Earthquake in Japan....9.0...ouch!

I think everyone is right to start freely questioning nuclear power regardless of there background because you don't need to be a nuclear physisist to be able to acknowledge that a nuclear power plant is a potentially serious hazard.

So do many other things in life, this topic just happens to be a political hot potato, miles more people die per year from plane or car crashes, so why is that risk acceptable?

It's the fear of the unknown and lack of control, death on a bigger scale is always less acceptable than one of two being killed every day, 90% of people know nothing about nuclear power, 98% of people have no idea what goes into the safety systems.

Just look at that accident list posted above, that's all thats gone wrong during the lifetime of 100's of plants over the combined running time, when compared to other industrys i'd say nuclear has a safety record second to none.
 
Of course you have to be careful, but then what are the alternatives?

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I honestly don't know, it's not something I can provide an answer to. I just think that it wouldn't be silly to take this japanese incident into account when assessing energy plans for the future, whatever those plans might be.

So we should question building nuclear power plants in this country (or in-fact any country) which does not suffer from such natural events but are built (I assume) to the same standards?

Most of the disasters are down to human error. Reminds me of a quote by Barnes Wallis: "It's so hard to make things foolproof because the fools turn out to be so damned inventive".

Same applies to everything. Put an idiot in-charge of a car, aeroplane, boat, gun. People die.

Nuclear when designed properly and operated correctly are perfectly safe, as is everything.
I already touched upon what I will say here in my last post, but I will say it again. If they didn't think the plant would have been safe there, they wouldn't have built it. The whole 'oh but it was in Japan' line is a large extent bogus because not even the japanese could predict or prepare for an earthquake of that magnitude and, ya know, they live in Japan.

Many disasters may well be down to human error, but I think we can fairly say this was not. Are you saying this was?

I would have said nuclear power was 'perfectly safe' a week ago, but looking at the news now, it's blatently not. This of course runs on my assumption that those working at a nuclear power plant in one of the most economicly powerful countries in the world are probably quite up to scratch on what is thought to be needed to make a nuclear power plant safe, more so than any of us.
 
I think the onus of proof is on you at the moment. Im curious why you didnt use any of the other pictures that show it splitting and releasing the energy rather than this absorbtion idea being the chain reaction mechanism. There is no text you can find on google to descibe u236 either?

Its like kicking a ball into a net of 235 balls, they dont just sit there with 236 balls then moments later the net bursts and two groups of the balls fly off in different directions with no additional energy input. Its the initial ball hitting the group, two main clusters seperate and between 2 and 3 random white balls fly off in other directions. At no point did the bag have 236 balls in.

Because the other pictures were less detailed, less accurate, and almost misleading, much like yourself. You are actually saying that U235 does not become U236, albeit briefly, before undergoing fission? How does it manage to absorb a neutron into its nucleus without changing isotope?

Your football analogy is useless as one football does not absorb another and change state before splitting.

And I think you'll find that the onus of proof is probably on you if anyone, considering your comment:

Jonnycoupe said:
The fuel rod is the Uranium mix of 235 and 238 (enrichment takes the 238 value up)

Anyway maybe this will help you understand the process a bit better:



"Uranium is the principle element used in nuclear reactors and in certain types of atomic bombs. The specific isotope used is 235U. When a stray neutron strikes a 235U nucleus, it is at first absorbed into it. This creates 236U. 236U is unstable and this causes the atom to fission. The fissioning of 236U can produce over twenty different products. However, the products' masses always add up to 236."

http://library.thinkquest.org/17940/texts/fission/fission.html

There are literally hundreds of references to U236's role in fission all over the web.
 
So do many other things in life, this topic just happens to be a political hot potato, miles more people die per year from plane or car crashes, so why is that risk acceptable?
I'm not sure if you want a serious answer to that or not because it has such an obvious answer :p

The magnitude of a nuclear disaster has much bigger and much longer lasting implications than a car or plant crash.

It's the fear of the unknown and lack of control, death on a bigger scale is always less acceptable than one of two being killed every day, 90% of people know nothing about nuclear power, 98% of people have no idea what goes into the safety systems.

Just look at that accident list posted above, that's all thats gone wrong during the lifetime of 100's of plants over the combined running time, when compared to other industrys i'd say nuclear has a safety record second to none.
I'm not doubting that nuclear power plants have a good safety record. At present however they are clearly not all immune from unforseen natural disaster, which in tandem with the above (the magnitude of such a disaster) it's cause for fair concern.

Not panic, but serious and fair concern.
 
But don't let this stop massive (un-needed) panic.
Shut them all down and build a windmill I say.

Sigh.

But then some crazy scientist will design a new windmill to increase power production. And then they'll design a new one to replace that. And so on! And so on!!!

Until they make a windmill so powerful that it destroys the world!!! :eek:
 
I honestly don't know, it's not something I can provide an answer to. I just think that it wouldn't be silly to take this japanese incident into account when assessing energy plans for the future, whatever those plans might be.


I already touched upon what I will say here in my last post, but I will say it again. If they didn't think the plant would have been safe there, they wouldn't have built it. The whole 'oh but it was in Japan' line is a large extent bogus because not even the japanese could predict or prepare for an earthquake of that magnitude and, ya know, they live in Japan.

Many disasters may well be down to human error, but I think we can fairly say this was not. Are you saying this was?

I would have said nuclear power was 'perfectly safe' a week ago, but looking at the news now, it's blatently not. This of course runs on my assumption that those working at a nuclear power plant in one of the most economicly powerful countries in the world are probably quite up to scratch on what is thought to be needed to make a nuclear power plant safe, more so than any of us.

The following things worked as designed (for a 40 year old reactor):

1. The structure of the reactor and it's building after the 9.0 earthquake.
2. The automatic shut down systems.
3. The backup systems started.

If the Tsunami hadn't of hit, then I think we can safely say the reactors would be fine now.

However then the Tsunami hit:

4. Generators died but battery systems came online and from what I can gather worked for the 8 hours they were designed for.

So in terms of design, the powerplant worked PERFECTLY. Why (given the information we have) should we question nuclear on the above?

What went wrong after that was the inability to restore power to the cooling pumps after the batteries ran out of power. This is a design oversight (According to the BBC the plugs didn't fit :confused:) and now will be double and triple checked at every nuclear power plant over the world.

Given that modern reactors have the ability to passively cool, even point 4 would not be an issue.

So from my PoV given the information we have I see absolutely no reason to doubt the safety of a nuclear power plant.
 
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I hadn't thought of that danger... :eek:
We best just not have electricity anymore because it's far too dangerous.
Shut everything down and kill modern day civilisation as we know it.
 
The following things worked as designed (for a 40 year old reactor):

1. The structure of the reactor and it's building after the 9.0 earthquake.
2. The automatic shut down systems worked as they should.
3. The backup systems started as they should.

If the Tsunami hadn't of hit, then I think we can safely say the reactors would be fine now.

However then the Tsunami hit:

4. Generators died but battery systems came online and from what I can gather worked for the 8 hours they were designed for.

So in terms of design, the powerplant worked PERFECTLY. Why (given the information we have) should we question nuclear on the above?

What went wrong after that was the inability to restore power to the cooling pumps after the batteries ran out of power. This is a design oversight (According to the BBC the plugs didn't fit :confused:) This is a design oversight (human error) and now will be double and triple checked at every nuclear power plant over the world.

Given that modern reactors have the ability to passively cool, even point 4 would not be an issue.

So from my PoV given the information we have I see absolutely no reason to doubt the safety of a nuclear power plant.

What you say is true and fair in terms of technicalities, there is no dispute.

As I said before, I am not against nuclear power (one week ago I would have been quite vocally pro), but current events do make me question it because there may be oversights or circumstances that do make emergencies possible. That's not an unreasonable possition to be in because if you look at the news, there is a nuclear emergency going on right now.
 
Anyway maybe this will help you understand the process a bit better:



"Uranium is the principle element used in nuclear reactors and in certain types of atomic bombs. The specific isotope used is 235U. When a stray neutron strikes a 235U nucleus, it is at first absorbed into it. This creates 236U. 236U is unstable and this causes the atom to fission. The fissioning of 236U can produce over twenty different products. However, the products' masses always add up to 236."

http://library.thinkquest.org/17940/texts/fission/fission.html

There are literally hundreds of references to U236's role in fission all over the web.

By students for students? I dont think so. Non of his equations show U236 either, the process is so instanteous and purely fission such that you get the two fragments not decay.

Fragments, although this is from MOX, ie U235 and Pu239 fuel. I believe reactor 4 is this?

distribution_of_fission_products.png


Unstable isotopes emit neutrons, they do not split, that is what defines fission. The instanteous release of the binding energy.

U235 is fissile so splits
U238 is 'fertile' so absorbs the neutron and forms Pu239.

I simply cannot draw parrallels between the creation of Pu239 and 'U236'

U236 as waste is actually a neutron absorber so slow the reactivity of the core.

fission1.gif



Far better and certainly they way i was introduced to BASIC nuclear physics. The poison control effect and its opportunity to extend reactor burn life is not really relevant to the basics, particularly as the poison lag in PWRs in Xenon not U236.

You didnt even understand the ball analogy, the ball net was the nucleus, why are you suggesting that I stated the football gets absorbed by another football? Neutrons do no absorb neutrons.
 
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So we should question building nuclear power plants in this country (or in-fact any country) which does not suffer from such natural events but are built (I assume) to the same standards?

Most of the disasters are down to human error. Reminds me of a quote by Barnes Wallis: "It's so hard to make things foolproof because the fools turn out to be so damned inventive".

Same applies to everything. Put an idiot in-charge of a car, aeroplane, boat, gun. People die.

Nuclear when designed properly and operated correctly are perfectly safe, as is everything.


Unfortunately you said it right there, most disasters are down to human error, in which case, location and outside situation is not irrelevant, but often is.

CHernobyl and Three mile were caused by human error in, somewhat routine use, yes Chernobyl was being tested but thats part of using a plant, what I mean is Chernobyl wasn't hit by an external situation to which they acted incorrectly.

Its also worth noting we don't know that the Tsunami's knocked out the generators, we can assume that but, timing seems off.

Earthquakes hit, they keep saying the generators worked for one hour before failing, didn't the Tsnuami hit in 10 minutes or so, its a little south of where the Tsunami hit first but, not that far, timing wise it looked like the generators worked for a while after the Tsunami, did they stand up to the Tsnuami but were damaged and eventually shut down, or were they old, faulty and simply died after an hour and would have died after an hour without the Tsnuami, maybe they were damaged by the Earthquake, I'm just saying thats not clear.

I can't be sure what happened with reactor 4, cooling was maintained on reactor 4 till recently? Thats not clear either, or simply because it wasn't in action it took a heck of a lot longer to heat up only from the spent fuel area?

Its all a bit of an unknown, but anyway, if most accidents have been user error, and you can't ever rule out human error, you really have to look at worst case scenario and decide if its worth dealing with.

Its STILL a debate, be honest, don't think well of mankind, what would happen in the UK if we ran out of power, industry, jobs, production, food production, food shipping around the country all eventually stop due to lack of power? Is the risk of a few thousand deaths every now and then a really bad alternative if a plant does go bad, maybe not.

Life as we know would change drastically without continual power usage.
 
What you say is true and fair in terms of technicalities, there is no dispute.

As I said before, I am not against nuclear power (one week ago I would have been quite vocally pro), but current events do make me question it because there may be oversights or circumstances that do make emergencies possible. That's not an unreasonable possition to be in because if you look at the news, there is a nuclear emergency going on right now.

Just so we are on the same page, you are saying that whatever we do we will always miss something and at some point that missed issue will cause a nuclear disaster?

Fair comment, however given the public will now think 'OMGZ nuclear is bad' because a 40 year old reactor has mildly melted down but pretty much contained it as it's supposed to.
 
Unfortunately you said it right there, most disasters are down to human error, in which case, location and outside situation is not irrelevant, but often is.

CHernobyl and Three mile were caused by human error in, somewhat routine use, yes Chernobyl was being tested but thats part of using a plant, what I mean is Chernobyl wasn't hit by an external situation to which they acted incorrectly.

Its also worth noting we don't know that the Tsunami's knocked out the generators, we can assume that but, timing seems off.

Earthquakes hit, they keep saying the generators worked for one hour before failing, didn't the Tsnuami hit in 10 minutes or so, its a little south of where the Tsunami hit first but, not that far, timing wise it looked like the generators worked for a while after the Tsunami, did they stand up to the Tsnuami but were damaged and eventually shut down, or were they old, faulty and simply died after an hour and would have died after an hour without the Tsnuami, maybe they were damaged by the Earthquake, I'm just saying thats not clear.

I can't be sure what happened with reactor 4, cooling was maintained on reactor 4 till recently? Thats not clear either, or simply because it wasn't in action it took a heck of a lot longer to heat up only from the spent fuel area?

Its all a bit of an unknown, but anyway, if most accidents have been user error, and you can't ever rule out human error, you really have to look at worst case scenario and decide if its worth dealing with.

Its STILL a debate, be honest, don't think well of mankind, what would happen in the UK if we ran out of power, industry, jobs, production, food production, food shipping around the country all eventually stop due to lack of power? Is the risk of a few thousand deaths every now and then a really bad alternative if a plant does go bad, maybe not.

Life as we know would change drastically without continual power usage.

Much much harder to make errors in newer plant, the C&I is far far more advanced than the hard wired systems of old.
 
Much much harder to make errors in newer plant, the C&I is far far more advanced than the hard wired systems of old.

The problem being that people often can't predict the stupid things people will do, IIRC the Three Mile accident was partially down to a stick/label hanging over a required warning light, I mean, it sounds so stupid, you wouldn't think of that when designing every last thing in the plant.

As I was getting at though, in principle, the choice between life without power, or life with a decent risk of even a pretty bad nuclear situation, its NOT an easy choice and not really leaning towards the no power side, I'd be the nuclear power side of that choice.

THeres lots of pro/con arguments, I just really dislike the "but it won't go wrong" argument because, its a bit daft. Things go wrong, they always do, every person thinks they've come up with a new infalible version of some old system, and then, someone breaks it, thats life.



New quake, "only" a 6.0 south west of Tokyo.
 
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