Canadian Nuclear Safety Commission (CNSC) executive vice-president and chief regulatory operations officer Ramzi Jammal said in a 28 November 2022 letter to OPG that the company had met the conditions for the removal of the hold-point and “fuel may now be loaded into the Unit 3 core”.
Hold points are mandatory checkpoints where CNSC approval is required before the licensee – in this case OPG – is allowed to move on to the next stage of the process to return the unit to operation.
OPG said it will now load 6,240 fuel bundles into the Candu 850 reactor core.
In February 2022, OPG said work had begun on the refurbishment of Unit 1 – the third of four nuclear reactors at the site to undergo mid-life refurbishment.
The 10-year project, which began in 2016, will enable Darlington to produce energy for an additional 30 years, if not longer.
The first refurbishment unit, Unit 2, was returned to service in June 2020. After a brief delay related to the Covid-19 pandemic, work on Unit 3 began in September 2020.
Unit 4 Refurb To Begin In 2023
OPG said in September it was well into the final preparations to begin work on the fourth and final unit to be refurbished at Darlington, which will start in the third quarter of 2023.
OPG said earlier this year that the overall project remains on track for completion by the end of 2026.
Darlington has four Candu 850 878-MW reactor units that began commercial operation from 1990 to 1993.
Refurbishment of a Candu reactor involves removing all the reactor's fuel and heavy water and isolating it from the rest of the power station before it is dismantled. Thousands of components, including those that are not accessible when the reactor is assembled, are inspected, and all 480 fuel channels and 960 feeder tubes are replaced during the high-precision rebuild.
Last month OPG submitted a construction licence application to the CNSC which could pave the way to the deployment of a small modular reactor (SMR) at Darlington.
In December 2021, OPG selected GEH as its technology partner for its Darlington SMR project. The first grid-scale plant is scheduled to be completed by 2028.
