Question 12 of 19: Management of Nuclear Wastes

Question 12: Management of Nuclear Wastes (3 marks)

Question text not reproduced: the examination questions are © Engineers and Geoscientists BC. Open the official past paper (linked at the top of this page) to read the question, then follow the worked solution below.

Nuclear waste is managed differently according to its classification. Low-level waste (LLW) — contaminated protective clothing, tools and filters — is compacted or incinerated and disposed of at licensed near-surface facilities. Intermediate-level waste (ILW) — reactor components and resins with higher, longer-lived activity — is packaged and stored at engineered surface or near-surface facilities pending eventual deep disposal. High-level waste, in Canada essentially synonymous with used (spent) CANDU fuel bundles, follows a staged management path: bundles are first stored underwater in a shielded, cooled used-fuel bay at the reactor site for roughly ten years to allow short-lived radioactivity and decay heat to fall substantially, then transferred to passively-cooled dry storage in concrete or steel canisters, either at the reactor site or a centralized interim facility. The long-term plan for used fuel in Canada is deep geological disposal, managed under the Nuclear Waste Management Organization's (NWMO) Adaptive Phased Management approach — siting, characterizing and eventually constructing a Deep Geological Repository hundreds of metres underground in stable rock, engineered with multiple containment barriers (the fuel matrix itself, a corrosion-resistant container, a bentonite buffer, and the host rock) to isolate the waste for the very long timescales over which it remains hazardous. All of this is regulated end-to-end — generation, transport, storage and eventual disposal — by the Canadian Nuclear Safety Commission (CNSC) under the Nuclear Safety and Control Act.