Performance of Ontario’s CANDU nuclear generating stations in 2022

By: Donald Jones, retired nuclear industry engineer, 2023 June 19

The raw performance data for 2022 are taken from the Power Reactor Information System (PRIS) database of the International Atomic Energy Agency (IAEA). Note that the Load Factor term used in the PRIS database has the same meaning as Capacity Factor (CF). CFs are based on the (net) Reference Unit Power and on the (net) Electricity Supplied, as defined in the PRIS database. 

The performance of some of Ontario’s nuclear generating stations is affected by the surplus baseload generation (SBG) in the province. Some nuclear units see electricity output reductions during periods of SBG. This means the CFs are not a true performance indicator for those units (reference 1). A better metric of performance in these cases would be the Unit Capability Factor (UCF – used by Ontario Power Generation and by Bruce Power). The Energy Availability Factor (EAF) is another performance indicator and is shown in the PRIS database. The EAF adjusts the available energy generation for energy losses attributed to plant management, planned and unplanned, and for external energy losses beyond the control of plant management while the UCF only includes energy losses attributed to plant management and excludes the external losses beyond control of plant management like load cycling/load following, grid failures, earthquakes, cooling water temperature higher than reference temperature, floods, lightning strikes, labour disputes outside the plant etc. For a more complete discussion of UCF, EAF and CF see references 2 and 3.