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

Guy on the radio this morning (Sir Richard Beddington I think, UK govt chief scientific advisor) was playing down the seriousness of all this, but he kept talking about the "reasonable worst-case". I want to know what the unreasonable worst-case scenario is now. I'm entirely sure I trust the Japanese authorities to be transparent enough about what's going on.
 
Worst case scenario is chernobyl again, which would be devestating for Japan as its a small country, and with wind shifting direction inland could have huge consequences on locations like Tokyo, it will certainly have a large impact on production so expect electronics to rocket in price.
 
From all accounts this cant be another chernobyl, the reactor designs are totally different. This is more akin to the bottom falling out a kettle if the material becomes molten, chernobyl was like the top blowing off a kettle sending a massive explosion into the air.

I believe the core material is different to the one used in chernobyl, so an explosion the likes of chernobyl wouldnt happen.

This doesnt stop there being a massive amount of radiation locally and it seeping into the ground and water table though.

It could mean that the surrounding area will become an exclusion zone much like the area around chernobyl due to extreme radiation exposure.
 
Defiant306 said:
From all accounts this cant be another chernobyl

It could mean that the surrounding area will become an exclusion zone much like the area around chernobyl due to extreme radiation exposure.
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Different scenario, same result though isn't it? which to me makes it a possibility of another chernobyl.
 
Yeah when i said Chernobyl i meant the masses of radiation contaminating the environment, which due to the size of Japan would be a bad thing, bare in mind also that the plant is on the coast line so the water would also be contaminated and that is bad as water doesnt stay put!
 
This is turning into a real disaster.

And from day 1, I've listened to numerous so called Nuclear power experts in the UK saying...... "the Japanese reactors are well prepared for these eventualities"...."the fuel rods are secure and cooled & they know what to do if they are exposed etc"

And even last night on the 10 o'clock news, yet another expert was spouting something along the lines of "there's no risk of fire" - and yet 6 hours later theres another explosion and a fire.

Why didn't the Japanese just admit the seriousness of the damage from the start, and our "experts" just keep their mouths shut until they knew exactly what was going on over there ?
 
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PASONIX said:
This is turning into a real disaster.

And from day 1, I've listened to numerous so called Nuclear power experts saying...... "the Japanese reactors are well prepared for these eventualities"...."the fuel rods are secure and cooled & they know what to do if they are exposed etc"

And even last night on the 10 o'clock news, yet another expert was spouting something along the lines of "there's no risk of fire" - and yet 6 hours later theres another explosion and a fire.

Why didn't they just admit the seriousness of the damage from the start, and get some major support in there ?
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Makes them all look like they have no idea what they are talking about, and seeing as they are "experts" it doesn't give us a lot of hope in future accidents. The lieing only fuels the motors behind the anti-nuclear power protestors.
 
They may well be prepaired for cooling it, but if the cooling systems fail as they have, what are they to do then.

I think anymore damage to the reactors and its game over, at the moment they have 3 reactors that are badly damaged with cooling systems that have either completely failed or not functioning correctly, something is going to give and if one reactor goes the levels of radiation will be so high and dangerous no one will be able to secure the others and armageddon will ensue!
 
Maximum Triceratops said:
Sorry if I have missed something here but does it not seem a little foolish in the first place building nuclear powerstations in an area so prone to earthquakes?
Awful situation and I hope it is not as serious as it seems
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the earth quake was not the issue, had it jsut been an eq they would have been fine...

the lack of power once the generators were washed away by the wave is where things started to go wrong...
 
A PDF has been going round work which contains the design of the GE BWR reactor and details its cooling and protection systems, interesting read, i will try and upload some screen captures today.

I'm not that up on the Nuclear side of our business but we have about 20 guys hear who vary from plant design / commissioning / control systems and finally 8 ex submariners who all specilised in reactor safety and maintenance of the subs whilst at sea.

Things are looking much more serious this morning, i feel very sorry for all those in Japan right now.
 
MadMossy said:
They may well be prepaired for cooling it, but if the cooling systems fail as they have, what are they to do then.

I think anymore damage to the reactors and its game over, at the moment they have 3 reactors that are badly damaged with cooling systems that have either completely failed or not functioning correctly, something is going to give and if one reactor goes the levels of radiation will be so high and dangerous no one will be able to secure the others and armageddon will ensue!
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Well, except of course that it won't, and this is hyperbolic drivel.

Let's get some perspective, firstly, no matter what happens, this situation cannot turn into a chernobyl, the conditions, reactor type, use of containment and so on prevent it. The worst case scenario (which may have already happened according to reports this morning) is that the containment unit of the reactor, or one of the fuel cooling ponds is breached.

Radiation levels this morning have been measured at around 400mSV, which is over the recommended exposure level, but still not that high. Again, for some perspective, the radiation levels around the chernobyl reactor were measured somewhere in the region of 3500-4000SV. So we are currently looking at several orders of magnitude difference, and that isn't likely to change that much. The affected area is also a lot smaller, because what caused the massive spread of radiation was a fire in the graphite reactor at Chernobyl, with radioactive particles carried up into the atmosphere and spread. There is little to no flammable material in the a BWR.

Finally, again for some perspective, Chernobyl is expected to be attributable to around 4000 deaths. (source) When compared to the tsunami impact, with potentially 10,000 people killed in some coastal cities alone, the deaths attributable to a full scale core breach in Japan are barely going to register.

To be honest, the mass focus on the nuclear issue, which is largely under control and just actually shows how safe nuclear power really is, when tens of thousands are still missing, and countless devastation has been laid on a whole variety of infrastructure, is starting to get to me now... The heartlessness of people trying to exploit the situation with regards to nuclear power is pretty foul.
 
edscdk said:
the earth quake was not the issue, had it jsut been an eq they would have been fine...

the lack of power once the generators were washed away by the wave is where things started to go wrong...
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And, vitally importantly, a 40 year old reactor with no passive cooling. If this had been a modern reactor, it wouldn't have mattered if the active cooling systems failed...
 
Few words on the containment measures:

Boiling Water Reactor Containments
The primary containment package provided for a particular product line is dependent upon the vintage
of the plant and the cost-benefit analysis performed prior to the plant being built. During the evolution
of the boiling water reactors, three major types of containments were built. The major containment
designs are the Mark I (page 3-16), Mark II (page 3-17), and the Mark III (page 3-18). Unlike the Mark
III, that consists of a primary containment and a drywell, the Mark I and Mark II designs consist of a
drywell and a wetwell (suppression pool). All three containment designs use the principle of pressure
suppression for loss of coolant accidents. The primary containment is designed to condense steam and
to contain fission products released from a loss of coolant accident so that offsite radiation doses
specified in 10 CFR 100 are not exceeded and to provide a heat sink and water source for certain safetyrelated
equipment.
The Mark I containment design consists of several major components, many of which can be seen on
page 3-16. These major components include:
• The drywell, which surrounds the reactor vessel and recirculation loops,
• A suppression chamber, which stores a large body of water (suppression pool),
• An interconnecting vent network between the drywell and the suppression chamber, and
• The secondary containment, which surrounds the primary containment (drywell and suppression
pool) and houses the spent fuel pool and emergency core cooling systems.
The Mark II primary containment consists of a steel dome head and either a post-tensioned concrete wall
or reinforced concrete wall standing on a base mat of reinforced concrete. The inner surface of the
containment is lined with a steel plate that acts as a leak-tight membrane. The containment wall also
serves as a support for the floor slabs of the reactor building (secondary containment) and the refueling
pools. The Mark II design is an over-under configuration. The drywell, in the form of a frustum of a
cone or a truncated cone, is located directly above the suppression pool. The suppression chamber is
cylindrical and separated from the drywell by a reinforced concrete slab. The drywell is topped by an
elliptical steel dome called a drywell head. The drywell inerted atmosphere is vented into the
suppression chamber through as series of downcomer pipes penetrating and supported by the drywell
floor.
The Mark III primary containment consists of several major components, many of which can be seen on
page 3-18. The drywell (13) is a cylindrical, reinforced concrete structure with a removable head. The
drywell is designed to withstand and confine steam generated during a pipe rupture inside the
containment and to channel the released steam into the suppression pool (10) via the weir wall (11) and
the horizontal vents (12). The suppression pool contains a large volume of water for rapidly condensing
steam directed to it. A leak tight, cylindrical, steel containment vessel (2) surround the drywell and the
suppression pool to prevent gaseous and particulate fission products from escaping to the environment
following a pipe break inside containment.
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gebwr1.png
 
Firestar_3x said:
A PDF has been going round work which contains the design of the GE BWR reactor and details its cooling and protection systems, interesting read, i will try and upload some screen captures today.

I'm not that up on the Nuclear side of our business but we have about 20 guys hear who vary from plant design / commissioning / control systems and finally 8 ex submariners who all specilised in reactor safety and maintenance of the subs whilst at sea.

Things are looking much more serious this morning, i feel very sorry for all those in Japan right now.
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I don't suppose it's a publically available document, if so, e-mail in trust :D:D:D

Not good to hear.

Dolph said:
Let's get some perspective, firstly, no matter what happens, this situation cannot turn into a chernobyl, the conditions, reactor type, use of containment and so on prevent it. The worst case scenario (which may have already happened according to reports this morning) is that the containment unit of the reactor, or one of the fuel cooling ponds is breached.
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Exactly, people 'thinking' it can happen is complete rubbish the reactor desgin are completely different and as already mentioned previously in the thread Chernobyl involved a huge explosion taking the whole damn roof off. This will not happen here. Let's hope the contaeinment vessels hold!
 
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