Could be worse than Chernobyl
Doctor Drivel
http://www.youtube.com/watch?v=rlZhUi1nhtE&feature=player_embedded
International regulating bodied should be put in place right now. One with
teeth.
Phil
wrote:
B*llocks.
Nick Leverton
One should be very careful when mixing teeth with b*llocks ...
Nick
--
Serendipity: http://www.leverton.org/blosxom (last update 29th March 2010)
"The Internet, a sort of ersatz counterfeit of real life"
-- Janet Street-Porter, BBC2, 19th March 1996
Doctor Drivel
"Phil" <philip_b...@yahoo.com> wrote in message
news:54eb91a3-6498-4e9c...@w7g2000yqe.googlegroups.com...
B*llocks.
<<<
You are an idiot.
Robin
>> B*llocks.
>
> One should be very careful when mixing teeth with b*llocks ...
>
Japanese usefully drop *people* on the reactors from helicopters rather
than seawater? The people would be less likely to blow away so more
would land on the targets. The bodies would stack (at least initially)
reducing the gamma radiation hitting the aircrew. And - the key
benefit - since the UK has offered aid and the Japanese have accepted we
could send them bodies we'd be well rid off - such as those who think
this could be worse than Chernobyl.
--
Robin
PM may be sent to rbw0{at}hotmail{dot}com
Doctor Drivel
"Robin" <s...@sig.sep> wrote in message
news:DCmgp.79772$5X6....@newsfe20.ams2...
But the man who says it could be worse than Chernobyl is in Japan, saving
the air ticket.
Robin
> But the man who says it could be worse than Chernobyl is in Japan,
> saving the air ticket.
? ABC introduced him as "at New York" - where incidentally he is a
theoretical physicist so I am unsure what he brings to the party over
and above the many nuclear engineers and IAEA, except perhaps that he is
a successful "populariser" of science and ABC know he'll give "good
headlines".
Doctor Drivel
"Robin" <s...@sig.sep> wrote in message
> >
>> But the man who says it could be worse than Chernobyl is in Japan,
>> saving the air ticket.
>
> ? ABC introduced him as "at New York"
He looked like he was in Japan with Japanese buildings behind him. Maybe
they were cardboard cutouts.
Worse than Chernobyl he says. He does.
Andy Dingley
> ? ABC introduced him as "at New York" - where incidentally he is a
> theoretical physicist so I am unsure what he brings to the party over
> and above the many nuclear engineers and IAEA,
Michio Kaku is far more than a "populariser" of science, he gets as
far as "utter meeja whore".
John Williamson
>
> "Robin" <s...@sig.sep> wrote in message
> news:6Omgp.39077$2H.1...@newsfe15.ams2...
>> >
>>> But the man who says it could be worse than Chernobyl is in Japan,
>>> saving the air ticket.
>>
>> ? ABC introduced him as "at New York"
>
> He looked like he was in Japan with Japanese buildings behind him.
> Maybe they were cardboard cutouts.
>
> Worse than Chernobyl he says. He does.
He also thinks that in a decade, we'll all be driving plastic cars
fuelled by hydrogen, or will they be battery powered? which will be
totally safely driven by computers and as comfortable as your living room.
See "related video" link on the page given.
--
Tciao for Now!
John.
Doctor Drivel
"Tim Streater" <timst...@waitrose.com> wrote in message
news:timstreater-8532...@news.individual.net...
> In article <ilsrfo$h1i$1...@news.eternal-september.org>,
This man is a clear plantpot.
Skipweasel
> One should be very careful when mixing teeth with b*llocks ...
>
That power station at Chewnobble?
--
Skipweasel - never knowingly understood.
Donwill
safety on the Today programme (radio4) this morning saying it was
nothing like Chernobyl.
Don
Doctor Drivel
Reactor 1: Partial meltdown, outer containment severely damaged due to
explosion, radioactive materials released (such as iodine)
Reactor 2: Partial meltdown, minor outer containment damage, containment
vessel breached, possible release of radiation
Reactor 3: Partial meltdown, outer containment severely damaged due to
explosion, containment vessel possibly damaged, release of radiation
Reactor 4: Shut down, but spent fuel rods exposed to air, fires and
explosion, outer containment walls damaged, radioactive gases emitted
Reactor 5: Shut down, no damage, but spent fuel overheating
Reactor 6: Shut down, no damage, but spent fuel overheating
Nightjar
> Status of reactors:
Fukushima No 1 power station.
> Reactor 1: Partial meltdown, outer containment severely damaged due to
> explosion, radioactive materials released (such as iodine)
Reactor building, which is mainly there to keep the weather off, badly
damaged by hydrogen explosion during planned venting of steam. Pressure
vessel, primary and secondary containment vessels all undamaged. Short
half life radioactive materials vented intentionally. Fuel elements
probably have suffered damage, but it is not currently possible to
determine whether there has been any melting of cladding or rods. Now
viewed as stabilised
> Reactor 2: Partial meltdown, minor outer containment damage, containment
> vessel breached, possible release of radiation
Reactor building damaged. Wetwell torus breached, resulting in an
unplanned release of short half-life radioactive elements. Despite
earlier concerns, pressure vessel and main containment confirmed as
intact. Fuel elements as reactor 1.
> Reactor 3: Partial meltdown, outer containment severely damaged due to
> explosion, containment vessel possibly damaged, release of radiation
As reactor 1.
> Reactor 4: Shut down, but spent fuel rods exposed to air, fires and
> explosion, outer containment walls damaged, radioactive gases emitted
Reactor offline at the time of the earthquake - undamaged and safe.
Reactor building slightly damaged by two fires, now extinguished. One
thought to be linked to a failed oil pump. Second possibly due to
hydrogen bubbling. Spent fuel rods have been exposed but water now being
injected.
The radiation monitor next to reactor 4 recorded a level of 100mSv and
that next to Reactor 3 recorded 400mSv at 10:22 on 15 March. Radiation
levels at the plant boundary 489.9 micro Sv/hr as at 16:30 March 15.
> Reactor 5: Shut down, no damage, but spent fuel overheating
Reactor offline at the time of the earthquake - undamaged and safe.
Spent fuel pool temperature increasing.
> Reactor 6: Shut down, no damage, but spent fuel overheating
As reactor 5.
Fukushima No 2 Power station
Reactors 1-4 in cold shutdown, undmaged and with core cooling operating
correctly.
Colin Bignell
Nightjar
'The widely-hyped possibility of some Chernobyl-like event is
inconceivable without a new, catastrophic disaster. '
http://tech.mit.edu/V131/N13/yost.html
Colin Bignell
Peter Scott
Sounds very informed and reassuring. There is one question that has not
been touched on anywhere and perhaps could be answered here. For neutron
emitters like uranium there is a critical mass. Once this is reached,
enough of the neutrons are captured by other atoms to create runaway
fission, in other words a bloody great bomb. I think this mass is about
10 kg for uranium. There must be more than 10 kg in the reactor. So if
it all melts and pools at the bottom won't it go bang? Am I missing
something? Is it to do with lower enrichment of reactor fuel?
Peter Scott
The Natural Philosopher
> On 17/03/2011 14:26, Doctor Drivel wrote:
>> Status of reactors:
>>
>> Reactor 1: Partial meltdown, outer containment severely damaged due to
>> explosion, radioactive materials released (such as iodine)
>>
>> Reactor 2: Partial meltdown, minor outer containment damage, containment
>> vessel breached, possible release of radiation
>>
>> Reactor 3: Partial meltdown, outer containment severely damaged due to
>> explosion, containment vessel possibly damaged, release of radiation
>>
>> Reactor 4: Shut down, but spent fuel rods exposed to air, fires and
>> explosion, outer containment walls damaged, radioactive gases emitted
>>
>> Reactor 5: Shut down, no damage, but spent fuel overheating
>>
>> Reactor 6: Shut down, no damage, but spent fuel overheating
>>
>
> Sounds very informed and reassuring. There is one question that has not
> been touched on anywhere and perhaps could be answered here. For neutron
> emitters like uranium there is a critical mass. Once this is reached,
> enough of the neutrons are captured by other atoms to create runaway
> fission, in other words a bloody great bomb.
No.
I think this mass is about
> 10 kg for uranium. There must be more than 10 kg in the reactor. So if
> it all melts and pools at the bottom won't it go bang? Am I missing
> something? Is it to do with lower enrichment of reactor fuel?
>
No, it is to do with the fact that
(a) the material is not sufficiently pure U235 to ever do more than get
white hot and
(b) if small pop happened, it would blow the neutron emmitting hot
spots apart
to make a bomb requires not only far higher purities of fissile
material, but also special shapes that are banged together by a
conventional charge to keep them in close proximity until the bomb
simply melts completely. In short you need the concentional explosion to
CONTAIN the vaporised A-bomb till its built up enough power to do the
business.
Power stations cannot blow up as a nuclear weapon does. Mostly they blow
up from hydrogen or steam, and then spread muck around. They are 'dirty'
bombs of sub conventional yield.
> Peter Scott
djc
>
> The radiation monitor next to reactor 4 recorded a level of 100mSv and that
> next to Reactor 3 recorded 400mSv at 10:22 on 15 March. Radiation levels at
> the plant boundary 489.9 micro Sv/hr as at 16:30 March 15.
>
from
<http://www.world-nuclear-news.org/RS_Attempts_to_refill_fuel_ponds_1703111.html>
Radiation at site border
Despite high levels of radiation close to the units, levels detected at the
edge of the power plant site have been steadily decreasing.
17 March, 4.00pm
0.64 millisieverts per hour
17 March, 9.00am
1.47 millisieverts per hour
16 March, 7.00pm
1.93 millisieverts per hour
16 March, 12.30pm
3.39 millisieverts per hour
--
djc
The Natural Philosopher
down, pumps partially restored. Some leakage of steam probably still
accounting for radiation levels
Ponds remain a concern. Probably leaking, but now being refilled.
All over bar the shouting now. Unless they get a bad aftershock.
John Rumm
Yup you are missing a few bits... making a viable A bomb is actually
quite difficult (just as well, as otherwise every nutter with an axe to
grind would be at it).
It requires fuel enriched way beyond that used for basic power
generation (and normally plutonium rather than uranium), you need the
right amount of it, and you need some way to contain it in close enough
proximity while the chain reaction initiates through all the material.
(done with a high explosive charge to provide the implosion, containment
and initiation). Its also very difficult to prevent pre-initiation -
i.e. having the reaction start before you have managed to squash it
together and achieved the required density, which gives you something
that gets very hot, but does not actually go bang.
--
Cheers,
John.
/=================================================================\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\=================================================================/
Peter Scott
Thanks for clarifying that. Yes I can see that a sheet of fissile
material would behave differently from a sphere. However I do remember
hearing about the storage sheds at Los Alamos. They kept the material in
sheets on shelves. They found that the internal temperature was getting
even higher than you'd expect in a desert. One bright spark did some
sums and found that they were approaching criticality even with the sheets.
So the degree of spread of danger can be restricted by limiting the
energy in the steam and the quantity of hydrogen. That's a relief
because I know someone currently in Hong Kong and they are beginning to
be apprehensive, especially as the wind is currently from the north.
Dave Liquorice
> It's the fact that a molten fluid, flowing into your basement through
> the ceiling (if it's got that far), will not go any further. It spreads
> out and ceases to be critical.
As I understand it the underneath of these reactors is also packed
with graphite and excellent neutron moderator so not only is the
molten core, if it gets out of the steel pressure vessel, spread out
it is also surrounded by stuff to absorb neutrons. Then you have an
awful lot of concrete...
--
Cheers
Dave.
Grimly Curmudgeon
drugs began to take hold. I remember Peter Scott
<pe...@peter-scott.org.uk> saying something like:
>Sounds very informed and reassuring. There is one question that has not
>been touched on anywhere and perhaps could be answered here. For neutron
>emitters like uranium there is a critical mass. Once this is reached,
>enough of the neutrons are captured by other atoms to create runaway
>fission, in other words a bloody great bomb. I think this mass is about
>10 kg for uranium. There must be more than 10 kg in the reactor. So if
>it all melts and pools at the bottom won't it go bang? Am I missing
>something? Is it to do with lower enrichment of reactor fuel?
Reactor fuel is indeed much less enriched than military grade weapon
stuff, also simply letting a lot of it sit together won't result in a
bang (as discussed above, up there, somewhere), but a fizzle (I reckoned
a dirty pop, TNP reckoned a nasty phlumph), but inherently self-limiting
to a dirty event, but not a bang. A real bang requires enrichment and a
suitably long period of criticality, and a tamper to hold the bang in
for a few microseconds - all carefully and painstakingly arrived at by
thousands of scientists over a period of time for the first uranium bomb
(which was actually the test bomb of its type, as there wasn't enough
uranium to make a second one at the time).
Matty F
> However I do remember
> hearing about the storage sheds at Los Alamos. They kept the material in
> sheets on shelves. They found that the internal temperature was getting
> even higher than you'd expect in a desert. One bright spark did some
> sums and found that they were approaching criticality even with the sheets.
I believe it was the great Richard Feynman himself who worked out that
the stored material was in danger of becoming critical.
Andy Champ
interested).
It appears a Chinese power plant has caused the deaths of 26,000 people
(official figures - others range as high as 230,000) 145,000 died in
resulting famines and epidemics, and 768km^2 have been made completely
uninhabitable.
But that's OK, because the Banqiao Dam
http://en.wikipedia.org/wiki/Banqiao_Dam
wasn't nuclear.
Andy
Peter Scott
I didn't know that. I hope it was the smoking and not the alpha
particles that caused his death. That would be an awful irony.
Skipweasel
no....@nospam.invalid says...
> It appears a Chinese power plant has caused the deaths of 26,000 people
> (official figures - others range as high as 230,000) 145,000 died in
> resulting famines and epidemics, and 768km^2 have been made completely
> uninhabitable.
>
Where did you get the uninhabitable area from? The only referrence I can
find to that area is the catchment area - and not just on the Wikipedia
page, either.
Actually - it seems rather small for a catchment area - it's not even 20
miles on a side.
Bolted
wrote:
There is no core-catcher on these.
There do seem to be serious concerns (in the industry, not from anti-
nukers) about on BWRs with Mark 1 containment.
See e.g. this conclusion on p76 of this
http://www.nrc.gov/reading-rm/doc-collections/nuregs/contract/cr6920/cr6920.pdf
"A very important feature of these results is that there is a very
high probability of a melt-through
failure. The probability of an early melt-through failure given core
damage is roughly 36% for all
cases"
Or try this, hardly from an anti-nuker:
http://blogs.knoxnews.com/munger/2011/03/ex-sandia-engineer-talks-about.html.
I'm pro-nuke generally, but there seems to be a whole heap of
complacency about this on this NG.
Nightjar
It is what pushes the deaths per TWh for Hydro up from around 0.10 -
less than wind power - to 1.4.
Colin Bignell
Nightjar
Possibly because the reactors were shut down within minutes of the
earthquake and the problems they have had since are not related to a
possible core meltdown. Some fuel rods may have reached melting point
and some fuel rod casings almost certainly have, but that is quite
different.
Colin Bignell
The Natural Philosopher
Wait till they get started on windpower.
> Andy
Bolted
wrote:
> On 18/03/2011 22:52, Bolted wrote:
>
>
>
> > On Mar 17, 9:19 pm, "Dave Liquorice"<allsortsnotthis...@howhill.com>
> > wrote:
> >> On Thu, 17 Mar 2011 17:40:25 +0000, Tim Streater wrote:
> >>> It's the fact that a molten fluid, flowing into your basement through
> >>> the ceiling (if it's got that far), will not go any further. It spreads
> >>> out and ceases to be critical.
>
> >> As I understand it the underneath of these reactors is also packed
> >> with graphite and excellent neutron moderator so not only is the
> >> molten core, if it gets out of the steel pressure vessel, spread out
> >> it is also surrounded by stuff to absorb neutrons. Then you have an
> >> awful lot of concrete...
>
> > There is no core-catcher on these.
>
> > There do seem to be serious concerns (in the industry, not from anti-
> > nukers) about on BWRs with Mark 1 containment.
>
> > See e.g. this conclusion on p76 of this
>
> > "A very important feature of these results is that there is a very
> > high probability of a melt-through
> > failure. The probability of an early melt-through failure given core
> > damage is roughly 36% for all
> > cases"
>
> > Or try this, hardly from an anti-nuker:
>
>
> > I'm pro-nuke generally, but there seems to be a whole heap of
> > complacency about this on this NG.
>
> Possibly because the reactors were shut down within minutes of the
> earthquake and the problems they have had since are not related to a
> possible core meltdown. Some fuel rods may have reached melting point
> and some fuel rod casings almost certainly have, but that is quite
> different.
"Melt-down" is exactly what they are fighting to prevent (and
hopefully will).
Nightjar
Meltdown has various meanings, particularly when used by the media. What
they are trying to prevent now is overheating of fuel rods, which could
cause meltdown of the fuel rod casings (1200C) or meltdown of the fuel
pellets (2800C). The risk from those events is only the release of
radioactive materials.
What they are *not* fighting to prevent is a core meltdown. That ceased
to be a possibility as soon as the core went sub-critical, shortly after
the emergency systems were triggered by the earthquake. However, the
events at Three Mile Island, where there was a core meltdown, showed
that the core cooled rapidly and froze when it hit the steel containment
vessel and only melted through 5/8 inches of the 5 inch thick steel.
Colin Bignell
The Natural Philosopher
rods in the tanks will crack where they are exposed, and the steam
boiling off them may react with the casing to produce yet another
hydrogen explosion, that will carry bitts of actual core up into the
air. Not very far, but still not nioce.
Total meltdown, barring a second massive earthquake, is no longer even a
possibility.
So its nasty, but not Chernobyl nasty.
The key is getting the pond filled up as fast as possible, and trying to
collect the water that is presumably leaking out, and fixing those leaks.
As long as the restarted pumps stay going, the cores are actually now
under control.
Andy Champ
It's the size of the lake, now they've rebuilt the dam.
Andy
Skipweasel
> >> It appears a Chinese power plant has caused the deaths of 26,000 people
> >> (official figures - others range as high as 230,000) 145,000 died in
> >> resulting famines and epidemics, and 768km^2 have been made completely
> >> uninhabitable.
> >>
> >
> > Where did you get the uninhabitable area from? The only referrence I can
> > find to that area is the catchment area - and not just on the Wikipedia
> > page, either.
> >
> > Actually - it seems rather small for a catchment area - it's not even 20
> > miles on a side.
> >
>
> It's the size of the lake, now they've rebuilt the dam.
>
That wasn't how I read it - that's Wikipedia for you.
harry
wrote:
> Serious stuff.
>
> http://www.youtube.com/watch?v=rlZhUi1nhtE&feature=player_embedded
>
> International regulating bodied should be put in place right now. One with
> teeth.
You need to be desperate to believe anything on US news.
harry
>
> - Show quoted text -
Not possible.
The Natural Philosopher
10kg of depleted uranium is of course roughly what's in an anti-tank round.
Being mostly U238. Stable, not radioactive, but definitely bloody
poisonous and a heavy carcinogen.
Fuel rods are about 3.5% U235, natural uranium about 0.72%: Weapons
grade is about 90% U235
U 235 is about the only radiosotope that is sufficiently long lived to
exist still but still be active enough to do something useful with.
BUT to get a proper bang, it needs to be relatively pure. No reactor is
able to become an atomic bomb. At the worst they just get so hot that
molten crud drips out and - if its designed properly - spread out to be
thin enough to stop getting so warm.
Chernobyl is as bad as a reactor can possibly ever get. Fuel rods
cracked, melted and cores totally exposed, and a raging fire carrying
crap for a long long way.
That isn't going to happen in Japan. Short of a aircraft being flown
into the mess that's left. Or a few mortar rounds.
Skipweasel
timst...@waitrose.com says...
> Personally I read "768km^2 have been made completely uninhabitable" to
> mean the lake surface area. Why would it mean anything else?
Well - it seems a bit of an odd way to put it. Why not just say it's the
area of the lake? Saying "768km^2 have been made completely
uninhabitable." suggests that you could otherwise live on it, were it
not for something unusual that'd happened to it - like it's full of
rotting corpses?
Anyway - calling it the catchment area is just plain wrong - the
catchment area of a reservoir is that area which feeds it with runoff
water, which obviously includes the area of the lake itself, but also
any land this side of the watershed which is higher than the lake - at
least approximately.
And as for editing it - I don't have the correct figures, but whatever
number 768km² is, I'm fairly sure it ain't the catchment area.
Bolted
wrote:
No reason why you should believe me (or me you). This was
Beddingfield's description of the worst case scenario. Being in the
position he is, I think we can reasonably assume he would err on the
side of the conservative rather than the extreme in describing the
worst case.
"Let me now talk about what would be a reasonable worst case
scenario. If the Japanese fail to keep the reactors cool and fail to
keep the pressure in the containment vessels at an appropriate level,
you can get this, you know, the dramatic word “meltdown”. But what
does that actually mean? What a meltdown involves is the basic
reactor core melts, and as it melts, nuclear material will fall
through to the floor of the container. There it will react with
concrete and other materials … that is likely… remember this is the
reasonable worst case, we don’t think anything worse is going to
happen. In this reasonable worst case you get an explosion. You get
some radioactive material going up to about 500 metres up into the
air. Now, that’s really serious, but it’s serious again for the local
area. It’s not serious for elsewhere even if you get a combination of
that explosion it would only have nuclear material going in to the air
up to about 500 metres.".
I read that as being the same scenario as described by the ex-Sandia
engineer in the link I posted - who spent a good deal of his life
studying/modelling BWR incidents for the DoE.
> So its nasty, but not Chernobyl nasty.
Agreed. I suppose on the other hand the populations densities
wouldn't help if this one did escalate.
> The key is getting the pond filled up as fast as possible, and trying to
> collect the water that is presumably leaking out, and fixing those leaks.
That and the half-full reactor vessels
> As long as the restarted pumps stay going, the cores are actually now
> under control.
So they got 1 & 2 pumps going? Excellent. Last I heard was lunchtime
when they said they had the power to reactors 1 and 2, but no news on
whether the cooling circuits are still working.
The Natural Philosopher
> In article <timstreater-2478...@news.individual.net>,
> timst...@waitrose.com says...
>> Personally I read "768km^2 have been made completely uninhabitable" to
>> mean the lake surface area. Why would it mean anything else?
>
> Well - it seems a bit of an odd way to put it. Why not just say it's the
> area of the lake? Saying "768km^2 have been made completely
> uninhabitable." suggests that you could otherwise live on it, were it
> not for something unusual that'd happened to it - like it's full of
> rotting corpses?
>
Or water.
> Anyway - calling it the catchment area is just plain wrong - the
> catchment area of a reservoir is that area which feeds it with runoff
> water, which obviously includes the area of the lake itself, but also
> any land this side of the watershed which is higher than the lake - at
> least approximately.
>
> And as for editing it - I don't have the correct figures, but whatever
> number 768km² is, I'm fairly sure it ain't the catchment area.
>
768 sq km is maybe 100k by 7 km, which is probably the size of lake
Mead, behind the Hoover dam.
http://en.wikipedia.org/wiki/Lake_Mead
says its 600 plus sq km.
Not that it was, in that case, inhabitable before, really, although a
town is still there underneath the surface.
BUT the point is still to be made, that 'renewable energy' does in fact
drastically alter the landscape and land use. It has to because you need
massive installations to get any decent power out.
Hydro is *cost effective* when Nature has done most of the job for you,
its true, but it still leads to massive land changes.
>
Bolted
I'm not sure what distinction you are drawing between a core meltdown
and fuel rods melting down. A core meltdown is the fuel rods
melting. If you mean that the control rods are in, that becomes a bit
irrelevant once the rods are melted (although obviously it does a
great deal to stop it happening anywhere near so fast).
As to impossibility, that doesn't seem to be a very common view. It's
a worst case of course.
>However, the
> events at Three Mile Island, where there was a core meltdown, showed
> that the core cooled rapidly and froze when it hit the steel containment
> vessel and only melted through 5/8 inches of the 5 inch thick steel.
Different type of reactor with very different containment. Loads of
penetrations through the bottom of the reactor vessel on these unlike
TMI.
Read the links I posted (not from anti-nuke nutballs, but from
industry/US DoE), that was the point of the research reported in that
paper.
The Natural Philosopher
I think core temps are stable, or we would have heard. we know that
parts of the cores HAVE melted by the radioactivity signature of what
came out in the hydrogen explosions. In fact the hydrogen explosions
themselves were indicative that the cores had over heated BUT they are
not out of complete control.
And there is no evidence the primary containment is breached. Yes, they
will need to keep it all wet for a year or five, but finally they should
be able to strip the cores out of the containment and deal with them via
reprocessing.
How bad the mess inside the reactor vessels will turn out to be, will be
of considerable interest. It's not the sort of experiment anyone wants
to do, but its now been done, and will be valuable data.
But every day that goes by without another bang, or any sign of
increased radiation is another day the decay products are decaying..in a
sense its a race against time, and the more time goes by, the better
placed they are to say they are winning the race.
Bolted
> >> under control.
>
> > So they got 1 & 2 pumps going? Excellent. Last I heard was lunchtime
> > when they said they had the power to reactors 1 and 2, but no news on
> > whether the cooling circuits are still working.
>
> I think core temps are stable, or we would have heard.
Just checked IEAE site, who seem to be as good a source as any since
the Japanese clammed up and went into news management mode.
"Efforts to restore electrical power to the site continue. It is hoped
that power will be restored to Unit 2 today [Sat], which will then act
as a hub for restoring power to Unit 1. However, we do not know if the
water pumps have been damaged and if they will work when power is
restored."
That's gone back to tomorrow apparently.
Maybe you are thinking of 5 & 6, where they got a diesel generator
going the other day? Those were nice and cold and down for
maintenance but good that the pools will be getting water as they were
heating up too.
> we know that
> parts of the cores HAVE melted by the radioactivity signature of what
> came out in the hydrogen explosions. In fact the hydrogen explosions
> themselves were indicative that the cores had over heated BUT they are
> not out of complete control.
There are some who claim that the hydrogen was from a passivation
system and deny that it is a sign of the zircalloy going. I suspect
you can find people who deny there is a problem at all, probably not
far from here.
> And there is no evidence the primary containment is breached.
IAEA have the "containment intergrity" on 3 as "damage suspected",
unlike the others.
That's the one where the wet-well torus is thought to have popped.
> How bad the mess inside the reactor vessels will turn out to be, will be
> of considerable interest. It's not the sort of experiment anyone wants
> to do, but its now been done, and will be valuable data.
I hope you are right and it turns out that simple.
> But every day that goes by without another bang, or any sign of
> increased radiation is another day the decay products are decaying..in a
> sense its a race against time, and the more time goes by, the better
> placed they are to say they are winning the race.
True.
Skipweasel
timst...@waitrose.com says...
> > And as for editing it - I don't have the correct figures, but whatever
>
> I don't mean that either. I mean that if you think the way it read was
> wrong, alter the way it reads.
>
Yebbut...I can't be sure of how it /is/ supposed to read - just that the
way it currently reads doesn't seem right.
Nightjar
...
> I'm not sure what distinction you are drawing between a core meltdown
> and fuel rods melting down. A core meltdown is the fuel rods
> melting.
The point I am making is that the reactor cores at Fukushima are now
stable and being cooled by seawater injection. It is the fuel rods in
the spent fuel pools that have been causing concern as partial melting
of those (i.e. melting of any bits that stick out of the water) can lead
to a release of radiactive material and it has been difficult to replace
water being lost to evaporation. One of the emergency generators has now
been returned to working order and is being used to pump water
alternately into two of the pools.
...
>> However, the
>> events at Three Mile Island, where there was a core meltdown, showed
>> that the core cooled rapidly and froze when it hit the steel containment
>> vessel and only melted through 5/8 inches of the 5 inch thick steel.
>
> Different type of reactor with very different containment.
The first containment vessel is still a thick steel pressure vessel.
Colin Bignell
Tim Watts
> The first containment vessel is still a thick steel pressure vessel.
>
<pedant>
Technically the 2nd containment:
1st - zircon rod casings
2nd - SS vessel
3rd - Concrete enclosure
</pedant>
;->
--
Tim Watts
fred
wrote:
> On Thu, 17 Mar 2011 17:40:25 +0000, Tim Streater wrote:
> > It's the fact that a molten fluid, flowing into your basement through
> > the ceiling (if it's got that far), will not go any further. It spreads
> > out and ceases to be critical.
>
> As I understand it the underneath of these reactors is also packed
> with graphite and excellent neutron moderator so not only is the
> molten core, if it gets out of the steel pressure vessel, spread out
> it is also surrounded by stuff to absorb neutrons. Then you have an
> awful lot of concrete...
>
> Cheers
> Dave.
ISTR that the dire predictions made about the time of the Chernobyl
disaster turned out to be a load of bollix predicated as they were on
the aftermath of Nagaski and Horoshima. Fact is they were all ill
educated guesses.
Paul Mc Cann
John Rumm
> "Let me now talk about what would be a reasonable worst case
> scenario. If the Japanese fail to keep the reactors cool and fail to
> keep the pressure in the containment vessels at an appropriate level,
> you can get this, you know, the dramatic word “meltdown”. But what
> does that actually mean? What a meltdown involves is the basic
> reactor core melts, and as it melts, nuclear material will fall
> through to the floor of the container. There it will react with
> concrete and other materials … that is likely… remember this is the
I recall this being predicted when TMI suffered a total core meltdown.
In reality it seemed that as soon as the core made contact with the
primary containment, it was sufficiently cooled to only penetrate a very
short distance through it.
--
Cheers,
John.
/=================================================================\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\=================================================================/
Bolted
> On 19/03/2011 20:07, Bolted wrote:
>
> > "Let me now talk about what would be a reasonable worst case
> > scenario. If the Japanese fail to keep the reactors cool and fail to
> > keep the pressure in the containment vessels at an appropriate level,
> > you can get this, you know, the dramatic word meltdown . But what
> > does that actually mean? What a meltdown involves is the basic
> > reactor core melts, and as it melts, nuclear material will fall
> > through to the floor of the container. There it will react with
> > concrete and other materials that is likely remember this is the
>
> I recall this being predicted when TMI suffered a total core meltdown.
> In reality it seemed that as soon as the core made contact with the
> primary containment, it was sufficiently cooled to only penetrate a very
> short distance through it.
I haven't checked whether that Sandia National Labs research was pre
or post TMI, but the failure modes they predicted for BWRs couldn't
have happened to the TMI vessel. Sir John Beddingfield will be being
advised by the UK nuclear science establishment, so I think it is
reasonable to take his view of what was then (it being a few days ago
now) the worst case scenario as being something rather more well-
founded than you rather scornfully suggest. The last thing he was
engaged in at the time was fear-mongering - his task was the complete
opposite of that.
Andy Champ
> Sir John Beddingfield will be being
> advised by the UK nuclear science establishment
ITYM Prof. Sir John Beddington, FRS.
Andy
The Natural Philosopher
Some were very WELL educated guesses, but guesses they remained.
Basically we know the square root of fuck all about low level radiation.
We know that most people don't die of cancer with background radiation
of what is typically found naturally.
We know that in some parts of the world where its naturally a lot higher
people don't die much more, either.
We know that radon, especially in conjunction with smoking, is far more
likely to give you lung cancer than either by itself.. Suggesting that
how radioactive materials interact with the body is less than
straightforward.
We know how much radiation is guaranteed to kill 50% of people.
What we don't have a clue about, is in between.
Safety standards are based on drawing a straight line between the dose
we know will cause death and cancer, and an implied zero rate at zero
radiation. There is no justification for the line being straight, other
than it seems likely that, on account of us living with radiation
anyway, if it were much worse than that, we would all be dead anyway
from natural sources.
There is considerable and mounting evidence that in fact it may be much
BETTER than that, and that we can, up to a point, self repair ourselves
from radiation damage, as with any other damage due to infections.
Safety standards use that straight line, and say what is safe is
something that according to statistics based on it, shouldn't give rise
to more than one excess cancer per 10,000, 100,000 or whatever population.
So there are two assumptions here already.
1/. That death rates are a linear function of radiation levels.
2/. That anything that exceeds regulatory limits constitutes a serious
hazard to health.
Both are probably erroneous.
That doesn't stop Green piss et al from saying that 'Chernobyl will
cause a million deaths world wide' based on that straight line and the
assumption that its relevant and on some pretty back of envelope calcs
about what exposure will happen through the complex food chains.
A million extra cancer victims would be rather noticeable. No such spike
exists other than very local to the actual event in both time and place.
The Chernobyl case more gives the opposite impression, that below a
certain level of radiation, it had almost no effect on anyone.
In the early days of Motor Vehicles, they were restricted to 3mph and a
man with a red flag walked in front. They being deemed as new fangled
and dangerous.
Road traffic accidents in London peaked at the same time. They only
started to all when the motor vehicle replaced the horse drawn wagon or
cart or carriage as the dominant means of transport.
Cars have better brakes than horses.
> Paul Mc Cann
Bolted
I did indeed, but he's a biologist I think. So he will be being
advised etc.
Andy Dingley
> Technically the 2nd containment:
>
> 1st - zircon rod casings
Fuel elements aren't considered as containment (in naming terms at
least), because the major neutron flux is outside them, thus there is
secondary activation of materials outside the elements.
The Natural Philosopher
..otherwise they wouldn't be much use in a reactor, would they?
Tim Watts
I took it from that article that was linked to the other day whose URL I
have now forgotten! ;->
--
Tim Watts
Nightjar
I have also seen the fuel pellets classed as a form of containment in
some articles, which would make the steel shell the third level.
However, I did say containment vessel, which I think justifies classing
it as the first.
Colin Bignell
Dave Liquorice
>>> Fuel elements aren't considered as containment (in naming terms
at
>>> least), because the major neutron flux is outside them, thus
there is
>>> secondary activation of materials outside the elements.
>
> I have also seen the fuel pellets classed as a form of containment in
> some articles,
No that is really starting to push the definition of "containment". I
can half see a case for the rods being the first OK the rod casing
doesn't keep the neutrons in but it does keep the uranium and fission
products in.
Yep you wouldn't want to be close to a used fuel rod for very long,
preferably not all but that's from the radiation not from exposure to
toxic heavy metals.
--
Cheers
Dave.
tony sayer
>
>ISTR that the dire predictions made about the time of the Chernobyl
>disaster turned out to be a load of bollix predicated as they were on
>the aftermath of Nagaski and Horoshima. Fact is they were all ill
>educated guesses.
>
>Paul Mc Cann
If you want to see something <really> scary look up "The Forgotten Fallen" its
on iplayer for a few days yet. It documents One doctors struggle to contain the
Spanish Flu in Manchester, quite a simple illness apart from that this one
behaved rather strangely in that it picked the strongest among the population
and killed them horribly in a day or two.
Around 228,000 dead in the UK and around 70 Million world-wide and we still
don't know that much about how to treat it now;!...
Kicks the Nuclear issue into a cocked hat..
http://www.bbc.co.uk/iplayer/episode/b00lz31y/Spanish_Flu_The_Forgotten_Fallen/
Not for the squeamish among you, but very well made and historically of
interest..
--
Tony Sayer
The Natural Philosopher
For those that actually WANT to get a sense of perspective.
Dave Liquorice
> Around 228,000 dead in the UK and around 70 Million world-wide and we
> still don't know that much about how to treat it now;!...
Well we do, it's a strain influenza virus, we can develop a vacine
but that takes time. Time that the virus uses to spread and kill.
Why do you think the WHO are a bit jumpy about flu? Swine Flu was
nothing, it was reasonably similar to one from the 50's or 60's IIRC
so people older than about 50 had already seen it and had some
immunity. That's why Swine Flu tended to get the younger end of the
population.
A really new, virulant and nasty flu with todays rapid global
transport and much higher population densities could be a *very*
serious problem indeed. Taking wikipedias figures for infection rates
for Spanish Flu (25%) and death (3%) that would mean 450,000
additional deaths in the UK. Say over 6 months that's 2500/day above
normal. I very much doubt the conventional burial or cremation
services could cope, think mass graves.
Swine Flu has offically killed something over 14,000 *globally*. Real
figure will be higher but still well below an order of magnitude
smaller the above numbers for the UK alone.
--
Cheers
Dave.
tony sayer
Liquorice <allsortsn...@howhill.com> scribeth thus
>On Mon, 21 Mar 2011 10:29:30 +0000, tony sayer wrote:
>
>> Around 228,000 dead in the UK and around 70 Million world-wide and we
>> still don't know that much about how to treat it now;!...
>
>Well we do, it's a strain influenza virus, we can develop a vacine
>but that takes time. Time that the virus uses to spread and kill.
Yes we can, but as you say and also a hospital consultant neighbour sez
too. Notice I wrote "treat" not prevent, course a lot more is known as
to how it spreads nowadays but the prevention - that'll cause some
disruption;!
Course there will be a lot of infected people by then and if the same
"Cytokine storm" operates the outlook doesn't look -that- good.
Some reading here;!..
Interesting that some types of blood pressure meds -may- be usable;).
>
>Why do you think the WHO are a bit jumpy about flu? Swine Flu was
>nothing, it was reasonably similar to one from the 50's or 60's IIRC
>so people older than about 50 had already seen it and had some
>immunity. That's why Swine Flu tended to get the younger end of the
>population.
>
>A really new, virulant and nasty flu with todays rapid global
>transport and much higher population densities could be a *very*
>serious problem indeed.
Quite.. The right/or in this case wrong mutation/s..
>Taking wikipedias figures for infection rates
>for Spanish Flu (25%) and death (3%) that would mean 450,000
>additional deaths in the UK. Say over 6 months that's 2500/day above
>normal. I very much doubt the conventional burial or cremation
>services could cope, think mass graves.
A friend of mine who works for a local council told me once that they
have this in their planning manual;!..
>
>Swine Flu has offically killed something over 14,000 *globally*. Real
>figure will be higher but still well below an order of magnitude
>smaller the above numbers for the UK alone.
>
Yes makes the nuclear issue pale away into insignificance ..
--
Tony Sayer
Andy Dingley
> I have also seen the fuel pellets classed as a form of containment in
> some articles, which would make the steel shell the third level.
"Containment" is there to physically isolate Nasty Stuff from the
outside world.
It's not there to contain a neutron flux. That's the function of the
biological shield (sometimes one and the same structure).
Fuel element cans aren't considered containment, because the neutron
flux outside them is enough to activate materials outside the can,
either short-tem or long-term. These secondary materials still need to
be contained, but obviously the element cans would be no help for this.
tony sayer
<Hu...@nowhere.much.invalid> scribeth thus
>On 2011-03-21, Dave Liquorice <allsortsn...@howhill.com> wrote:
>
>> Why do you think the WHO are a bit jumpy about flu? Swine Flu was
>> nothing, it was reasonably similar to one from the 50's or 60's IIRC
>> so people older than about 50 had already seen it and had some
>> immunity. That's why Swine Flu tended to get the younger end of the
>> population.
>
>
>http://en.wikipedia.org/wiki/Cytokine_storm#Role_in_pandemic_deaths
>
As per below usually 25 to 30 odd year old adults with a good immune
system which is what did them in;(..
http://en.wikipedia.org/wiki/File:W_curve.png
--
Tony Sayer
Bolted
I note the French aren't dismissing a possibility of melt-through
quite as firmly as the experts on this thread:
"L’IRSN analyse les causes potentielles de défaillance du confinement
du réacteur n°3. Une des hypothèses
examinée par l’IRSN concerne l’éventualité d’une rupture de la cuve du
réacteur suivie d’une
interaction entre le corium (mélange de combustible et de métaux
fondus) et le béton au fond de
l’enceinte de confinement."