OT - Probable Meltdown in Japan

Submitted by ZooWolverine on March 12th, 2011 at 11:32 PM

No real information yet, but just got this awful CNN e-mail update:

"We are assuming that a meltdown has occurred" at a quake-damaged nuclear reactor, Japan's chief Cabinet secretary says.

 

Thoughts and prayers are with everyone nearby for their safety.

Comments

readyourguard

March 13th, 2011 at 8:59 AM ^

This is incredibly sad.  I can't imagine living through something so utterly devastating.  My family and I are praying for those people.

Meanwhile, MSNBC, just as they were about to go to break showed another clip of that asshat Charlie Sheen. What a disgrace.

andrewG

March 13th, 2011 at 9:15 AM ^

i'm a graduate from u of m's nuclear engineering department, so let me try to clear some of this up. right now, i can definitively say that we have no idea what's going on. there is a TON of misinformation out there right now on this topic. (the absolute worst of which is coming from bill nye)

they're working under the assumption that a meltdown has already occured because that's the most conservative approach to take. like when a football player is injured and they immobilize the neck, proceeding with caution until they can prove that he doesn't have a serious spinal column injury.

as for whether or not a meltdown has occured, it's tough to say with the data that's out there right now. i would lean towards no, since there hasn't been a significant release of radiation. a full core meltdown seems unlikely, but a partial melt may occur (or may have occurred).

but let me re-remphasize: the amount of misinformation surrounding this topic right now is preposterous. when the media can put the words 'nuclear' and 'disaster' in the same headline, they're going to ride it for all the frenzy it's worth. that doesn't mean this isn't a very real risk with possibly severe consequences, but right now, we don't know much except that there hasn't been a significant release of radiation to this point.

ZooWolverine

March 13th, 2011 at 10:39 AM ^

I appreciate your responses.  I have heard that the fact that they've detected cesium is a strong indication that there has been a meltdown to some extent--is that the case or is it possible that it would be produced through less-catastrophic problems?

I think this does make a good argument for nuclear energy in a weird way if it ends reasonably well--plants are getting safer all the time, but even with older plants in the non-Soviet (i.e. better designed for safety) world, the worst two incidents ever (TMI and this) will hopefully have fairly small repurcusions, especially when you compare them to incidents with coal or oil.  We still need to wait and make sure this does end as well as it can now, because that's not a given, but seems like it's very likely.

I do think it's human nature to have a hard time internally computing maximum likelihoods--something huge and unlikely to harm you is often more terrifying and influences behavior more than something smaller but more likely to harm.  A second reason this has a great impact is that we're selfish--I think a lot of people have an easier time accepting disasters that happen to people at risk for them.  Even though we're emotionally moved by them, tragedies with coal miners don't scare the average consumer about coal, so our usage/political support isn't as influenced.  Those aren't arguments against what you're saying at all, though, quite the opposite, it's an encouragement to keep saying it.

ZooWolverine

March 13th, 2011 at 10:49 AM ^

And as soon as I write this, there are reports of another explosion (sounds like the other reactor that was having trouble) and a state of emergency declared due to "excessive radiation levels" reported, though I don't see any indication yet how excessive they are (could be very bad or could again be terrible-sounding but not going to affect many people).

ZooWolverine

March 13th, 2011 at 1:37 PM ^

The state of emergency and excessive radiation levels were from a breaking news e-mail (basically the same that was in the banner headline) though that's now I think being clarified as from another location (Onagawa) which they're saying is under control.

The second explosion was listed in an article below that was just below the main headlines but it's not on the main site anymore since the rescers getting to Sendai has replaced the reactor news--and it looks like CNN has backed down on that claim to just a possible second explosion (http://www.cnn.com/2011/WORLD/asiapcf/03/13/japan.nuclear.reactors/index.html?hpt=T1) .

andrewG

March 13th, 2011 at 11:10 AM ^

After reading up some more on this, it's probably safe to conclude that at least a partial core meltdown has occured at this point. Cesium-137 is a fission product that is constantly produced in a reactor (functioning normally or otherwise). It emit a strong signature gamma ray that is easy to detect/quantify, so it is typically used as a benchmark.

They have to continue to vent the reactor and associated equipment to prevent the buildup of hydrogen, which could cause another explosion. However, without power, they have probably lost the normal filtration means, so they will be releasing radioactive particles when they vent, which is why they're detecting cesium (and other isotopes) outside the building.

The big issue now is containment. As long as the reactor pressure vessel continues to provide containment, the radiation releases should be managable. These are incredibly strong vessels that are built to survive extreme pressures and temperatures, but the current conditions are probably testing those limits.

Not a Member

March 13th, 2011 at 11:13 AM ^

I found it an incredibly odd choice that CNN was using Bill Nye "The Science Guy" as their "expert" on the reactor situation.  I'm sure he has some credentials to comment on the matter but from a PR standpoint it does not scream credible information.

I joked to my wife that I half expected Mr. Green Jeans to provide his analysis on how the tsunami has affected the agricultural industry.

 

 

 

 

Phoenix

March 13th, 2011 at 10:32 AM ^

This situation sucks so much. I keep thinking: why does it have to be Japan who is worrying about the event of a nuclear melt down? Haven't they suffered enough nuclear damage already?

MGoNukeE

March 13th, 2011 at 11:23 AM ^

Andrew has already been dead-on with regards to what is going on in Japan and how the general public should react to the incident. To summarize:

1) A nuclear meltdown may or may not have occurred, but assuming that it did, this should not cause any significant alarm unless the meltdown breaches containment; otherwise, there are no negative health effects on the public or even plant workers. For reference, containment was not breached in Three Mile Island, where the core was completely melted down. 

2) People in general are stupid and do not understand this; thus, Three Mile Island was used as a scare that was compared directly to Chernobyl. However, the incident occurring at Chernobyl did not occur as a result of a meltdown; rather, poor reactor design led to a sudden increase in power level during operation, which acted like a bomb with enough TNT Equivalent to breach containment. Modern reactors are designed such that this (called a Criticality Accident) cannot happen even if the operators tried very hard.

When Three Mile Island occurred, engineers tried to use the incident as an illustration for just how safe nuclear reactors are (we do the worst possible thing we can and no one dies and illness is rare). This was not the result, as the government greatly increased regulation so as to prevent this accident from occurring again. While this method probably had good motives at the time, the problem is that other power-producing methods such as coal are not held to the same standard as nuclear power (in case you didn't know, mining and burning coal have high risks. This results in significantly raising the cost to build a nuclear power plant to the point that nuclear power could not compete with coal as a means of producing energy.

It hasn't been until recently that economics has allowed nuclear power to recover from Three Mile Island (aided by the fear of pollution and greenhouse gases), but another incident like what happened could lead to increasing regulation even more and killing the demand for nuclear energy again. This is what nuclear engineers such as me and other proponents of energy aside from fossil fuels fear the most*.

*Note that if containment does get breached from natural disasters, I will personally donate money to any help fund to aid efforts to help those in need from the released radiation. If it is also proven that natural disasters are not accounted for when discussing plans for a nuclear power plant I will join the mob that protests this.

andrewG

March 13th, 2011 at 12:15 PM ^

beautiful concept from a physics perspective, but the use of liquid sodium as the coolant probably means it will never happen. there have been a few experimental liquid metal cooled reactors in the past, but i think the PR hurdle will prevent it from ever being used to generate power commercially. filling your reactor core with an element that explodes when exposed to water is a tough sell. plus cleanup is a BITCH. just ask the folks out at idaho national lab who had to clean up after EBR-II.

andrewG

March 13th, 2011 at 11:32 AM ^

I'm interested to see what comes out of this in the following days and weeks. Obviously, all reactors in Japan are built to high seismic standards, but I'm not sure you can defend against an 8.9. The real failure seems to be in the backup systems. Why weren't the backup deisel generators able to operate the pumps and continue providing cooling to the core?? There are clearly going to be some valuable lessons learned for the nuclear industry from this event. Let's just hope that they don't come at too high of a cost.

andrewG

March 13th, 2011 at 11:57 AM ^

i'm in slight disbelief, but cnn actually has an update which downplays the chance of a catastrophic disaster and is technically correct (at least mostly):

http://www.cnn.com/2011/WORLD/asiapcf/03/13/japan.nuclear.reactors/index.html?hpt=T1&iref=BN1

this confirms a lot of what i've been saying (hooray me!), namely:

1) it is highly likely that there has been a partial core melt.

2) this reactor(s) is done-zo. even if the core did not melt, flooding it with sea water was equivalent to signing a death certificate for the reactor

3) there is still containment. a change is this status would signify a transition from bad accident to disaster.

one other point i'd like to bring up is the difference between high radiation levels and a radioactive release. the high radiation levels at the plant are obviously not good, but it doesn't mean anything unless you're near the plant, since most of the radioactive particles are still contained within the plant boundary. if there's a significant release of radiation, that's when it would get bad.

SysMark

March 13th, 2011 at 2:22 PM ^

It won't be used any time soon, if ever.  It still remains to be seen how far the damage is going to progress...they are racing against time to get it cooled and stop the melting. Even after the temperature is stabilized it could take a long time to get in and assess the extent of damage.  This is a very bad situation.

andrewG

March 13th, 2011 at 2:33 PM ^

The reactor is not salvagable, but the plant as a whole may still be. After the Three Mile Island accident, the other reactor was brough back online a few years later. I believe there are 3 reactors on the Japanese site, so if they are still operable, the plant may continue to operate. There's not nearly enough information at this point to tell if that's likely or even possible.

The reactor core as a whole will not be buried. I'm not sure what Japan typically does with their spent nuclear fuel, but they will likely defuel the reactor and treat it as a specialized case of spent nuclear fuel. That probably means offsite storage or burial. One thing is for sure, those will be some damn expensive trash cans.

I Bleed Maize N Blue

March 13th, 2011 at 3:16 PM ^

According to this BBC report, all 3 reactors have had sea water pumped into them.

 

Reactor 1 - shut down, under inspection because of Saturday's explosion, sea water and boric acid being pumped in

Reactor 2 - water level "lower than normal", but stable

Reactor 3 - high pressure coolant injection was "interrupted"; but injection of sea water and boric acid were under way.

Later, officials said sea water and boric acid were also being pumped into reactor 2.

andrewG

March 13th, 2011 at 4:13 PM ^

in that case, the whole plant is probably one giant decommissioning project now. theoretically, new reactors could be built to utilize the existing turbines and such (assuming they are still servicable), but the chances of that happening are roughly on par with me deciding to move to c-bus and become an osu fan.

EDIT: so there are actually 6 reactors on site. i would be shocked if they shut down the other 3 permanently.

NOLA Wolverine

March 13th, 2011 at 3:29 PM ^

Chances are nothing of real consequence will come from the radiation release/meltdown here. There's going to be some serious issues with power it appears though, as rolling blackouts have been ordered to try and bring the energy market back to an efficient level. I wonder how much of an affect this will have with rescue efforts, and just on Japan as a whole. I hope that the rolling blackouts are just a temporary fix before more desirable plans can be initiated to bring Japan's grid back to a fully operatiional level.  

MfaninOH

March 13th, 2011 at 3:38 PM ^

Intense prayers for everyone affected.  I just can't believe what that tsunami did.  The power and speed was amazing, and it seemed like it would not stop going.

It reminds us WHO is in control.  I hope those people were right with God.  I cannot imagine what an earthquake is like, let alone a tsunami.

Makes basketball tournaments pretty insignificant.