Worst possible Fukushima disaster?

Telegraph said:
Japan's prime minister at the time of the 2011 earthquake and tsunami has revealed that the country came within a “paper-thin margin” of a nuclear disaster requiring the evacuation of 50 million people.

In an interview with The Telegraph to mark the fifth anniversary of the tragedy, Naoto Kan described the panic and disarray at the highest levels of the Japanese government as it fought to control multiple meltdowns at the crippled Fukushima Daiichi nuclear power station.

He said he considered evacuating the capital, Tokyo, along with all other areas within 160 miles of the plant, and declaring martial law. “The future existence of Japan as a whole was at stake,” he said. “Something on that scale, an evacuation of 50 million, it would have been like a losing a huge war.”

The rest of the article.

I'm not a nuclear engineer, so I can't vouch for this article. How accurate is it? Could it really have been so catastrophic?
 
It might be possible but seems bit implausible. OTL Fukushima was probably about so bad as it could have been with most plausible scenario.
 
So far i know Japan escape a worst scenario just by months

Tepco started at Fukushima Daiichi nuclear plant a refueling of the reactors with MOX fuel
MOX is salvage plutonium blended with natural uranium, reprocessed uranium, or depleted uranium.
It a way to get rid of nuclear waste by salvage it and "burn" it in nuclear reactor
Imagine those 4 reactors spitting out plutonium over west Japan like in Chernobyl...
 
Imagine those 4 reactors spitting out plutonium over west Japan like in Chernobyl...
So what? Plutonium's worse than Uranium, but that isn't saying much - uranium at the enrichment levels in these reactors is safe enough to use as a doorstop so long as you keep it sub-critical! The real issue are the decay products, and they're about as bad for Uranium and for Plutonium, both being millions of times worse than the fuel.
Actually, a plant which had recently been refuelled with MOX would be vastly safer than one which had been using enriched uranium for a number of years and was now due for refuelling - fresh fuel contains the minimum quantity of the dangerous decay products, while fully burned-up fuel contains the maximum of decay products and so is the most dangerous.

Still, for the great unwashed Plutonium = Nuclear Weapons = DANGER!!!!!!!: in reality the radiation dose rate level set for Fukushima would make commercial air travel illegal and force the UK to evacuate the whole of Cornwall. Given their history the Japanese sensitivity to radiation is understandable, but by any reading of the statistics it is clear that the Fukushima evacuation has killed far more people than it has saved. There are some small areas that are dangerous, but overwhelmingly the real risk stops at the plant fence.
 
Still, for the great unwashed Plutonium = Nuclear Weapons = DANGER!!!!!!!: in reality the radiation dose rate level set for Fukushima would make commercial air travel illegal and force the UK to evacuate the whole of Cornwall. Given their history the Japanese sensitivity to radiation is understandable, but by any reading of the statistics it is clear that the Fukushima evacuation has killed far more people than it has saved. There are some small areas that are dangerous, but overwhelmingly the real risk stops at the plant fence.
ISTR that someone calculated that if you applied the premature mortality rates corresponding to the Fukushima exclusion zone, virtually the entire population of China was living in areas made uninhabitable by coal fumes.
 
It might be possible but seems bit implausible. OTL Fukushima was probably about so bad as it could have been with most plausible scenario.

Agreed. "Being hit by an earthquake and tsunami" doesn't get much worse. It seems to me wrong that virtually all the public comment and discussion is about the nuclear aspect, and the possible increase in cancers resulting, almost entirely forgetting that more than 18,000 people definitely died in the tsunami. But mentioning 'Fukushima' is instant shorthand for "dangers of nuclear power" for the current generation just as "Chernobyl" was in the 80s.
 
Plutonium

Plutonium is deadly stuff if it gets into the body, because it can concentrate in the bone marrow; plutonium is, as far as I know, significantly more dangerous than uranium. I don't know if a release would be in a form that can move into the body, but if it can, it's bad news indeed.
 
Plutonium is deadly stuff if it gets into the body, because it can concentrate in the bone marrow; plutonium is, as far as I know, significantly more dangerous than uranium. I don't know if a release would be in a form that can move into the body, but if it can, it's bad news indeed.

Plutonium is deadly but a lot of other things are even more deadly including arsenic and caffeine.
 
So what? Plutonium's worse than Uranium, but that isn't saying much - uranium at the enrichment levels in these reactors is safe enough to use as a doorstop so long as you keep it sub-critical! The real issue are the decay products, and they're about as bad for Uranium and for Plutonium, both being millions of times worse than the fuel.
Actually, a plant which had recently been refuelled with MOX would be vastly safer than one which had been using enriched uranium for a number of years and was now due for refuelling - fresh fuel contains the minimum quantity of the dangerous decay products, while fully burned-up fuel contains the maximum of decay products and so is the most dangerous.

Still, for the great unwashed Plutonium = Nuclear Weapons = DANGER!!!!!!!: in reality the radiation dose rate level set for Fukushima would make commercial air travel illegal and force the UK to evacuate the whole of Cornwall. Given their history the Japanese sensitivity to radiation is understandable, but by any reading of the statistics it is clear that the Fukushima evacuation has killed far more people than it has saved. There are some small areas that are dangerous, but overwhelmingly the real risk stops at the plant fence.

As far as we can tell no one actually died from the accident Fukushima Accident and probably no one ever will. It takes about 10 Rem of radiation to have a noticeable effect on human health. At that level it increases your chance of getting cancer in your lifetime from about 4000 out of 10,000 to 40001 in 10,000. In any case it is a far safer source of energy than coal, oil, or natural gas and either solar or wind per unit of energy.
 
Plutonium is deadly stuff if it gets into the body, because it can concentrate in the bone marrow; plutonium is, as far as I know, significantly more dangerous than uranium. I don't know if a release would be in a form that can move into the body, but if it can, it's bad news indeed.

My training in this subject is in weapons use contamination, & I'm not suposed to talk about that. As NHBL wrote the serious problem is not the increase in local background or ambient radiation, but in ingesting fragments (dust particles). As with so many toxins long term and cumalative effects make many of the 'safe exposure' guidelines problematic. This is compounded by large holes in the research of long term exposure effects.
 
My training in this subject is in weapons use contamination, & I'm not suposed to talk about that. As NHBL wrote the serious problem is not the increase in local background or ambient radiation, but in ingesting fragments (dust particles). As with so many toxins long term and cumalative effects make many of the 'safe exposure' guidelines problematic. This is compounded by large holes in the research of long term exposure effects.

Along with many other contaminants that don't render people panic stricken.
 
As far as we can tell no one actually died from the accident Fukushima Accident and probably no one ever will. It takes about 10 Rem of radiation to have a noticeable effect on human health. At that level it increases your chance of getting cancer in your lifetime from about 4000 out of 10,000 to 40001 in 10,000. In any case it is a far safer source of energy than coal, oil, or natural gas and either solar or wind per unit of energy.
Well, probably - the issue is that at low doses we're relying on the Linear No-Threshold model, and if there's one thing we know reliably about that particular model it's that it is total bollocks. Personally I suspect that the people supporting the Radiation Hormesis theory have an axe to grind, but the evidence that low doses are not as dangerous as the LNT model would predict is pretty persuasive.
The fundamental problem is that we have two good data points for radiation exposure: Hiroshima and Nagasaki. For high doses and fast dose rates they actually give us really good data, but for lower dose rates the risk is small enough we can't reliably measure it.
And there were a significant number of fatalities at Fukushima - two plant workers died of multiple injuries in the Tsunami, and around 60 were killed by the evacuation itself, with several hundred dying of related causes since. A further two workers have been killed by their protective gear (heart failure in elderly workers).
There almost certainly will be radiation-induced casualties in the years to come, but we'll never know for sure who or even how many - best estimates are around 100, of whom about 10 will be workers on the plant.
 
My training in this subject is in weapons use contamination, & I'm not suposed to talk about that. As NHBL wrote the serious problem is not the increase in local background or ambient radiation, but in ingesting fragments (dust particles).
That's true of just about every contaminant from a civil reactor - the nasties are mostly α and β emitters, there aren't many neutrons emitted when the plant isn't operating and what there is tends to be transmuted parts of the building which don't go very far in even the most severe accident. That leaves you with fission products, mostly Cs-137 and Sr-90, and they're overwhelmingly an inhalation/ingestion hazard - after a few months the danger is mostly from contaminated food and water rather than free dust.
 
Well, probably - the issue is that at low doses we're relying on the Linear No-Threshold model, and if there's one thing we know reliably about that particular model it's that it is total bollocks. Personally I suspect that the people supporting the Radiation Hormesis theory have an axe to grind, but the evidence that low doses are not as dangerous as the LNT model would predict is pretty persuasive.
The fundamental problem is that we have two good data points for radiation exposure: Hiroshima and Nagasaki. For high doses and fast dose rates they actually give us really good data, but for lower dose rates the risk is small enough we can't reliably measure it.
And there were a significant number of fatalities at Fukushima - two plant workers died of multiple injuries in the Tsunami, and around 60 were killed by the evacuation itself, with several hundred dying of related causes since. A further two workers have been killed by their protective gear (heart failure in elderly workers).
There almost certainly will be radiation-induced casualties in the years to come, but we'll never know for sure who or even how many - best estimates are around 100, of whom about 10 will be workers on the plant.

I admit I overstated the case a bit , I should have said no radiation related deaths instead of no deaths.According to the IAEA there were no radiation deaths although there were about 1600 evacuation deaths with maybe 160 cancer deaths over time, but I doubt it.Radiation Deaths Like you I think that the Linear No-Threshold is silly, it is like assuming if you had a 50% chance at dying at x feet you have a 0.5% chance of death falling a few inches.
 
The fundamental problem is that we have two good data points for radiation exposure: Hiroshima and Nagasaki. For high doses and fast dose rates they actually give us really good data, but for lower dose rates the risk is small enough we can't reliably measure it.

Actually we have excellent data points for medium and long term exposure to low levels of radiation. The results overwhelmingly support the hormesis theory.
 
Actually we have excellent data points for medium and long term exposure to low levels of radiation. The results overwhelmingly support the hormesis theory.
That's stretching things a bit - the Taiwanese paper makes no attempt to control for some really obvious factors, or doesn't mention it if it does (most obviously, age of those living in the apartments - cancer is a disease of old age, by and large). The Ramsar paper is more interesting and indicates that over many generations humans can adapt to higher radiation doses, which is hardly surprising - life on earth evolved to deal with vastly higher cosmic ray doses. What it doesn't indicate is whether a population which hasn't been exposed to high levels of radiation for many generations and is suddenly given a chronic low-level dose will react in the same way.
There is also some evidence of cases where low-level radiation exposure is clearly dangerous. The data for Radon exposure alone is a bit murky but strongly suggests that exposure is a bad thing, while the data for tobacco smoke is clear that it's fairly dangerous. The interesting bit is the data for people exposed to both Radon and tobacco smoke - the mortality rate is vastly higher than can be explained by adding up the two factors. To me that suggests that the body is much better at repairing low doses of damage to cells than high doses, and that the Hormesis model is probably wishful thinking. My best guess would be either the linear-quadratic or linear-with-threshold models would be the most accurate, but for radiation protection purposes the LNT model works just fine, even if it does produce annoying numbers from time to time (e.g. my permitted annual dose of 2mSv per year in my last job!).
 
Hmmm... leaving aside quibbles on how people die. How much worse does the reactor failure/s have to be to raise the 'death rate' to 3000+ ?
With the Fukushima reactor design, I'm not sure whether they could actually have had a failure that bad, particularly given that the mortality rate for the most common potentially lethal illness (cancer of the thyroid) is essentially zero with first world medical treatment.
Best guess is even if they'd built an RBMK and disabled all the safety systems after the Tsunami hit they probably wouldn't have had that death rate unless they got very unlucky with the weather since the prevailing winds are out to sea. Even then they'd probably have to be hit with a stupid stick to not evacuate the population and ban them from consuming food and drink from the affected area.
 
Hmmm... leaving aside quibbles on how people die. How much worse does the reactor failure/s have to be to raise the 'death rate' to 3000+ ?

It isn't a quibble but a very important point, those 1,600 needn't have died if there wasn't a panic. It wasn't the accident that caused the deaths but the panicked reaction to it. To raise the death rate have people panic even more.
 

Delta Force

Banned
Fukushima essentially was the worst case scenario.

First, Fukushima was a multi-reactor facility suffering a station blackout (loss of all external and on-site AC power).

Second, the Fukushima station blackout occurred during the worst electric grid collapse in recorded history. It took a day or two to restore grid power to Tokyo, and there was still instability until a month later.

Third, the Fukushima station blackout occurred during one of the worst earthquake and tsunami events in modern history. This complicated efforts to send in relief crews and expert assistance, and also complicated evacuation efforts.

Fourth,the Japanese nuclear power industry didn't have very good personnel training and procedures in place for what to do in the event of a nuclear incident.

Fifth, the Fukushima units lacked a number of safety systems that could have recovered the reactors or mitigated the effects of a meltdown. For example, American nuclear reactors have several portable generators that can be used to power the facility, and Japanese and Spanish nuclear reactors are the only units in the world that lack catalytic converters capable of removing most of the radiation from gasses vented from a reactor in the event of meltdown.

Despite this, the only fatalities at Fukushima were from the tsunami itself. No one died from radiation or even from non-nuclear component failure, such as steam explosions.
 
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