Evolution of Waste Storage Approaches at CNL’s Chalk River Laboratories

Abstract

At the Canadian Nuclear Laboratories (CNL) Chalk River Laboratories (CRL) site, radioactive waste has been generated and safely stored for over seventy years. During this time, the approaches for storage of Low-Level Waste (LLW) and Intermediate-Level Waste (ILW) have evolved significantly to align to new standards and regulations, new technologies, new perspectives, and new benchmarks of best practices. Over the past eight (8) years, CNL has made substantial progress towards evolving practices while reflecting radioactive waste storage as an intermediary step in the radioactive waste management lifecycle.

CNL, and AECL before 2015, has been a pioneer in radioactive waste management on a domestic and international scale. This experience has involved an approach of continuous improving practices for LLW and ILW that have evolved from emplacement in below-grade trenches, to emplacement in below-grade engineered structures, to emplacement in above-grade configurations for monitoring and ready accessibility.

Radioactive waste storage is also increasingly contextualized as a component of the waste management lifecycle; a component that impacts pre-storage management (characterization, packaging, and processing) as well as future disposal. The objective for CNL Waste Generators is not to characterize, process, and package waste to simply meet the storage facility Waste Acceptance Criteria. The new objective is to characterize, process, and package waste to meet transportation requirements, the storage facility Waste Acceptance Criteria, and the Waste Acceptance Criteria of the future disposal facility, recognizing the inherent uncertainty. There is also an increasing priority to minimize the volumes of LLW and ILW requiring storage and future disposal.

This paper will discuss the background evolution of waste storage practices at CNL’s CRL site, with a focus on current practices highlighting the operational experiences and lessons learned from establishing new approaches and capabilities related to characterization and radiological clearance, sorting and segregating waste, and transitioning to disposal readiness.