CANDU nuclear power plants: safety, licensing, and environmental considerations

CANDU nuclear power plants have a number of safety-related and environmental characteristics, which differ substantially from those of light-water-reactor (LWR) plants. Among the principal of these CANDU characteristics are: (1) the presence of a large low-temperature heat sink dispersed throughout the core region, (2) the absence of thick-walled, highly radioactive primary system components, and (3) the possibility of replacing vital core internals, including pressure tubes. The paper examines these and other characteristics and concludes that (a) the CANDU reactor can be expected to have a quite favorable overall probabilistic risk profile, (b) the environmental impact associated with CANDU reactors is expected to be favorably affected by the possibility of reusing the same site and civil engineering structures for successive generations of power plants through refurbishing and decommissioning of old plants. It is expected that introduction of CANDU reactors into a country, having a licensing process which has been strongly influenced by LWR technology, will not present any serious licensing problems.