By: Donald Jones, retired nuclear industry engineer, 2019 April 21
The two lead CANDU 6 projects were Gentilly 2 in Quebec and Point Lepreau in New Brunswick and these were quickly followed by Embalse in Argentina and Wolsong, now Wolsong 1, in South Korea and all came into service in the early to mid 1980s. These can be regarded as the first tranche of CANDU 6 build.
The second tranche of CANDU 6 units came with Wolsong 2, 3 and 4 in South Korea, Cernavoda 1 and 2 in Romania, and Qinshan 3-1 and 3-2 in China (the other units at Qinshan site are not CANDU), all entering service between 1996 to 2007. Each of the second tranche CANDU 6 units incorporate lessons learned from operation of the earlier units with changes to meet latest regulatory codes and standards.
The Capacity Factors are taken from the PRIS (Power Reactor Information System) database of the IAEA (International Atomic Energy Agency). Note that the Load Factor term used in the PRIS database has the same meaning as Capacity Factor (CF). Capacity Factors are based on the (net) Reference Unit Power and on the (net) Electricity Supplied figures, as defined in the PRIS database. 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. The Unit Capability Factor (UCF), another performance metric, 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. The UCF seems a much better indicator of how well the unit is being managed than either CF or EAF but it is not specifically identified in the PRIS database (reference 1). Note that Bruce Power and Ontario Power Generation use UCF as a performance indicator.
CANDU 6 Units
Point Lepreau, New Brunswick, Canada. At the end of 2018 the lifetime CF since start of commercial operation in 1983 was 70.9 percent, including the refurbishment outage, and the annual CF for 2018 was 84.6 percent (EAF 84.5 percent).
Gentilly 2, Quebec, Canada. Unit came into commercial operation in 1983 October. The unit was permanently shutdown at the end of 2012 by Hydro-Quebec after election of the short lived Parti Quebecois government earlier in the year. At the end of 2012, when it was shutdown, it had a lifetime CF of 76.2 percent with an annual CF for 2012 of 70.7 percent.
Wolsong 1, South Korea. The unit was permanently shutdown 2018 June 19. The unit was licensed to operate up to 2022, the time of its next Periodic Safety Review, but the government decided to shut the unit down early in its push to increase the amount of renewables and natural gas at the expense of nuclear and coal. Since Kori unit 1 has been permanently shutdown Wolsong unit 1 had became the oldest operating nuclear unit in Korea. The lifetime CF at end of 2017 since start of commercial operation in 1983 was 72.6 percent, including the refurbishment outage. At the end of 2017 its annual CF was 40.4 percent.
Wolsong 2, South Korea. At the end of 2018 it had a lifetime CF of 92.0 percent and an annual CF for 2018 of 83.1 percent (EAF 82 percent).
Wolsong 3, South Korea. At the end of 2018 it had a lifetime CF of 89.1 percent and an annual CF for 2018 of 73.3 percent (EAF 73.2 percent).
Wolsong 4, South Korea. At the end of 2018 it had a lifetime CF of 93.5 percent and an annual CF for 2018 of 82.5 percent (EAF 83.2 percent).
Embalse, Argentina. The unit achieved criticality 2019 January 4 following a major upgrade including reactor retubing, replacing the steam generators and control computers, and an increase in output. The unit is expected to operate for another 30 years.
Cernavoda 1, Romania. At the end of 2018 it had a lifetime CF of 90.0 percent and an annual CF for 2018 of 86.6 percent (EAF 86.6 percent).
Cernavoda 2, Romania. At the end of 2018 it had a lifetime CF of 94.3 percent and an annual CF for 2018 of 97.1 percent (EAF 97.2 percent).
Qinshan 3-1, China. At the end of 2018 it had a lifetime CF of 90.2 percent and an annual CF for 2018 of 96.6 percent (EAF 98.8 percent).
Qinshan 3-2, China. At the end of 2018 it had a lifetime CF of 90.6 percent and an annual CF for 2018 of 79.0 percent (EAF 81.6 percent).
CANDU 6 summary
The average lifetime CF for the eight operating CANDU 6 units at the end of 2018 was 88.8 percent and their average annual CF for 2018 was 85.4 percent (EAF 85.9 percent). Except for the two Qinshan units there is no significant difference between the EAF and the CF which means the EAF could be the UCF with no external losses or the EAF could really be the EAF, for example the Wolsong units (reference 1). If it is assumed that the EAF should not be significantly different from the CF this would mean the EAF for the Qinshan units is really the UCF and external events reduced output somewhat.
1. Confusion with the IAEA reactor performance data in the PRIS, Don Jones, 2017 July 28, https://thedonjonesarticles.wordpress.com/2017/07/30/confusion-with-the-iaea-reactor-performance-data-in-the-pris/