Heat Wave Shuts Down Alabama Reactor

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."

Comments

In Soviet Russia

[davidwr]

In Soviet Russia, overheating nuclear reactor shuts down YOU!

Re:In Soviet Russia

[Oktober Sunset]

Actually, it's to distinguish it from Russia now. The original joke just said Russia, it was only after the collapse of the USSR that it changed.
There's not really much worry about people think the jokes are about Tsarist Russia is there?

(After writing this bit, it bacame clear to me that subconciously, I envision 1st Dude to be Brian Griffin, and 2nd Dude to be Stewie.)
1st Dude: "In Russia overheating reactor shuts down YOU."
2nd Dude: "Oh yea, thats funny, I get it, cos like, they just used uranium for yellow pottery glave back in Tsarist times right? Thats funny. No wait, Don't get that, that makes no sense"
1st Dude: "No, like I mean the Soviet era, like Chernobyl blowing up"
2nd Dude: "oh right, like why didn't you say"
1nd Dude: "I dunno, I figured it was obvious"
2nd Dude: "wasn't umm wasn't Chernobyl in the Ukraine"
1st Dude: "What am I like, a geography teacher now?"
2nd Dude: "that's like pretty poor taste man, a lot of people died"
2nd Dude: "That's not really funny at all"
1st Dude: "In Soviet Russia, taste poors YOU! heh heh"
2nd Dude: "that one wasn't even a sentence"

Reasons right?

[Anonymous Coward]

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?

[hankwang]

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, for example for residential heating in cold climates or for the industry.

Meanwhile Back In Alabama

[cluckshot]

A little noted fact of the cold war is that a very large amount of the US total electrical generation capacity is in the TVA region (Tennessee River - Dependent) The loss of this reactor is serious as the whole USA has no reserve capacity at peak load and with the heat wave over the East USA this is a critical loss. If it were the only reactor in danger this might be of no concern. The US TVA operates 5 big reactors and numerous coal fired plants all of which have the Tennessee River at thermal capacity to cool them and the river is dropping daily.

If heavy sustained rain does not fall on the Tennessee River Valley over the next 3 to 4 months an event which is historically unlikely, the loss of something close to 15 times the Browns Ferry reactor in capacity is likely to hit the USA. There is nothing to pick up the load. The loss of this one reactor is nearly equal to all the wind energy the USA generates. This loss threatens the operations of every one of the 48 US States. With the possible loses in Alabama Power pools and their reactors etc as well as Georgia Power, this poses the very real risk of cutting the energy supply of the USA by a very large fraction. As I write the North Alabama region is short 60 inches of rain over the past 18 months. The US TVA has been drawing down storage for 5 years now. There is no reserve and little prospect of one for some years to come.

I had warning of this imminent event when the City of Huntsville requested from TVA more water for its treatment plant and was turned down for supply. I knew then that the supply was gone.

Re:paddle wheels in the heat stream

[QuickFox]

Are you thinking a forest of insulated two-foot steam pipes running all around town? Sounds pretty ugly, noisy, expensive and environmentally disruptive. Here in Sweden we've had this in the cities forever. It's not ugly, noisy, expensive and environmentally disruptive. Instead it's underground.

Generally they don't transport steam, they transport hot but liquid water.

See, engineers are not idiots. You must be new here.

Re:Some people sell their "waste" heat

[fabu10u$]

Some people sell their "waste" heat
To heat domestic water, space heating and even to power adsorption chillers which can reduce AC requirements.

Try selling the US public on steam heat from a nuke. Yes, the coolant loop neither touches the core nor picks up radioactive ions, but see if you can get the unwashed masses to believe they'll be safe with it!