British Take on the Crisis
On the British Tokyo Embassy’s web site, they have posted a Q&A with Chief Scientific Officer Professor John Beddington. Below is his take on a “reasonable worst case scenario.” It was one big chunk in the original article, so I have divided it into more easily readable paragraphs.
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.
If you then couple that with the worst possible weather situation i.e. prevailing weather taking radioactive material in the direction of Greater Tokyo and you had maybe rainfall which would bring the radioactive material down do we have a problem?
The answer is unequivocally no. Absolutely no issue. The problems are within 30 km of the reactor. And to give you a flavour for that, when Chernobyl had a massive fire at the graphite core, material was going up not just 500 metres but to 30,000 feet. It was lasting not for the odd hour or so but lasted months, and that was putting nuclear radioactive material up into the upper atmosphere for a very long period of time.
But even in the case of Chernobyl, the exclusion zone that they had was about 30 kilometres. And in that exclusion zone, outside that, there is no evidence whatsoever to indicate people had problems from the radiation. The problems with Chernobyl were people were continuing to drink the water, continuing to eat vegetables and so on and that was where the problems came from. That’s not going to be the case here.
So what I would really re-emphasise is that this is very problematic for the area and the immediate vicinity and one has to have concerns for the people working there. Beyond that 20 or 30 kilometres, it’s really not an issue for health.
You’ll want to read the rest of the press conference, he says other things as well–but essentially, he sees worst-case as being not disastrous outside the local area.
Thoughts?
Hi, Luis — thank you for the very calm, balanced, objective posts on this blog. The messages we are seeing on the media are far more spectacularized & alarmist. Thank you for putting things in perspecive and giving us an insider’s view of the events unfolding. You continue to be in our prayers. Please let us know if / when / how we can help in tangible ways.
>If the Japanese fail to keep the reactors cool and fail to keep the pressure in the containment vessels at an appropriate level
Two of the three containment vessels with cores active on Friday are already breached at the steam suppression pool level.
These cores have also suffered some degree of damage, having lost coolant for hours already.
This means seawater injections into the primary reactor vessel will emerge as unfiltered radioactive steam somewhere in the reactor building.
Seawater is not ideal for this since the minerals in it also become radiological emitters.
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 is also possible for a meltdown to just steam and smoke for some period of time. THIS is the worst-case scenario, a steady plume of crap being carried towards Kanto by spring winds.
Most of it will drop out in Fukushima, and other neighboring provinces, and I don’t know how much will make it to Tokyo.
This is the word we don’t want to see next week — “plume”.
and you had maybe rainfall which would bring the radioactive material down do we have a problem?
WTF is this, special pleading? Plus the plume dropping out will still wipe out all agriculture wherever it hits. The Japanese are very picky about their food.
But even in the case of Chernobyl, the exclusion zone that they had was about 30 kilometres. And in that exclusion zone, outside that, there is no evidence whatsoever to indicate people had problems from the radiation.
This guy is another clown.
http://en.wikipedia.org/wiki/File:Chernobyl_radiation_map_1996.svg
Beyond that 20 or 30 kilometres, it’s really not an issue for health.
While I agree current conditions agree with this state now, the situation is far, far from turning any corners.
The water dropping was abandoned as the joke it was so now things depend on the ground crews getting close enough with their cannons.
I have hopes that 5 & 6 won’t join the party, but 1 through 4 all have deeply concerning issues still. The SDF just contradicted the US guy about lack of coolant in #4’s spent fuel pool, but earlier this week they released temperatures of that pool hitting 86 degrees. Plus it has TONS of stuff in it, including the full reactor assembly that was apparently removed late last year.
The information and press conferences coming out of this event has been a joke. Thereporters are asking stupid questions and the officials are being evasive.
There’s been nothing realtime and I think tons of things are being withheld (or I’m not finding the right places to find new information).
I have not seen any studies that talk about what happens when a BWR core melts through the metal vessel. However, I am sure that looking at this is a big part of reactor design. I did listen to one interview today by a nuclear engineer that talked about how the geometry & components of a liquid core effects what it does during meltdown. If one gets alot of uranium mass in a small volume (e.g. several hundred kg in a bucket), then it will go critical and start to heat up. Yet then it would break appart as it did this, and become less hot. The explosion thing mentioned by the British fellow might refer to a cement containment structure under pressure and exploding due to the pressure. Yet if one released the pressure w/ a valve, then it might not explode. I would think that an 500m explosion would be one of a possible number of scenarios.
Troy:
Here’s an article I am sure you’ll agree with.
Now the workers are paying the price. Kinda makes you want to draft a law saying that the first ones to go in and absorb high radiation levels are the executives making these decisions…
yeah, it’s not just TEPCO or the Japanese, it’s human nature.
NASA lost two shuttles in two events that were basically engineering failures.
I forget if I mentioned it here but I think the “old” “bad” TEPCO was the one who put this plant where it is without fully thinking things through about the tsunami risk.
The very word tsunami in Japanese minimizes the true potential. I do wonder if the Indonesian tsunami woke anybody up to the potential of a subduction slip to really move a lot of water in an event that in no way is a mere ‘harbor wave’.
http://en.wikipedia.org/wiki/869_Sanriku_earthquake_and_tsunami
is interesting.
TEPCO didn’t bother to retrofit hydrogen igniters in their plants. This sloppiness is probably an institutional unwillingness to admit any weakness in existing plants.
This same thing probably kept them from hardening the Fukushima plant against the Indonesian-scale tsunami they just got.
Thing is, the very design of the plant was fatally flawed, with the emergency generators and electrical switching room very vulnerable to flooding.
A responsible engineering response would be to figure out a backup power plan, but maybe the 6 years since the Indonesian event wasn’t enough time to get it through the process.
Then again, maybe TEPCO people figured if they’ve survived 1240 years, getting through another 20-30 until retirement is easy enough.
I knew they were going to cancel the ground cannon operation.
This would be a “giri giri” thing if there were only 1 reactor having problems.
To have all four in a line going out of control is just insane.
The core damage means the first line of containment was lost — the fuel rod lining.
Reactors 2 & 3 lost full containment and thus are dumping radiation with every steam vent they have to do.
Reactor 4 has its own problems with all the fissile material they were storing in the spent fuel pool.
They say the ground radiation in front of Unit 1 is 3 millisevierts/hr and thanks to the big hill behind the row of reactors the pump trucks have to approach and leave this way.
They’re not apparently saying what the radiation in front of 2 is but it can’t be good. Trucks also have to pass this unit to get close enough to 3.
Or they could try going by 4, but 4 has the most fissile material to worry about.
They started a new ground attempt with SDF vehicles.
The worst would be if these chopper and truck missions prove to be “photo ops” for the media while endangering personnel.
I still hope for power line news and stand-by generators on Friday.
Less than 40 minutes then aborted. 40 tons of water sprayed. Hmm.
Why doesn’t the professor talk about the
http://en.wikipedia.org/wiki/Spent_fuel_pool
I couldn’t find a single line on this.
The pools have little or no water left and there is no containment at all. They are in the air.
As troy mentioned, there needs to be 100+ tons of water.
Hopefully Friday brings better news.
Each pool needs 2000 tons for full coverage.
We know of two pools in trouble.
TEPCO’s evidence that pool 4 has water is really dubious if the picture they’re showing on the news is that evidence.
They’re not saying what’s happening in 1, 2, 5, 6 any more, though the 5 & 6 reactors may pull through this still since they still have their generator and stuff.
Radiation at the main office building is 3.6mSv, and they’re 100m upwind from reactor 1 (as long as the wind stays from the west).
Radiation 20m from the plant might be 1Sv, dunno, TEPCO isn’t saying and the press is too stupid to ask.
@Z
A big question – do the spent fuel pools have MOX fuel rods in them ?
This article
says #3 started MOX just last September, and wikipedia says refueling is done every year or so.
Here is a good article on the spent fuel pools:
http://allthingsnuclear.org/post/3892719255/spent-fuel-pools-at-fukushima
Japanese media is slowly catching up on this danger after the water operations today.
Again, the British super-expert does not mention these pools problems once as far as I could see.
@rockhead. Apparently reactor 3 does, but I have no detailed information. I don’t want to spread rumors.
But there simply wasn’t enough media coverage in Japan about the growing danger of these spent fuel pools.
Why talk about containments and potential small cracks when there are spent fuel pools with no or very little water left.
I was glad the US concerns and media coverage brought up the issue.
OK, this sounds good, but it doesn’t seem to be getting much play in terms of being really good:
The Tokyo Electric Power Company (Tepco), which runs the plant, has been attempting to connect it to the main grid via a 1-km (0.6-mile) electricity cable. Once power is restored, engineers should be able to re-activate the pumps which send coolant through the reactors and the pools where spent fuel rods are stored.
I’ve heard about these power lines being restored for a bit now. When it is mentioned, though, it is not mentioned in the context of really fixing anything. So, is this a actually good thing? Or in fact useless in some way? Are the pumps maybe damaged, or would be ineffective?
The control rooms could use power no doubt, and it’s an important baseline to get more (new) pumps going since they can’t keep bringing in fuel.
I guess the first priority is just getting water into those pools.
Keeping the 1,2,3 cores from melting down may not be in the cards any more, so we’ll finally get to see how well Mark I GE containers contain one.
5 & 6 still don’t have power now so getting that situation under control would be good. The pools were 65 degrees at the last report I saw.
According to Kyodo News:
NEWS ADVISORY: Electricity restoration for No. 3, No.4 reactors eyed for Sun.: nuke agency
Take for what’s it’s worth, situation might change any minute. But at least a date is given.
I feel for the employees checking the grid and installing the new system under these radiation levels.