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Author Topic: what happens (could) if a power station was flooded?  (Read 3630 times)

paul.fr

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Below is a picture of my local power station (coal fired), The army had to be called in a few months back to prevent it flooding. With this weeks and the coming forcast of rain, it is again at risk from flooding.

Would there be any serious implications if this plant did become flooded?



 

another_someone

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what happens (could) if a power station was flooded?
« Reply #1 on: 20/01/2008 05:22:07 »
Economically, it could be very expensive.  It could have a knock on effect in that (as with the case last year when an electricity sub-station was flooded) the loss of power would make it more difficult to pump water, so possibly increasing the risk of flooding elsewhere.
 

Offline daveshorts

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what happens (could) if a power station was flooded?
« Reply #2 on: 23/01/2008 12:59:44 »
Flood water will bring in all sorts of things that are bad for power stations - water which will conduct electricity where you don't want it, silt which will act as a grinding paste on any moving machinery etc etc. generally very bad news...
 

another_someone

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what happens (could) if a power station was flooded?
« Reply #3 on: 23/01/2008 16:24:03 »
Flood water will bring in all sorts of things that are bad for power stations - water which will conduct electricity where you don't want it, silt which will act as a grinding paste on any moving machinery etc etc. generally very bad news...

One would assume that by the time the floods hit, the power station would have been shut down (could be a bigger headache for a nuclear power plant).

Ofcourse, even a shut down power plant, if only recently shut down, will still have a lot of hot components that could be effected by the cold water hitting it.

In any case, as I said, all of that is primarily an economic issue, in that the power station would need substantial amounts of money spent on it to get it serviceable again (but the same is true of all the people who get flooded out of their domestic residences).  The difference is the knock on effect of not having the power available from the power station and how this will effect other attempts to manage, or clean up after, the flooding elsewhere.
 

Offline rhade

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what happens (could) if a power station was flooded?
« Reply #4 on: 30/01/2008 16:24:51 »
Lets not miss an obvious point. Wet coal won't burn too well!
« Last Edit: 12/09/2008 17:16:02 by rhade »
 

Offline Alandriel

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what happens (could) if a power station was flooded?
« Reply #5 on: 30/01/2008 16:34:41 »
Since this kind of belongs in here I hope you don't mind me asking also in here, Paul

Quote from: Dave
water which will conduct electricity where you don't want it...


I've always wondered about that. Just how 'far' would electricity conduct?
Sorry if the questions seems a bit strange but I don't know how to put it in any other way.

If you have a large area flooded and then a power station (or relay station) get's flooded also how far would that current go and what kind of 'powerage' would be involved?

Now I know I sound really silly but hopefully one of you clever bots will understand and bridge the knowledge/language gap here. Thanks :)


 

another_someone

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what happens (could) if a power station was flooded?
« Reply #6 on: 30/01/2008 17:24:50 »
I've always wondered about that. Just how 'far' would electricity conduct?
Sorry if the questions seems a bit strange but I don't know how to put it in any other way.

If you have a large area flooded and then a power station (or relay station) get's flooded also how far would that current go and what kind of 'powerage' would be involved?

Now I know I sound really silly but hopefully one of you clever bots will understand and bridge the knowledge/language gap here. Thanks :)

There is no inherent distance limit to how far electricity will conduct (after all, we have electricity conducted over the grid for at least hundreds of miles).

The problem rather is how much is left after that distance (which depends on  the total resistance it has to travel through), and what is the voltage drop left.

If you have two contacts, both at 1000V, and you grab both of them (and are not earthed, or in contact with anything else), then absolutely no electricity will travel through you, because there is no voltage drop (1000V - 1000V = 0V = no voltage drop).

If you grab one contact at 1000V, and another contact at 0V, you get a massive great voltage through you (1000V - 0V = 1000V = big voltage drop).  How much power goes through you depends on the resistance of you, and the resistance of the conductors, but assuming the conductors are low resistance, then the remaining resistance within your body is quite low enough to allow enough current to travel through your body to fry you.

On the other hand, if you have a relativly good insulator (i.e. something with a high resistance) separating you from the 1000V contact (what matters is the total amount of resistance - so the resistance can be a sort distance of good insulator, like a few inches of Teflon, or a large amount of a medium insulator, like 3000 metres of water), then the amount of current that will flow through that is very slight, so you will not even notice it is there.

The conductivity of metal is about 10 million times that of sea water (drinking water can be between 100 to 10,000 higher resistivity), so you can still use a metal as an insulator, but you would need about 10 million times as much of it as you would need of sea water to offer the same resistance to electricity.

A good insulator (such as glass or Teflon) on the other hand gives about 1024 better insulation than a metal does, and thus about 1017 better insulation than sea water.

The other issue is not just how much resistance is offered, but what other paths can the electricity take.  Although sea water is 10 million times less good an insulator than a metal, if you pass a current through the sea, you not only have the resitance of the water to prevent the current passing through, but the fact that the sea bed itself will form an alternative path for the current, so most of the current will in fact quickly be earthed into the sea bed rather than trying to find a route to the other side of the sea (this is different from if you were trying to pass a current through a plastic lined swimming pool, where the current could not pass to earth through the bottom of the pool).
 

Offline Alandriel

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what happens (could) if a power station was flooded?
« Reply #7 on: 31/01/2008 13:23:10 »
Thanks George, you do these things exceedingly well as usual.
But, may I take it a bit     s  l  o  w  l  y    (perhaps the dementia is seeping over)

Quote from: George
If you have two contacts, both at 1000V, and you grab both of them (and are not earthed, or in contact with anything else), then absolutely no electricity will travel through you, because there is no voltage drop (1000V - 1000V = 0V = no voltage drop).

So, if I hold a 1000V cable in my right and another 1000V one in my left and I float in midair (I've always wanted to levitate btw) then there is no electricity traveling through me?


sorry - I'm not picasso though I try and after all, this is my first *ever* diagram on here


Do I act like a total stop block? Or does the electricty arch through thin air?
Or do you mean to say that although a current travels through me I simply don't feel any negative effect because I'm (in this case) levitating?



You'll be relieved to know that I get how holding a 1000V and a 0V would give me a nice perm. It's the above that does rather boggle me.



Quote from: a heavily edited and condensed George but still true to his words
On the other hand, if you have a large amount of a medium insulator like 3000 metres of water separating you from the 1000V contact then the amount of current that will flow through that is very slight, so you will not even notice it is there.

I'm with you.
Yes - unbelievable really.............             but

3000 meters is a rather large distance, 3 kilometers. Now take poor Paul. Although I'm sure he does not live directly on the doorstep of the powerplant, what if he - let's say - paddled by in a canoe as the flood is ongoing (since he's a concerned citizen perhaps that's something we would do...... or then perhaps not, as he's probably smarter than that - but anyways, let's just speculate for a moment).
So Paul paddles towards the power station and as he reaches the (probably locked) wire gates the unthinkable happens.
zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzap!
He's a mere 500m from 'ground zero'.


Will Paul survive?

And since I'll make (this totally fictional of course) Paul a rather daring character, how close could he actually get to ground zero and still live to tell the tale?




*) important note (or maybe it's not important but since George always thinks of everything): Paul's canoe leaks
but not enough to make him sink


 ;D


« Last Edit: 31/01/2008 13:25:32 by Alandriel »
 

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what happens (could) if a power station was flooded?
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