Expert says 2 Sendai reactors in danger from active volcano

Sounds like some one is upset they didnt get consulted.

Wonder if they plan to listen to the professionals this time.

If you've got a 40 km. pyroclastic flow, radiation from a damaged nuclear power plant is the least of your problems.

But hey, the government will listen to the people directly out to make a profit -- not some experts who warn of the obvious dangers! Why would common sense prevail in this one instance?

Just thinking. What is keeping the cores cool now?

Whether they are running or not, don't they still need electric to keep them cool?

Fujii said ash falling as thick as 10 centimeters would make any vehicle, except for tanks, virtually inoperable. Power lines would be severed due to the weight of ash on them, causing blackouts and possibly cutting off electricity to the reactor cooling system.

Even a couple of centimeters would block air inflow vents, the ash could also short out any exposed circuit boards, and water coming into the cooling system will be contaminated and block intakes and filters.

There are probably a dozen or more other problems that will only become apparent when this happens and there'll be the same post-Fukushima bowing and saying, "Oh, we really should have thought of that!".

Guy_Jean_DailleultOct. 18, 2014 - 08:29AM JST If you've got a 40 km. pyroclastic flow, radiation from a damaged nuclear power plant is the least of your problems.

Pyroclastic flows will inflict immediate damage in the area and prevent access (either ground or air), but the flow will stop, and people normally get enough warning to evacuate the area (days or hours), so direct casualties should be limited.

One cannot move a nuclear power plant, nor can one protect the plant in any meaningful way from a volcanic eruption without completely rebuilding it.

The radiation resulting from the damaged nuclear plant will affect a MUCH wider area (at least half of Japan) and the damage will continue for decades.

In short, a single volcanic eruption is unlikely to make Japan uninhabitable. A combination of an eruption and nuclear power plants close by would guarantee most (if not all) of Japan was uninhabitable for decades.

The regulators ruled out a major eruption over the next 30 years until the reactors’ reach the end of their usable lifespan.

These reactors were built in 1984 and 1985. They are currently 30 years old, which is what they were designed for. What they're saying is that the regulators have extended the "usable lifespan" of reactors from the 30 years originally agreed to 60 years???!!

This is utter b.s.! These nuclear power plants were not built with modern earthquake safeguards, and have been exposed to 30 years of Japan's regular microquakes. Look at any 30 year old building in Japan, whether it is an office building or a town hall and you'll see cracks up the walls from minor earthquake damage. The idea that a nuclear power plant should have LOWER safety requirements than an office building is so utterly ridiculous that I'm wondering how these people can sleep at night?

These nuclear regulators are utterly insane, the puppets of an industry so insanely greedy and selfish that it would destroy Japan just to make a buck.

“If they still need to be restarted despite uncertainties and risks that remain, it’s for political reasons, not because they’re safe, and you should be honest about that.”

NowTHAT's the fact! I wonder is there is a politician with the guts to admit this.

Quote: "nuclear power is stable and relatively cheap compared to other energy source" (sic)

Stable, compared to wind and sunlight maybe, on a stable base with all other things being equal.

Cheap?!?!?

Here the government is trotting out the old chestnut, despite everyone else knowing this has been disproved. It may be 'cheap' when looking at imported coal and oil and the exchange rates, but in the long term nuclear power is astronomically expensive.

@shonanbb ... Just thinking. What is keeping the cores cool now? Whether they are running or not, don't they still need electric to keep them cool?

You are right. Choose any subset from earthquake, tsunami, volcanoes, typhoon, meteor, war, disease, cost cutting , or stupid accident, and you have sufficient ingredients for a disaster. Any reactor which is not structurally self extinguishing is a problem waiting to happen just at the most inconvenient time.

I would suggest that they are taken off-line and a complete shutdown before two new Fukushimas take place.

The NRA and politicians won't directly debate these findings. I'm sure that most of them have heard about this announcement but you probably won't hear any responce until after the secrecy act is up and running. If you don't think that details of the nations energy production will be considered a secret, then you have another thing comming.

He said at best an eruption can be predicted only a matter of hours or days.

Correct me if I'm wrong, but catastrophic eruptions capable of 40km+ Pyroclastic flows show warning signs a bit more in advance than a few hours. Mt St Helens had flows of less than half that, and there was significantly more than a couple of days.

This is important because there are a hell of a lot lf people living in the area. Is it an unacceptable risk to have Kagoshima where it is? How about the other couple of dozen cities and towns in a 40km radius? Why aren't we talking about relocating those cities?

The Mount St Helens eruption began with steam venting two months before the major eruption. I don't know that there was any warning before that start to the eruptive activity. It may depend on the geology and perhaps this guy was referring to ALL eruptive activity rather than a major eruption. Also, there are lots of problems with Japan's monitoring system, including few staff and no centralized authority - unlike places like the U.S., Italy and even Indonesia and the Philippines.

A volcano is like a truck flying down a hill out of control. You can't stop it. You can't reason with it. All you can do is get out of its way. But an astonishing number of people are perfectly content to live in the shadow of a potentially dangerous volcano and will not even move when the mountain does erupt. It's like living in the path of doom.

@zichi ... The reactors have mains power, emergency back up generators and a cooling system like isolation condensers which does not need power.

All of those cooling methods require active human interaction, without which there is serious disaster. A design which in absence of human interaction, with all machinery failing, still will passively shutdown is required.

Here's a link to an interesting article on the lack of funding for monitoring volcanos, and the lack of experts in the field (less than 40).http://the-japan-news.com/news/article/0001619874

"“Scientifically, they’re not safe,” he said of the Sendai reactors"

How about all reactors?

ref: http://www.youtube.com/watch?v=ov5mv9zzPdU

zichiOct. 18, 2014 - 06:10PM JST

@CraigHicks

All of those cooling methods require active human interaction, without which there is serious disaster. A design which in absence of human interaction, with all machinery failing, still will passively shutdown is required.

The emergency generators will start with the loss of the offsite mains power. Probably, the isolation condensers need to be turned on but even in a volcanic eruption the operators won't abandon the plant but will have to remain indoors. I think the plant needs to have emergency breathing equipment in case the operators need to go outside to unblock filters. I would agree with you that safety systems need to be able to operate automatically but from experience I would say not without some form of operator intervention. The final decisions must be made by the plant manager.

Have you ever tried to unblock a filter during a dust storm? I have. It is impossible. The moment you unblock it the dust in the air re-blocks it, and when you remove the filter dust gets into the system you're trying to protect.

A dust storm is very similar to the constant ash fall during a volcanic eruption, and the bottom line is that trying to unblock filters is going to cause more damage to the system, and is ultimately futile.

The current safety systems are completely insufficient for this sort of contingency. The bottom line is that if something like a volcanic eruption happens near these plants then a melt down isn't a possibility, it is guaranteed.

So Professor Toshitsugu Fujii is calling for moving every industry and every person that is within 100 km of the volcano? If the nuclear plants are at that much of a risk then everything within the area he mentions, which apparently includes Tokyo, is at the same risk and the only safe decision is to move everything now before anything happens.

"In short, a single volcanic eruption is unlikely to make Japan uninhabitable. A combination of an eruption and nuclear power plants close by would guarantee most (if not all) of Japan was uninhabitable for decades. "

Why am I not surprised that my original statement was answered with standard anti-nukester hysteria and hyperbole. Evidence provided for above quoted statement - none. Basis for the statement? No doubt the criminally corrupt and scientifically bogus LNT hypothesis, which has been used so effectively the last 3.5 years to scare the sheep.

Reality is a 40 km+ pyroclastic flow will kill everybody in its path, meaning anyone actually close enough to Sendai NPP for radiation to actually pose a REAL health risk, will in fact already be dead. Fujii is just another shyster cashing in by playing everybody for a fool. Or to be more accurate, cashing in by being a mouthpiece for the shysters

There seems to be some misinformed comments on the issue:

1) The Sendai Plant is on the seashore. If ash cuts off road and air communications, it can be reached by sea. 2) The Sendai Plant is designed to cope with 15 cm of ash falling on it. 3) The retired professor has not given any solid figures on ashfall, or how a pyroclastic flow on Sakurajima is going to get over the mountains to the Sendai Plant. 4) If the risk of a massive pyroclastic flow is so dangerous to the Sendai Plant, why are there not calls to abandon Kagoshima?

Lastly, we always get these reports with low or zero actual data. It would be nice to have actual presentations with solid data from the people behind these news stories. For example, what volcano errupted 90,000 years ago? How deep was the estimated ashfall? How much ash is likely to fall on Sendai from Sakurajima, etc.

So Professor Toshitsugu Fujii is calling for moving every industry and every person that is within 100 km of the volcano?

No, that's not what he said at all. Were you reading a different article?

No, that's not what he said at all. Were you reading a different article?

No I was reading this article. He says an industrial facility many tens of miles away from the volcano is completely unsafe. By simple extension that means the EVERYTHING closer to the volcano than the NPP is completely unsafe and if keeping people safe is the goal then the only logical conclusion from his claims is that EVERYONE needs to be immediately removed the unsafe zone that he has defined.

Whatever logic you want to use (which is a fairly ridiculous leap in 'logic'), the point is that he didn't say that, you did.

zichiOct. 18, 2014 - 06:58PM JST I remain of the opinion that none of the reactors should be restarted.

Let's start here, because this is the real sticking point. You've stated your position, and you now find yourself unable to back down, no matter how mistaken your original position is proved to be.

There's no shame in simply saying, "I hadn't considered that. I'm changing my position". I wish people would realise this. We can change our minds!

I disagree because the emergency generators are located indoors and the isolation condensers don't require power or air so at least a meltdown would be avoided. Although, there should be a review of the various safety systems after the statement by Professor Toshitsugu Fujii.

The isolation condensor system is only present in some models, and it relies on a body of water open to the atmosphere to work... an open body of water that would rapidly become polluted with volcanic ash. That ash would be pulled into the condensor that reclaims the evaporating water from the system and it would become clogged in short order. The condensor system is not effective in a volcanic scenario. and if you've been informed that it would then you have been misinformed.

A volcanic scenario, even without lava anywhere near the station, would be a complete disaster.

What's more important, that on paper Japan's economy stays third or that the country doesn't become a radioactive wasteland

zichiOct. 18, 2014 - 11:56PM JST I don't know what I need to back down about. I understand and agree with you that if volcanic ash were to hit the nuclear plant there could be a problem with any external filters. But I disagree with your comment that the ash would lead to reactor melt downs. There are systems to cool the reactors without the need for external filters or offsite power. Those I believe would prevent meltdowns because the reactors would continue to be cooled if in a shutdown position.

Really? Please name these magical systems that need no offsite power and don't rely on anything being filtered from outside, because I am dubious about their existence.

The pool of water for isolation condensers are located indoors in the reactor buildings but I retract my comment because I believe PWR's use another emergency cooling system.

You believe incorrectly. If you check out Asahi Shimbun's illustration of the Fukushima reactor you'll note that it is open to the air through a vent for the steam. This vent would allow ash in, and become clogged (water + heat + ash = problem think ash brick), resulting in steam being unable to escape and the system becoming ineffective.

The auxiliary feedwater system and the steam dump system work together to allow the operators to remove the decay heat from the reactor. The auxiliary feedwater system pumps water from the condensate storage tank to the steam generators. The water is allowed to boil to make steam which can be dumped to the main condenser through the steam dump valves. The water will then condense the steam and take the heat to the environment. If the dump system fails the steam can be dumped directly through the atmospheric relief valves.

Without external power the main condenser system certainly will be taking strain and will dump occasionally to the asmospheric relief valves... which will contain ash. Ash + water + heat again. Problem!

Well, I disagree there would be a complete disaster from the plant being hit with volcanic ash.

That's because you've decided there's no problem and are unprepared to even contemplate it. We have adequate proof that the safety systems in these plants have been badly neglected, the personnel under-trained, and some of the safeguards even omitted because of cost-cutting.

Add to that something as simple as volcanic ash and I have every confidence there will be a meltdown.

Sadly I won't be in a position to say "I told you so.", which is the real problem with these things. Once the worst happens people who were claiming that it would never happen are nowhere to be found.

I recall some people a few months ago denying that Ebola was any danger to the US and that it would never make it to the US... now that it has happened I see there's no sign of them.

Vulcanologist claims nuclear reactors are not safe. Nuclear engineers say vulcanologists know nothing about nuclear reactor safety. Vulcanologists say nuclear engineers know nothing about effects of volcanic eruptions.

Catch 22, or maybe time for both parties to talk seriously to each other and understand their respective positions....

zichiOct. 19, 2014 - 08:52AM JST I have never stated there are no problems with the Sendai plant but the question which needs an answer is whether the reactors could continue to be cooled if the plant was hit by ash from a volcanic eruption. There are many unknowns in the question.

Assume the worst realistic scenario is the rule. Assuming "normal" event is what caused the Fukushima disaster, and we all know the problems with that sort of logic.

When the eruption occurs which way will the wind be blowing at the time and how much ash will land on the Sendai NPP. If the eruption is from Mount Sakurajima which is the most likely I guess the real concern would be for the residents of Kagoshima.

Typical wind patterns for the area are north-easterly or north-westerly. Go and do some research.

I don't understand how ash would short out any exposed circuits boards since first they are never exposed and secondly the ash isn't conductive?

Dry volcanic ash isn't conductive. Volcanic ash combined with moisture from the air (and Japan is a very moist country) is most definitely conductive (http://www.sciencedirect.com/science/article/pii/S1474706511002592).

And if you read the paper you'll notice that volcanic ash shorting out electrical systems IS a real concern.

The PWR cooing systems are closed systems so I don't see how it could be contaminated by ash. In all my years working has an electrical engineer I never saw what you state.

You claim to be an electrical engineer. If you were you'd be aware that volcanic ash + moisture is highly conductive and is known to short out systems.

As for the system being closed, the diagram of Fukushima daiichi published by Asahi shimbun disagrees with you, several articles on nuclear power station cooling systems disagree with you. Your only "evidence" is your claim to be an electrical engineer... one who isn't aware of a common danger to electrical systems in volcanic countries.

The current safety systems are completely insufficient for this sort of contingency. The bottom line is that if something like a volcanic eruption happens near these plants then a melt down isn't a possibility, it is guaranteed.

No its not guaranteed!

It is guaranteed. You're simply not in possession of all the facts, like that volcanic ash + steam = problem.

I don't see why the eruption and the ash would cause the loss of the offsite power but if some of it was lost then there are emergency generators and a cooling system which could cool provided the reactors are in shut down position which I would assume would happen if there was any volcanic eruptions.

Read the article. Volcanic ash is a real risk. One that you are unaware of despite your claim to being an "electrical engineer".

I do not accept your opinion that in the event of the plant being hit by some level of ash would cause meltdowns in the reactors and you haven't shown enough reasons to back up your claim. But since there has never been a nuclear plant covered with volcanic ash we can't know for sure what would happen.

You're arguing from a position of ignorance. Similar facilities covered in ash have shown the dangers of your type of thinking.

Whatever logic you want to use (which is a fairly ridiculous leap in 'logic')

Just because you want to ignore it doesn't make it ridiculous. If a NPP tens of miles away is completely unsafe then everything closer has to be completely unsafe also. Or do you believe the ash and lava leaps over all the intervening land to just hit the NPP?

Frungy,

Have you ever tried to unblock a filter during a dust storm? I have. It is impossible. The moment you unblock it the dust in the air re-blocks it, and when you remove the filter dust gets into the system you're trying to protect.

Well, I guess centrifugal sand filters, like those used on helicopters which work in desert environments would help. Perhaps something electrostatic?

However, if manual filter-cleaning is needed, then the intakes could be bifurcated - with one intake in operation whilst the other is covered, and its filter removed and replaced. That might be possible either from the inside, so no concern with ash - or under a sealed cover.

Just because you want to ignore it doesn't make it ridiculous

Where did you get the idea that I want to ignore it?

frungy @ zichi: Your only "evidence" is your claim to be an electrical engineer... one who isn't aware of a common danger to electrical systems in volcanic countries.

Electrical engineering education is somewhat specialized. I was computer track and took extra computer courses. I didn't take any power systems courses, and less semiconductor courses than other tracks. So discussion of electrical power transport was probably limited to a few class sessions of the AC/DC machines course, and that may have been because the instructor was a power systems engineer. Everyone had to fit different courses into their four-year basket. It's not like medical education where they make you earn an entire possibly-unrelated degree before they let you into med school.

Even if I had taken some power systems courses I doubt they would have mentioned volcanic ash at all. Just for the Mt. St. Helens eruption? Not much left to a power transmission system after tons of rock and ash have tumbled over it. The only similar news I can remember is one Icelandic volcanic disrupting European air traffic.

zichi mentioned he/she's an instrumentation engineer. Power transmission systems are open-air because air's a significantly cheaper insulation (cost, and cost due to weight) I would guess.

Where did you get the idea that I want to ignore it?

Because you are ignoring it. It is simple logic, much less common sense, and yet you ignore it by calling it a fairly ridiculous leap. Can't be much more dismissive than that.

Because you are ignoring it.

And there is where your logic falls apart. No, I'm not ignoring it. In fact, I'm quite involved in it.

It is simple logic

Yes, I agree your logic is simple, which is why it doesn't fit with the real world, which is complex. And the very fact that you are incorrect with your suppositions about what I think are a perfect example to show how trying to apply simple logic to complex situations doesn't result in an accurate supposition.

Yes, I agree your logic is simple, which is why it doesn't fit with the real world

So let us see. My simple logic says that if lava flow from a volcano can reach and make unsafe a facility at location A, then location B which is between the volcano and location A must also be unsafe. That sure sounds like the real world to me.

Unless the lava and ash can teleport in the real world and bypass location B on the way to location A. But since teleportation doesn't exist in the real world, even in all its complexity, your dismissal of simple common sense as a fairly ridiculous leap is extremely ridiculous.

And the very fact that you are incorrect with your dismissal about what anyone with any sense knows is true is a perfect example of ignorance compounded with ego.

Unless the lava and ash can teleport in the real world and bypass location B on the way to location A. But since teleportation doesn't exist in the real world, even in all its complexity, your dismissal of simple common sense as a fairly ridiculous leap is extremely ridiculous.

Keep grasping.

The fact is, your supposition about what the professor was saying was ridiculous. If a volcano explodes, an wipes out the area, lots of people will die. Other people can move back afterwards and recolonize. If that volcano wipes out the a nuclear plant causing a meltdown at the same time, no one can move back, and the entire area for a significantly wide radius cannot move back for decades.

There are different levels of danger, and different amounts of risk. It's a complex situation. You are trying to apply simple logic. And it fails. In fact, your logic has repeatedly failed both in extrapolation of what the professor meant, and in my motivations, and in what I was saying. So you should stick with facts, and avoid extrapolation.

So you should stick with facts, and avoid extrapolation.

Sure no problem.

If lava travels from point A to point C and point B is between point A and point C then the lava will travel through point B. The facts can't be any simpler than that.

If that volcano wipes out the a nuclear plant causing a meltdown at the same time, no one can move back, and the entire area for a significantly wide radius cannot move back for decades.

I thought you wanted to use facts and avoid extrapolation? Your claim is, at best, an extrapolation.

So it appears to be you that should stick to facts, and avoid extrapolation.