Tuesday, August 08, 2006

Countering More Propaganda

Eric sent me a link and asked my opinion about an article quoting a few people with an antinuclear agenda saying that the heat wave in Europe is evidence that nuclear plays no part in combating global warming. My short answer is "hogwash." My long answer is below.

It doesn't matter if you're burning uranium, coal, oil, or cow dung, anything that uses a steam cycle has the potential problem of exceeding discharge limits if temperatures are excessively warm. Since only about 1/3 of the heat is usable to turn a turbine, the waste heat has to go somewhere. To not have this problem you can:

--Not make the environmental regulations overly conservative
--Build a bigger heat sink
--Build a smaller plant
--Invent a thermodynamic cycle better than the ones the world's best minds have come up with in the past two centuries or so (and be sure to include my name on the patent).

Now, I'm not advocating a reduction in environmental protection, but it's true that many environmental regulations are over-conservative and not based on today's best available science. In some cases, with proper analysis, it might make sense to revisit those limits or allow periodic exemptions. The whole hubbub with the proposed North Anna Unit 3 in Virginia was over a potential rise in temperature of I believe 1-2 degrees (Eric, would you check this out for me and provide the link?). Now Dominion's license application states that they will build a cooling tower--they're adding to their heat sink. They also get some extra MWs out of it.

Economics play a role in the size or rated capacity of the plant. If you never ever want to have the kind of problem stated in the article, you design the plant assuming the highest ever recorded temperature of your cooling water source. So instead of assuming, say, a mean maximum summer temperature and building a 1000 MW plant for which you MIGHT have to reduce power to 80% now and then, it means you'll build an 800 MW plant that you know you can always operate at 100%. But does that make sense when there are maybe 10 days every few years that exceed your thermal assumptions? The bean counters will tell you "no."

To me, it all goes back to 1)having a diverse energy portfolio and 2)having adequate supply margins. If you have five 1000 MW units operating at 80%, that's the equivalent of losing one unit. I say that if losing one unit causes that much heartburn, the problem is with our overall generation capability, not with the nuclear plants. The very hottest days of summer are what peaking units are for, and nukes don't make good peaking units anyway.

And consider the other extreme. When the Northeast U.S. gets hit with several blizzards and the trains carrying fuel can't get through (it happened a few years ago) and natural gas prices are through the roof, and all the while the nukes are humming along better than ever, don't try to tell me that solar, wind, corn and biomass are going to save the day. Just like nuclear power, they all have their place in a diverse energy portfolio, they all have their pros and cons, but none alone is the answer to our energy and environmental problems.

EDITOR'S UPDATE: The post concerning North Anna that Lisa refers to can be found here.

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12 comments:

Doug said...

The idea that thermal pollution from power plants is the cause of these heat waves is idiocy. Humanity's 400 quads of annual primary energy use are less than an hour or so of solar radiation reaching earth. Human influence on climate is due to more subtle effects such as greenhouse gassed and changes in land use. Thermal pollution is a localized effect. It is indeed warmer in urbanized areas, but let's look at why that's true. First, there's all those human bodies, not much to say about that. Then there's all the fossil energy they're burning in place. Then there's the dissipation of energy from electricity use, which is going to be the same locally no matter how the electricity is produced at a remote power station. Finally there is all that land surface that's covered with dark, sun-absorbing surfaces. Nuclear power is part of the solution, not part of the problem.

P.S. Lisa loved you on the Glenn Beck show.

Stewart Peterson said...

Doug: It's not that it's the cause of the heat waves, but that the plants underperform during heat waves. This, of course, borders on victim-blaming.

Lisa: there's also district heating and various industrial uses of that waste heat.

Brian Mays said...

If this ever did become a persistent problem, the plant's owner could just build a cooling tower. The tower would use a small fraction of the concrete required to replace the plant's capacity with wind turbines. I shudder to think what would be required to replace its capacity with photovoltaics.

Anonymous said...

"Just build a cooling tower"? Like it's a patio or spare room? Think again. Those things cost hundreds of millions of dollars, and require extensive plant mods.

GingerMary said...
This comment has been removed by a blog administrator.
Brian Mays said...

Sure. Why not?

I'm not saying that it's a small investment. Let's say that you own a plant, and your plant is forced to go offline because environmental rules have removed your heat sink. Thus, you would have to find power to replace the generation of your plant, which will cost you on the order of a million dollars for each day the reactor is down. Now, if you predict this to happen on a fairly regular basis over the years remaining in your plant's life, then the feasibility of a large investment such as a cooling tower begins to make more sense.

If that is not the case, then this "problem" is no big deal, and the "limits of nuclear power" that the article and environmental activists complain about is pure rubbish. That's my point.

KenG said...

Adding cooling towers is no big deal. These are called "helper cooling towers" and can be sized as required. These have been installed in a number of places as environmental standards were raised to restrict discharge temperature increases. A good example is Crystal River that has cooling towers, as I recall, not only for the nuclear units but also for the fossil power units on site.

Daniel said...

Nukes shutting down because of anything to do with "heat" is going to draw significant (& bad) media attention.

Also it appears that only nuclear plants have had to shut down due to increasing feed water temperatures. Or have I just missed all the bulletins about coal, natural gas, and solar thermal plant shutdowns?

What I take away from the media attention is that nuclear is not as reliable as I'd been told, and it will become increasingly less reliable as average temperatures rise.

As for the proposed solutions:
1) Ease environmental regs for nukes...LOL holy smokes you gotta be f'in kidding. Maybe that will fly in the boardroom, but it will never work for the public.
2) Build (better) heat sink/cooling tower--this could work, it will cost serious change for R&D and implementation but it looks like one of the best options.
3) Build smaller nukes--also viable option although it too will raise costs and lower efficiencies.

In summary, this IS a nuclear problem, which along with nuclear waste and decommisioning needs to be seriously addressed by the "industry" if it hopes to build anything more than demo plants in the US this decade.

I don't expect the nuke lobby to take the heat issue seriously since they haven't addressed the others yet. But it should.

KenG said...

I'm not sure how you can conclude this isn't being taken seriously. A number of affected plants have either built helper towers or investigated the economics of helper towers. In the US, we're looking at only a few of the 103 operating units where temperatures have been an issue. At North Anna, where two new units are planned, the first additional unit will probably use a wet cooling tower rather than the existing lake and the second unit will likely use a dry cooling tower. As far as I know all planned units will use cooling towers and none will use lake or river cooling. I'm sure experience will dictate considerable margins in the tower designs.

Lisa Stiles-Shell said...

Doug--thanks for watching the GB show.

Daniel, thanks for joining the discussion.

With regards to reliability--a nuclear unit operating at 80% power for a small portion of the year STILL has a higher capacity factor (read: reliability) than anything else that you can propose. In this country, the best capacity factor for wind farms is 35%. I believe the capacity factor for solar is similar.

With regards to environmental regulations--I wasn't talking at all about what flies in a boardroom. As an undergrad I worked at the university's Occupational Health and Safety office which, among other duties, was responsible for radiation protection and hazardous waste management. It's just a fact that some environmental limits have been set arbitrarily or before we had adequate scientific data. Does it make sense that for some substances the limit for discharge is LESS than what occurs naturally? All I was saying is that some limits, WITH PROPER ANALYSIS, may be found to be overly conservative.

As far as the cost of a cooling tower, the R&D has already been done, and others have pointed out that "helper" towers could be a solution and that the cost of adding one is likely significantly less than replacing the power by other means.

Regarding waste, I posted this comment on your blog where you praised solar, "Is there a reason you don't mention the same issue when writing about solar? Per kilowatt-hour produced, solar panels and their production generate about the same amount of toxic waste as nuclear power--waste that never decays or becomes less dangerous. It needs to be monitored and sequestered, something that the nuclear industry already does with its used fuel. I'm not against solar at all, but we need to evaluate all energy technologies by the same set of objective criteria. If we do that, I'm convinced that we'll find that there is a proper time and place for all of our generating methods including solar and nuclear." Furthermore, I worked for nearly 10 years in used fuel management and I can say with certainty that the issue is political, not technical.

I'm not sure what issue you see with decommissioning, but the industry has proven that it can decommission plants successfully.

Lisa

Daniel said...

Points in reverse order:

decommisioning...how much does it cost to decom relative to building the new plant? Is this cost fairly well established and is it factored into the cost of nuclear energy calculations? Or perhaps more relevantly, do nuclear operators fully fund their decom obligations?

waste...I actually don't know what the amount of waste solar generates per kW produced (I assume you mean PV, because for solar thermal the waste is nearly negligable--relative to anything else that is made using industrial processes). If we want to use standard metrics, we should talk in terms of kW delivered, since this is what a customer sees/pays for.
I hope you are not trying to insinuate that nuclear waste is more benign (since it decays) than toxic waste from industrial processes...
I do think all waste should be minimized and hope that my work in the solar field will reduce toxic waste by ~ 30% per delivered kW. (By using 30% less silicon per delivered kW...)

enviro-regs..."Does it make sense that for some substances the limit for discharge is LESS than what occurs naturally?" I suppose that depends on what you are specifically referring to...I can imagine scenarios where it makes sense to limit discharges to less than natural levels, if "natural levels" would be considered harmful.

reliability...fair enough, nukes have a higher capacity factor than solar or wind. But it is a shame that the nukes seem to go down at peak demand.

David Bradish said...

It costs about $300M to decommission a plant. If a plant is operating for 60 years that means the utility needs to stash away $5M a year. That's chump change to these utilities. Some CEO's salaries of these utilities are up to $30M.

I suggest reading Dr. Ivanco's Letter to the Editor on the issue of reliability.

The one plant in the middle of the desert he's talking about is Palo Verde which I mentioned to you on Makower's site.