Disasters in Japan


The death toll is simply factual on the basis of people who died as a direct result of the initial explosion and subsequent sickness. The problem then is how many other conditions are attributed to the explosion and that's where it gets tricky. But based on epidemiological studies, the actual cancer rate and birth defect rate isn't actually any (or significantly greater) than the average.

As to the exclusion zone, it's still an exclusion zone because of the levels being significantly above recommended doses. However, the conflicting science is that even though the levels are so high, the area has effectively returned to nature and has an abundant wildlife. Even though when tested, the wildlife is massively radioactive, they still thrive seemingly without any significant illness, early death, birth defects etc. It's not conclusive, but the question is whether the science behind the permissable levels is 100% correct.

However, as with everything there's conflicting reports and my problem is that out of all the scientific reports very few are independent most are egregiously pro or anti nuclear power before they even begin. Chernobyl was bad, very bad, but it may not be as bad as it was first thought it could be. And that's about as much as you can say either way.

However, Japan will not have a Chernobyl explosion as it's a completely different type of station. It can't explode like Chernobyl and the explosions we are seeing is only to be expected but are hydrogen explosions. They are blowing off the shells of the buildings, but the reactor cores are well protected and are not being damaged (or so we're told). Besides, 3 Mile Island is the better analogy in this case.


Splitting hairs, but the ship was a tad closer, more like 100km. However, to give persepctive to the dose they received, while it sounds high, Astronauts get doses 10 times that every time they pass through the Earth's radiation belt and in the entire history of the space programme not one has become ill or suffered any ill health.

Any other nation and it's likely that the death toll would be in the hundreds of thousands rather than the thousands, Japan's committment to engineering in preparation has mitigated and much much worse disaster. Similarly, this nuclear powerstation is about 40 years old, the fact that there still hasn't been a meltdown after such an earth quake, tsunami and explosions is actually impressive and again shows the engineering that went on to make these stations as safe as is foreseeably possible.

While Sky News continue to look at each plume of smoke as if it were an atomic bomb and make wrong comparissons to Chernobyl, fear and panic will spread. No form of power generation is safe, look at what this thing has been hit with and it's still a more than good chance that the sea water cooling will work and the rods will cool safely.
 
Latrade said:
While Sky News continue to look at each plume of smoke as if it were an atomic bomb and make wrong comparissons to Chernobyl
Click to expand...

Agreed, as a rule I don't watch Sky News. Its the reason I got rid of cable TV.
 
Great post Latrade, and some interesting points that I had only heard as snippets on various news reports. What I think will be interesting is how the nuclear power debate will be affected. If, and lets hope this will be the case, the reactors are safely contained, then this should be a very good argument for the expansion of nuclear power generation.
What baffles me is the comments from protest organisers in Germany who are protesting at the Neckarwestheim power plant. I heard one of the organisers on Euro News last night question what would happen if the same thing that happened in Japan were to happen at that power plant. This is a power plant that is 600km from the sea, is not in an earth quake zone and got one of the best safety and operational certificates by the IAEA in 2007.
 
Some figures to try and make sense of the radiation levels:

After the second explosion the radiation levels went from 0.073 milliseverts(msv) to 11.9 msv in about 3 hours.

First thing to note is that many print media sources are quoting the figures in microseverts in order to make it look much greater (that'd be 73 micro sv going to 11,900 micro sv).

11.9 msv is still high enough to cause alarm, but not immediately for human health. The recommended annual maximum dose is 50 msv/year, but that doesn't mean if you're exposed to 51 msv you're doomed. That is based on those working daily in an environment where they will be exposed to ionising radiation, so effects can be cumulative. Therefore, a safe limit is given for day-to-day, repeated exposure.

One off doses of ionising radiation can obviously be fatal, but they would need to be at much higher levels than even 50 msv. So the comparissions to "month's dose" or "annual dose" give perspective, but don't mean you're about to die.

Some comparissons though at around the msv level:

Modern Chest Xray - 0.04 msv
Terrestrial background radiation - 0.28 msv/yr
Human Body - 0.4 msv/yr
Radon Gas - 2 msv/yr
Smoking (20 a day) - 13 msv/yr.

So the closest analogy to where the levels rose to after the second explosion is that while high, it was still less ionising radiation than someone who smokes 20 a day receives in a year. But then that analogy probably wouldn't cripple us with fear.
 

Even John Snow made the comment about how this "ends the Nuclear debate". I really like John, but that made me cringe (as did the BBC's ignorance of plate techtonics and asking whether global warming means more of these events).

Given how active the region is in Japan, given just how huge this event was and we still haven't had a meltdown shows how good engineering can be.

Even so this whole event could have been avoided, but that's with the benefit of hindsight. They expected to get more time out of the generators before any tsunami would hit. In fact they focussed too much on earthquake protection (as they happen a lot) and didn't really give enough attention to diesel generators working while swamped by a tsunami. The battery back ups weren't adequate (due to relying on other means) and when they did get additional generators in as the last fail safe, they had the wrong connections.

But then my memory is hazy of the last huge earthquake and tsunami to hit these shores.
 
Please explain how this is not going the way of Chernobyl? We're way beyond TMI as this stage.

With Chernobyl, the main explosion happened when they were try to insert the control rods, and they didn't have much in the way of containment.

Here we now have a fire in a spent fuel rods pool and multiple reactors in various degrees of meltdown. According to NHK, a rupture may have occurred inside the containment vessel at Fukushima's number two reactor. As the situation gets worse, it gets more difficult to deal with.
 

It won't be a Chernobyl for a few reasons, but mainly the design and build of the plant here means it won't get to the Chernobyl explosion.

I'm not saying the worst case scenario isn't serious, but it won't be an event like Chernobyl that's just how it is.

It looks like the some rods have lost their protective coating and if the sea water doesn't work, they'll overheat, the fuel will melt and could then melt through the floor and contaminate the ground. That's a meltdown, that's why it's comparable to 3 Mile Island. It will be serious ground contamination, but it won't lead to a massive radioactive cloud affecting spreading over a vast distance.

Chernobyl was a plant built on the cheap by USSR, it did not have the levels of protection put into this plant or 3 Mile Island, that's why Chernobyl went boom very quickly and 3 Mile Island had only a minor leak with no illness or injury and why several days into this event there is no meltdown (yet), only one employee with minor radiation sickness and only one fatality (which was caused by a crane and not the radiation) in Japan.
 
I understand that the reactors have different designs (negative void Vs positive void being the main one). However, you're not explaining how this can not turn into a Chernobyl type scenario. What is in the design that will make this different? I also understand one of the reactors in Japan was fuelled by MOX.

I didn't realise they had a full meltdown in TMI. They didn't even have a full meltdown (to the earth) in Chernobyl. See 'elephant's foot' footage to see how close they got.

Most of the immediate deaths in Chernobyl were not attributed to radiation, but the force of the explosion. It'll take at least a month before we see the death toll from acute radiation sickness in this case.

There is partial meltdown. The fuel rods have melted in at least one reactor.
 

The simplest design difference is the containment of the core. TMI and Fshima has them, Chernobyl didn't. At Chernobyl the core exploded before the full meltdown occurred. Given that this has been ongoing for a while, if we were to have a Chernobyl, it would have happened already.

TMI wasn't full meltdown, you're right, that's because, yet again, of the design of the plant which helped prevent this.

The levels of radiation released during Chernobyl at its peak was enough to kill you in 45 seconds of exposure. Radiation sickness is acute and so the effects are within a short space of time. A number of years ago there was amuch greater leak at a Japanese plant and several employees died within days of radiation sickness.

This situation could go very bad and into full meltdown, so saying it won't be a Chernobyl isn't downplaying the seriousness of it, it's just that the conditions and precautions at Chernobyl were a disgrace. Even though this plant is 40 years old, the designs (though not perfect seeing as generators failed) have mitigated against or at least hopefully delayed long enough to take action to mitigate against a full meltdown.

Also Chernobyl was complete and utter human failure and poor management of the plant. Here we're faced with one major natural disaster and we still have radiation levels significantly below safety limits.
 

Main design difference is positive/negative void coefficient. This is now largely irrelevant as we've past that stage when the whole cooling system broke down. As for the containment, well reactor two's containment is said to be breached. This is inner containment, not the outer building. Even more worrying is the spent fuel rods.

If someone was to stand next to reactor two right now, they would of course die pretty quickly, from extreme exposure. If you are interested in how low death from ARS takes, check Johnstons archive. For Chernobyl, it was up to about a month.

There wasn't a full meltdown in Chernobyl. Many people sacrificed themselves to stop this from happening. This was the main thing they were worried about - the core hitting groundwater. That could still happen here.
 
Hopefully the lack of core explosion will help to (relatively) contain the problem. Over the years I took an interest in the whole Chernobyl disaster as it was just one of those 'bane of childhood' type stories. In that instance the question was more "how could it not happen?" than "how could it happen?" I do think it's most impressive that the Japanese have kept the disaster at the level they have.

It does, however, prove once again that planning against all eventualities is something of a moot exercise. When you plan against the possible something 'impossible' happens.
 
Over the years I took an interest in the whole Chernobyl disaster as it was just one of those 'bane of childhood' type stories.
Click to expand...
I have too. A morbid fascination. Mayak also has some terrible stories.

Throughout this, every time I went to bed I would think that they would have it all under control by the morning. It seems to be getting worse each day. I really wish it were a TMI, when I think of the workers and their families.
 

I'm not entirely sure what this whole debate is about other than arguing for the sake of it. This situation is likely to be a much worse TMI and not a Chernobyl, that will mean some serious local harm, but not a radioactive gas cloud. The media report a Chernobyl like situation is a deliberate scare tactic and one coming from a position of ignorance. That is all that is being pointed out, not that the worstcase scenario isn't going to be serious or harmful, just that it will not be on the scale of Chernobyl.

At Chernobyl you had no containment, and a large reactor made out of graphite. For a number of days (maybe even weeks) the graphite was on fire pumping out as part of the smoke the radioactive isotopes that had built up during operation and the explosion. So, lack of containment, completely different construction, completely different operations such that the core just cannot burn like at Chernobyl mean it is extremely improbable that a Chernobyl-like explosion and radioactive gas cloud will occur to the extent that you can say we will not have an explosion like Chernobyl.

Instead we have a serious incident, where the longer it goes on without incident the better as the fuel will also be cooling naturally.

There are failures that need to be addressed, but it is a 40 year old design. The fact that it's even still standing after such a huge eathquake (it was designed to withstand many many magnitudes less) is a marvel in itself. The fact that even with the failures it could still turn out
 
This situation is likely to be a much worse TMI and not a Chernobyl, that will mean some serious local harm, but not a radioactive gas cloud.
Click to expand...
Why do you keep coming out with statements like this?
No one is going to know where this ends up. We'll know in a couple of months time maybe, but this is an on-going event.

What we do know is that it's already worse than TMI. Radiation levels are rising in Tokyo (that in itself would indicate some kind of radioactive cloud), and we have spent fuel rods on fire.

This is what is currently being reported.
 
umop3p!sdn said:
Why do you keep coming out with statements like this?
Click to expand...

Mainly because that's how it is. It'd be nice for the sake of controversy to ignore physics. Unfortunately it's a pesky bit of science that frequently gets in the way of fantasy and delusion.

How many more times though do I have to say that the situation is a concern? It is, the fire at plant 4 is a concern (seeing as it was supposed to not be operating), but then the misrepresentation from the media is frustrating.

Radiation levels are spiking at certain times (following planned steam release, explosions, leaks), but drop very quickly. That short life of the isotopes is a good thing, not just from the point of view of long term damage, but from the point of view of the source of the radiation.

Trying to get through the scant information is hard enough without inaccurate media reporting. I don't get how people can slam the media reporting of swime flu and/or global warming as being deliberately inaccurate and panic-based yet expect this set of circumstances to be any different or that the media has suddenly turned to accurate reporting of science.
 
Mainly because that's how it is. It'd be nice for the sake of controversy to ignore physics. Unfortunately it's a pesky bit of science that frequently gets in the way of fantasy and delusion.
Click to expand...

We've heard so many times since Chernobyl that such accidents could never happen again, because of different design. Now, here we are with this, but this time with four potential meltdowns and burning fuel rods. That to me, that is the result of people 'ignoring physics', or letting 'pesky science' (or money) get in the way.
 

How? It was a plant designed and built 40 years ago. It wasn't designed to cope with both a scale 9.0 earthquake and size of tsunami (in terms of probability both together would be considered a 1 in 1000 year event). No plant anywhere, nuclear or otherwise is designed to survive in that scale of event largely because to insist on such would mean just no building anything.

But again, this is plant built before the chernobyl disaster and it has currently survived with limited release an earthquake many many times its design spec. If that's what could be done 40 years ago, imagine how well engineered modern plants are.

If it had been a chemical plant at that location, we'd have a different disaster to deal with and possibly greater disaster. If it had been an oil refinery, ditto. It just happens to be a nuclear power plant.

We have a handful of nuclear power "big" events. Three attributed to human failure (Windscale, TMI, Chernobyl). TMI shows how engineering actually averted a disaster. Chernobyl shows how lack of engineering and short cuts creates a disaster. Windscale shows how you just change the name of the plant to pretend it never happened.

This event was as a result of the 5th worse earthquake ever recorded on the planet. The biggest failure is the failure to plan for the unprecedented and unforeseeable.
 
Latrade said:
It wasn't designed to cope with both a scale 9.0 earthquake and size of tsunami (in terms of probability both together would be considered a 1 in 1000 year event).
Click to expand...

But dont earthquakes and tsunami go hand in hand - especially in the Pacific where the fault lines are mainly under the sea. Wouldnt building it on high ground protect from tsunami (as opposed to practically on the beach). Ok you'd have to move stuff up the hill from the ships but worth the hassle.
 

Yes and yes. But other issues play a part in the location of the plant. Again though, the extent and scale of the disaster is huge, really huge. It's difficult to build anything that would withstand that. Is that an argument against nuclear power? Maybe in areas of such a high risk of tectonic activity, but not against the whole industry.

There are refineries further inland that are on fire, still. There are chemical plants (a lead acid battery manufacturer) that have suffered massive structural damage and now have huge health and environmental concerns. All of these plants were designed to withstand earthquakes and tsunamis, just not one this big. But we don't hear for calls to have all refineries closed of chemical plants.
 
You must log in or register to reply here.
Menu
Log in
Register