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

Even though the radiation levels have quadrupled they still aren't high enough to cause any problems, at the current levels you'd need direct exposure for sustained periods (read hours) for it to have any effect.
 
-Ad- said:
I don't suppose it's a publically available document, if so, e-mail in trust :D:D:D

Not good to hear.
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I think the document is part of the GE training package for future operators, so it's not publically available, so will stick some snipets up but won't send anyone the full thing :p
 
I've learnt a bit about nuclear power lately as a result of this whole tragedy, and I do find it very interesting, particularly how this one has held up so well despite being subjected to stress way over what it was designed to withstand. It's just a shame as Dolph said that the media focus is so often taken away from the real tragedies, i.e. the thousands of missing/dead people :(

I'm trying to understand the scale of it... How big is all the equipment inside the BWR? I.e. the reactors, fuel rods, pressure vessels etc? Is it all on quite a small scale, just contained within massive concrete walls inside the big buildings?
 
really didnt want to wake up to this :( ... it would be nice to get a explanation of the health effects of dosages, rather than me trying to speculate by comparing numbers... heres a source i quoted y'day http://www.zerohedge.com/article/ga...nwind-ibaraki-disclosed-30-times-above-normal

and heres a reuters article which briefly mentions the effects of dosages

http://uk.reuters.com/article/2011/03/15/us-japan-radiation-factbox-idUSTRE72E14R20110315


i get confused with the readings because some are measured as instantaneous measurements, and some as measurements over time, which doesnt make sense to me, also i guess its the type of radiation thats given off that matters.. i suppose alpha is the best, so long as you're not ingesting it, as then it becomes the worst, and gamma isnt great either since you can't really shelter from it...
 
Firestar_3x said:
I think the document is part of the GE training package for future operators, so it's not publically available, so will stick some snipets up but won't send anyone the full thing :p
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No worries, thought it was worth a punt anyway :D

Will search around the web to see what I can find anyway, I need my fill of engineering!
 
Howard said:
I'm trying to understand the scale of it... How big is all the equipment inside the BWR? I.e. the reactors, fuel rods, pressure vessels etc? Is it all on quite a small scale, just contained within massive concrete walls inside the big buildings?
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Take a look at the picture on the previous page, should give you some idea of scale.

-Ad- said:
No worries, thought it was worth a punt anyway :D

Will search around the web to see what I can find anyway, I need my fill of engineering!
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http://en.wikipedia.org/wiki/Boilin...production_BWRs_.28BWR.2F1.E2.80.93BWR.2F6.29
 
From Kyodo

The following is the known status as of Tuesday evening for each of the six reactors at the Fukushima No. 1 nuclear power plant in Fukushima Prefecture, crippled by Friday's magnitude 9.0 earthquake and ensuing tsunami.

-- Reactor No. 1 - Cooling failure, partial melting of core, hydrogen explosion, seawater pumped in.

-- Reactor No. 2 - Cooling failure, seawater pumped in, fuel rods fully exposed temporarily, partial melting of core, damage to containment system.

-- Reactor No. 3 - Cooling failure, partial melting of core, seawater pumped in, hydrogen explosion.

-- Reactor No. 4 - Under maintenance when quake struck, fire caused by hydrogen explosion at pool holding spent fuel rods, pool water levels feared receding.

-- Reactor No. 5 - Under maintenance when quake struck.

-- Reactor No. 6 - Under maintenance when quake struck.
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R5Rich said:
Anyone else have the urge to go and help?

Wouldn't know where to even start tbh
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I really wish I could too.

After my final year of uni I will be including Japan in my travels, doing volunteer work if there is any available.

But for now all I can do is donate.
 
Obviously it's not this simple, but...I'm surprised if there's no way to automatically withdraw the U-235 or whatever it is from the fuel rods / core, so that the U-236 is never created and the heat is not produced. Too much reliance seems to be placed on the cooling systems which are obviously fragile in cases like this.

My knowledge is next to nothing, which is why I'd be interested if anyone has any explanation of why nuclear reactors are apparently so fragile in their failsafes!? I suspect the answer will be something to do with cost / benefit at the design phase :(.
 
japan40.jpg
 
I think this is holding up well considering the trauma that the site has been exposed to, by the earthquake and the tsunami.

By all accounts the design is an older one, which relies on active cooling where the newer designs do not.

I'm paraphrasing. Someone correct me if I'm wrong?
 
Ugghh.. Just watched some fox news where they were reading out the jokes some of the so called american celebs have been twittering...
 
Robbie G said:
Obviously it's not this simple, but...I'm surprised if there's no way to automatically withdraw the U-235 or whatever it is from the fuel rods / core, so that the U-236 is never created and the heat is not produced. Too much reliance seems to be placed on the cooling systems which are obviously fragile in cases like this.

My knowledge is next to nothing, which is why I'd be interested if anyone has any explanation of why nuclear reactors are apparently so fragile in their failsafes!? I suspect the answer will be something to do with cost / benefit at the design phase :(.
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Dont take this the wrong way...

but why have you even replied with a post like that? The first paragraph is a farce why not just start the post with the second one.

The fuel rod is the Uranium mix of 235 and 238 (enrichment takes the 238 value up) clad in a zircalloy material to contain the fuel. When you have had fission that uranium splits and the elements are still in the rod emitting a number of particles (radiation) and generating heay (decay heat).

U235 does not turn into a 236, this is fission, not fusion. The control rods have already stopped Uranium fission interaction.

If you take them out they melt, thats what the whole cooling thing is about. Plus you would need to take the lid off the RPV to take the rods out....

They are not fragile at all.
 
Robbie G said:
Obviously it's not this simple, but...I'm surprised if there's no way to automatically withdraw the U-235 or whatever it is from the fuel rods / core, so that the U-236 is never created and the heat is not produced. Too much reliance seems to be placed on the cooling systems which are obviously fragile in cases like this.

My knowledge is next to nothing, which is why I'd be interested if anyone has any explanation of why nuclear reactors are apparently so fragile in their failsafes!? I suspect the answer will be something to do with cost / benefit at the design phase :(.
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The problem is they can't stop the reaction instantly. They can remove the rods from the core, but the reaction will still continue to produce heat for some time. That's just the physics of it.... there isn't much they can do to change it.
 
jimbob27 said:
The problem is they can't stop the reaction instantly..
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Well they can to all intents and purposes if you consider the fission of uranium as the reaction, you need water between the uranium for the reaction so that rules out the fuel rod... (unless they crack or warp),and the control rods prevent neutrons getting from one rod to the other. Its the decay heat that they can't stop.
 
Jonnycoupe said:
Dont take this the wrong way...

but why have you even replied with a post like that? The first paragraph is a farce why not just start the post with the second one.

The fuel rod is the Uranium mix of 235 and 238 (enrichment takes the 238 value up) clad in a zircalloy material to contain the fuel. When you have had fission that uranium splits and the elements are still in the rod emitting a number of particles (radiation) and generating heay (decay heat).

U235 does not turn into a 236, this is fission, not fusion. The control rods have already stopped Uranium fission interaction.

If you take them out they melt, thats what the whole cooling thing is about. Plus you would need to take the lid off the RPV to take the rods out....

They are not fragile at all.
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So much wrong with this I don't know where to begin :(.

- I 'replied with a post like that' because I wanted to be enlightened, preferably not by some smug arse with mega-nerd-rage, especially one that obviously doesn't know what they're talking about. But hey, beggars can't be choosers.
- U-235 DOES turn into U-236 in nuclear fission...the U-235 nucleus absorbs a neutron, which turns it into U-236. U-236 is unstable, which causes the fission.
- I see no valid reason to start the post with the second paragraph nor do I see why it really matters.
- Enrichment increases the proportion of the U-235 isotope, not U-238.

If you're going to give it the big 'I-am', at least have the knowledge to back up the attitude :(. Hence I'll have to disregard the rest of your post about the control rods and hope that someone that knows what they're talking about turns up.
 
Robbie G said:
- I 'replied with a post like that' because I wanted to be enlightened, preferably not by some smug arse with mega-nerd-rage, especially one that obviously doesn't know what they're talking about. But hey, beggars can't be choosers.
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I've found posts like that are always met by smartass replies like that from quite a few people on these forums :( not knowing EVERYTHING is apparently an offence on here.
 
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