In its Report to Parliament October 4, 2022, the Commissioner for the Environment and Sustainable Development (CESD) made observations about Canada’s handling of low and intermediate-level radioactive waste. The CESD audited three organizations:
- Natural Resources Canada (NRCan), the government department that leads the development and implementation of Canada’s policies on nuclear energy and radioactive waste management;
- the Canadian Nuclear Safety Commission (CNSC), which serves Canada as the independent nuclear regulator; and,
- Atomic Energy of Canada Limited (AECL), which manages certain nuclear services and facilities for the Government of Canada.
This document provides commentary on the AECL audit and excludes issues related to NRCan and CNSC.
The CESD audit makes two recommendations about AECL’s waste-management practices. The first relates to improving the accuracy of AECL’s radioactive waste database. The second relates to the need to provide the public with clear, understandable information about AECL’s radioactive waste management approach.
AECL, via the work done by its contractor, Canadian Nuclear Laboratories (CNL), characterizes its waste streams to identify their content. Characterization means that experts analyze the atomic elements within each stream to identify them, calculate their quantity, and analyze each element’s emission of radioactive particles and energy, including heat. Then it prepares its waste for storage, recycling, or disposal in line with legislation, regulations, government policies and international best practices. (In Canada, the CNSC describes disposal as “long-term waste management. The International Atomic Energy Agency refers to this as “disposal,” the term used here for a global readership.)
AECL groups all its radioactive waste in three CNSC-defined categories. The categories differ by level of radioactivity.
- Low-level radioactive waste: contaminated soil, debris from demolished laboratory structures, protective clothing, cleaning rags, mops, filters, and so on. This waste requires containment and isolation but generally has limited amounts of long-lived activity.
- Intermediate-level radioactive waste: Anything that exceeds the radioactivity threshold used to define low-level waste, that falls within a defined limit for heat, and that requires shielding during handling and interim storage. This waste requires containment and isolation for several hundred years or more.
- High-level radioactive waste: Used nuclear fuel that is highly radioactive, thermally hot, and that requires containment, isolation and shielding for hundreds of thousands of years.
Within each category, AECL’s waste exists in bulk form. Radionuclides (the radioactive form of elements) may be stored alongside non-radioactive waste which may mix toxic and non-toxic substances. As the CESD noted in its audit, “We did not identify any health or safety concerns” with AECL’s waste-management practices. The auditors also noted that AECL’s approach aligns with international standards.
AECL’s waste comes from two sources: “legacy” waste, from decades of AECL’s nuclear research and development; and “historic” waste from other entities that was assigned to AECL by the Government of Canada in 2015. Whether it is legacy or historic, the waste must be managed properly.
AECL is working today to place its low-level waste into containment mounds, where its radioactivity will fade away over time. It is consolidating its intermediate-level waste from all AECL-owned sites at Chalk River. Initially this waste will be stored above ground. When a deep geological repository becomes available, AECL will move its ILW there where. AECL’s high-level waste will be moved to a future deep geological repository under the jurisdiction of the Nuclear Waste Management Organization (NWMO).
As AECL cleans up its waste, its inventory records will become more accurate, ensuring that all content are recorded correctly.
Waste management facilities require approval by Canada’s nuclear regulator, the Canadian Nuclear Safety Commission (CNSC). The CNSC will monitor and inspect them regularly. Before entering an approved waste facility, all waste will be either re-characterized or verified against the facility’s CNSC-approved Waste Acceptance Criteria.
AECL has been working with its contractor, CNL, to improve the accuracy of the waste database. The current eMWaste database is the fourth database used since 1955 to track waste. It entered service in March 2021 and replaces three predecessors. It contains a greater number of data fields per record, enabling better quality inventory information.
The CESD audit sampled the eMWaste database and its immediate predecessor, the Waste Tracking System (WTS) used to capture data from 2018 to March 2021. The CESD audit did not examine the two previous databases.
The CESD audit sampled fifty records in the eMWaste database and identified discrepancies between source information (the waste forms) and database content (electronic record) for four records among these 50. This is an error rate of eight per cent. The source information is correct; the inaccurate database entries are keying errors.
It is important to note that no error resulted in a change to the category of waste. No intermediate-level waste was shifted into the low-level category or vice versa. In other words, the errors led neither to a change in risk nor the appropriate waste-disposal process or inventory reporting. Nor were the errors large enough to trigger any changes in the volume of current and proposed storage or disposal facilities.
As the CESD audit noted, AECL’s waste-management practices align with international standards. The audit found no evidence of health or safety concerns.
Since the end of the CESD audit, Canadian Nuclear Laboratories has brought international expertise to support its staff to review and verify the existing records, and to improve the quality controls over data entry and verification.
Specifically, with AECL oversight, Canadian Nuclear Laboratories is conducting a 100% review of approximately 35,000 waste records entered in the databases since 2018, the beginning of the period audited by CESD. CNL will complete this review in early 2023. This review will ensure 100% accuracy for these records.
CNL is also reviewing a sample of database records generated between 2015 and 2018 to understand the extent and impact of any discrepancies in the database from this period.
To strengthen inventory controls over the radioactive waste database further, AECL is overseeing CNL’s plan to improve eMWaste data entry and verification.
Starting in 2023, AECL will disclose its waste inventories through its website, using plain language, and updating quantities annually. AECL will also provide Canadians with accessible information that accurately describes AECL’s entire radioactive waste inventory and its waste-management plans.