For all the arguments made by the opponents of nuclear power -- that it is uneconomical, unsafe, a potential boon to terrorists, poses waste-disposal issues, and all the rest -- nuclear's biggest threat may come from the one problem it is purported to address: climate change.
If, as many climatologists suggest, the heat waves in Europe, the U.S., and elsewhere are an indication of shifts in global climate patterns, it could spell doom for nuclear power, whose viability is directly linked to the availability of adequate water supplies.
Consider what's happened lately on both sides of the Atlantic.
"The extended heat wave in July aggravated drought conditions across much of Europe, lowering water levels in the lakes and rivers that many nuclear plants depend on to cool their reactors," reports the Christian Science Monitor, adding
As a result, utility companies in France, Spain, and Germany were forced to take some plants offline and reduce operations at others. Across Western Europe, nuclear plants also had to secure exemptions from regulations in order to discharge overheated water into the environment. Even with an exemption to environmental rules this summer, the French electric company, Electricité de France (EDF), normally an energy exporter, had to buy electricity on European spot market, a way to meet electricity demand.
Meanwhile, in the U.S., the utility giant Exelon last week cut the power at its nuclear power plant in Quad Cities, Ill., after a heat wave warming the Mississippi River valley reduced the supply of cooling water, according to a Reuters report cited by the blog energy.buzz. The story cites similar drought-related cuts in nuclear plants in Minnesota and elsewhere in Illinois.
Such problems may be short-lived -- these plants' output have likely since been restored -- but the question remains: What happens to nuclear power's future if climate change reduces the availability of the water on which they depend?
Lack of water isn't the only problem associated with heat-stricken nuclear plants. The French government announced last month that nuclear power plants situated along rivers will be allowed to drain hot water into the rivers at higher temperatures than normal, according to IPS News. The heat wave since mid-June has led authorities in France, Germany, Spain, and elsewhere in Europe to override their own environmental norms on the maximum temperature of water drained from the plants' cooling systems.
Of course, it's not just nuclear. Hydroelectric power plants are similarly affected by droughts, especially crucial for an economy in a country like Norway that is dependent on hydropower. In northern Italy this summer, low water levels in the River Po affected hydroelectric supplies, prompting power shortages in Rome that knocked out air-conditioning and left people trapped in elevators, reports the International Herald Tribune.
Indeed, any power plant that uses a steam cycle "has the potential problem of exceeding discharge limits if temperatures are excessively warm," as nuclear engineer Lisa Stiles-Shell points out in an industry blog. She notes that "only about 1/3 of the heat is usable to turn a turbine, the waste heat has to go somewhere." The point seems to be that nuclear is just as inefficient as other large, centralized power plants, so why pick on us?
Point taken. Still, these real-world problems should concern the nuclear industry more than they seem to. Droughts and releases of heated water into rivers don't show up much in the industry literature -- or in anti-nuclear activists' arguments. Perhaps they should. Access to water supplies is being seen increasingly as an economic, political, public health, and human rights issue. Overall, about one-third of all water used in Europe is used for cooling electrical generators, including those powered by both nuclear and fossil fuels. How will our growing need for power reconcile with our growing need to quench our farmlands, our wetlands, and our bodies?
As for nuclear in particular, the water issue needs to float to the top of concerns addressed by both advocates and opponents when make their respective cases. For now, the burden of proof seems to be on the nuclear industry. As Stéphane Lhomme, a spokesman for a French group Sortir du Nucléaire (Abandon Nuclear), told the Christian Science Monitor: "Global warming undermines the arguments we've always heard about nuclear power, that it doesn't damage the environment. Nuclear is not saving us from climate change. It's in trouble because of climate change."
What is particularly disturbing about this recent development is that James Lovelock, the scientist who most recently surprised environmentalists by advocating nuclear power as a solution to global warming, only advocated nuclear power because it was an immediate source of energy that did not have a significant carbon footprint. Lovelock, also the scientist who authored the Gaia hypothesis, feels that global warming is a far more immediate concern than most scientists, even those that aknowledge human induced climate change, believe it is. He simply doesn't think we have enough time to rebuild an entirely new energy infrastructure before we radically decrease our global GHG emissions. Now it seems he may be right to the extent that global warming is already beginning to disrupt our existing energy ifrastructure. But it appears that nuclear power, even despite all the other great reasons to abandon it, won't be able to combat GHG emissions at all. Irony upon irony. Tragedy upon tragedy.
There is at least one type of reactor which can use air cooling (GTMHR by General Atomics). Also, What about using the ocean for cooling?
I seem to remember hearing about how some pebble-bed reactors can be cooled with Helium (i think - sorry, i don't have time to double check any of this). I know that very few (if any?) of these reactors are online now, but is Helium cooling worth looking at?
Perhaps I'm missing something about nuclear energy production and its biproduct of heat. Isn't heat energy? shouldn't it be captured instead of being used to further heat the earth?
Like all heat-based electrical stations, nuclear power is bound by the laws of thermodynamics. Essentially, in order to convert heat (high temperatures) into work (like electricity), you have to run a thermodynamic cycle. These cycles have a maximum efficiency that is related to the high and low temperatures they have access to. The Carnot efficiency is the maximum achievable due to the law of thermodynamics:
efficiency <= (1 - LowTemp/HighTemp)*100%
with the temperatures on an absolute scale (like degrees Kelvin = degC+273)
Typically in a power plant about 40% of the heat can be converted to work - the rest must be removed from the "low temperature" sink in order to maintain the efficiency.
This is why the lack of cooling water matters - if you can't keep your low temperature down, your efficiency goes to crap and you loose more than you gain if you continue to run at full power.
You can read all about thermodynamics on wikipedia
The reason that oil and natural gas plants don't have this water cooling issue is because they have a large stream of exhaust gases that can carry their waste heat away. Nuclear power's big benefit is lacking those exhaust gases (no carbon dioxide or other pollutants), but its direct side effect is the need for massive amounts of cooling water.
oops, my equation got eaten by the less-than symbol. Here it is again with proper escaping:
efficiency <= (1-LowTemp/HighTemp)*100%
with temperatures on an absolute scale (like degrees Kelvin = degree Celcius + 273)
Using the ocean for cooling puts the power plant into conflict with humans and the marine environment. Years ago, the Clamshell Alliance fought the Seabrook Nuclear plant in New Hampshire directly on the potential harm done the sensitive estuary and foreshore habitats by high temperature water discharge. The plant is also near popular beaches, and the approval was held up for year because local Civil Defense groups in Massachusetts would not submit evacuation plans because they said there was NO safe evacuation possible in case of an accident at Seabrook. The nuclear regulators solved the problem by reducing the evacuation radius to within New Hampshire. Most coastlines in populous countries are inhabited, so there will always be a conflict with people.
"Overall, about one-third of all water used in Europe is used for cooling electrical generators, including those powered by both nuclear and fossil fuels."
How exactly is the water being used? Isn't most of the used water simply coming into the plant, being warmed up and then leaving from where it came? I would guess that some leaves as steam but the majority is put back where it came. In this way, power plants use water like dams do. The key point is that if the plants weren't there, there would not be extra water for other uses. Yes they need water, but they don't use it up like we do when we use gasoline. The water is still available for others to use downstream.
If this is the case, why should we be concerned about how much water they use?
As for Rob's point, couldn't you just have a long series of tubes (but not a dump truck) that sucks water from farther out at sea? This would bypass the estuaries and shorelines.
There sodium cooled nuclear power plants such as are used on nuclear submarines. The added benefit of these is if there's a leak it just solidifies and doesn't become part the biological enviroment.
You stated: "The reason that oil and natural gas plants don't have this water cooling issue is because they have a large stream of exhaust gases that can carry their waste heat away. Nuclear power's big benefit is lacking those exhaust gases (no carbon dioxide or other pollutants), but its direct side effect is the need for massive amounts of cooling water."
Any electrical generation plant that uses turbines in a steam cycle requires cooling water. It matters not if it's nuclear, coal, gas or oil.
The waste heat "could" be used for clean potable water but fear and doubt prevail. California would need 40 new n-plants to replace gasoline consumption.
I think it's a good point to factor in water shortages when judging the viability of nuclear energy. We'd do this for hydroelectric, right? But I don't think this is really going to slow or hasten the adoption of nuclear energy in countries like China or India.
China and India, to their credit, are trying to address environmental issues (Frankly they really have no choice!) but their burgeoning economies need a lot of electricity and they seem to be willing to use whatever means they can to get it.
They may shoot themselves in the foot as snow pack in the Himalaya and other mountain ranges dimishes but we'll see how it turns out.
Marc wrote: "There sodium cooled nuclear power plants such as are used on nuclear submarines. The added benefit of these is if there's a leak it just solidifies and doesn't become part the biological enviroment."
Not so simple! Elemental sodium reacts violently with even tiny amounts of water, and spontaneously combusts when exposed to air. Also, the sodium is used in the primary coolant loop, and goes through a heat exchanger to heat up -- guess what -- water. Not only does this mean that sodium-cooled reactors DO require water, but it means that the sodium becomes radioactive from neutron bombardment. So a sodium leak results in spontaneously combusting radioactive material -- not pretty!
I grew up within five miles of the only commercial LMFBR (Liquid Metal Fast Breeder Reactor) to ever be built in the US. It suffered a catastrophic cooling failure during the first full-power testing, and very nearly melted down. The father of guy I was in a garage band with was an engineer there, working during the crisis. He died within a decade of cancer in his early 50's. Funny everyone knows about Three Mile Island, but the story of Fermi I is nearly unknown. See John Fuller's "We Almost Lost Detroit" for an accurate (if somewhat sensational) account of that event.
Fermi I was decommissioned following the accident (or "event", as the NRC euphamizes) at a cost of several times what it cost to build it in the first place, never having produced a single watt-hour of commercial electrical power. In its place sits Fermi II, a conventional water-cooled design.
On the other hand, France's Super Phoenix LMFBR design has not had huge problems, although its availability record has been much lower than water cooled designs. These are the ONLY other (I think there's two or three) commercial sodium cooled reactors.
You can't compare military technology with commercial technology. The former is relatively free from budgetary and environmental constraints, and has much tighter control over procedures and labor force. Fermi I dramatically demonstrated that the world was not ready for commercial LMFBRs in 1966, and little has changed since then.
I was discussing the nuclear issue with a housemate this evening. He seems to be coming around to James Locklock's pro-nuclear stance; that it is so urgent to reduce carbon emission that we need nuclear.
Apart from the water shortage and other problems mentioned above what about the following points:
* By far the cheapest and easiest way to reduce our carbon emissions is to use less.
* It takes a very long time to build a nuclear reactor
* There is a very limited supply of Uranium (not many Uranium mines here in the UK for example!)
To me the first point is the most important. The whole nuclear vs. renewables debate is nonsense.
We don't need more power, we need to cut our consumption and use what we do much much more efficiently (yet another reason not to invest in large centralised solutions that are incredibly inefficient).
Why don't we make roof insulation mandatory for a start?
The original article made a vital point. Nuclear reactors aren't viable at a time of water shortage. They aren't viable for other reasons too.
1. The total energy from a nuclear reactor in its lifetime is less than the total energy consumed in mining uranium, transporting it, processing it, making everything needed to build a reactor, building a reactor, maintaining, repairing and running a reactor, transporting waste from it, disposing of waste from it, storing that waste for the rest of time. Plus closing a reactor down, sealing it off and guarding it.
So - overall - nuclear reactors don't increase energy supplies - they REDUCE energy supplies.
And the cost are HUGE. Just decomisisoning reactors costs billions.
2. There is no such thing as a safe nuclear reactor. All reactors release 'low level' radiation into both air and water as part of normal functioning. For years 'low level' radiation was considered safe. But the latest science shows it is does genetic damage to both animals and people and causes cancer. Do we really want more damage to fertility or more sources of cancer?
3. There is no way uranium can be mined without the miners getting cancer. Do you want other people to die so you can enjoy air conditioning and watch TV? Surely not.
4. We are the people who managed to get a rocket to the moon. Do you really think that we can't create safer and more efficient ways to generate power? Don't you think our scientists are bright enough to do that? Of course they are! We have some of the best in the world.
If a fraction of the huge sums spent on nuclear reactors was spent on research on other ways of tapping into or creating energy we could have safe, efficient, energy production that did not depend on water or radioactivity.
We would then have energy production to suit the future - not the past. For at a time of increasing climatic. economic and political instability, our future access to energy will only be ensured if our energy sources are highly DE-centralised, local, and robust. Meanwhile many more of us need to be generating our own energy via sun and/or wind. Government subsidies to do that would cost a fraction of a reactor in our area and be a great deal safer. Whereas,, if we try to solve tomorrow's problems with yesterday's thinking - and nuclear reactors ARE yesterday's thinking - we will be asking for trouble.
I write with feeling. I have cancer from a nuclear reactor accident, & some of my family have had it too. If you don't want to risk cancer for yourself and those you love don't back nuclear power. The information we're given on nuclear reactor safety and efficiency is as accurate as Enron's accounts.
The water used for cooling power plants is indeed generally "just" warmed up and put back where it came from. The result of all that hot water is significant rises in the temperature of river water. The rivers ecosystems can't stand that, lots of things die. We had that happening here in the Netherlands (and much of Europe) some time ago. This is what prompted much of the regulations on maximum temperatures of cooling water and the like...
There's an air-cooled coal-burning plant in South Africa and at least one nuclear power station, the THTR-300, was air-cooled. So Makower's question implies an absolute dependency on water that is not actual. Plus, of course, lots of seawater-cooled reactors were unaffected.
Other posters seem to think directly cooling the reactor with sodium or helium somehow gets a designer out of finding an environmental source of coolness, and that submarine reactors are sodium-cooled. Neither is true. But the universal temperature is -270 Celsius with a cooling trend; if waste heat is, as some petrolistic commentators have said, nuclear power's Achilles heel, then Achilles must have slipped out of the midwife's grip and got entirely dunked.
--- G. R. L. Cowan, former hydrogen fan
Burn boron in pure oxygen for vehicle power
1. Nuclear plants produce net energy, and quite a lot. Not even Storm van Leeuwen and Smith (http://www.stormsmith.nl) manage to calculate a negative balance for nuclear power, and they tried damn hard. With a lot of unrealistic assumptions they were able to hint that nuclear power could be a losing proposition 50 years from now.
2. Everything releases "low level radiation", from mining rock salt to tilling a field to burning coal. The releases from nuclear plants are rather low compared to that.
3. People should not die needlessly. That's why I prefer nuclear power to coal power. Uranium miners don't get cancer if the mines are vented. I invite you to present a study that shows uranium miners getting more cancer (in any mine you like other than Wismut Aue in Eastern Germany, which was run by the soviets rather recklessly). Meanwhile, I'll dig up some statistics that show the opposite.
4. Of course we are able to find technological solutions. They are called PBMR, IFR, MSR, just to name a few. It's not even rocket science, it's simpler than that.
5. You don't have cancer from a nuclear incident. You have cancer from something you cannot identify. Any number of nasty chemicals in your food, heavy metals in the drinking water and natural radioactivity are far more likely to be the cause, not to mention plain coincidence. Find someone else to blame. How about "I have cancer from the Seveso explosion"? We know that dioxine causes cancer, we don't know the same of low level ionizing radiation.
This whole line of reasoning--that climate change makes nuclear energy obsolete--is incredibly misinformed. Take a look at this picture and tell me how many coal plants you see along these rivers. Each of these coal plants is making steam and rejecting waste heat to the river just like a nuclear plant (or solar thermal) plant would.
BTW, there's only a handful of nuclear plants on these same rivers.