on grout and grout formulations to the revised draft EIS that has recently been submitted to the CNSC.

CNL has conducted additional detailed quantitative analysis to assess how a catastrophic earthquake – one that might occur once every ten thousand years – would affect the facility. Results show that cracks would develop mainly in the areas of the NPD facility which are above the bedrock level. The grouted reactor vault would not be affected as it is well below this depth, with the grout providing increased protection against the stresses of the earthquake. Modelling updates show that any impacts to the public or environment from such an earthquake would be well below the regulatory limits.

CNL also conducted additional geological site characterization work to strengthen our understanding of the geology around the NPD site. This characterization work strengthened our confidence in bedrock elevations and characteristics, including quality and rates of water flow. It also confirmed the soundness of the bedrock at the site. That is, nothing was encountered that would preclude this location as a disposal site. This information was important to confirm assumptions made in seismic modeling and to demonstrate the suitability of the site for long-term stability.

Ensuring the continued protection of the Ottawa River is a key focus of CNL’s work and is reflected in the EIS. CNL has undertaken additional detailed modeling of potential releases from the facility to assess how they could affect the river. This new analysis supports the conclusion of the EIS that the Ottawa River will continue to be protected. CNL has also updated the Post Closure Safety Assessment, which evaluates the potential long-term effects of the project on the public and environment. The update included the final grout design, results from the geological site characterization and the new, more detailed earthquake assessment. Finally, the project team has developed draft follow-up monitoring plans, which are available for review by interested parties.  CNL held a workshop to discuss the draft effluent monitoring plans in 2019 that included members of the public.  Additional workshops will be held for the environmental and groundwater plans in the near future and CNL looks forward to input from the public and Indigenous communities.

CNL received questions about the International Atomic Energy Agency’s (IAEA) guidance in their safety standard for decommissioning which states that in-situ decommissioning is not a suitable option for all nuclear facilities and should be considered only under certain conditions. CNL agrees with this assessment and considers that NPD has features which make it suitable for long-term disposal such as its location 80 feet below grade into bedrock and the thick concrete basement structure.  The NPDDF project is creating a disposal facility by decommissioning the existing reactor and then utilising the remaining below grade structure to create a new disposal facility. In this case decommissioning of the NPD reactor ends following partial removal of the structure, and does not involve entombment of the facility. The decommissioned waste is then placed into the disposal facility which when complete undergoes closure. The strategy used is therefore not entombment but partial removal, which is acceptable according to GSR-6, (IAEA 2014).

CNL is considering IAEA guidance in their safety standards for the closure of the facility, and more importantly is also considering IAEA guidance in their safety standards for waste disposal, since the facility – in its end state – would be classified as a disposal site.

It is important to note that CNL is licensed by and is accountable to the Canadian nuclear regulator, the Canadian Nuclear Safety Commission (CNSC). CNL is following Canadian standards and regulatory requirements for decommissioning the NPD facility and Canadian regulations for the creation of a disposal facility.

CNL received several requests for information on the exact radiological content of the NPD facility that will be on-site for disposal. CNL has updated the Environmental Impact Statement to include recently completed neutron flux modeling using modern 3-dimensional codes and libraries, to improve the certainty of the radiologic inventory of the reactor components. CNL has also completed a full building characterization, including all remaining nuclear systems, to verify the total radiologic inventory. Since the reactor contains most of the remaining radiologic inventory (the fuel was removed in 1988), the completion of these additional analyses, incorporating field sampling measurements, allows CNL to better conservatively define the total radiologic inventory proposed for disposal.

At the time of the submission of the 2017 draft Environmental Impact Statement, CNL had completed only a preliminary design of the disposal facility. Now that CNL has a more detailed design of the disposal facility, including the engineered barrier and the finalized grout formulation, an update has been incorporated in the revised draft Environmental Impact Statement (EIS), submitted to the CNSC in 2020.

CNL, as a steward of the NPD property on behalf of Atomic Energy of Canada Limited (AECL), is committed to meaningful engagement with local Indigenous communities and is working to establish long term agreements with them. These interactions are on-going and allow CNL to learn how the Project could impact the rights and interests of Indigenous groups, and to identify actions to be taken. At the same time, Canada’s nuclear regulator, the Canadian Nuclear Safety Commission, is also undertaking consultation activities with Indigenous communities, to ensure the Crown’s duty to consult is upheld.

What is the duty to consult?

The Crown’s unique relationship with Indigenous Peoples gives rise to the duty to consult, and where appropriate accommodate Indigenous peoples when the Crown contemplates conduct that might adversely impact potential or established Indigenous and/or treaty rights.

As an agent of the Crown, the CNSC has responsibility for fulfilling its legal duty to consult, and where appropriate accommodate Indigenous Peoples when its decisions may have an adverse impact on potential or established Indigneous and/or treaty rights.

As proponent, CNL engages with Indigenous communities and seeks to build long-term and meaningful relationships with those communities that have traditional territory and/or modern interests where we operate.