Canada is refurbishing nuclear reactors instead of replacing them — extending 40-year-old machines to run for 40 more years at a fraction of new build cost.

 

Canada is refurbishing nuclear reactors instead of replacing them — extending 40-year-old machines to run for 40 more years at a fraction of new build cost.

The CANDU reactor fleet at Ontario's Darlington and Bruce nuclear stations was built between 1971 and 1993. Forty years of continuous operation have taken their toll on pressure tubes — the hundreds of zirconium alloy tubes through which pressurised heavy water coolant flows past the fuel bundles in each reactor. Pressure tube degradation is the primary life-limiting factor in CANDU design, and the refurbishment programme replaces every pressure tube, calandria tube, and feeder pipe in each reactor — essentially rebuilding the reactor's core structure while leaving the reactor building, the turbine generators, the electrical infrastructure, and the grid connections in place.

Ontario Power Generation's Darlington refurbishment programme — four reactors, each undergoing a 3.5-year outage for complete core replacement — is delivering refurbished reactors at a cost of approximately CAD 1.5 billion per unit. A new equivalent reactor, if one could be built on the same timeline, would cost CAD 10 to 15 billion. The refurbished reactor has a further 30 to 40 years of operational life at full rated power. The economics are as close to obvious as major infrastructure decisions ever become.

The refurbishment programme has trained 4,000 Canadian nuclear workers in precision heavy water reactor maintenance — skills that transfer directly to the new small modular reactor construction programme beginning at the same Darlington site. Bruce Power's parallel refurbishment of six Bruce B reactors will extend their operation to 2064. Canada will have a fully operational nuclear fleet for another forty years built largely from reactors that first generated electricity before most of the engineers maintaining them were born. The machines that powered Ontario through the 1980s will power it through the 2060s.

Source: Ontario Power Generation & Bruce Power — CANDU Reactor Refurbishment Programme Status Report 2024