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. Show Figure

---

Figure 1: Time Evolution of Radiotoxic Inventory of Used Nuclear Fuel.

Radiotoxic lifetime of Direct Disposal will be slightly less with newer, more highly enriched fuels. Other authors cite $\sim 200,000$ years. In practice, the difference will be negligible. FP $\to$ fission products (Sr, Cs). MA $\to$ minor actinides (Np, Am, Cm).
Source: M. Salvatores Advanced Nuclear Fuel Cycles, page 19. Also Actinide and Fission Product Partitioning and Transmutation, page 89.

---

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.

As of 2014 California had 6,020 MW installed wind capacity, or 1.8 GW average at 30% Capacity Factor.¹⁴ 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.¹⁵

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:

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:

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,¹⁷ 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.

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.¹⁸ 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:

• Wikipedia: Hoover Dam.
• Wikipedia: Glen Canyon Dam.
• Wikipedia: Wind power in California.
• American Wind Energy Association: California Wind Energy.
• World Nuclear Association: California’s Electricity.
• E&E News: Receding Lake Mead poses challenges to Hoover Dam’s power output 30 June 2014
• IEEE Spectrum: Colorado River Hydropower Faces a Dry Future 19 Sep 2013.
• High Country News: Glen Canyon Dam’s Evaporating Hydropower.
• Forbes: Are California Carbon Goals Kaput? James Conca, 2 Oct 2014
• California Council on Science and Technology: California’s Energy Future – Powering California with Nuclear Energy, Burton Richter, Robert Budnitz, Jane Long, Per Peterson, and Jan Schori, July 2011.
• James Hansen, Kerry Emanuel, Ken Caldeira and Tom Wigley: Nuclear power paves the only viable path forward on climate change The Guardian, 3 Dec 2015.