Is there a problem with nuclear power that most people don't know about?

Question

Apparently nuclear power plants can have trouble operating on hot days because they need a cold water system in order to run.

http://www.npr.org/templates/story/story.php?storyId=13818689
http://earthsci.org/education/teacher/basicgeol/nuclear/nuclear.html#NuclearEnergy

Nuclear energy is often touted as a major component of the solution to global warming, but if global warming can cause both hotter water and water shortages - particularly on hot days when energy is at very high demand - can we really afford to rely heavily on nuclear power?

Pobept K, try reading your own article next time. It talks about the potential that global warming will CAUSE a mini-ice age in Europe.

Answer 1

Good Question. More complex then I think most people realize and hard to answer briefly. But I will try and explain.

In short, yes nuclear power plants need cold water to provide electricity. So do coal burning power plants. The general concept is that both produce energy that is used to heat water to form steam. The steam turns a turbine which produces energy. The steam is then cooled using a heat exchanger.
Here is where the warm water first becomes a problem. The heat exchanger usually uses water drawn from a river/lake to cool the steam, before the steam is cooled and then injected downstream back into the river. If the temperature of the drawn water is too high you do not cool the steam enough to meet regulations.

(Heat exchanger design and operation are described here: http://www.me.wustl.edu/ME/labs/thermal/me372b5.htm ) Take home idea is that the greater the temperature difference between the two streams, the more the temperature of the hot stream is reduced. The regulations are in place to protect the local river ecologies from the additional heat. A similar occasion to France occurred in the US
http://www.chron.com/disp/story.mpl/business/energy/5061439.html

I like this page for its simple and to the point illustration on how a power plant works:
http://science.howstuffworks.com/nuclear-power2.htm

The difference between coal combustion and nuclear power plants is that nuclear power plants emit more energy, thus operating at a higher temperature, and requiring more water to meet its regulated temperature output.

Nuclear power requires more water in addition to some of the other drawbacks. Such as the long term and permanent storage of waste, the potential hazards as well as potential terrorist targets. But nuclear power does have the least amount of emissions and provides the most energy.

For people who are interested in the future of nuclear power a good thorough report can be read here: http://web.mit.edu/nuclearpower/

Be warned that the report is very large and takes awhile to download (~30MB). In fact, it is easier to read in small chunks as well. I hope this helps and that people realize that there is not one answer to solve energy needs or global warming.

So what needs to be done to help global warming? Well a mixture of things. Biofuels should be used more in conjunction with nuclear power and where feasible solar, wind and hydropower. This would limit the use of fossil fuels. Then carbon sequestration of taking gaseous CO2 and converting it into solid minerals needs to be used.

What can someone do today? Use a bike more, limiting your carbon footprint. Convince people that global warming is REAL and a problem and that we CAN do something about it. Let people know there is not a singular solution, and that carbon sequestration IS NOT storing CO2 in caves in the ground. (This is a very common misconception). The most important thing is to keep people informed and educated. If you would like more info let me know. I hope this helped!

**Edit**
I must be a slow typist as this question has since been answered several times already. Some of my points above have already been made.

Answer 2

This is not a very powerful argument.

Designing a nuclear power plant to deal with hot weather is simple engineering. So the French possibly didn't include an appropriate safety factor for high ambient temperatures. Hardly an argument against nuclear power.

As you well know, the change in temperature with global warming is actually relatively small (although that small increase has major environmental implications). Designing plants to deal with average temperatures say 5 degrees higher and max temps 20 degrees higher is a piece of cake. Remember that's off a base temperature of 293 degrees or so, and the heat being rejected is many degrees hotter. The added heat exchanger capacity is trivial.

The risk from global warming is clearly far greater than the risk of more nuclear power plants. We can build nuclear power plants that are safe, and safe from terrorist attacks. We're very very good at that sort of engineering.

We also know how to bury the waste safely, it's simply a matter of the political will to pick a site. See:

http://www.wipp.energy.gov/

for one example.

We will need nuclear plants in a relatively short time to make electricity or hydrogen for cars. No way will solar and wind do that economically now, or in the near future. A reasonable goal is to run the nuclear plants for one 30-50 year life cycle, and reduce them thereafter as alternative technologies improve.

I recommend to you James Lovelock's book, The Revenge of Gaia. His backing for nuclear power is a surprise. It's also very much data based.

I'm pretty much aligned with Jello on this one. So you actually don't have to worry - surely the world is about to end.

Answer 3

My boyfriend is a nuclear engineer and he tells me that the cooling is a problem mostly for reactors more than ten years old. The reactors that were built inland had cooling systems designed to meet the power needs at the time they were built. the demand for energy increased and the cooling systems are sometimes inadequate on hot days.
Currently he is working on designing cooling systems. He says that new cooling systems don't have those problems. He did say that putting a new cooling system on a reactor that is already up and running is so expensive and hard to do that it's not worth the trouble. You can make additions to the pumping equipment and a few other things, but that's about it.
The cooling systems he's designing use the reactors own natural convection to cool the reactor.The makes them more efficient because you don't have to use any energy to pump water in and out. I don't know much about how it works but he says that cooling a reactor on a hot day is no longer a concern for new reactors.

Answer 4

There are a couple problems with Nuclear power.

1st of all is the waste. It does not generate large amounts, but what is produced has an incredibly long half life and is extremely hazardous. Half like is the amount of time it takes for half of an amount of a material to decompose into something else, in this case, lead. Say you have a pound of nuclear waste, and within say 1000 years you would have a half of pound of it turn into lead. You still have a half of pound of hazardous material. However the solution to this is breeder reactors. From what I understand, you can recycle the waste from a breeder reactor and possibly create more fuel then you use. Yet going this route presents its own form of problems, I will get to in a minute.

The other problem is the bureaucracy and insane amount of red tape it would take to run a nuclear plant. Good idea to have safety rules in place, yet when people are faced with doing routine maintenance and obeying regulations and getting the job done in order to make profits, guess which will be done and which one will be left in neglect? I know this for I was part of an citizens group to shut down a local nuclear plant for it was coming close to causing a melt down do to the shell of the reactor being eaten away by boric acid. This could have been prevented, yet when the owners of the plant were faced with the decision to shut down the plant and lose millions of dollars per hour to fix "minor" problems or keep running and hope it goes away and keep making money, the latter was always preferred.

The last one is security issues. A nuclear plant (especially a breeder reactor) can cause diplomatic concerns and friction between other nations in the world and the US. A lot of people would blame us of creating more nuclear weapons under the guise of a "energy program" Sound familiar? If yes, then my point has already been proven.

Answer 5

i would guess this is only a minor engineering issue that may increase new plant costs slightly. Increase cooling tower capacity and add more heat exchange plumbing. I am sure the current western style plants were designed to operate safely under much hotter weather conditions than they currently operate under now (i would hope).

edit
according to the npr link the water temp was not posing a safety issue, but an environmental one. Hot water into a river kills fish ect. Therefore it may be feasible to cool the outlet water using a refridgerator system which would consume far less energy than the plant puts out. If the refridgerator fails some fish would die, but the reactor would not be in danger.

Also, since coal plants also draw river water just like a nuke plant, this should be an issue for all non-renewable power plants, not just nuclear.

Answer 6

the costs are far greater than even renewable energy, put a few billions on wind, geothermal and solar and you wont have waster and have to rebuild every 50 years, the life of these plants. that being said, there are places for nuclear, some small 50Kw nuclear batteries for vilages or deep mines for example. We've also got nuclear FUSION already working, 93 million miles in space :-) It maybe time to personalize energy, like the personal computer. Lots of small generators instead of multi billion dallar plants.

Answer 7

This problem is simple thermodynamics and any power plant that boils water to generate electricity is going to run into this problem. The maximum theoretical efficiency of a power plant is ~ the temperature of the water leaving the boiler divided by the temperature of the water entering the boiler. If the temperature of the water entering the boiler increases then the efficiency of the power plant and thus the energy created will go down.

Answer 8

No---I think we know all the main issues. The regular water used for once-through cooling will be fine, even with global warming. There are issues with sucking up fish and invertebrates in the pumps and warming the ocean or lake with the released water....but the real issues with nuclear power are:

No good way to dispose of the waste...safety and terrorism hazard
Reprocessing (often touted) only produces high-level bomb grade material. The world DOESn't need more of that! (but you don't have to wonder why all these countries want nuclear reactors...that's where the bomb grade material comes from!).
They are hugely expensive and take a long time to build and have a life-span (30 yrs? 50 yrs?) after which they have to be major overhauled or rebuilt or moth-balled.

Lets not go this route, please.

Answer 9

Nuclear power plants need to be substantially redesigned and standardized. In the past, nuclear plants have been one-off designs. That needs to change. The revised design could encorporate features of gas-cooled, unconditionally stable reactors. The processing of fuel also needs to be standardized. In principle, there is no real problem with long-term storage of waste: it's an engineering and geology problem. The amount of high-level waste is really quite small. High-level waste has produced so much power duing its useful life as fuel that it is actually economically viable to put it on the Moon using Saturn V technology. If you really want to get rid of it, it could be buried in subduction zones that will carry it into the Earth's mantle.

Answer 10

I heard that nuclear power was too hazardous. I wonder why we don't use wind, solar, some nuclear, sugar and/or corn ethanol-combine them all. See if that and our learning to be less wasteful would do the trick.
I forgot the name of the person who said Nat'l Geographic was warning about a mini Ice Age. I'm not sure if he/she is trying to get ppl to read the article, which, IN CONTEXT says, Global Warming is causing the North-Eastern section of Europe's climate to act as if it's having a mini Ice Age b/c of the ice water being dumped into the Gulf Stream, which was predicted in the movie 'The Day After Tomorrow' except, of course, it is not as dramatic as the movie. Or, if that person isn't quite comprehending the message of the article.