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Heat Wave Shuts Down Alabama Reactor

CowboyNeal posted more than 6 years ago | from the weathering-the-heat dept.

Power 401

mdsolar writes "In a first for the US, one of three nuclear reactors at the Browns Ferry nuclear plant in Alabama has been shut down because the Tennessee River is too hot to provide adequate cooling for the waste heat produced by the reactor. This is happening as the TVA faces its highest demand for power ever, reports the Houston Chronicle. This effect has been seen in Europe in the past, forcing reduced generation, but the US has until now been immune to the problem. The TVA will buy power elsewhere and impose higher rates, blaming reduced river flow as a result of drought."

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This is actually really good news (2, Funny)

Anonymous Coward | more than 6 years ago | (#20276149)

As for a while, they were planning to use one engineer's idea of cooling it with ice cold beer.

Re:This is actually really good news (-1, Flamebait)

Anonymous Coward | more than 6 years ago | (#20276197)

You stupid coward. What's wrong, not man enough to post with your account? Of course not. You just want to be a faggoty ass coward. Crawl into a hole and die you shit for brains coward, then post your lame ass beer jokes somewhere else. I'm bound to get modded up as informative for sure with this post!

Re:This is actually really good news (2, Insightful)

ericrost (1049312) | more than 6 years ago | (#20276765)

Says the AC

Re:This is actually really good news (2, Funny)

creimer (824291) | more than 6 years ago | (#20276373)

Nah... They need to build another nuclear reactor to run the chiller for both the reactors AND the beer.

Re:This is actually really good news (4, Insightful)

Bloke down the pub (861787) | more than 6 years ago | (#20276709)

s/ice cold beer/frosty piss/

If the beer's Bud, don't bother - there's no difference.

In Soviet Russia (5, Funny)

davidwr (791652) | more than 6 years ago | (#20276187)

In Soviet Russia, overheating nuclear reactor [wikipedia.org] shuts down YOU!

Re:In Soviet Russia (0)

Anonymous Coward | more than 6 years ago | (#20276515)

if anything than 'soviet ukraine' and even that is bollocks.. but what the heck is soviet russia supposed to be anyway? the 'r' in USSR has never had the meaning of 'Russia'.

Re:In Soviet Russia (0)

Anonymous Coward | more than 6 years ago | (#20276579)

It's a meme. It doesn't have to make sense.

Re:In Soviet Russia (3, Informative)

Belacgod (1103921) | more than 6 years ago | (#20276641)

Soviet Russia doesn't refer to USSR. It's to distinguish it from Tsarist Russia, or Kievan Russia, or any of the other regimes that ruled Russia. Similar usages in other countries: Napoleonic France, Imperial Rome, Colonial America, Nazi Germany.

Re:In Soviet Russia (-1, Offtopic)

Anonymous Coward | more than 6 years ago | (#20276737)

sorry, i didn't know i had to use a different name for a thing that already had a unique name. my bad, i've missed my propaganda lessons this week

not immune (3, Insightful)

thhamm (764787) | more than 6 years ago | (#20276191)

>but the US has, until now, been immune to the problem.
no, not immune. it just hasn't happend until now.

Reasons right? (5, Informative)

Anonymous Coward | more than 6 years ago | (#20276209)

I work at a nuclear power plant. We have a limit for the temperature of the river downstream of our returned cooling water for environmental reasons, not reasons related to the power generation process. I suspect the TVA has a similar requirement.

I noted from the nrc website (www.nrc.gov) that their other reactors are operating at reduced load, which is what our reactors must do to limit the heat input into the river.

So this is nothing remarkable.

Re:Reasons right? (4, Interesting)

Toad-san (64810) | more than 6 years ago | (#20276341)

I see those huge cooling towers and water cooling systems .. and I have to wonder ...

How efficient is a power generation plant that throws away gigawatts of power as waste heat?

Isn't it about time you find a more efficient way to generate power, turbines and generators that don't waste so much heat that we just went to all that trouble to make in the first place?

I don't expect 100% efficiency, but what we're doing now is crazy.

Re:Reasons right? (4, Informative)

Wonko the Sane (25252) | more than 6 years ago | (#20276469)

Physics: It's not just a good idea, it's the law [wikipedia.org] .

Some people sell their "waste" heat (4, Informative)

Colin Smith (2679) | more than 6 years ago | (#20276735)

To heat domestic water, space heating and even to power adsorption chillers which can reduce AC requirements. Even coal power stations can hit 88% efficient.

http://www.helsinginenergia.fi/en/tuotanto/benefit s.html [helsinginenergia.fi]

US power stations are still only 40% efficient because ... Well you decide for yourself.

 

Re:Some people sell their "waste" heat (1)

Wonko the Sane (25252) | more than 6 years ago | (#20276783)

You are just playing word game with the definition of "efficient". There is a fundamental limit of how much work can be extracted by heat flow between two temperatures.

I would expect a country with a colder climate to be able to extract more work out of a nuclear reactor. Those super-efficient reactors won't do so well with a 90 Fahrenheit cooling medium

Re:Some people sell their "waste" heat (1)

Colin Smith (2679) | more than 6 years ago | (#20276921)

You are just playing word game with the definition of "efficient".
No. I am not. It's energy used for a useful purpose.

There is a fundamental limit of how much work can be extracted by heat flow between two temperatures.
And extracting work isn't the only use for heat...

 

Re:Some people sell their "waste" heat (1)

Waffle Iron (339739) | more than 6 years ago | (#20276867)

That works great assuming that you're close enough to a power plant so that it makes economic sense to dig a tunnel full of big fat steam pipes to your house. Unfortunately, only a tiny fraction of the population lives that close.

Re:Reasons right? (5, Informative)

hankwang (413283) | more than 6 years ago | (#20276517)

How efficient is a power generation plant that throws away gigawatts of power as waste heat?

From the heat source to electrical power output is usually in the range 35--50%, depending on the plant design. A fundamental problem is the theoretical limit of the efficiency of a heat engine, a device that converts a temperature difference into mechanical power. It is 1 - Tcold/Thot, where Tcold and Thot are the temperatures of the cold and hot parts, in kelvin. For a steam-operated heat engine, the cold end is around the boiling point of water (373 K), and the hot end might be 1000 K, which limits the efficiency to 63% if there are no other losses. But one can use the waste heat for other purposes in a cogeneration plant [wikipedia.org] , for example for residential heating in cold climates or for the industry.

Re:Reasons right? (1)

Colin Smith (2679) | more than 6 years ago | (#20276789)

The "waste" heat can power adsorption chillers in hot climates.
 

Re:Reasons right? (3, Informative)

Cyberax (705495) | more than 6 years ago | (#20276519)

Nope. You can't beat http://en.wikipedia.org/wiki/Carnot_cycle [wikipedia.org] in efficiency. The practical upper limit for nuclear power plants is about 50%. And we're already getting closer to this limit.

We can use some insane things like high temperature (thousands degrees) reactors with gas cooling to get another 10%-15% of efficiency, but it is just not practical.

Re:Reasons right? (0)

Anonymous Coward | more than 6 years ago | (#20276555)

Your understanding of physics is amazingly bad.

Re:Reasons right? (1)

turgid (580780) | more than 6 years ago | (#20276643)

Isn't it about time you find a more efficient way to generate power, turbines and generators that don't waste so much heat that we just went to all that trouble to make in the first place?

There is a British design called the AGR [wikipedia.org] which operates at thermal efficiencies of up to 40% compared with 30-33% in a PWR (what they used in the USA). The thing is, it's terribly expensive and no more will ever be built.

As another poster has already stated, look up the Carnot Cycle to learn about thermal efficiency of heat engines.

You're right it is insane. 88% is possible (1)

Colin Smith (2679) | more than 6 years ago | (#20276757)

Especially considering the coming energy crunch.

 

Re:Reasons right? (0)

Anonymous Coward | more than 6 years ago | (#20276761)

When you're a few thousand megawatts of power, you have to reject a few thousand megawatts. It shouldn't be that surprising. Even if the reactor were 10% more efficient, it's still going to dump a metric assload of heat into the river.

paddle wheels in the heat stream (1)

Quadraginta (902985) | more than 6 years ago | (#20276831)

Heat is disorganized motion, right? Atoms and molecules just bumping around any which way. If you want organized motion, which is useful energy -- such as an organized motion of electrons, a.k.a. electricity -- then you have to get that heat motion organized, flowing in one direction.

You do this by making the heat flow from one place to another. But here's the catch: you need a source and a sink to have a flow. The hot reactor core is the source. The river is the sink. Heat flows from the former to the latter, and the turbines, in essence, dip a "paddlewheel" into that current.

If you get rid of the sink, nothing flows, your "paddlewheel" doesn't turn, and you get no useful energy.

Re:paddle wheels in the heat stream (1)

xaxa (988988) | more than 6 years ago | (#20276919)

You can move the sink to somewhere more useful than a cooling tower and a river though.

http://en.wikipedia.org/wiki/Combined_Heat_and_Pow er [wikipedia.org]

My University has one, it heats the whole campus (and non-University owned buildings within/around it), provides hot water, and electricity too.

Re:Reasons right? (1)

mdsolar (1045926) | more than 6 years ago | (#20276447)

According to the article, this is different from environmental requirements on the down stream temperature. This is a lack of cooling capacity problem. The the energy transfer rate for the waste heat is just not high enough with the river temperature at 90 F.
--
Better electricity: http://mdsolar.blogspot.com/2007/01/slashdot-users -selling-solar.html [blogspot.com]

Re:Reasons right? (1)

TheLink (130905) | more than 6 years ago | (#20276583)

Sounds strange to me.

In other countries it's usually because the water _released_ will be too hot. I bet the reactors could take water in as long as it's liquid, release steam and not blow up, but the stuff in the river won't be happy.

90F is pretty cold compared to the temperatures the turbines run at, not even comparing the reactor core. I'd thought the safety margins would be higher.

If the river has too little water, then it's a bigger problem.

Re:Reasons right? (1)

Wonko the Sane (25252) | more than 6 years ago | (#20276851)

The temperature inside your condenser is always higher than temperature of the water you send back into the river.

The temperature of your condenser is directly related to the pressure of saturated steam/condensate mixture. Higher temperatures correlate to higher pressures in the condenser.

  1. Condensers are only designed to withstand a certain amount of pressure
  2. The work your turbine can produce is directly proportional to the difference in pressure between the steam supply and the condenser.

Re:Reasons right? (3, Informative)

Dachannien (617929) | more than 6 years ago | (#20276759)

Actually, if you really do read the article carefully, nowhere does it state that the water itself is incapable of cooling the reactor. It merely states that the river water is "too hot", which could just as well indicate that adding more warm water - especially in drought conditions where the river level is probably lower than normal - would make the river temperature too hot to safely sustain its ecosystem.

Nothing Remarkable? (0)

twitter (104583) | more than 6 years ago | (#20276649)

The TVA thinks this is remarkable:

"We don't believe we've ever shut down a nuclear unit because of river temperature," said John Moulton, spokesman for the Knoxville, Tenn. based utility.

I don't know about you, but I'm used to rivers being cool. From mountain springs to the Mississippi, I've never seen a whole river at 90 F. It's crazy and says something about global warming and the extensive drought the US is experiencing.

Someone who works at a nuke should care more than you do. Reducing capacity is one thing, but turning off a reactor is a pain in the ass. Depending on burnup and time down, you may have to wait weeks before binging it back on line. I pity the people who work there. An outage in that kind of heat is going to suck for everyone who has to crawl around. It's also bad for the people you serve. Essentially, you have lost 1 GW of baseline power. According to the article, that's about 3% of their best generation capacity. An idle nuke makes expensive electricity. Using coal instead is just going to make things worse - more pollution and more carbon emissions.

Re:Nothing Remarkable? (0)

Anonymous Coward | more than 6 years ago | (#20276855)

Oh, having generation capacity offline is remarkable from a financial aspect (and the associated problems with buying power generated from some other source), but this is spun as being related to some nuclear plant problem, not a river volume/river temperature problem. Previously discharge permits for higher river temperatures were granted by state (other?) governments as the threat to human health from lack of electricity for air conditioning/fans was deemed too urgent. Now granting those permits is less likely than in previous years, though I am unaware as to the reason for the change.

Of note, all reactors at Browns Ferry are BWR (boiling water reactors). BWRs have the advantage of NOT being Xenon-precluded because the Void coefficient of reactivity is non-existent. Thus, startup won't be delayed due to waiting for Xenon to decay.

A useful site on nuclear power in general: http://www.nucleartourist.com/ [nucleartourist.com]

Re:Nothing Remarkable? (1)

Wonko the Sane (25252) | more than 6 years ago | (#20276883)

BWRs have the advantage of NOT being Xenon-precluded because the Void coefficient of reactivity is non-existent.
What you are saying might be true for a specific reactor design, but zero void coefficient is by no means inherent to all BWRs.Not to mention that void coefficient has nothing whatsoever to do with xenon-precluded startups

Don't trust what he says! (0)

Anonymous Coward | more than 6 years ago | (#20276857)

How conveniant, Gomer. I work at a nuclear power plant too. I've been trying to take aways these people's AIR for the longest time.

I found its easier to induce birth defects into the populous to get them breathing another gas, and then I'll scare the world that they're illegal aliens from a far-away galaxy trying to steal somthing. I'll ship them out to a Mars outpost to begin colonization of Mars to mine iriidium and dilythium crystals. I'll put Hauwser into the Memory-Whipe machine and install him as a Governor of a dilapidated State full of under-terrestrial aliens, and begin shipping them out in my new-fangled Shanghai ice-cream booth service; they'll all think they're getting jobs driving ice-cream trucks, but the Saturn-Rocket boosters will kick-in and send their ass to Mars complete with a Klingon cloaking device to shield their exit from Earth from paranoid on-lookers.

Ha!

Other Options? (1)

pavon (30274) | more than 6 years ago | (#20276891)

Yeah the big question to me is what other options are there for cooling a power plant other than using river water, and are they more sustainable / resilient to climate change? I don't think that underground cooling would be sufficient. I looked at how some of the desert plants operate and they too use running water - from the sewage lines of "nearby" cities, which is treated before use in the plant and then returned for reuse.

Seeing as how nuclear is really the only option we have for decreasing our power-plant C02 output on a large scale, and that low water levels, and increasing water temperature are only going to become more frequent (especially if more plants are using them for cooling) that seems like a pretty important issue. It may already be solved - this is just the first I have heard of it.

Hm... (-1, Troll)

morari (1080535) | more than 6 years ago | (#20276215)

I don't know that I'd mind if the Alabama and the whole of the Deep South went Chernobyl. :P

Re:Hm... (1, Funny)

NeverVotedBush (1041088) | more than 6 years ago | (#20276315)

They are already red states. Might as well make them glowing red.

It would give a whole new meaning to Louisiana Hot Sauce...

Re:Hm... (0)

Anonymous Coward | more than 6 years ago | (#20276415)

The Louisina Witch Queen Moussette is in charge of that area so forget glowing red she makes every thing glow green.

River too hot? (4, Funny)

MMC Monster (602931) | more than 6 years ago | (#20276219)

Why not just run the river through a refrigerator to cool it down? After all, you can generate the electricity for the refrigerator in the plant.

(I'd patent the idea, but the patent office has a silly rule regarding perpetual motion machines that gets in the way...)

Re:River too hot? (1)

Hubbell (850646) | more than 6 years ago | (#20276241)

Why not just run it through a huge radiator like setup that way the water is basically seperated from one huge volume to thousands of smaller volumes which can cool down much faster.

Re:River too hot? (1)

jimbug (1119529) | more than 6 years ago | (#20276275)

Why not just get a bunch of engineers and blow on the reactor to cool it down?

Re:River too hot? (1)

NeverVotedBush (1041088) | more than 6 years ago | (#20276291)

You mean like a cooling tower already does?

Re:River too hot? (1)

mforbes (575538) | more than 6 years ago | (#20276741)

Think about what you're proposing. The river temp is likely in the 80s, and the air temp is in the 100+ range for the last two weeks. A radiator only exchanges heat (in this case warming the water, rather than cooling it). It doesn't cool the source flowing through the radiator unless the temperature outside the radiator is cooler than inside.

End effect: You end up with water that's even warmer than before.

Re:River too hot? (0)

Anonymous Coward | more than 6 years ago | (#20276271)

The reactor consumes the fuel rods, therefore it would not be a perpetual motion machine.

Re:River too hot? (0)

Anonymous Coward | more than 6 years ago | (#20276293)

Actually, this would work just fine, because you would be transferring a portion of the heat from the water into the air and then using the heat from the reactor to warm the water. You wouldn't have to cool it much, but boy would it be expensive.

This, plus the fact that you're not moving heat just back and forth from the reactor and water, means that you've escaped the perpetual motion ride...

Anon

Re:River too hot? (2, Informative)

Anonymous Coward | more than 6 years ago | (#20276369)

Why not just run the river through a refrigerator to cool it down? After all, you can generate the electricity for the refrigerator in the plant.

Actually, it would be quite possible to do such a thing and you wouldn't even violate the second law of thermodynamics since you are only pumping the heat. One example of such a mechanism is the electrically powered fan on radiators in cars that improve cooling when the car is not moving.

However, it wouldn't change the problem: Where to dump the waste heat. Instead of pumping it in the river, you would be pumping it into the air, which may be better but you only shifted your waste disposal. Lastly, there is this slight technical problem that the waste heat of a nuclear power plant is enormous, usually around 2 GW, which would require a MASSIVE heat pump (i.e. "refrigerator"). That in turn would eat up a large portion of the generated electricity, greatly reducing efficiency.

As it turns out, however, an active heat pump isn't even needed to dump the heat into the atmosphere instead of pumping it into the river, usually that is accomplished with a cooling tower, though in this case there aren't enough available since the plant is not designed to run on towers alone.

What to do with all that waste heat... (0, Troll)

NeverVotedBush (1041088) | more than 6 years ago | (#20276267)

I hadn't heard of this before now but can see how it can really be a problem. It takes temperature differences to make heat energy flow and without that, or without enough of one, it doesn't. This will also affect regular power plants too.

Looks like future plants - nuclear or conventional (coal/natural gas) will need to be engineered to carry more of the work of cooling their water. It can be done. It's just less efficient as there are more parasitic loads on the system.

Just remember - there is no such thing as global warming. Hurricanes blasting up to category 5 in a few days, droughts, floods, etc. - all of it is just coincidence and would happen whether we pumped billions of tons of CO2 into the atmosphere or not.

;-)

Re:What to do with all that waste heat... (0)

Anonymous Coward | more than 6 years ago | (#20276345)

Sir we have been in a global warming cycle since the last ice age ended. Oh yeah and there have been endangered life forms as well coming to an end. Nothing new here move on.

Re:What to do with all that waste heat... (1)

b0s0z0ku (752509) | more than 6 years ago | (#20276507)

Sir we have been in a global warming cycle since the last ice age ended.

The sign of a trend (upward or downward) matters. However, so does the MAGNITUDE of the trend, and the magnitude of temperature increase has gone up over the past few decades.

-b.

Re:What to do with all that waste heat... (1)

EveryNickIsTaken (1054794) | more than 6 years ago | (#20276347)

Just remember - there is no such thing as global warming. Hurricanes blasting up to category 5 in a few days, droughts, floods, etc. - all of it is just coincidence and would happen whether we pumped billions of tons of CO2 into the atmosphere or not.
Correlation does not imply causation.

Re:What to do with all that waste heat... (2, Insightful)

Evilest Doer (969227) | more than 6 years ago | (#20276553)

Correlation does not imply causation.
Sigh. Learn to use actual logic instead of mindlessly quoting logical fallacies. The GP was mentioning a bunch of things, which are well known, that give a preponderance of evidence for global warming. Add to that the fact that the mechanism causing the problems are well known.


To give you an example. Someone starts screaming in public that they are going to kill you. They show up at your house with a large handgun and force the door. A couple minutes later, several shots are heard. The man runs out of your house without the handgun. You are found dead and the coroner determines the hour of your death to be around the time the man with the handgun showed up at your door. Noone else has shown up that day other than the man with the handgun. The bullets which have blasted what little brains you have out the back of your head are determined to come from the gun lying on the floor, which is the same one brought in by the man who forced his way into your house.


Now, given all this, you would apparently parrot the rule saying "Correlation is not causation".

Re:What to do with all that waste heat... (2, Insightful)

Ajehals (947354) | more than 6 years ago | (#20276833)

I would hope you would parrot the rule saying "Correlation is not causation", or rather I would hope that any other alternatives are also investigated (like suicide or possibly even that a third person did the shooting) sure Its unlikely, but its worth the effort to prevent a miscarriage of justice.

How this applies to climate change though isn't all that clear. We are sure that temperatures are rising, we are fairly sure that they will continue to rise, and we are inclined to believe that the changes are brought about by our own actions. In that scenario we need to tackle what is apparent whilst also making sure that there are no other explanations.

Much like you would arrest the potential murderer in your first example immediately and then discount any other possibilities, we should be looking to tackle climate change (by addressing the issues we believe cause it) until we know more one way or the other, what we should not do is close down any other avenues of investigation until we are sure that we have all the information we need, after all if something else turns out to be the culprit (regardless of how unlikely that is) we may need to take some other action, something we couldn't do if we stopped looking.

It is about boiling rivers (4, Insightful)

SmallFurryCreature (593017) | more than 6 years ago | (#20276363)

It ain't about problems with the cooling itself, for that the rivers would need to be far hotter. The problem is enviromental, if you add extra heat to an already warm river you risk that it rises to the point were you destroy the eco-system. Simply put, the fishes get cooked and the algea grow out of control.

This is considered to be a bad thing.

Re:What to do with all that waste heat... (1)

Sponge Bath (413667) | more than 6 years ago | (#20276423)

...need to be engineered to carry more of the work of cooling their water

They need to be engineered in parallel with a large reservoir
to provide a more stable source of cooling water.

Re:What to do with all that waste heat... (1)

Artifakt (700173) | more than 6 years ago | (#20276523)

The Carnot cycle determines the theoretical maximum efficency of heat transfer. There are basic topside limits (In a pipe that's uncapped at the end going into the river, water can't be hotter than 100 C or it's not water anymore). Practically, all the heat exchange systems, even ones with molten sodium and such, have absolute thermal upper limits. These are usually above the sensible ecological limits, so engineers normally design for the more restrictive, environmentally safe limits.
      But, the difference between cold and hot determines maximum efficiency possible even for a theoretically perfect system. If the top stays fixed, and the low temperature base goes up, the cycle HAS to become less efficient. This applies to all power-plants, not just nuclear ones. A coal plant that uses a river for cooling, a sterling cycle solar engine, or the internal combustion engine under the hood of your car, all become less efficient from this effect. While this power-plant has to stay shut down, every single car driving across the south and southwest is running at lower efficiency than usual, and wasting more gasoline.

Not too unusual for power plants (2, Informative)

Anonymous Coward | more than 6 years ago | (#20276279)

This is not that unusual for power plants. Some coal fired units are off as well, for example Dynegy's Wabash River is currently experiencing similar problems. Obviously this hurts everyone (the company loses generation during times when wholesale power prices are high and, if load gets too high, the consumer might experience brown outs or black outs). This problem will likely get worse as well as global warming takes hold.

Re:Not too unusual for power plants (1)

FooAtWFU (699187) | more than 6 years ago | (#20276813)

By what mechanism will global warming make rivers sooooo much warmer? I mean, I'm hearing about projections that say it will be about half a degree (C) warmer by 2030.....and, mapping this directly to the river as well, I just doubt that this sort of pathetic little increase in water temperature is enough to prevent the proper operation of their reactor (or its compliance with environmental regulations limiting how hot their cooling processes are allowed to make the river). Do you propose an alternative mechanism which will more substantially raise river temperatures?

Air conditioning ruined the South (-1, Offtopic)

Anonymous Coward | more than 6 years ago | (#20276283)

Before air conditioning, yankees stayed in yankeeland. After air conditioning they moved to places where they weren't welcome. They cranked on the AC so that their sweaty bodies, which were filled with saurkraut and matzos, wouldn't drip so much.

They used electric driers to dry their sweaty clothes. Yankees suck energy away like there is no tomorrow. The South never had a "carbon footprint" before yankee glutons moved to Miami and Atlanta. Most of us grew up without air conditioning and were happy that way. We used clothes lines to hang and dry our clothes, not electric driers. Life was good.

Re:Air conditioning ruined the South (0)

Anonymous Coward | more than 6 years ago | (#20276355)

Yeah, you guys had black people to do all the sweaty work.

Mod up insightful (0, Flamebait)

b0s0z0ku (752509) | more than 6 years ago | (#20276457)

Mod parent up -- BTW, the same think is being done in the desert West (Phoenix, etc). Easterners are moving with the expectation that they can have green lawns and cool houses, and straining the region's energy and (especially) water resources.

-b.

Too hot! (0)

Anonymous Coward | more than 6 years ago | (#20276319)

I live in Alabama, and it's been in the 100s+ for at least a week now. Glad today's Saturday and I can sit inside!

This is the insiduous impact of Climate Change (2, Interesting)

NeutronCowboy (896098) | more than 6 years ago | (#20276327)

To anyone arguing that Climate Change is actually a good thing - in general, it isn't, and this is an example. Especially in the US, our entire infrastructure, agriculture and manufacturing is built and created under the assumption that things will stay the same. Pipelines in Alaska were built under the assumption that permafrost was, well, permanent. Nuclear reactors were built under the assumption that the temperature changes of rivers are known and won't change. Levies are built with certain assumptions about local rainfall. Agriculture is built on certain assumptions about the local weather.

Yes, we can adapt to it, but it's an expensive proposition. All the stuff about cities flooding, people dying and malaria becoming the new bane of the US is extreme cases being blown up to make good news stories. It's the accumulation of small things like this that'll hurt.

Re:This is the insiduous impact of Climate Change (0)

Anonymous Coward | more than 6 years ago | (#20276749)

Yeah, it will be expensive to adapt as you point out. But, not nearly as expensive as over-engineering everything just in case.

sounds like life (1)

Quadraginta (902985) | more than 6 years ago | (#20276945)

Um...isn't this the nature of time, life, existence, et cetera? Things change. Even if there were no such thing as man-made global warming, the Sun would still vary its output, the continents would continue to drift, evolution would continue to produce new and interesting diseases, et cetera and so forth.

What do we call individuals who run their lives under the assumption that things will always stay the same? That they'll never get old or sick, that their job will never disappear or their skills become obsolete? "Intelligent" doesn't come to mind.

Besides, consider the advice you give people bemoaning the fact that their life has changed (e.g. they had to get a new job, now they have a baby and can't party all night, et cetera). We tell them, hey, change is an opportunity. So it is with climate change, natural or man-made. It's not a lot different than new and disruptive technology (cf. the RIAA and the Internet). Some folks will lose, yes. But others, especially if they're flexible and intelligent, will win.

Personally, I think the lesson to be learned from global warming (from whatever cause it stems) is not to resolve to hold back the tide, this time or next time. That's just futile. The Earth will always be producing some new surprise or other. The general solution algorithm is not to try to put fingers in every dike that develops cracks. There aren't enough fingers, and too many dikes. The trick, as individuals and as a species, is to think creatively and adapt. Otherwise, we're just dinosaurs wondering what that flash in the sky was, and why the swamp is drying up steadily.

TVA net metering policy (4, Interesting)

mdsolar (1045926) | more than 6 years ago | (#20276377)

The cooling problem is a result of TVA's interest in building more reactors. Browns Ferry is now operating with two reactors instead of three because they recently added a reactor. They are also planning on adding a reactor upstream at Watts Bar http://www.tva.gov/news/releases/julysep07/wbu2.ht m [tva.gov] adding to the heat load on the Tennessee River. So, next time, they may have to take two Browns Ferry reactors off line at seasonal peak demand. This makes electricity more expensive because it requires buying rather than selling electricity when it is most expensive.

But, the fairly natural solution to the problem, reducing summer demand through net metering of customer generated solar power, a solution being implemented in 41 states and DC, is hampered in the TVA service territory by TVA's net metering policy: http://www.tva.gov/purpa/net_metering.htm [tva.gov] which is a billing period-by-billing period policy rather than an annual carryover policy used in net metering states. Adopting a reasonable net metering policy would allow TVA to become a summer time peak demand power exporter and gain by arbitrage, reducing the risk of higher overall rates it is building for itself by not paying attention to the capacity of the river system to handle the 60% of wasted energy nuclear power generation creates.
--
Power when you want it most: http://mdsolar.blogspot.com/2007/01/slashdot-users -selling-solar.html [blogspot.com]

Re:TVA net metering policy (1)

b0s0z0ku (752509) | more than 6 years ago | (#20276471)

Can't they use air cooled condensers (aka cooling towers) rather than using river water to cool the steam directly? River water is only one way to cool a power plant.

-b.

Re:TVA net metering policy (1)

Wonko the Sane (25252) | more than 6 years ago | (#20276613)

Almost always the river water is cooler than the air temperature and has a much larger specific heat capacity. If the plant was modified to run completely on air cooling, it would be far less efficient 99.9% of the time,

Re:TVA net metering policy (1)

b0s0z0ku (752509) | more than 6 years ago | (#20276685)

If the plant was modified to run completely on air cooling, it would be far less efficient 99.9% of the time,

But nonetheless, there are air cooled plants that were designed as such and work just fine.

As far as river water, yes on the higher specific heat, but no on it being almost always cooler than the air -- in winter, it's normally warmer. A static body of water will have the same year around average temperature as the air, but the instantaneous temperature will lag the air temperature due to the heat capacity of the water. A river's AVERAGE temperature may be a bit lower if it's sourced from the mountains where it is colder (snow melt, etc).

-b.

Re:TVA net metering policy (1)

Wonko the Sane (25252) | more than 6 years ago | (#20276743)

A static body of water will have the same year around average temperature as the air, but the instantaneous temperature will lag the air temperature due to the heat capacity of the water.

Not true; besides the effect of snow melt you mentioned there is the effect of evaporation which keeps the river cooler that the ambient air on average.

Re:TVA net metering policy (1)

mdsolar (1045926) | more than 6 years ago | (#20276897)

Cooling towers are usually part of the design of a power plant, but they need to be run hot enough to to get a good energy flow rate and cool enough so that steam is properly condensed. Final cooling is usually handled by the river or tidal system. Apparently what is happening here is that the cooling towers can't do the last stage. More cooling towers might help but this increases costs so looking at other options for power generation becomes important.
--
A better way: http://mdsolar.blogspot.com/2007/01/slashdot-users -selling-solar.html [blogspot.com]

Waste heat? (1, Insightful)

Khyber (864651) | more than 6 years ago | (#20276393)

Why not just figure out a way to turn waste heat into energy to avoid heating the river up unnecessarily?

Re:Waste heat? (2, Insightful)

gardyloo (512791) | more than 6 years ago | (#20276509)

Because "heat" is the most difficult form of energy to convert to other forms. Not difficult in an engineering sense, but difficult from a basic thermodynamics perspective. In order to convert heat into another form of energy, you have to have a reservoir available with lower heat density -- temperature. Otherwise your process won't spontaneously go (and that's the problem with energy; non-spontaneous conversion to another form only _appears_ non-spontaneous; thermodynamics guarantees that you've just overlooked a pathway in which the energy is being converted to a "less useful", or higher entropy, form). In this case, the reservoir with lower heat density (the river) doesn't have low _enough_ heat density (or it's restricted by environmental concerns).

That's just what the TVA is having problems with. After all, nuclear plants essentially use the heat produced by degrading high quality nuclear energy to lower quality steam or the equivalent. This is allowed to degrade to even lower quality by taking a steam jet with well-defined momentum, and impacting it on a turbine. After the turbine (producing electricity, etc.), the steam has almost no quality, and perhaps can be used for secondary heating purposes. At this stage, you have to get rid of the still-high-temperature but low quality steam, and they do that by rejecting the heat into the river.

Quick thought (1)

Khyber (864651) | more than 6 years ago | (#20276689)

Heat rises. Vertical turbines in the nuclear reactor towers might work if they could figure out how to circulate the heated water around inside the towers?

Re:Waste heat? (4, Insightful)

Wonko the Sane (25252) | more than 6 years ago | (#20276559)

If only it were that simple.

Imagine one of those old-style water wheels. Your question is akin to asking, "Why not figure out a way to use the energy of that flowing water without wasting it by allowing it to flow away?"

Re:Waste heat? (1)

hairykrishna (740240) | more than 6 years ago | (#20276591)

Assuming that by 'into energy' you mean 'into electricity', I'm afraid you're running into thermodynamics limitations, the heat-steam-electricity process is about as efficient as it's going to get. It has been developed over many years, for example exiting steam is used in re-heaters to boost efficiency (along with a bunch of other neat tricks). The river is not being heated up 'unnecessarily'. You think nobody ever considered this? It's sort of the whole essence of power plant engineering...

You can claw some back by using waste heat directly for central heating etc. Not really viable at this time of year though.

Re:Waste heat? (1)

marimbaman (194066) | more than 6 years ago | (#20276615)

Why not just figure out a way to turn waste heat into energy...

Because it's impossible.

Re:Waste heat? (0)

Khyber (864651) | more than 6 years ago | (#20276809)

And that's why we have Stirling engines, which run off of waste heat, yes?

Re:Waste heat? (1, Funny)

Anonymous Coward | more than 6 years ago | (#20276681)

Repeal them pesky thermodynamics laws now!

Seriously, you're talking out of your ass. Shut the fuck and go write a poem or something.

Re:Waste heat? (0)

Anonymous Coward | more than 6 years ago | (#20276695)

Well, extracting the waste heat is already critical to the operation of the reactor. Remember that you can't extract energy from heat: only from a temperature gradient of some kind. The reactor functions because it generates hot steam, which drives a turbine. But if you don't re-condense that steam into cooler water, then the entire loop would be uniformly hot and you wouldn't be able to drive the turbine. So removing the "waste heat" is actually a critical part of the design: the reactor makes the water really hot on one end, the river keeps the water cooler on the other end. The bigger the temperature disparity you generate, the better your conversion to electricity will be.

Ultimately, for this to work, you need to dissipate heat somewhere. If the excess heat isn't ending up in the river, it just means it's going somewhere else (air, ground, etc.).

Re:Waste heat? (2, Funny)

xxMSAxx (648692) | more than 6 years ago | (#20276719)

Why not just pump it into a giant tower and we can all have hot water despite the jackass taking a 2hr shower!!!!

They avoid mentioning Global Warming... (1)

Asmor (775910) | more than 6 years ago | (#20276425)

River's too hot to adequately cool their equipment, yet they're...

blaming reduced river flow as a result of drought.
Curious, no?

Re:They avoid mentioning Global Warming... (1)

mdsolar (1045926) | more than 6 years ago | (#20276661)

The drought in the southeastern US has not yet been conclusively linked to global warming. The problems described in Europe have been linked. It takes time to get that stuff figured out and it was not until the most recent IPCC report (this year) that the heat wave deaths in Europe were strongly linked. The main problem is that TVA is overloading the capacity of the river system as it is by over reliance on nuclear power so that it is increasing costs for rate payers.

Because nuclear power involves such long term decision making, and many of those decisions were made before warming was understood to be a problem, the consequences of warming for nuclear power are likely to be worse than for other means of generation. This is tied to siting decisions which place many nuclear power plants in tidal areas which will be affected by sea level rise http://mdsolar.blogspot.com/2007/08/cliffhanger.ht ml [blogspot.com] . But, changing flow rates and temperatures for river systems will also have an impact. Climate models probably need to be improved before they can be used well to assist in siting decisions so the investment risk for new nulear power plants is probably higher than it will be in a decade or so when models are better able to look at watershed-by-watershed level effects of warming.
--
Reducing the cost of electricity: http://mdsolar.blogspot.com/2007/01/slashdot-users -selling-solar.html [blogspot.com]

Re:They avoid mentioning Global Warming... (0)

Anonymous Coward | more than 6 years ago | (#20276903)

No. Less water in the river means that the river heats up quicker. Like dumping a bucket of boiling water in a bathtub and a swimming pool of cooler water; assuming both starting temps are the same, the bathtub water's temp will rise more than the swimming pool's. Of course difference between a drought and non-drought river isn't quite as large as that, but it's still a perfectly plausible explanation. Basic thermodynamics, really.

They didn't mention that the drought might have been caused or worsened due to global warming, so if you really want to accuse them of ignoring global warming, go with that instead.

Simple solution (0)

Anonymous Coward | more than 6 years ago | (#20276459)

Eliminate nuclear and coal power in favor of solar and wind power, and replace the stupid cars with bikes. Eventually the global warming will take care of itself and we won't need as much energy as air conditioning will no longer be needed. The added bonus would be less obesity in the world.

Re:Simple solution (1)

Tom DBA (607149) | more than 6 years ago | (#20276597)

That would also get the lard off of so many of us as well. Drive down health care costs. "Eliminate nuclear and coal power in favor of solar and wind power, and replace the stupid cars with bikes. Eventually the global warming will take care of itself and we won't need as much energy as air conditioning will no longer be needed. The added bonus would be less obesity in the world."

The overly-simplified solution (4, Insightful)

westlake (615356) | more than 6 years ago | (#20276747)

Eliminate nuclear and coal power in favor of solar and wind power, and replace the stupid cars with bikes.

The bicycle as a commuter vehicle works only under ideal conditions and only for the young and fit. You won't be taking a bicycle into Buffalo, NY in mid-winter. You won't be taking a bicycle into Houston, TX in mid-summer.

Re:The overly-simplified solution (1)

sessamoid (165542) | more than 6 years ago | (#20276849)

The bicycle as a commuter vehicle works only under ideal conditions and only for the young and fit. You won't be taking a bicycle into Buffalo, NY in mid-winter. You won't be taking a bicycle into Houston, TX in mid-summer.
Bollocks. Go visit the Netherlands. Or Seattle for that matter. Lots of old people commuting on bicycles in the Netherlands, and it rains a hell of a lot there. It doesn't freeze there, but there are plenty of places in the US that bicycle commuting would be viable if we had the infrastructure for it (which isn't that expensive compared to the alternatives).

What "waste heat"? (0)

mi (197448) | more than 6 years ago | (#20276527)

Seems like an inherent design flaw, if the reactor meant to produce energy has a problem throwing some of the energy away.

In theory, it should be possible to have no "waste heat". In practice this is an engineering problem — as the energy is converted from heat to electricity, some of the heat "escapes". The newer designs should either eliminate the leak completely or reduce it significantly... Maybe, by using a significantly cooler gas, than the currently employed steam?..

Re:What "waste heat"? (4, Funny)

Wonko the Sane (25252) | more than 6 years ago | (#20276587)

In practice this is an engineering problem
You misspelled "fundamental limit of thermodynamics"

Re:What "waste heat"? (1)

NeverVotedBush (1041088) | more than 6 years ago | (#20276711)

It would sure be nice if more people had a better grasp of basic scientific principles, wouldn't it?

Re:What "waste heat"? (2, Insightful)

Wonko the Sane (25252) | more than 6 years ago | (#20276941)

It's really amazing that these basic principals of thermodynamics were all figured out in the early 1800s [wikipedia.org] , but almost 200 years later people still don't get it.

Renewables question.... (4, Interesting)

fantomas (94850) | more than 6 years ago | (#20276529)

Interesting in the article that the journalist doesn't include power generated by hydroelectric dams as renewable energy...

"TVA gets about 60 percent of its electricity from coal-fired power plants, 30 percent from nuclear plants and 10 percent from its 29 hydroelectric dams. Renewable energy sources such as wind and solar account for less than 1 percent."

Any idea why that might be? Political slant? ignorance?

Umm, I mean the water flows through the dam, it goes out to sea, it evaporates, and it rains back up in the mountains and comes through the dam again. Seems pretty renewable to me.... at least some of it is coming back up through that cycle if not all...

Journalists ain't scientists (1)

camperdave (969942) | more than 6 years ago | (#20276793)

Interesting in the article that the journalist doesn't include power generated by hydroelectric dams as renewable energy...

Journalists ain't scientists, and scientists ain't journalists... in general. So if you're reading something in the news that's science related, don't count on it being accurate.

Learn to spell "its". (1, Informative)

Anonymous Coward | more than 6 years ago | (#20276561)

Spelling matters.

Re:Learn to spell "its". (1)

mdsolar (1045926) | more than 6 years ago | (#20276729)

Thanks. I do know the difference but often fail to catch the error.

Waste Heat (0, Redundant)

okmijnuhb (575581) | more than 6 years ago | (#20276571)

How can there be "waste heat"?
This does not seem like an efficient use of the power generated.
Doesn't the fission reactor produce heat, to boil water, to make steam, which runs turbines?

Re:Waste Heat (0)

Anonymous Coward | more than 6 years ago | (#20276795)

In this house we obey the laws of thermodynamics.

Atmospheric vortex engine cooling (1)

Baldrson (78598) | more than 6 years ago | (#20276633)

It sounds like its time for the nuclear industry to do some testing of the atmospheric vortex engine (see slide 18 (warning PowerPoint) [vortexengine.ca] :
  • delivers the performance of a $60 million natural draft tower at the cost of a $15 million mechanical draft tower
  • eliminates need for fans, saving 1% of the energy produced by a power plant
  • eliminates need for tall chimney, saving 2/3 of the capital cost
  • replaces conventional cooling towers
  • delivers the heat to the upper atmosphere where it radiates into space
  • solves problem of re-circulation
  • solves problem of fogging

Now of course there is the minor problem of having a tornado by the tail near a nuclear reactor -- but aside from the fact that you can channel hot water quite a distance economically, the hydrodynamic models (computational and scale) indicate that the base of the vortex can, indeed, be contained in a location. The real problem is that this system hasn't been scaled up to a sufficient size -- in an appropriately isolated test area -- to validate the models to the degree required by public safety.

Editing Nazi (1)

noidentity (188756) | more than 6 years ago | (#20276927)

Sorry, just a compulsion. Here's a more readable summary:

"In a first for the US, one of three reactors at the Browns Ferry nuclear plant in Alabama has been shut down because the Tennessee River is too hot to provide adequate cooling. This is happening as the TVA faces its highest ever demand for power, reports the Houston Chronicle. This has occurred in Europe in the past, forcing reduced generation. The TVA will buy power elsewhere and impose higher rates, blaming reduced river flow as a result of drought."
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