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When the MD of TEPCO Mr Akio Komori weeps on National Television, we can no longer escape accepting that the plant is in big trouble.

Newly released images and video show clearly a crane that is used to handle spent fuel that is visible from the outside. Based on the normal location of the crane on the edge of the spent fuel pool, the pool, though not visible in the shots, is definitely there, open to the world.

When the owner of the fourth largest power company in the world and the largest in Asia breaks down in tears, you know how bad it is. Or you know that he probably wishes the earlier cover ups of security threats at the plants had not been exposed.

I am not one to panic. Initially, when I heard about the crisis, I went about supplementing what I remembered reading with information that would reflect happenings and risks without getting into nuclear advocacy or criticism. I shared my findings on nuclear meltdown and other nuclear risks to prevent panic.

All this has changed since the second explosion at the site. I am no longer able to pretend that it isn't serious. Not the crisis itself, but I am quite worried about the Government's approach to it. Its been quite leisurely and now, its in a panic. This doesn't help. In crisis, the authority figure being consistent is unmatched in its power to bring order and stability. Unfortunately, the US paranoia seems to have infected the world, and the Government of Japan, who had earlier been puzzled at the safety zone America recommended for its citizens in the region being three times that for locals, is now discovering how much in danger their people are.

The best help in a crisis would probably be a media blackout of the US Government response to it. Wouldn't be surprised to later discover that people headed out into radiation to escape because the US predicted the apocalypse. Or to find out that more people died of heart attacks from fear than radiation.

The world seems to have discovered it too. The people claiming that it wasn't a big deal or that nuclear energy is quite safe are mostly conspicuously silent, or their efforts now focus on how the radiation spreading vast distances is not really a risk beyond the evacuation zone. So, from saying that there would be no significant release of radiation, we have gone to explaining that the significant release of radiation isn't all that big a deal. Because we can no longer pretend that the radiation is not spreading. The West coast of the US and Russia have both registered elevated radiation levels - neither of them dangerous, but they exist and that is enough for people to hit panic levels. Might be good to remember that the Chernobyl explosion, which was definitely worse than this blew radioactive winds across Europe. Europe is thriving, thank you very much. Japan went through Hiroshima and Nagasaki and has better longevity than most places in the world - US included. The cancer rate is far lower for workers in nuclear plants than among general population - go figure!

Yes, the plant is devastated, but its hardly flimsy. Look at the destruction it is sitting in the middle of and still is sheltering its precious responsibility with considerable security under the circumstances. That's not accidental - its design.

<strong class='StrictlyAutoTagBold'>Japan</strong> Fukushimi Nuclear Reactor #4 exposed and possibly in full meltdown

Photos from the fourth reactor at Fukushima Daichi show clearly a green crane in the building. The green crane by itself may not sound like a big deal, but it is used to transfer fuel rods from the reactor to the spent fuel tank, and is standing right next to the tank. If you can see the crane, you can't see the pool, only because it is lower.

This video gives a better idea of the situation:

http://www.youtube.com/watch?v=gTZ9C42mOPM

It is just as exposed. Check out the picture  of the reactor from inside (before the explosion, of course).

Spent fuel pool inside reactor

The rods are in the pool, as we see. The water itself forms a barrier while it keeps the rods cool as well so that the people can work safely, with reasonable precautions.

The fuel rods stay 'hot' for quite some time post being removed, and it takes several years before they can be considered safe to be packed "dry". This water is cooled regularly to take away the heat from the decay and the water levels are managed to that the rods are always submerged.

What likely happened was that when the cooling systems failed after the earthquake and Tsunami, while the water meant that there was no immediate crisis, it did start heating up. The rods themselves were not all that old out of 'action', having been removed about three months ago, so the decay heat, while not the inferno of an active reactor, was still enough to start reducing the water in the fuel tanks.

Once the fuel rods got exposed and thus not cooled at all, the heating only picked up pace. The temperature for the zirconium around the uranium pellets to melt is about 1200 deg. Once this starts, we are in the process for a meltdown, and the mass gets increasingly difficult to manage.

The zirconium reacts with the water at a high temperature and gets oxidized and releases hydrogen gas (remember the hydrogen related experiments in school?). The thing is that hydrogen is highly reactive, and once vented, combines "violently" with the oxygen in air to form water. Water, of course is not dangerous, but the problem is that the explosion blows the building apart, and the radioactive particles contained in the steam are dangerous. This is actually the good part, because with the fuel rods exposed, they are able to release radioactivity directly into the air.

This, described above is the problem at plant 4. We have had the explosion, the damaged wall only means even less barrier from the radioactive substances, and we see that crane from outside, which is standing next to the spent fuel tanks. Do the math. If there is water, its well on its way to becoming steam.

And the biggest problem with this situation is the combination of the limitations of operations due to radioactivity and the number of reactors needing to be pulled back from the 'edge'. The most dangerous by far are Reactor 3 and 4. Reactor 4 because its wide open to the world, and the only way to cut off that radiation is going to be getting those rods underwater and keeping them there. Reactor 3, because it contains Plutonium, which is really bad news. So tell me again who had the bright idea of recycling nuclear weapons to produce the MOX fuel? Sigh. Its probably a great idea. No one could predict this. Regardless, this stuff is something that would be far more complicated to mop up, so the attempt is to keep it in, where it belongs.

There are engineers discussing the possibility of burying the reactors under tons of concrete, a la Chernobyl. However, that is for the future and more to prevent further escape of radiation, and it can be done in Fukushima, but its not much use with our current priority - getting those reactors stone cold. Without that happening, we are risking fission and explosion rather than simple leaks, however radioactive. Also, it isn't like fission needs oxygen that pouring concrete on it will smother it. It won't. Plus, the heat from the still hot and heating fuel will mess up the concrete, while the concrete messes the reactor, and only create much more radioactive debris to tidy. The proximity of the reactors is another complication they will have to work around when they do it. I don't think there is any question of "if" any more.

US and UK have advised their citizens to give the area a wide berth - 50 miles. Japan's zone of course is still 20km, which is not enough, but residents till 30km are being asked to remain indoors, which should protect them too, with precautions. For all the hysteria in the media, there seems to be little actual data to support sustained levels of dangerous radiation. That is not reassuring only because the Government of Japan seems to increasingly become opaque, so we don't know if its the whole story.

The name Chernobyl cropping up constantly doesn't help either, because one of the main reasons Chernobyl had to be evacuated was the radioactive material that spewed out of the reactor and the vast quantities of radioactive dust from the burning graphite (in other words, radioactive soot). There is no way to clean the ground of each of these gazillions of pieces which will keep emitting radioactivity long after you and I are gone. This is very different from venting a little radioactive steam, or contamination. Even if radioactive material has been leaked, as long as its on the reactor site, and not blown to bits and scattered over entire continents, there is no reason why it can't be decontaminated later.

Yes, the situation is dire, it is critical. But not because it can get to a Chernobyl scale. It is critical, because we are trying to contain damage to a minimum and without electricity, the safeguards built into the reactor are failing. Even if they totally fail, Chernobyl is extremely unlikely. That was  a situation where there was no containment at all. There was no precedent, there was far less technology. Japan has a crisis only because it doesn't want any abandoned zone at all, or, a very tiny one. So far, there doesn't seem to be any radioactive debris that would make the area unlivable.

The danger for the people largely will "switch off" once the fuel is isolated. Radioactive debris on the other hand will send out radiation - mostly contaminating through becoming a part of the place itself - the whole area will have to be isolated.

However, and I'm not saying this just to make you feel better, there are many good things happening as well. There is now a good chance that this thing will be under control soon.

  1. The idea of the fire trucks spraying water directly on the tanks right through the hole in the wall seems to be working.
  2. Surveillance from a helicopter also showed that the tanks were not completely empty. Not that it means anything particularly good right now while the rods stand exposed, but it will mean that much less water to fill in to submerge rods.
  3. Electricity has reached the plant from the grid.Power has been restored at the plant, though it will still mean a lot of testing before the cooling systems go online. This is good, because it means that instead of exhausted workers using puny efforts fighting upstream of huge odds, we can engage the pumps and cooling systems that were designed precisely for this job. This will help make the cooling really fast, as well as free up workers from maintaining to recovering damage.

What remains to be seen is how far the radioactive contamination spreads before this show comes to a stop.

My bet is that if the electricity brings the pumps back online and some of the cooling systems work at least, the rest will be a "recovery without incident". If not, then its going to be an uphill struggle. With the electricity there, the choices are considerably expanded, but they will still have to be tried and tested. That takes time. But one way or the other, the way ahead is all about getting the fuel underwater, cooled and isolated. In that order.

In the meanwhile, while I understand that the Japanese are angry with the government and TEPCO for the risk they are facing, it isn't the workers putting them at risk. The workers are volunteering their lives away to keep them safe, and they deserve some acknowledgment for what they are doing. I want to criticize some Japanese who have been quoted in news as saying that the workers battling the reactors are just doing their jobs that they are paid for. In saying this, they show how utterly dehumanized their world is. Their words are an embarrassment to them, not to the country, and certainly not to the workers who are fighting death each moment - explosion, accident or radioactivity. I feel quite certain that this arrogant person cannot afford to foot the bill for the things he claims have been paid for. He reminds me of the people shooting at the rescue helicopters after Hurricane Kartina.

To end this post, I want to throw in my estimation of what will happen. First, I think that since at least the spraying water from fire engines is working, it will be continued while more robust solutions are searched. Very likely, some electricity powered solution that can be switched on and left alone will happen, at which point everyone can forget about this while it cools down while the employees at the plant get around to fixing leaks and other problems. It will happen within hours if the cooling systems are working when they get electricity, or in another day if something new is brought in.

I think the residents in the immediate vicinity may not be allowed to return home, but the remaining will, once the radiation leaks are stopped, and any possibility for recurrence is prevented.

Here is to Japan and its spirit to live, to endure, and most of all its incredibly pragmatic attitude. I leave you with a cartoon for Kids to understand what's up with Fukushima. It is clearer about what is happening than many detailed accounts. Don't miss this.

32

We have been hearing the reassurances. But there are holes. Big, glaring ones. I'm no nuclear scientist, but since I can't stop this planet and get off, there are a few answers important.

  • When they say radioactivity is low or minimal or can now cause human harm, what numbers exactly are we talking about? Those numbers were reassuringly told earlier, and somewhere in the narrative, they have become "idiot friendly" rather than numbers, we are being told their implications. If I could understand the lower numbers, I can understand the higher ones. Tell me.
  • Nuclear reactor buildings contain other items that give off radioactivity. There are spent fuel tanks, and now vast quantities of sea water - at least as much that didn't evaporate off. This much, an utter layman like me knows. When the buildings are blowing up, we are told that the main containments are not breached. Fine. But what about the rest of the radioactive stuff in them? Is it dispersing in the air right now? Should people be taking precautions that are being discarded for not creating panic?
  • No Chance of Chernobyl we hear. Again and again and again. Of course, but this is Fukushima. Not being Chernobyl is not necessarily reassuring. Each of these six malfunctioned plants and the remaining safely shut down plants is more powerful than the one that blew in Chernobyl. Sure, they have more safeguards as well, but if those safeguards were foolproof, we wouldn't be engaging in these mass evacuations and sea water orgies while the country could really do with more facilities free for the deluge of tsunami survivors.
  • This is the big thing no one seems to be talking about. If one plant breaches containment. ONE. Does work on the remaining continue? Could it be possible? In that case, is there any way at all of preventing all of them from blowing up post the first?
  • The other thing I have been wondering about (and I also wonder if I am being unfair, considering the full frontal assault that nature has mounted on Japan), is how come three reactors at Fukushima Daichi all had the same problem? As in Earthquake >> Tsunami >> till here I can understand, but now >> failure of emergency generators with MULTIPLE REDUNDANCY - Multiple generator backups on THREE reactors failed? Who are you kidding? What is the meaning of an emergency backup if not a single one worked? >> Then, progressive fall-backs all failed on THREE reactors right down to the desperate measure of pumping in sea water, explosions, destroyed secondary containments in two and core container in one. We hear of fuel rods being exposed.
  • We hear of generators running out of fuel through being IGNORED!!!! What the hell is this? Somehow, I don't believe anyone ignored anything. Not with their lives at stake. It is just too 'good' to be true. Though it is possible for things like this to happen, seeing as how the workers are probably spending brief spurts of hurried work in the radioactive area and heading to safety as fast as possible. <-- this is normal for working with radioactivity.
  • From the sound of this disaster, it is increasingly looking like desperate PR management by the honchos while poor workers risk their lives to desperately do whatever it takes to cool down reactors that have essentially gone rogue without power. The redundancy and fall backs that seemed so impressive till the first explosion are looking utterly unrealistic after the fourth - yes there was a fourth in the spent fuel tanks of a reactor that had freaking not been working in the first place. This is a massive cover up it is looking like. Someone simply hadn't done what it took to secure a reactor. Reports are coming in from sources as diverse as wikileaks to IAEA.
  • Spent fuel pools. What was done to secure them, if at all?
  • Apparently, there is trouble keeping rods covered in water. This is half the story. What is happening? I see two possibilities. The first is that the rods are so hot that water is instantly being converted to steam faster than it can be replaced. While this is good that water is taking away all the heat, this steam is being released in the atmosphere. The other possibility is that there is a leak that doesn't allow the tanks to fill beyond a certain point. In which case, since no leak is described in the media, is it safe to assume that this water is draining out where we don't know? As in, into the environment?

Japan began beautifully with its transparent information and prompt responses. However, as responses fail, the information is becoming more and more obscure. With people's lives at stake, they have a right to know exactly how bad things are. There are many people from many countries who can return home. There are many people in Japan who have the possibility of leaving the country completely for a while. This wouldn't cost the government anything, but people would be free to make informed choices on their own initiative.

For that matter, refugee evacuations can be requested into other countries or much, much further away than 20km. If we look at the horror stories of the Chernobyl disaster or Japan's own Hiroshima and Nagasaki, I think it is fair to be a little proactive and at least get kids and pregnant women out of there so that the cost to human life is relatively limited to the current generation. While I understand that panic will not help, I think there are some situations where panic works far better than anything else.Get people moving urgently and safe, and then you are free to organize them to taste. Use their collective energy rather than spend your own depleting energy moving people.

I just read what I wrote and want to make clear that I am not scare mongering. However, I think things in Japan have well reached a place where it is not a matter of "if" but when. Waiting to enact a crisis response at the last moment will help no one. If it turns out that things didn't go bad (they already are), people can return with sheepish smiles and nothing is lost but a little embarrassment over a very natural mortal fear. If things continue on the path they are on, will someone keep in mind that the wind can change at whim, location of millions can't.

This reminds me of the stories of Chernobyl, where the people of the town were not even told for three days, which has changed too many lives forever.

14

Twitter is ablaze with news of nuclear meltdown being imminent in Japan and some tweets are along the lines of "OMG! the reactors are going to explode! God save the world". This sounds a little extreme, and I thought I'd share what I found out in extremely non-tech terms for anyone to get an overall "panic-rating" kind of grip on the subject.

The Japanese reactors are light water reactors. Without getting into the scientifics of it, in the words of an expert, Naoto Sekimura, a professor at the University of Tokyo, a major radioactive disaster is unlikely.

"No Chernobyl is possible at a light water reactor. Loss of coolant means a temperature rise, but it also will stop the
reaction," he said.

"Even in the worst-case scenario, that would mean some radioactive leakage and equipment damage, but not an explosion. If venting is done carefully, there will be little leakage. Certainly not beyond the 3 km radius."

IAEA seems to agree on the whole, though they are concerned and actively monitoring.

Nuclear reactors use radioactive fuel to generate electricity. In the process, the fuel gets hot, and much like say, the engine of your car, it needs to be kept cool. This is a big deal, because unlike your car, if this stuff explodes, we can forget using that area of the earth for a long, long time because its radioactive contents will get scattered in the blast. Thus, the fuel is kept at desired temperatures and prevented from overheating. There is massive planning and enginnering around this, with several methods used simultaneously, each capable of cooling the core independently. In addition to that, each method has back ups and fail safes till a mind numbing redundancy is achieved. This is in order to set things up so that once the reactor is in operation, there is absolutely no possibility that there is a failure in cooling it down. The fuel needs to be cooled for a day or two after shutting a nuclear reactor down.

Another factor is the pressure. Evaporating coolant can create high pressures that can threaten the integrity of the containment dome. This can be released by venting, which is a management mechanism and not procedure, since it means that some quanitites of radiation can get released along with the steam. This isn't radioactive materials, but the water itself absorbing neutrons from the cooling process, which are shed off quickly. This radioactivity isn't supposed to last long because the water used is specially demineralized for the purpose, thus making it extremely resistant to this kind of radioactivity. Not that the core cares what cools it, but the water not being radioactive makes it easier for managing the plant.

Sometimes, this system can fail, like it is failing in Japan, right now. When the earthquake happened, the reactors were shut down. This was pretty much instantly. Well before the tsunami. It means the control rods came and fitted in between the fuel rods, so that the ricocheting neutrons had less space to move and less power and less targets, till it would finally wind down and stop in a day or two. This is normal. Nuclear reactions are like that.

And the backup generators took over the cooling since the reactor was no longer producing electricity (and there were back up generators for the ones in operation too). This worked well for about an hour till the tsunami hit and took out all the generators. This was unfortunate, because the cooling system needs constant power. However, the third line of back up kicked in and the generator switched to battery power, which would last for 8 hours or so. Post this point, things seemed to go into chaos. For some reason, they were not able to use the time provided by the battery to rig up yet another power source, and when the battery was exhausted, the reactor started heating up. Without a circulation mechanism for the coolant, the whole thing is overheating and pressure is increasing from the evaporating water.

There are plans to let off steam. US has flown in coolant. Japan has been extremely transparent and proactive in dealing with the exposure to people. The area was evacuated well before any radiation could be found.

My suggestion would be to not panic. Yes, it can blow up, like the US Pennsylvania's Three Mile Island Meltdown. Mushroom cloud and all. Nothing is impossible. The venting could run into problems (though I don't see how). Everything to prevent a disaster could fail. But more likely it won't.

The domes that are so characteristic of nuclear reactors are basically built to contain any meltdowns. You can read about the architecture/engineering of a nuclear reactor facility, but I have, and without boring you with the details, there are vastly reassuring quantities of steel and very, very thick leak proof concrete structure. Its purpose is to contain any explosion/radiation that may occur. And there is no evidence that this integrity is breached.

Japan is a country with a reputation for engineering and efficiency. It has survived the only two atom bombs explosions in the world. I think its fair to say that they aren't going to give this up without a good fight. And, their expertise, ready aid from the world and the inherent safeguards built into every aspect of a reactor are on their side.

So, like the Hitchhiker's guide says, "Don't panic".... if the worst happens, I promise you you will have plenty of time.

Update: there has been an explosion OUTSIDE Japan's nuclear power plant at Fukushima 1. Doesn't seem to be a nuclear explosion, but building is damaged. 2killed, 4 workers injured. Uh... don't freak out just yet. Unlikely that a nuclear blast will result in 4 injuries at ground zero. More likely to do with the pressure building up or steam from some drastic cooling measure or hydrogen exploding from the venting. Let's wait for news. The only thing I am worried about is the radioactive stuff outside the containment - like spent fuel. Building gone means that is exposed, right? Or worse - exploded? But nothing in the news, so obviously I don't know as much as I imagine.

Update 2: Yep, like I said - steam. People within 20km asked to evacuate. Radiation leaking from damaged building. Residents advised to remain indoors, not drink tap water, and to cover their faces with wet towels (? for how long with covered face - but I guess for as long as it takes to get a green signal ?)

Update 3: Early, unconfirmed tweets on mushroom explosion spotted over reactor, but from an Australian, from the look of it. Could be a reaction to earlier blast, or something new? Scientists didn't seem to have invested much belief in the explosion idea for a light water reactor (like these are). Wait n watch  - you'll get to panic or breathe a sigh of relief soon.

Update 4: Stray initial tweets about pressure having been successfully released from the reactors, but paranoid Tweeters on and on about "Japanese reactor just exploded, OMG!!!" The links provided are all to the video footage of the earlier explosion OUTSIDE the reactor that damaged the building and *possibly* raised leakage. Nothing remotely like a nuclear explosion has happened yet, nor is it scheduled.

More quotes:

Robin Grimes, Professor of material physics at Imperial College, London

Despite the damage to the outer structure, as long as that steel inner vessel remains intact, then the vast majority of the radiation will be contained.

Professor Paddy Regan, Nuclear Physicist from Britain's Surrey University

"If the pressure vessel, which is the thing that actually holds all the nuclear fuel ... if that was to explode -- that's basically what happened at Chernobyl -- you get an enormous release of radioactive material.

"It doesn't look from the television pictures ... as though it's the vessel itself.

Update 5: For those who absolutely must follow microdetails (like me), a better source is http://www.tepco.co.jp/en/press/corp-com/release/index-e.html you will get all the techy things like timings for different things done, status of reactors, worker accident status, etc.

Update 6: News of problems at reactor 3 at Daichi.