Ontario’s Darlington B must be on line before 2020 and must be CANDU

By: Donald Jones, P.Eng., retired nuclear industry engineer, 2012 August.
A condensed version of this article will appear in the upcoming 2012 September edition of the Canadian Nuclear Society’s BULLETIN journal.
By the end of 2012 after the restart of Bruce units 1 and 2 and with all eight units on line there could be up to 12,900 MW of nuclear generation being fed to the Ontario grid. Over the next 12 years or so units 3 and 4 at Bruce A, all four Bruce B units and all four Darlington units will be refurbished and Pickering A and B stations will be shutdown for good. This will have significant impact on the Ontario grid.
Both Pickering stations are slated for shutdown in 2020 so this will bring an immediate loss of around 3,000 MW. If this loss is replaced by combined cycle gas turbine units it will result in the annual dumping of 9.75 million tonnes (reference 1) of the greenhouse gas (GHG) carbon dioxide into the atmosphere just from the burning of the fuel. Life-cycle emissions would be more especially from the increasing use of “fracked” gas which, according to some reports, has life cycle emissions comparable to coal. If replaced by a less efficient coal-fired Nanticoke and Lambton converted to gas it will result in nearly 14 million tonnes being dumped. If replaced by nuclear there will be zero emissions.
On Darlington, a World Nuclear Association report, “Nuclear Power in Canada”, 2012 June 26, says, “OPG plans to shut the reactors sequentially for 3.5 years each for refurbishment from 2016: unit 2 then, unit 1 in 2018, unit 3 in 2020 and unit 4 in 2021, so that no more than two are out of action at the same time.” This means that from 2018 until half way through 2024, up to 1,760 MW to the grid from Darlington will be absent.
Bruce Power has said units 3 and 4 will be able to operate to 2020 after the present unit 4 outage work. The four Bruce B units started up
in 1984/87 so based strictly on years in service they would likely need refurbishment before that date. So, by 2020 there could be two units at Bruce A/B being refurbished at the same time with the loss of around 1,600 MW. The exact number of Bruce units off line and their timeline will depend on the refurbishment schedule which has not yet been released.
Altogether this will be a loss of around 6,400 MW of nuclear generation around 2020, half the nuclear generation capacity at the end of 2012. The exact amount will depend on the timing of the refurbishment outages. Assuming by 2020 up to 9,000 MW of baseload and intermediate/peak load hydro and around 9,000 MW of gas, excluding the 2,000 MW Lennox oil/gas-fired thermal station, gives total Ontario generation of about 24,500 MW, without wind/solar, imports, and demand management. Natural-gas fired units seem to come and go on political whims so any figure on the capacity around 2020 is an estimate. This supply would also have to include an operating reserve, spinning and non-spinning, of around 1,500 MW. Wind and solar are expected to be around 9,500 MW by 2020 but since wind is unreliable the Independent Electricity System Operator (IESO) assumes that only around 13 percent of this will be available on the highest demand days – of course it could be zero. There could also be some generation from biomass. Weather/climate change could eat into the hydroelectric generation, particularly that from stored water, and forced and planned outages would mean other generation may not be available when required. Any imports from the U.S. will be from GHG and pollution emitting coal and gas-fired generation. Cleaner imports from Quebec would be expensive since Ontario would be competing with the U.S. market, and long term planning would have to consider the weather/climate imponderables on Quebec’s hydroelectric generation and long transmission lines. So far in this summer of 2012 there have been peak hourly market demands of 26,000 MW and Ontario demands of 24,000 MW.
Even before 2020 there could be four nuclear units undergoing refurbishment, at Darlington and Bruce. To reduce the generation loss reducing the number of units undergoing refurbishment at the same time would help but this brings with it the risk of exceeding the operating life of critical components in one or more units and they would have to be shutdown anyway.
More expensive gas-fired generation to replace nuclear undergoing refurbishment will lead to increased electricity costs and a big increase in GHG emissions. Gas-fired generation will be operating as baseload as well as intermediate load. Reduced hydroelectric generation because of lower than normal precipitation so far in 2012 has already resulted in an increase in coal and gas-fired generation and even use of the rarely used Lennox oil/gas fired thermal station, that has high operating costs, during afternoon peaks. Low precipitation years could become more frequent due to changes in climate caused in part by gas and coal-fired generation. The expected extended outage of Bruce unit 4 from early 2012 August, with units 1 and 2 still out for refurbishment, will worsen the present situation and give some idea of what is to come. Wind is of no use since it is not there when it is needed. Some turbine replacements have recently been carried out on Lennox so it seems there will be more use in the future of this high heat rate (low thermal efficiency) station that is normally held in reserve to support the grid under continuing reliability-must-run contracts between the IESO and Ontario Power Generation (OPG). OPG has wanted it shut down but the IESO wanted it kept available, good thinking in view of likely future shortages. GHG emissions from Lennox when burning gas would be around 43 percent higher than from Ontario’s combined cycle gas turbine plants for same output – Nanticoke and Lambton coal-fired stations would be the same if converted to burn gas. There would be a reduction of only 40 percent in the carbon dioxide emissions by converting the coal burners in Nanticoke and Lambton to gas firing. Replacing them by efficient combined cycle gas turbine units would give a reduction of around 58 percent. Replacing them with nuclear would give a reduction of 100 percent.

There is a strong case for getting Darlington B on line as soon as possible and certainly before 2020 to avoid power shortages. Even more than the proposed 2,000 MW should be considered for Darlington B since the new units would be flexible enough to significantly reduce power overnight during periods of low demand. The IESO now calls the output of Bruce B “flexible nuclear” based on the limited manoeuvring capability of the units using steam bypass without reactor power changes. CANDU fuel costs are very low and new CANDUs will make use of steam bypass and reactor power changes to manoeuvre electrical output down to zero if necessary and respond to five minute load-following dispatches from the IESO as well as having the capability to provide second to minute automatic generation control. The IESO might want to call this “ultra flexible nuclear”. This means that  4,000 MW of new nuclear could operate at 2,000 MW or less overnight if needed meaning that the grid could accommodate 14,000 MW of installed nuclear rather than the 12,000 MW of Ontario’s Long-Term Energy Plan (reference 2). This would be a start in weaning Ontario off fossil fuels with the long term aim of an emission free reliable nuclear/hydro grid (reference 3). The next power crunch will likely come around 2045 to 2050 when the refurbished nuclear will need to be replaced, or refurbished once more if it can. Planning for this should be made part of Ontario’s Long-Term Energy Plan at its next revision.

Canada’s Enhanced CANDU 6 (EC6) is an enhanced version of units that have been operating around the world for almost 30 years with exceptionally high lifetime and annual capacity factors. The Canadian Nuclear Safety Commission would be able to approve this design much quicker than any competing foreign technology that it is not yet familiar with and which is not yet in operation and Canadian companies in the supply chain are more familiar with CANDU than with foreign technology. Rather than delay Darlington B construction by studying different technologies, fiddling while Rome burns, the first 2,000 MW or more of Darlington B should be EC6 units. If thought necessary foreign technologies could compete for subsequent projects. However, in the future ultra nuclear flexibility will be one of the most important attribute in replacing non-renewable gas for
electricity generation and this has to be a major consideration in any vendor selection process (reference 4). Going with the EC6 provides this flexibility and is the only way to get Darlington B online before 2020. The two CANDU 6s in China were each built in less than five years from first concrete to full power on line but that should not be assumed for Ontario.
The new nuclear plants would operate for 60 years providing emission free energy at a reasonable consistent cost that is little affected by fuel cost increases unlike gas-fired plants that produce greenhouse gases and other emissions and whose generation costs are very sensitive to the price of gas which will inevitably increase in the future. The cost of gas generation would increase even more if the government were really serious about GHG emissions and climate change and put a cost on carbon. While methane and other fossil fuels are non-renewable and will eventually become too expensive as supplies run down nuclear fuel will be around for many thousands of years using inherently safe fast reactors that can be used to breed new fuel or be used to “burn” the used fuel from the present and past generation of reactors. The waste from these burner fast reactors will have radioactivity that declines to that of the original uranium ore in around 300 years so there will be no need for deep in-ground waste storage repositories built to last many millennia. In any case this fear of small doses of radiation is unfounded – no one is going to die or get ill from small amounts of radiation say like that received from the event at the Fukushima nuclear power stations, not even the workers at the plants. In the “short term” CANDU reactors can burn uranium or the more abundant thorium.

Burning gas just to produce electricity is a travesty and deprives future generations of this versatile commodity. Instead of tying Ontario into more gas, under the guise it is “backing up” wind which does not work anyway (reference 5), the government should move much more quickly to get construction started on Darlington B by selecting EC6 and giving OPG permission to apply for a construction licence. The Ontario future is with nuclear, not with short-term, nonrenewable, expensive, GHG methane, and worthless, unreliable wind.

1. Carbon dioxide emissions are based on data from, “Coal-fired Electricity Generation in Ontario”, 2001 March, Ministry of Environment, Ontario,
2. “Ontario needs more than 2,000 MW of new nuclear despite what the Long-Term Energy Plan says”, Don Jones, 2011 Jan. 20, http://coldaircurrents.blogspot.ca/2011/01/ontario-needs-more-than-2000-mw-of-new.html
3. “An alternative Long-Term Energy Plan for Ontario – Greenhouse gas-free electricity by 2045”, Don Jones, 2011 May 30, http://coldaircurrents.blogspot.ca/2011/05/alternative-long-term-energy-plan-for.html
4. “Ontario’s CANDUs can be more flexible than natural gas generation and hydro generation”, Don Jones, CNS BULLETIN, 2011 December, and,  http://atomicinsights.com/2011/12/ontarios-candus-can-be-more-flexible-than-natural-gas-and-hydro.html
5. “Why wind power does not work in Ontario – and the solution”, Don Jones,  CNS BULLETIN, 2012 June, and,  https://thedonjonesarticles.files.wordpress.com/2012/08/why-wind-power-does-not-work-in-ontario-and-the-solution-2012-aug.pdf

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