On Nuclear Power Losing its Glow in California

On Nuclear Power Losing its Glow in California

Celebrating Climate Change 2015

Posted by Edward Leaver, 3 December 2015 (Updated 10 Feb 2016)

Michael R. Blood’s AP piece Nuclear power losing its glow in Calif. that appeared in The Denver Post Sunday, 29 November 2015, reported on movement to close California’s last remaining nuclear power plant. We examine some environmental costs of such action.

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Hoover Dam Diablo Canyon Lake Powell

Diablo Canyon’s two nuclear reactors combine for 2.24 GW and 87% capacity factor. Pacific Gas and Electric, seeking a 20-year extension to their operating license, faces determined opposition from traditional environmental organizations. Prematurely closed, 20 lost years operation would have generated 340 TWh essentially zero carbon electricity and 1100 tons1 readily stored used fuel which, if not recycled, would decay to natural pitchblende levels in about 250,000 years. Properly recycled, about 500.

1 TW is 1,000 GW, or 1 million MW.

Lakes Powell and Mead today combine for 2.8 GW and 25% capacity factor. Diablo Canyon generates four fifths the peak power and over 2.5 times the total yearly energy as the entire lower Colorado – about the same as that generated by California’s 33 year accumulated build-out of solar and wind.

Were Diablo Canyon forced to close, it’s replacements – whatever they might be – might as well have avoided 340 TWh coal generation somewhere else, generation that over those 20 years will release 300 million tonnes of dangerous carbon dioxide, as an irretrievable and essentially permanent gas, into our atmosphere.2

One wonders why we’re losing our war with coal.

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Supplementary Material

Table 1: Hydropower and Nuclear: Clean Reliable Generation (Updated 10 Feb. 2016)
Yearly Production
    Source     nameplate    current     average    Cap. factor     current     historical
Glen Canyon     Hydro     1.30 GW     1.2 GW     316 MW avg    30% Cf     3.6 TWh/y     3.85 TWh/y3
Hoover Dam     Hydro     2.08 GW     1.6 GW     400 MW avg    25% Cf     3.5 TWh/y     4.20 TWh/y4
Davis Dam     Hydro     0.25 GW     (0.25)     600 MW avg    52% Cf     (1.15)     1.15 TWh/y5
Parker Dam     Hydro     0.12 GW     (0.12)     52 MW avg    44% Cf     (0.46)     0.46 TWh/y6

Total:         3.75 GW     3.17 GW    1,370 MW avg    31% Cf     8.7 TWh/y     9.71 TWh/y 

Diablo Canyon    Nuclear    2.24 GW     2.24 GW    1,940 MW avg    86% Cf     avg 17.0 TWh/y    19.60 TWh/y7

As of 2014 California had 6,020 MW installed wind capacity, or 1.8 GW average at 30% Capacity Factor.8 In an average year Diablo Canyon Nuclear Power Plant puts out more usable electricity than all of California’s wind farms, installed over 33 years, combined.9

The combined yearly output of the four large Colorado River dams, 8.7 TWh, is roughly half Diablo Canyon’s 17 TWh average generation. Considering the environmental cost of those major river dams, and utter lack of remaining sites for their like, I’d hope opponents of Diablo Canyon would carefully think through their position. The 17 TWh/y base load gas needed to replace Diablo Canyon will emit at least 6.2 million tonnes CO2 each year, and could alternatively replace nearly all of California’s remaining 3 GW base load coal which is currently emitting today at least 15.1 million tonnes CO2 each year to generate the same 17 TWh:

Table 2: Three ways to generate 34 TWh a year.
Diablo Canyon averages 17 TWh/y. California proposes to replace it with an equivalent amount of fracked gas, and perhaps some wind. Since Diablo Canyon can almost certainly be recertified for operation through 2044, the proposed early replacement generation might alternatively be used to retire baseload coal instead:

Current emissions from 34 TWh/y, coal and Diablo Canyon:    15.1 Mt CO2 from coal + 0 from Diablo Canyon    15.1 Mt/y CO2
Emissions if fracked gas replaces Diablo Canyon:     15.1 Mt CO2 from coal + 6.2 Mt from gas     21.3 Mt/y CO2
Emissions if fracked gas replaces coal:     0 from coal + 0 from DC + 6.2 Mt from gas     6.2 Mt/y CO2
1 Mt = 1 million tonnes. We assume 360 tonnes CO2 is emitted for each GWh of natural gas generation operating as combined cycle baseload, and 890 tonnes for each GWh of coal.10 (1 tonne = 1000 kg = 2,200 lb.)

By installing 17 TWh/y of new gas generation and retiring either 17 TWh/y of old coal or old uranium, we can either reduce the associated emissions by 15/6 = 2.5 fold, or increase them by 40%. Choose wisely. But do keep in mind that possible 2.5-fold reduction realised by replacing old coal with new gas won’t be enough: we’ll need essentially zero emissions from the electric sector if we’re going to meet climate requirements.

As for the ongoing 2015 U.N. Framework Convention on Climate Change, COP21 in Paris, we’ve all seen the figures illustrating who is most responsible for present and historic carbon emissions:

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Source: James Hansen Isolation of 1600 Pennsylvania Avenue: Part I, 27 November 2015.

Of course, our collective war on uranium did not start at Diablo Canyon, nor will it there end. Kewaunee, Vermont Yankee, Pilgrim, FitzPatrick, Oyster Creek, San Onofre, Diablo Canyon, Indian Point. Eight plants either closed prematurely, announced to be closed prematurely, or vociferously desired to be closed prematurely. And not one of them – not even San Onofre – for reasons of safety. With a combined 9.76 GW, if operated over twenty years at 85% average capacity, those eight plants alone would generate us another 1,453 TWh dispatchable electricity, essentially carbon-free,11 sparing us from emitting another 1.3 billion tonnes carbon dioxide, emissions avoided simply by not burning coal.

Shutting down safely operating and fully licensable domestic nuclear power, to satisfy what amounts to provincial ideological whim, represents perhaps the epitome of fossil fuel profligacy, and sends a clear message the Rest of the World might not want to hear.

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Throughout, I have advocated continued operation of safely operating reactors. Nuclear opponents might contend there is no such thing, at least in seismically active regions of the planet which, arguably, would be all of it. Such concerns have been ongoing since the beginning of the nuclear power era, particularly around Diablo Canyon, and there is little I can say to allay them here.12 I will suggest that ongoing thermal pollution lawsuits and demands that PG&E replace ocean discharge with expensive cooling tower retrofit, are a red herring: that ecological damage has been done. Retiring the plant prematurely will needlessly introduce more ecological damage elsewhere.

And everywhere. No human activity is completely without risk. Regrettably, that includes nuclear power generation. Here I’ve tried to illustrate it also includes all probable alternatives to nuclear power generation. For nuclear advocates who might think it a black-and-white issue, I might suggest, global warming and environment notwithstanding, politically it is anything but: see The Diablo Canyon Timeline.

References and Reading:

1The Table of Material Balance at the end of WNA’s Nuclear Feul Cycle Overview gives an approximate 27 tonnes Used Fuel per year of GW nuclear power reactor operation. 40 reactor years would produce 1080 tonnes, or 1188 short tons.

2Statistically, those 340 TWh of continued coal generation will result in 5 thousand deaths from coal-related mining and pollution in the United States. There would be about 30 deaths from uranium – and those only if one assumes both the Linear-No-Theshold (LNT) radiation hypothesis, and includes Chernobyl in one’s statistics. See Gail Marcus, PhD, in A Comparison of Energy Sources. Chernobyl’s RBMK-1000 reactor was of a design that could never have been approved anywhere in the West.

3Update: There were Glen Canyon production errors in original version of table: 2.6/2.85 TWh/y instead of 3.6/3.85 TWh/y. I was unable to find precise estimate of Glen Canyon power generation at time of this article. Most sources cite an 8% derating beneath its nominal maximum, or 1.2 GW. The power conversion factors cited in Glen Canyon Dam’s Evaporating Hydropower suggest it may be nearly twice this: 15% or 1.1 GW. Glen Canyon saw 18 construction deaths

4Hoover Dam’s current output is limited by historical low water levels due to drought. Hoover saw 112 construction deaths not counting carbon monoxide poisoning.

5I was unable to find drought de-rating for Davis Dam or construction casualties, if any.

6Half of Parker’s output is required to pump water along the Colorado River Aqueduct. I was unable to find information on Parker drought derating or any construction casualties.

7Maximum yearly production. Diablo Canyon does not de-rate during drought, and saw no construction casualties.

8Update: California’s 2014 wind Capacity Factor was actually 26% for 1.58 GW average and 13.8 TWh generated that year. See Wikipedia Wind power in California

9California also has huge in-state hydropower that in 2014 generated 17 TWh of its own – the same as Diablo Canyon. See Mapping drought’s impact on electricity generation High Country News, 7 July 2015, and The Scorching of California City-Journal, winter 2015.

10WNA’s Energy Analysis of Power Systems, citing Swedish experience, suggests 450 tonnes CO2/GWh for combined cycle gas. In that case 360 tonnes/GWh would make a fairly generous allowance for wind.

11Roughly three-fifths nuclear carbon dioxide emission occurs during construction – steel and concrete – and decomissioning. For existing plants, those emission costs are sunk. Emissions during Uranium mining and refinement are tiny relative to the amount of carbon emission-free fission energy obtained while operating.

12Little but repeat the suggestion that while no deaths or even injuries are likely from radiation released at Fukushima, the same cannot be said for the forced evacuation, which has resulted in over a thousand quite unneccesary stress-related deaths. Those were real people, radiophobia is a deadly disease. See J.A. Sigel, PhD, W. Sacks, PhD, MD, and M.G. Stablin, CHP, PhD in LNT 999, Health Physics News, Vol 43 No. 10, October 2015, pages 23-24.