#219426 - 03/16/11 06:42 PM
Re: Get water to the reactors?
[Re: Arney]
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Pooh-Bah
Registered: 02/16/08
Posts: 2463
Loc: Central California
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... it seems that they will be restoring grid power soon. If successful, then it sounds like they can restart the normal cooling systems .... I hope they are successful in restoring grid power, especially if that is all it will take to get things under control. So one answer to the "get the water there" question would be to get enough power there to allow the in-place infrastructure to "get the water there." If true, then the question might be more usefully transformed, or at least become a companion to the original questions, into how to "get and keep the power there." Then some questions would be: 1. How much power do they need? 2. Is there a practical way to generate enough power onsite with generators? 3. If onsite generation is not practical, then what offsite power sources are close enough, or can be moved close enough, to provide the needed power?
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#219428 - 03/16/11 06:45 PM
Re: Get water to the reactors?
[Re: unimogbert]
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Pooh-Bah
Registered: 02/16/08
Posts: 2463
Loc: Central California
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If the piping is intact. If the pumps will run. If the valves will open/close. If the electrical power to the pumps is intact. If the controllers for the pumps are intact. If the intake supply to the pumps is/are intact. If the operators can get to the manual valve handles.
There are probably a half-dozen more IFs involved. Yep.
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#219429 - 03/16/11 06:45 PM
Re: Get water to the reactors?
[Re: Arney]
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Geezer
Registered: 06/02/06
Posts: 5357
Loc: SOCAL
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Even with grid power available, restarting the normal cooling systems presumes that the normal cooling systems are intact. Considering the fires and explosions in the Fukushima reactors, grid power may not be enough.
They really needed those back-up diesel systems to function as designed. Back-up systems don't need to be efficient, but they do need to be reliable under the most adverse conditions.
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Better is the Enemy of Good Enough. Okay, what’s your point??
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#219432 - 03/16/11 07:06 PM
Re: Get water to the reactors?
[Re: JIM]
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Old Hand
Registered: 05/29/10
Posts: 863
Loc: Southern California
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Fugushima's right next to the pacific ocean..
Well, isn't there a way to transport the fuel rods and dump them into the sea? That will keep them cooled right?
Eventally they are going to have to remove the fuel rods, or what's left of them. The problem is at the moment those rods are too hot and too damaged to move. Also, if transported unshielded, they will administer a lethal dose of radiation to anybody in the area within 18 minutes. For reference; A dose of 6-10 Sieverts (Sv) is fatal even with treatment, and Chernobyl (which had exposed rods) was pumping out 20 Sv/hour.
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The object in life is not to be on the side of the majority, but to escape finding oneself in the ranks of the insane
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#219436 - 03/16/11 07:21 PM
Re: Get water to the reactors?
[Re: Mark_R]
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Old Hand
Registered: 08/10/06
Posts: 882
Loc: Colorado
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I did a little more reading on BWRs.
Rod groups of 75 to 100 rods per bundle. About 800 rod bundles per reactor.
That's a lot of rods. 140 tons or so.
Easier to bring the ocean to the rods. (even if it isn't very easy)
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#219438 - 03/16/11 07:28 PM
Re: Get water to the reactors?
[Re: dweste]
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Pooh-Bah
Registered: 01/21/03
Posts: 2203
Loc: Bucks County PA
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Each of the ideas you have is noble and well intentioned, and if they could be done, they would be done. No expense is being spared here - they have already deliberately destroyed $26 billion dollar reactors in an effort to control the reaction, there's no lack of willingness or ability to try ANYTHING to cool the systems. The reality is that the scope of destruction is so incredibly vast and the most basic assumptions we have (Get a crane! Get a fire boat!) are crippled by a lack of roads, fuel, debris in the ocean, on the land, everywhere. Roads completely gone. No food, no water, it's snowing.
This is, in every definition an apocalyptic disaster.
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#219446 - 03/16/11 08:35 PM
Re: Get water to the reactors?
[Re: dweste]
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Old Hand
Registered: 03/03/09
Posts: 745
Loc: NC
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Y'all do realize the steam from the hot radioactive rods is radioactive. And when the rods are uncovered they get hotter, so when water is introduced, they make steam.
The problem is getting water to the plant, then somehow containing the steam which if left unfettered will contaminate a large area. Think of steam heat in a house; the steam has to go someplace to condense, and in this case, it must be a closed protected system.
Next problem is that workers just can't be in there. They have to be in suits, and work in rather short shifts, or they get dead pretty quick.
So you have a plant that's basically in pieces, contaminated by radioactivity, and it can possibly blow up at any moment.
And not to mention that somehow the water was being split into component parts and that is an explosive risk - hydrogen and oxygen in an area makes a boom with a small spark capable of igniting it.
I know I wouldn't want the job of fixing this mess.
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#219450 - 03/16/11 09:15 PM
Re: Get water to the reactors?
[Re: MartinFocazio]
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Enthusiast
Registered: 09/09/06
Posts: 323
Loc: Iowa
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Some additional perspective on the size of the problem.
A typical house faucet moves 2.5 gallons per minute. A firetruck can pump around 1,500 gallons per minute. One of the pumps used in a BWR can move over 100,000 gallons per minute.
That means that it would take a whole lot of firetrucks to equal just one of the normal pumps.
Another way to look at it. The electrical generating capacity of unit #1 is around 460MW. The actual thermal capacity is much higher due to inefficiencies in converting heat to electricity. The notional thermal capacity of a shut down reactor is approx. 5% of operational load. Ignoring the inefficiencies that makes the shut down reactor core the equivalent of at least a 23MW heater that needs to be kept cool. I can't recall the loss rates for steam turbines and generators at the moment but I would suspect we could easily double that to 43MW and still be low. Multiply by 3.4 to get rough BTUs.
That is a lot of heat to transfer.
- Eric
_________________________
You are never beaten until you admit it. - - General George S. Patton
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#219457 - 03/16/11 10:03 PM
Re: Get water to the reactors?
[Re: dweste]
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Pooh-Bah
Registered: 02/16/08
Posts: 2463
Loc: Central California
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Is there a straightforward answer to the question: will getting a lot of water to the reactor site help?
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#219460 - 03/16/11 10:20 PM
Re: Get water to the reactors?
[Re: dweste]
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Enthusiast
Registered: 09/09/06
Posts: 323
Loc: Iowa
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Is there a straightforward answer to the question: will getting a lot of water to the reactor site help?
Only those on scene could actually answer the question. For those of us in the bleacher seats there is no simple straight forward answer. Generally more water is a goodness but there are all sorts of exceptions and complications that vary by circumstances and we just don't know enough to reliably make the call. Edit/Add - a lot of water is a variable quantity, if you only have enough capacity to turn a lot of water into steam without getting everything covered again that may be worse than leaving things uncovered. When talking megawatts of heat generating capacity the definition of a lot grows very quickly. -Eric
Edited by Eric (03/16/11 10:29 PM)
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