some more on the hot water nuke plant closing

[donsu]

http://hisz.rsoe.hu/alertmap/index.php?smp=&lang=eng


The Tennessee Valley Authority shut down one of three units at the Browns Ferry nuclear plant Thursday because water drawn from a river to cool the reactor was too hot, a spokesman said. The nation's largest public utility shut down Unit 2 about 5:42 p.m. CDT because water drawn from the Tennessee River was exceeding a 90-degree average over 24 hours, amid a blistering heat wave across the Southeast. "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. He said TVA would compensate for the loss of power by buying power elsewhere. The utility announced earlier Thursday that it was imposing a fuel surcharge on customers because of lower hydroelectric power production caused by drought conditions. Two other units at the plant were operating, as well as towers to cool the water. But searing temperatures and a lack of cooler water in the upper part of the Tennessee River system made it too difficult to provide cool water for all three reactors. There was no safety threat posed by the shutdown. Moulton said the average high temperature Thursday was 103 for five of the largest cities in TVA's coverage area: Huntsville and Knoxville, Chattanooga, Memphis and Nashville in Tennessee. "It's the hottest in 20 years," he said.

He would not estimate when the unit would go back on line, saying it will depend on the weather. "Temperatures are supposed to moderate some, but it will take a while for the river temperature to do that, too," Moulton said. He said demand for TVA power set a record Thursday but the figures would not be available until Friday. The old record was 33,344 megawatts set last Wednesday. 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. TVA, the country's largest public utility, supplies electricity to about 8.7 million consumers across an 80,000-square-mile territory that includes most of Tennessee and parts of Alabama, Mississippi, Kentucky, Georgia, North Carolina and Virginia. All three of the plant's reactors were mothballed in 1985 for safety reasons, but the other two units returned to service in the 1990s after extensive work. The Unit 1 reactor, which is still online, was restarted in June after 22 years following a five-year, $1.8 billion renovation.)
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when WILL the water cool down?


(an aside: this site's home pg. interactive world map shows Dean coming ashore around Brownsville, Tx.)

[ChairmanAgnostic]

1. the weather's too hot for the neocon's favorite

oil substitute?

[Dogmudgeon]

2. The neocons' favorite oil substitute is solar energy

GE, Siemens, Mitsubishi, and every semiconductor company on the face of the Earth are backing PV.

Then check out:

• Who they contribute to.
  
• The chemicals required to make solar cells.
  
• The chemicals required to make the next generation of solar cells.
  
• The laws (or lack thereof) pertaining to toxic waste control.
  
• The per-kilowatt price.

I'll never understand how this has become known as a "green" technology.

--p!

[AndyTiedye]

4. If You Think Semiconductors are so Evil, What Are You Doing On a Computer?

[MH1]

5. Simple answer to your question.

I don't claim to have researched this, I am telling you how I think people look at it, that makes them think it is "green". If you can disprove, please provide the links.**

Any toxins and waste created by solar energy production are created in the process of making the solar cells and other equipment - "upfront cost." Once the equipment is installed, maintenance is minimal, and further waste is not generated.

ANY power generation facility will have similar* "upfront costs". The difference is that those other methods (nuclear, coal, even wind to some extent) have significant OPERATIONAL costs as well (and at least for hydrocarbons and nuclear, the waste issue).

To someone who doesn't have time to think hard about it, or look up a bunch of figures, it does seem "obvious" that the lifetime costs/ kwh of "big plant" energy would far exceed those of decentralized, near-zero maintenance energy production such as solar. (A + B > A + 0).

* remember I am not claiming to be expert. Just presenting the thought process.

** I won't be reading a mega-long post or links that don't get right to the point. Please don't take that personally, it's just the way it is...

[TheWraith]

7. Quite the opposite, actually.

"To someone who doesn't have time to think hard about it, or look up a bunch of figures, it does seem "obvious" that the lifetime costs/ kwh of "big plant" energy would far exceed those of decentralized, near-zero maintenance energy production such as solar. (A + B > A + 0)."

Completely the opposite. The lifetime costs of small production is far higher than large plants, because they don't benefit from economies of scale. Even something like solar, which has very little maintainence needed, takes 20 years of production to come close to the kilowatt-hour price of a large plant.

[krispos42]

11. Is that true?

For a solar cell, power output is dependent entirely on the square footage of solar cells, the efficiency of the cells, and the hours of daylight per year. It doesn't matter if a square mile of solar cells are in one big chunk or a ten thousand little chunks.

On the other hand, I bet the efficiency of the DC-to-AC conversion of the big plant is a lot better then ten thousand smaller ones.

On the third hand, the big plant has transmission losses, and localized doesn't.




Other power sources have economies of scale. I don't know if solar does. However, my thought on this is.... what else are you doing with your roof? It might as well be producing electricity while it's keeping the rain out and the AC in! :-)

[TheWraith]

12. Economy of scale affects solar less, but it's still there.

For starters, it's easier to build a single large facility that to wire a large number of small dwellings. Plus, there's running it through the inverter to produce AC grid electricity. In that case, you're talking about a single large inverter versus hundreds or thousands of smaller ones.

The thing about solar is that it suffers from poor energy density, and thus a very bad dollars to watts ratio, compared to other alternatives. Even if you wired every house with a solar roof, you still wouldn't even come to the break even point for energy, and it would take ten years for a solar system to pay itself back in energy costs. In contrast, something more energy dense like a hydro dam, nuclear plant, or even a wind turbine has a much better return ratio, and thus far lower costs.

[lapfog_1]

3. They could always use the electricity produced

by the plant to run the water through a refrigeration unit before it enters the reactor.

Yeah, that's the ticket!

:sarcasm:

[TheWraith]

6. Actually, that could work.

But given the time it would take to build such a system, it would probably be faster to wait for the weather.

[Gruenemann]

8. Actually, it wouldn't

Unless the water refrigeration plant had greater than 100% efficiency.

[TheWraith]

10. How do you figure?

It's not like they're extracting energy from the coolness of the water, and thus looping extraction. The water is just coolant for a much higher power reaction. Certainly a a nuclear reactor which is generating gigawatts of power can spare even a couple of kilowatts for such an apparatus.

[Tsiyu]

9. Here's hoping the TVA gets this figured out

TVA is an incredible thing.

My power bill was less than $50 this month ( I do live the simple life :)). Our elec co-op buys from them and they really do all in their power to keep the rates low.

Also, seems even the rivers are sending us a message...