Nuclear power. Is it renewable?

Recently a discussion occurred between Adriana Mugnatto-Hamuand members of the ZCO committee. The following are the salient points of the discussion. It was triggered by a reference to an article at Peak Oil

Nuclear power is clearly not renewable

There are people who call it "green energy", but nobody says it's renewable unless they are extremely uninformed.

Let me be clear, I am not in favourof nuclear power and it is not my impression that ZCO is in favour.

That said, much of this articlerefers to exaggerated claims or bogus research.

Nuclear plants do not produce CO2 in their operation in Ontario or anywhere. They may have backup generators to ensure safe continuity of the controls in case of a problem (like hospitals have backup generators, along with every high rise ever built), but nuclear power itself is produced by a fission reaction that produces no CO2. It does produce a lot of nasty radioactive elements, but that's a completely different problem. I don't like it when people who have very good reasons for opposing nuclear power start to make bogus claims about it in an attempt to make it look bad in every way. It makes us lose credibility if we use arguments that are demonstrably false.

There have been a number of studies showing the lifetime emissions of nuclear reactors, including mining and processing uranium. There are several things to note about this.

Nuclear power is low carbon

I have seen studies from three sources. The nuclear industry, when it evaluates life cycle emissions, comes up with emissions rates per unit of energy produced that are comparable to wind and better than solar. That number is likely to be too low, because the sources are clearly biased. Greenpeace put out a study a decade or so ago that claimed that nuclear energy produced as much carbon as coal. That study has been quoted a lot by environmentalists and anti-nuclear activists but it is not taken seriously by reputable scientists. Greenpeace and other ENGOsare also clearly biased and the study has been pretty much demolished. Even Greenpeace has stopped referring to that study and now acknowledges that nuclear emissions are dramatically lower than coal emissions, though their estimates of emissions from nuclear power still tend to be high.

There have been a few peer reviewed papers evaluating life-cycle emissions from nuclear. Those I have seen were all written by scientists with an anti-nuclear bias, so if anything, their estimates for CO2 emissions from nuclear are going to be high.

Only one that I'm aware of evaluated decommissioningand storage. This is potentially huge, but also possibly pretty trivial. Certainly the nuclear industry believes that decommissioning is relatively easy. The only little bit of experience we have with large-scale nuclear decommissions are Chernobyl (not entirely fair since that plant was contaminated much more than you would expect the normal reactor to be) and the recent British endeavours to decommission Sellafield, which is massively over budget and behind schedule. The Sellafield experience suggests that nuclear industry estimates of the complexity of decommissioning were absurdly low. At the high end is one peer-reviewed assessment I remember which didn't evaluate emissions directly, but suggested that decommissioning may use up several times more energy than construction. If that estimate proves to be true, then the net energy production from nuclear plants becomes laughably low, and so the emissions associated with each unit of net energy produced are correspondingly huge. That's compounded if the energy that goes into decommissioning is primarily from fossil fuel sources. But that's one estimate by a guy who clearly had it in for the nuclear industry. There is no empirical evidence to back up his claim and no other estimate suggests anything so extreme. This is something to watch for, but for now we have very little reliable information to evaluate decommissioning.

Overall, peer-reviewed scientific assessments for emissions from nuclear power are certainly higher than those from the nuclear industry, averaging about 3 times as high as the industry claims. But that's as high as we can reasonably quote. If we take these academic assessments seriously, then we can say that wind is much better than nuclear, and solaris substantiallybetter, but nuclear is still better than burning fossil fuels, even with carbon capture, and by a lot.

There is an additional opportunity cost that is rarely measured

One of the only people who have evaluated the carbon impact of investing in nuclear power is Mark Jacobson, who pointed out that waiting for a new reactor (the evaluation is completely different for replacement reactors) to be built to replace a coal plant means that you effectively count on a further 20 years of sustained coal use. If we add that into the calculation, nuclear power looks significantly worse. But it's still better than coal with carbon capture, and an order of magnitude better than the most efficient natural gas plant.

From a climate point of view (ignoring the other hazards of nuclear which are separate reasons to oppose it), that opportunity cost is our greatest argument against investing in nuclear power. It's what Amory Lovins refers to in the quote in this article. When governments commit large amounts of money for reactors, that's money they can't use for options that are faster, more efficient and more effective.

In my opinion, we should not be making the argument that nuclear power is a high carbon option, since it is widely accepted to be lower carbon than our current mix. However, we should be making the argument that since our goal is to reduce and eliminate carbon emissions as quickly as possible, we should focus on cheaper, faster and more effective options. That argument has the benefit of being supported by a large body of academic and other non-biased assessments, like those from insurance industries or market evaluators who devalue utilities that invest in nuclear power.

In other words, we concede that nuclear power is low carbon, since that's what non-biased studies appear to show, but point out that non-biased studies also show that there are even lower carbon options out there that are both cheaper and faster to install, so nuclear power is a poor investment if the objective is to reduce carbon emissions. There are simply better options out there.

Lifecycle emissions would go down, not up, if we had more nuclear power

One of the things this articlestates is that when we run out of cheap uranium, emissions from nuclear power will rise. The problem with calculating embodied emissions of industrial processes that are required for building power plants, mining, processing and transporting fuel and so on, rather than the energy production itself, is that these can change. In other words, if all the mining trucks that extracted and hauled uranium ran on batteries that got their juice from nuclear power, and if all the uranium processing facilities were powered by nuclear source electricity, then they would be emissions-free. Nuclear power is no different in this respect than wind power or solar power. When we run out of cheap copper which is critical in wind turbine production, we will end up putting more energy into mining and processing it. Not a problem if our energy for the mining and smelting comes from wind-sourced electricity, but an increasing problem if our energy continues to come from burning fossil fuels.

The important thing to note is whether the energy production is inherently CO2 producing or not. Burning fossil fuels, whether coal, natural gas or oil, always produces CO2. At best you can try to bury that CO2 but you can't get any useful energy out of a coal lump unless you burn it and release some carbon. That is not true of nuclear power. It is inherently not CO2 producing. Embodied emissions from mining and processing uranium are currently emissions intensive, but they don't have to be, and if we had more low-emissions energy, they would likely be less emissions intensive.

Net energy gain from nuclear power

There is an entirely different argument about the net energy gain from nuclear power that the articletouched on. And that is devilishly difficult to evaluate. In part it's difficult to evaluate because there is a huge divergence of views about just how much uranium remains to be found. But in part it's difficult to evaluate because we have no idea how popular nuclear power will be in the future. If Ontario were to build a reactor today and no other reactors were ever built again anywhere in the world, then this hypothetical reactor would be extremely low-emissions, efficient and cheap to run. That's because countries would be competing with each other for who got to offload their bomb waste onto this reactor. The fuel would be essentially free, and the energy yields would be huge. If, on the other hand, the industry's hoped-for "nuclear renaissance" actually happens and 50% of global power is produced by nuclear energy, then it's very likely we'll be getting into extremely low ore grades with very little net energy gain. That's a problem with all non-renewables. The more you use them, the more you have to scrape the bucket for the nastier, dirtier, yuckier stuff. So it is likely that nuclear power will have increasingly poor energy yields, but only if we expect the future to have a lot of nuclear power. Our hope should be that there will be few reactors but that they will be running very efficiently on bomb waste.

It's an indirect problem for renewables as well. Yes, the wind will always keep blowing, but the materials to build wind turbines won't be as easy to get in the future. The more turbines we make, the more difficult it will become to get the materials to build more. That said, renewables are at a distinct advantage over nuclear and other non-renewables in that they don't consume fuel. The copper to build turbines may get increasingly difficult to find and process, but wind turbines don't destroy copper as they run, so the speed at which you run out of options is inherently not as problematic with renewables, unless they rely on very rare elements to operate. Wind turbines do have some rare elements in their magnets, but as I understand it, we're not really very close to running out of economical alternatives. Though reasonable people have disagreed.

Decommissioning does not need to create emissions

It can be done emissions-free if done by machines powered by emissions-free energy. That doesn't mean it will be. But the more low-carbon we envision the future to be, the less we should worry about decommissioning as a climate concern.

We cannot shut down all reactors today

Even Greenpeace isn't advocating that. The public would never agree. Ontario manufacturing would collapse, with unemployment above 50%, possibly as high as 80% if we count associated services. Most buildings would crank up their emergency generators. As a result, emissions would climb despite the fact that people were not driving to work any more. For the majority of us, it would probably mean rolling blackouts. If we're lucky, these would be controlled. I suspect we'd have riots with all the unemployed people having nothing better to do than throw bricks at government buildings. Most people would leave the province for other jurisdictions where they were better taken care of. Assuming the government survived, which it could only do if it hired a mercenary army to keep control through brutal methods.

Alternately, we'd just import very dirty energy from the United States. Given the scale, it's quite possible that some of the energy we imported would be nuclear sourced. Most of the energy would come from coal, which in my opinion is much worse.

Transitioning off nuclear

Realistically, we need to figure out a transition strategy where we replace the energy we use with a lot of conservation and a lot of alternative sources. I'm all for speeding that up. But not to the point that the economy, the government and civil society collapses entirely.

In Germany, reactors are closed as coal plants are opened. From a purely climate perspective, maintaining a nuclear plant is preferable if the alternative is to build any kind of fossil fuel plant, including one with carbon capture.

I understand there are other considerations than just climate. I do not mean to ignore them. I'm just not going to get into that because it's much harder to compare apples and oranges. How do you measure the small possibility that a reactor will melt down and take out an entire city of millions tomorrow against the certainty that you will increase the world's temperature by a tiny fraction of a degree, in a future where millions will already be dying in droughts?

In general, my approach is to suggest investing only in a sane mix of the cleanest, fastest and most efficient possibilities while eliminating the nasty stuff. I would eliminate coal long before I eliminated nuclear power, but it's not irrational to reverse priorities if you assess the nuclear risk to be higher than the climate risk. However, it is wrong to close perfectly good, functional infrastructure at enormous cost if you're going to replace it at additional cost with a long-term commitment to something that many people believe is even worse.


As to your question of timing, while I am against closing nuclear plants before their time if they are going to be replaced with fossil fuels, I am not suggesting that nuclear reactors should continue to run when they have outlived their useful lives. A lot of reactors in the world are hobbling along with dozens of exemptions for safety failures. It is an inherently risky technology and the minute it isn't operating in near perfect condition, it should not be operating at all. If Ontario is reasonable, it will have to shut down a number of reactors before we are likely to build up the alternative energy sources. So we will have to import power, mostly produced by Ohio coal. That's a looming disaster (and especially a climate disaster) which is unavoidable but we should minimize as much as possible with a lot of rapid investment in smarter options.

However, I have a lot more tolerance for using existing technology when you don't have smarter options in place than I do for pouring billions of dollars of investment into a destructive build that will tie our hands for many decades into the future. I don't mind using power from existing Ohio coal plants temporarilynearly as much as I would object to building a new coal plant in Ontario to fill a gap.

Heat losses

The articletalks about heat losses. They are real, it's all true. It's also not a problem. There have been a number of analysts who have looked at the contribution to climate change from pure heat generation and the effect is negligible. You won't even notice it. The amount of warming we've experienced is thousands of times higher than the heat from all power plants and still people doubt climate change. And unlike CO2, which continues to heat the planet for many decades, the direct heat from thermal plants is released once and eventually lost. And keep in mind, the heat doesn't have to be wasted. There are parts of Russia where home heating is supplied by heat exchange with nuclear plants. It increases the efficiency of the nuclear plant too. A win-win situation. I do not actually think this is a great idea, for anyone who is confused. But if you're worried about energy balance and waste heat, it does make sense.

Water cooling

What is more relevant, when we're talking about heat, is that reactors rely on enormous amounts of water for cooling. This doesn't cause climate change, but it does make nuclear power an especially bad safety bet on a warming planet. In a heat wave, thermal plants (whether fossil fuelled or nuclear fuelled) need additional cooling, right at a time when the cooling power of the surrounding air and water goes down, and the volume of the water can also decrease dramatically through evaporation. And unlike coal plants, which can turn themselves off safely if the level of water they sit on goes down, nuclear reactors end up in crisis. During the European heat wave a few years ago, a lot of the French reactors were operating outside of regular limits. They all took on more water than they were legally allowed to, a few operated in spite of normally fatal security concerns because the government worried that the risk of mass death from lack of power in a heat wave (no air conditioning, no water, no fans, no elevators, restricted hospital services, etc) was greater than the risk of mass death from nuclear meltdown in a reactor that could no longer cool itself. But even if the government had stepped in and ordered a reactor to shut down, it would still continue to produce obscene amounts of heat that required massive cooling efforts for many weeks.


I'm annoyed by a lot of the stuff about Germany. They state that the nuclear phase-out helped Germany achieve emissions. None of the supporting statements actually support that. In fact, one of the supporting statements points out that they achieved it "in spite of" closing down reactors in one year, partly due to a warm winter. O yay. We can probably cut out heating entirely when the planet is like Venus, but that's hardly an argument for shutting down nuclear. There was also no mention made of the fact that while on paper Germany has reduced emissions, in practice, a large part of the explanation is that they have off-shored their emissions, primarily to China, so that the lifetime emissions of all the products Germans buy and use is actually higher, not lower than they were before.

There was also no mention made of the fact that Germany continues to build coal plants. That tradeoff - shutting down nuclear while opening coal plants - is clearly a net negative for the climate.

Germany needs to be praised for its incentives for conservation and the overall efficiency. They get points for the strength of their renewables programme. They do public transitright. And it's all within an overarching economy that begins to put something approaching a fair price on carbon. Germany does many things smarter than we do. But shutting down nuclear plants before end of life in order to invest in 50 more years of coal is insane and not something to praise at all.

Canadian reactors

The reality is that all of our reactors will reach the end of their useful service life long before we can replace them with anything sensible. And I'm not for building new ones. So if we follow my logic, we'll be off nuclear long before renewables are at 50%, and playing catch-up later. We'll be forced to import powerin the meantime, no matter what strategy we pursue. So the number it would take to replace nuclear is a moot point, and a big distraction. It would also be deceptive for us to suggest that we favourgetting off nuclear when we replace that capacity with renewables, because that's not what we're going to do.

Emissions from nuclear compared to renewables

Purely from an emissions standpoint, nuclear power falls into the same emissions category as renewables, while not being renewable itself. That is, if we look at just the energy production (the reactor, the turbine or the solar panel) then there are zero carbon emissions.

If we look at life cycle emissions, none of them are emissions free. In fact, nothing is. If you made a list of energy sources that had lifetime zero emissions, your list would be empty. So if you have a list of zero carbon sources that includes wind and solar and hydro, then it makes sense to put nuclear in there. In fact it wouldn't make sense not to. That's going to confuse/annoy a lot of people who are used to being told that nuclear power has emissions by anti-nuclear activists who don't bother to mention that "by that logic, so does wind, solar and hydro power". We can either confront those people or re-name the list "low carbon sources" just to avoid pointless confrontation.

Or we can make a list of "renewable sources" or even "low carbon renewable sources", which by definition would not include nuclear power. I am not aware of any renewable sources that are emissions intensive so that second option seems a little redundant. It wasn't always. Solar power used to not be a low carbon source, because solar panels used to be less efficient and had huge emissions embodied in their manufacture. There were some studies a few decades ago that suggested that solar panels used more energy in production than they ever produced, so obviously the energy produced was very emissions intensive. But that was aeons ago. Solar power these days is low carbon.

Some questions and answers

Q. In other places around the world, do their economies collapse when dirty energy is pulled out? I know some go for bad energy to even worse energy but what about others? I am thinking about Japan mostly.

A. Japanhas replaced nuclear power with a dependence on fossil fuels:

That's a terrible long-term strategy, and they are going back on it now. Several reactors have been restarted. However, I'm a lot more sympathetic to the Japanese case than I am to the German one. The Japanese were re-evaluating their reliance on nuclear power in light of a terrible tragedy that exposed their vulnerabilities. They always said they wanted to replace nuclear with renewables. Increasing the power output from existing fossil plants is a stop-gap measure. They didn't build any new coal or natural gas plants.

Q. Isn't the source of energy used in nuclear plants, Uranium? If so, why are we looking at the plant only when on other energy sources we look at the life cycle?

A. Actually, in general when we evaluate energy sources we almost never look at life cycle. That's why wind energy is said to be "emissions free". It wouldn't be emissions free if we looked at the life cycle analysis. That's also why coal plants look so much worse than natural gas, because coal is still relatively easy to extract. Natural gas is getting more and more complicated. But natural gas plants are still said to be much cleaner, because the emissions at the plant are lower. While there have always been energy nerds who were looking at life cycle analysis (and not just life cycle emissions analysis, but even more importantly net lifetime energy gains), it has been anti-nuclear activists who have pointed out the importance of life-cycle analysis to bolster their claims. And that was part of what enabled Greenpeace to say that nuclear was as bad as coal. Because they looked at the life cycle analysis for nuclear but compared it to plant only emissions for everything else, among many cheats. Life cycle analysis is getting increasingly important and there are now academics doing careful analysis for climate impacts. So they are comparing life cycle for everything. That's why we understand that fracked gas is so much worse than what goes on at the plant. But a realistic assessment of the life cycle of everything still puts nuclear, from a carbon emissions perspective, much better than fossil fuels. I am talking two orders of magnitude here - fossil fuels are responsible for 100 times higher emissions than nuclear. It's not a slight difference. Wind is the best, and solar beats nuclear as well. A lot of renewables come out at the top. But nuclear is still in the low emissions category. Wikipedia has a summary:

While I favourlooking at life cycle analysis in general, it's important to separate the inevitable carbon releases from the avoidable ones. Because even if a process is emissions intensive today, it could become less emissions intensive in the future. There is no part of the nuclear process that inherently depends on burning fossil fuels or releasing emissions. That's not true for fossil fuels. There will always be emissions if we burn fossil fuels. And some process emissions are unavoidable with fossil fuels as well. For example, all fossil fuel extraction involves fugitive emissions. These could potentially be reduced but they can't be eliminated. With the renewables and nuclear, there are no inevitable emissions at all. Done right, all of these sources could be emissions free over their lifetime.

Q. Are you saying that renewable energy is looked upon worse by the public than other energy sources? I would have to say that renewable energy opposition gets the loudest voice but nuclear power opposition is up there too. I am only talking about people who live near or in the communities where this is built.

A. Not sure what this refers to. Most people support renewable energy except when they have to see it and get no benefit from it. The opposition to nuclear is more widespread, and people who live near nuclear plants are more likely to support nuclear power because they get economic benefits from it, either directly or indirectly.