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As a nuclear engineer, it is depressing to read the recent reports on the Fukushima nuclear incident — not because of the incident itself (at this point I strongly believe that we will remember Fukushima as evidence of how safe nuclear power is when done right) — but because the media coverage of the event has been rife with errors so glaring that I have to wonder if anyone in the world of journalism has ever taken a physics class. My favorite: in one article, boric acid was described as a “nutrient absorber” instead of a “neutron absorber.” How many editors signed off on that line without asking, “Why would a nuclear reactor need to absorb nutrients?”

Whether it is confusion of radiation with radioactive material, flailing comparisons to past accidents, or hopeless misuse of terminology, reporting on Fukushima has been a mix of hype and speculation entirely devoid of useful information. Let’s set the record straight: the situation is under control, it is unlikely that the nuclear fuel has melted, the risk to the public is effectively zero, and, depending on whether facts on the ground have been reported correctly, it is possible that the reactors will remain capable of producing power in the future.

The Nuclear Basics

A nuclear reactor is effectively a big device for boiling water. Instead of using the combustion of fossil fuel as its heat source, a nuclear power plant uses atomic fission, mostly of uranium. This method presents two major risks. The first — which occurred at Chernobyl but is virtually impossible in a responsible reactor — is a criticality accident, in which the nuclear chain reaction becomes uncontrolled. The second, which we are dealing with today, is an overheating of the reactor core. Unlike coal, which quits generating heat as soon as combustion ceases, nuclear fuel does not stop generating heat when you stop splitting atoms.

There are several layers of protection that keep nuclear fuel contained within a nuclear plant. The first barrier is what is called the cladding — a zirconium alloy sheath that surrounds the fuel, keeps it in a geometry that is conducive to reactor management and cooling, and contains any gaseous fission products.

The second layer of protection is the reactor vessel, a steel container that houses the reactor and its coolant and makes up part of the coolant loop. Damage to the reactor vessel would mean a loss of coolant and make it difficult to keep the nuclear fuel cool.

A third layer of protection is the containment building. This is a thick, steel-reinforced concrete structure built to withstand very high heat and pressure. If the reactor vessel is breached, the job of the containment building is to withstand incredible force and contain the nuclear fuel.

Finally, in the case of Fukushima, there is a fourth layer of protection, which is essentially a dry-wall building surrounding the containment building. This building is not designed to withstand force or heat, and is basically just meant to protect workers from the weather as they work around the containment building.

Unlike most of the world’s nuclear power plants, which are pressurized water reactors (PWRs), Fukushima uses boiling water reactors (BWRs). In a BWR, the game plan is simple: just keep pouring water on, and if pressure gets too high, vent steam into the containment building. Fukushima’s engineers likely had a very clear strategy for accident mitigation in the aftermath of the earthquake. Moreover, BWRs often have large chimneys (empty volume above the fuel rods within the reactor vessel). During regular operation, this chimney would be filled with a liquid/steam bubble mixture from the boiling water — in an emergency, this volume can be packed with surplus coolant, effectively raising the thermal capacitance of the reactor vessel. Given the reactor type and the engineering rigor of the Japanese, I think we have good reason to be optimistic.

What happened?

The earthquake struck at Friday, 14:46 local time, at which point the reactor automatically inserted its control rods (neutron absorbers) into the core and ceased the fission of the nuclear fuel. At this point, reactor power was at 6.5 percent, and full cooling was in effect — a combination that should reduce the temperature of the reactor from its normal operating temperature. At 15:41, the tsunami hit and destroyed the on-site generators that were powering the coolant pumps. Once the generators were destroyed, the pumps switched to battery power. Here, the timeline gets murky — either coolant flow continued until roughly 19:46, at which point a pump failure caused flow to stop or be reduced, or it continued until roughly 23:41, at which point the battery life ran out. In either case, problems with mobile generators that had been brought in to replace the batteries prevented cooling from being immediately re-established. During this time the reactor’s power output continued to fall — at 5–9 hours after shutdown, power should have been 0.8 percent of normal. Coolant flow was re-established on Saturday, around 01:30. It is also likely that there were small coolant leaks due to the earthquake breaking seals in the coolant system, which might have further reduced water levels in the core, but not by much — I would think only 1 percent of core volume could have been lost through small seal breaks, and no larger leaks were reported.

This is the window of time in which core damage, if it occurred, had to occur. My back-of-the-envelope calculation looks like this: The Fukushima 1 Nuclear Power Plant produces about 1350 MW of thermal power during normal operation and has a core volume of roughly 300 cubic meters, made up of about three-quarters water and one-quarter uranium dioxide. Coolant flow was interrupted for a period of 2–6 hours, during which time the core’s power output was roughly 1 percent of normal, or 13.5 MW. This means that 100–300 GJ were dumped into the core without active cooling to remove the heat. Assuming the core began at 250°C, two hours without forced cooling would be insufficient to cause any damage, while six hours brushes against an uncertain region in which cladding melt might be possible, depending on the heat distribution within the core and the assumed heat removal rate from the primary loop without forced coolant flow.

Without exact knowledge of how long the core went without pumped coolant flow, it is difficult to determine the degree of damage the reactor might have sustained. We have two pieces of information to use, neither of which is conclusive.

The first piece of information is an explosion on Saturday at 15:30, which destroyed the outer containment building (the drywall “fourth” layer). The explosion itself was not a serious risk — the building was never meant to be a serious form of containment, but it suggests that the vapor vented out of the reactor vessel and inner, “real” containment building included some amount of hydrogen. Hydrogen can be formed from a number of pathways, including the oxidation of Zircaloy, which would suggest that somewhere in the core, the temperature had risen past 2200°C.

The second piece of information is the detection of cesium and iodine in the vented steam. The presence of these isotopes suggest, at minimum, a degradation of the fuel clad. Whether this degradation was merely an existing point defect in the cladding (not an uncommon occurrence during normal operation) or from a melting of the clad is difficult to determine without knowing how much fission product was detected. It also raises the possibility of a partial fuel meltdown.

It has been widely reported that engineers are pumping seawater into the reactor vessel to keep the fuel cool. If this is true, the reactors are effectively scrap — pumping seawater into the core would introduce too many contaminants for the reactor to remain viable. However, I think that the reporters have misunderstood. Yes, Japanese officials say that they are pumping seawater into the reactor containment. But this is likely a confusion of terms: the officials have been referring to the outer building — the one that exploded — as the “containment building” and calling the containment building the “reactor containment.” If they have been consistent in their terms, then actually, the volume between the containment building (the third layer) and the reactor vessel (the second layer) is being filled with seawater to aid in cooling.

What is the take-away?

From the information we have, we can draw a conclusion anywhere between “the reactor is undamaged and being cooled” to “the reactor cladding and/or fuel has been partially damaged, but the damage is contained and the reactor is being cooled.” The question that should be asked now is whether the reactor has any future value as an electricity-producing asset. The widely-hyped possibility of some Chernobyl-like event is inconceivable without a new, catastrophic disaster. Coolant flow has been re-established and the public is in no danger. Given the magnitude of the precipitating event — a 9.0 earthquake — and the vast property damage it caused, the events at Fukushima are not a serious reason to re-evaluate our own nuclear policy in the United States.

IAEA: "Unit 1 is being powered by mobile power generators on site, and work continues to restore power to the plant. There is currently no power via off-site power supply or backup diesel generators being provided to the plant. Seawater and boron are being injected into the reactor vessel to cool the reactor."

Good article - thanks for that. Two questions though, if the cladding has been degraded (causing the caesium and iodine in the steam), is that likely to affect the fuel rod's geometry and lead to a potential criticality?

If so, is there any way of 'poisoning' the fuel to stop fission?
You lost me at the situation is under control. If 3 explosions in 4 days at a nuclear power plant is control, then your industry has lost a grasp on reality. Anything is safe if the standards of what is safe are lowered enough. Apparently for a nuclear engineer its pretty darn low. I saw MIT on the link and thought I might some reasonable reassurance here, instead I get what in sports is called a homer, a bandwagon fan that thinks his team can do no wrong.
If as you say, the reactors were in shut down mode and not producing much heat at all by Saturday, why was there a hydrogen explosion on Monday?
Thank you for providing a level headed article amidst the rabbit media speculation.
I'm disappointed to see an article like this with the MIT name associated with it. Clearly the safeguards on these reactors were not designed to result in this level of failure. Just as clearly, no one knows what the eventual result will be. The honest way to respond to this event would be for nuclear designers to say, this shouldn't happen, and we need investigate and find a way to fix it so it doesn't happen in the future. That doesn't mean shutting down all of the reactors in use, but it does mean reviewing current reactors to see if they have similar vulnerabilities and attempting to address those. It also means coming up with better designed reactors for the future that are more resistant to major calamities. That's what a professional engineer would do.
4 6 (and anyone else who might start tsk-tsking MIT after reading Mr. Yost's piece):

This is an opinion piece in a student paper. Nothing more. Says so right up there in the headline.

Nowhere does it indicate that it is an official statement from MIT or even MIT's Dept. of Nuclear Science and Engineering on the situation in Japan.

I don't even tend to agree with Mr. Yost on most of his views, but at least have the sense to recognize that an opinion piece is just that - one person's view.

While I think that nuclear engineers should definitely look to Fukushima to see how to improve current plant safety precautions, the notion that this could happen at any other plant is ridiculous. Fukushima was hit by a 9.0 earthquake and then a tsunami. How many nuclear plants are active in earthquake threatened areas, or tsunami threatened areas? It's necessary to examine what went wrong and how to prevent a similar calamity in the future, but this incident should not reflect poorly on nuclear safety as a whole.

Nuclear power will never be completely risk free, but unless something drastic happens in the near future at Fukushima, I think it remains an excellent example of how safe nuclear plants are. It took a huge earthquake and tsunami to threaten the plant, and even then a meltdown isn't possible, just radioactive steam leaks. I'm not sure how dangerous that is in itself, but I don't think the OP was taking the issue lightly.
Please note that the 2200 C number quoted above should be 2200 F (1204 C). However oxidation of the cladding can occur as low as 800 C (1470 F) sufficient to produce some hydrogen, given enough time. Therefore, the hydrogen explosions do not necessarily equate to very high temperatures in the reactor or an indication that melting occurred. Please correct the units of temperature quotation above.
Re: 2200C - I believe that should be 2200F or 1200C? That's a big difference.

Melting pt of UO2 2800C (5070F)
Melting pt of Zr-2 1850C (3362F)Melting pt of SS304 1400-1455C (2550-2650F)
Thanks for the very helpful article. I run a blog for science teachers down here in Namibia and all we have access to is inaccurate alarmist nonsense.

It strikes me, however, that the twin problems that we have seen, pump failure and exposure of fuel rods to steam have nothing to do with the earthquake and the tsunami, they are both design failures that I recall we were discussing back in the sixties. The tsunami was the trigger, not the cause
1: If the IAEA is saying "reactor vessel" then I am more confident that seawater is being injected into Unit 1's reactor, though that still leaves Unit 2 and 3 as question marks.

2: With the control rods inserted, it is unlikely that melting would reconfigure the core into a critical geometry.

3: I think safety is a matter of whether or not the public gets harmed, not whether you have to hear loud noises.

4: Either the hydrogen came from a reaction with the zircaloy, or it came from somewhere else (like the hydrogen in the feedwater), but in any case, there would have been a buildup and the explosion would only happen later after some triggering event.

6: What vulnerabilities do you think the reactors have? This was a once-in-300 years earthquake. If no one in the public gets harmed, and Japan's nuclear assets, on average, suffer less damage than its fossil fuel ones, what do you think needs to be reviewed?

9: 2200 C is the point in my mind in which clad melting is sufficient to expose the nuclear fuel to the water (giving us a spike in radioactivity)-- you are absolutely right, clad oxidation occurs at a lower temperature (you could see hydrogen without melting of the clad). Also, it looks like it got edited out (the original article was 2000 words), but I put fuel melting at 3000 C. We can slap 200 C of conservatism on both those numbers if we want, but it still puts me in the same position-- 2 hours of no cooling is fine, 6 hours puts us in a range where clad melting is possible. The bigger uncertainties are 1) What is the temperature distribution (how hot is the peak channelrod vs the average?) and 2) How long did the core go without cooling?

11: The pump may not have failed (I'm doing my best to decipher the press releases, the timeline that I have constructed could be wrong), or maybe it failed because of damage sustained during the tsunami. Was it a failure of the "design?" It seems a little semantic.

The first real failureerror I have seen so far has been the safety valve sticking on Unit 2 (the article was written on the 13th, so I didn't get a chance to comment). A valve, either between the containment building and the outer building, or between the reactor vessel and the containment building, became stuck closed, which caused venting to stop and pressure to increase. The consequences are relatively mild, but operators should have been on top of this.
Perhaps it will be concluded that the greates vulnerability for this accident was the location of the diesel backup power. Had they been placed at a higher elevation (away from the tsunami waters) reserve electricity would have been available. A design error? I think not; it's best classified as a "lesson learned".
Great article. However, your not going to be able to convince a bunch of nimrods that have never even heard of terms like critcality or decay heat (directed at you Ken 3). Thanks again!
"Let's set the record straight: the situation is under control, it is unlikely that the nuclear fuel has melted, the risk to the public is effectively zero, and, depending on whether facts on the ground have been reported correctly, it is possible that the reactors will remain capable of producing power in the future."

Mr. Yost is mistaken on all four points made here. Need we read the remainder of his opinion piece? Only if we want a condescending lecture on how "safe" nuclear reactors work from an inexperienced, self-proclaimed "nuclear engineer". Maybe Mr. Yost should consider another line of work.
While the reactors themselves may or may not be under control, the spent fuel pool for reactor 4 is certainly not. Spent fuel rods exposed to open air? To the point that they're considering using helicopters to drop water on them? No way that doesn't impact public health.
16: The situation with the spent fuel pool at Unit 4 is, to me, confusing. Management of spent fuel is so simple it is practically a non-issue; the spent fuel simply can't get very hot over the course of a few days, even without fresh coolant. In fact, we can dry cask spent fuel after 5 years out of the reactor-- the power output is so low that just normal air flow over a concrete case is sufficient to keep the rods cool. A fire seems to me like an egregious operator error.

At the same time, let's not get ahead of ourselves. The spent fuel rods were not "exposed to the open air," nor have I heard any serious suggestions that we need to drop water in by helicopter. And as for the claim that the spent fuel rods are impacting human health, if that were the case we would have seen a much, much larger increase in radiation detection.

The summary of Unit 4's spent fuel pool, in my mind, is that reactor operators overlooked a minor issue, it became a minor problem, and once recognized, the minor problem was fixed.
Depending on firepumps to prevent complete meltdown --- safe? Not exactly part of the defense in depth strategies I guess, but commendable resourcefulness. Highlights an issue with depth in defense planning scenarios ... the tails of the distribution of events are always going to be longerfatter than estimated based on short term (human) historical records. Luckily it looks like the issue is being contained with few fatalities in this case, but can the industry continue to maintain public confidence and credibility while relying on engineering system safety factors which are going to be periodically evidenced to be inadequate in dramatic public displays?
Excellent article. What nobody seems to be looking at is that, also in this disaster, a hydroelectric dam ruptured, destroying homes and killing over 1500 people. The media is putting too much attention into the nuclear aspect. All the other nuclear reactors in the affected area have shut down without incident.
Keith Yost at 1:50 PM on March 15, 2011: wrote ''The situation with the spent fuel pool at Unit 4 is, to me, confusing.''

To help you overcome your confusion the following facts may help.

''The government ordered the plant's operator, Tokyo Electric Power Co., on Tuesday night to inject water into the pool at the No. 4 reactor to cool it down ''as soon as possible to avert a major nuclear disaster.''

TEPCO said the water level in the pool storing the spent fuel rods at its Fukushima No. 1 nuclear plant's No. 4 reactor may have dropped, exposing the rods. Unless the spent fuel rods are cooled down, they could be damaged and emit radioactive substances.

The firm said it has not yet confirmed the current water level or water temperature in the pool .... Due to high radiation levels at the No. 4 reactor, workers on Tuesday were unable to prepare for the pouring of water into the troubled pool.

The firm said its workers were only able to remain in the central control rooms at the Fukushima plant for 10 minutes to avoid exposure to excessive radiation levels. They have retreated to a remote site to monitor data on the reactors, it added.''

from -- http:english.kyodonews.jpnews20110378352.html

''Once the water drops to around 5-6 feet above the assemblies, dose rates could be life-threatening near the reactor building. If significant drainage occurs, after several hours the zirconium cladding around the irradiated uranium could ignite.

On average, spent fuel ponds hold five-to-ten times more long-lived radioactivity than a reactor core. Particularly worrisome is the large amount of cesium-137 in fuel ponds, which contain anywhere from 20 to 50 million curies of this dangerous radioactive isotope. With a half-life of 30 years, cesium-137 gives off highly penetrating radiation and is absorbed in the food chain as if it were potassium.

In comparison, the 1986 Chernobyl accident released about 40 percent of the reactor cores 6 million curies. A 1997 report for the Nuclear Regulatory Commission (NRC) by Brookhaven National Laboratory also found that a severe pool fire could render about 188 square miles uninhabitable, cause as many as 28,000 cancer fatalities, and cost $59 billion in damage. A single spent fuel pond holds more cesium-137 than was deposited by all atmospheric nuclear weapons tests in the Northern Hemisphere combined.''

from -- http:www.ucimc.orgcontentmeltdowns-grow-more-likely-fukushima-reactors

Your quoted source is Paul Alverez. A political activist.

I got this from the IPC website:

Robert Alvarez
Robert Alvarez is a Senior Scholar at IPS, where he is currently focused on nuclear disarmament, environmental, and energy policies.
20: Spent fuel rods take a long time to heat up, and even after they have been exposed, they emit radiation, not radioactive material. It would take quite a long time for the zircaloy to ignite-- Even assuming no cooling of the rods, it takes a long time for the temperature to get to a point where zircaloy oxidation is possible, and even longer to reach a temperature in which a fire would combust the spent fuel itself.

A fire in a spent fuel pool is like being run over by pavement roller. Yes, it is as bad as you say. But it is easy to sidestep, and you have plenty of time to react. Even without the shielding from the pool, the beam of radiation is collimated by the walls of the pool itself-- the idea that you would rip off the top of the pool building and pour in water by helicopter is absurd-- give me a long enough garden hose and a ten-foot pole and I could take care of it for you. I don't think people familiar with spent fuel pools are very concerned with Unit 4 as a long-term problem.
Further more, I'd be willing to bet my paycheck that more people die from the dam breach in this story than die from any of these "nuclear disasters":

I am currently at the Department of Nuclear Science's briefing on the Japan nuclear crisis. I will be looking for answers to twelve questions:

Q1: In the 24 hours following the earthquake and plant shutdown, when and for how long were units 1, 2, 3 without pumped coolant flow?

Q2: Have there been any events after those initial 24 hours that have interrupted coolant flow, and for how long did those disruptions last?

Q3: Have there been any leaks or losses of coolant from Units 1, 2, and 3, and if so, approximately how large were those leaks?

Q4: TEPCO reports that it is cooling the reactor cores using the Make Up Water Condensate System, but also reports that they have been injecting seawater into the "primary containment." Where exactly is the seawater being injected, and what is the proper nomenclature?

Q5: Could recent damage to Unit 2's suppression tanks initiate a loss of coolant accident, and if so, how sever would that LOCA be?

Q6: Of what significance are the hydrogen explosions? Do they indicate that the core temperature has risen to a point at which Zircaloy oxidation is possible, or are their alternate explanations for either the explosions or the presence of hydrogen?

Q7: Of what significance is the detection of Cesium and Iodine? Are these the result of a partial clad or fuel failure, or are they due to existing point defects in the cladding?

Q8: What is the explanation for the recent issues with Unit 4's spent fuel pool?

Q9: What, in your assessment, is the current state of units 1, 2, and 3? Has the clad been damaged? Has the fuel been damaged? Is the reactor vessel intact? Is the containment vessel intact? Are the cores being adequately cooled?

Q10: What, in your assessment, are the radiation health risks posed to:
a) Workers on Site
b) The public within a 20-mile radius of the plant
c) The public within a 100 mile radius of the plant

What has been, or likely will be, the radiation doses for these populations?

Q11: If you had to grade them from A to F on how well they have informed the public, how would you grade
b) The Japanese Government
c) The Media

Q12: What will be the likely consequences of this incident on nuclear power, both in Japan, as well as the wider world. Do you believe these consequences are justified?

Will post answers soon.
19 and others: To which hydroelectric dam rupture are you referring? Where did this occur?
JAIF has released a table from TEPCO sources showing they are saying Unit 1 and 3 are in fact damaged (read partial melt.) Unit 2 is "partially" damaged. The PCV (primary containment vessel--four foot thick concrete and steel) is intact for all units. For Unit 2, the supression chamber (part of the containment pressure boundary) is damaged and has a pressure of 0--should be same as PCV presure.

The release also says Units 1-3 have had seawater injected into the reactor core, and Units 1 and 2 have had seawater injected into the PCV.

Each unit has it's own spent fuel pool located directly next to the PCV. For Unit 1 and 3 these pools are now exposed to the open air--therefore water could be added by helicopter if necesary (though that would result in more contamination of the site who cares at this point.)

It sounds to me that most of the leaked CONTAMINATION has come from the spent fuel pools--so since evacuation has occurred, this is probably TMI but Chernobyl. In all I agree with most of your assessment.
Keith Yost at 4:15 PM on March 15, 2011 wrote;
I am currently at the Department of Nuclear Science's briefing on the Japan nuclear crisis. I will be looking for answers to twelve questions:
Q4: TEPCO reports that it is cooling the reactor cores using the Make Up Water Condensate System, but also reports that they have been injecting seawater into the "primary containment." Where exactly is the seawater being injected, and what is the proper nomenclature?

As of Mar 15 1700hrs Tokyo time the Japan ATomic Industrials Forum has a comprehensive summary of teh condition of teh six reactors at Fuushima Daiichi, indicating seawater injection to the RPV for No.1, 2, 3 and seawater injection to the containment for No. only. see -- http:www.jaif.or.jpenglishnews_imagespdfENGNEWS01_1300189582P.pdf
Your conclusions sound overly optimistic to me. The dose levels reported by IAEA at 400 mSv per minute (between the buildings of reactor 3 and 4) as well as the surprising amount of hydrogen accumulated consequently to the steam release and the substantial presence of iodine and cesium in the atmosphere surrounding the facility lead me to make much pessimistic conclusions.

I strongly disagree with your statement concerning the sea water being pumped outside the RPV. To me, the mere fact that they are injecting boron proves that they are doing it in the reactor core to further help slow down the chain reaction which suggests that they fear (know?) the control rods are damaged (possibly following partial melt of the fuel assemblies), hence partly inoperative.

This is a desperate measure showing the lack of faith remaining in the conventional response procedures.

Additionally, what do you make of the fire in reactor 4 which is believed by the utility authorities to have been caused by hydrogen too ? This was unexpected too and remains to be elucidated.

Why do you silence the issue of cooling the used fuel pool which has, for an unknown cause too, lost its roofing and his now open to the atmosphere ?
Keith Yost at 3:19 PM on March 15, 2011 wrote
''give me a long enough garden hose and a ten-foot pole and I could take care of it for you.''

Keith I'd like to take you up on that offer ...

NHK TV is reporting that TEPCO has informed the local Fire Department that there is a second fire in the Fukushima Daiichi No.4 reactor spent fuel pool.

from -- eg http:www.kcet.orgdisasterinjapan
Mr.Yost states " At 15:41, the tsunami hit and destroyed the on-site generators that were powering the coolant pumps. Once the generators were destroyed, the pumps switched to battery power."
Is it true that the backup generators were in the basement or low areas of the complex to where any flood waters would naturally flow? Why was it not possible to fly in generators and attach them to the emergency grid powering the circulating pumps much more efficiently and quickly?
Fukushima incident is evidence of safety of nuclear power?

Also, your most immediate worry is the future value of the reactor, never mind let's say the workers which haven't been evacuated already working under horrible conditions?

I mean, seriously...
26: The primary source of radioactive contaminants is NOT the spent fuel pool. How would the contaminants get out? No, much more likely is that the small amounts of volatile fission products that we have seen have come with in-core contact with water that was subsequently vented out.

28: The 400 msv reading was one reading from one monitor, and disappeared quickly. Rad monitors have failure rates too, and in either case, the public doesn't live between reactors 3 and 4. The top dose to any worker has been about 10 mrem, which is an extremely small dose when you consider that normal background dose over a year is 250-500 mrem.

As for the borated water, there would be no reason not to add the boron. The fact that they added it is not indicative of anything-- I would borate the water regardless of whether or not it was being injected into the core.

All of the control rods are fully inserted. The chain reaction has stopped.

The fire in unit 4 is not believed to have been caused by hydrogen, as you claim. TEPCO reports it was an oil fire from a nearby pump, and that conclusion is much more logical than fuel overheating and certainly more logical than any hydrogen-based explanation.

The roof on unit 4 is still on. It has not lost it, let alone for an "unknown cause."

29: See the previous comment on the causes of the fire.

30: No, it would have been faster to connect to existing battery power rather than fly in new generators. Also, flooding of the generator connections would mean you would have to not just ship or truck in new generators, but you would have to pump the water out of the area before you did so. Switching to battery power is the preferred option.

31: As I said before, the max recorded dose to a worker has been 10 mrem. Many reactor workers here at MIT often have lifetime doses about 1000 times larger. The radiological threat that the workers face is much less than the other threats, namely injuries sustained during the earthquake, tsunami, normal workplace accidents, and so on. There is no need to demagogue the issue.

And yes, if a reactor successfully goes into shutdown after enduring a once-in-300-years event, that is a success. You have to remember that the reactors are only designed to remain operational up to an 8.2 earthquake, and beyond that they are designed merely to safely fail.
Seems like the author's rather religious belief in "safety of nuclear power" may take a hit with the latest news and photos of the "normal" situation at Fukushima. Gives the acronym "SNAFU" all new meaning.
Keith, have any of the questions you had posted earlier been answered? They all seemed like very good questions that needed answering so that we could get all of the facts.

I also have a few questions of my own:

1. Is the rupture of number 2's suppression tank (the donut around the bottom in all the diagrams) a critical rupture? Does this mean the main containment structure been breached or is this only a loss of coolant pressure?

2. Were there spent fuel pools at reactors 1 and 3 where the outer buildings suffered hydrogen explosions and if so what is their status afterwards? Are they similarly protected like the reactors themselves?

3. If the radioactive material being vented only has a half life of a few minutes how is it being detected by navy ships off the coast and even in Tokyo?
Ah, this is obviously some strange usage of the word 'safe' that I wasn't previously aware of.
Good morning Mr Yost
I am not engineer, I am just economist and I have a question for you.
These days in Europe there are a lot of information and really confusion abuut situation and consequences of Fukushima incident.
My wife is japanese so part of my family live in Tokyo.
For you which is the most likely escenario? and which is the worst expected situation for the people living in Tokyo?
Dimitri???? Really?????? Your using the mainstream media as your source. Of course it is not normal there, there was a record earthquake. All I can say is, you are a moron. Unfortunately for this country, you are not in the minority. I proposed to my colleges yesterday that starting tomorrow, we should shut down every nuke and coal fired power plant in this country. We will then exist on solar and wind power. I'm sure Dimitri would love this. He can sit in the cold and the dark, eating berries and twigs. It will be great.

Keith, I appreciate your article, but its kind of like a whisper in a hurricane. The only thing people will be able to hear is us turning their power off.
Your using the mainstream media as your source

No, I am using TEPCO official status charts, which are posted here and other places:


All I can say is, you are a moron

That may be but it did not preclude the Institute of granting me a degree in AeroAstro in 1986

I proposed to my colleges yesterday that starting tomorrow, we should shut down every nuke and coal fired power plant in this country. We will then exist on solar and wind power. I'm sure Dimitri would love this. He can sit in the cold and the dark, eating berries and twigs. It will be great.

When people's deep religious beliefs are challenged they usually lash out with anger and hate.
Keith, what's the latest on the spent fuel pool? This is what Greenpeace are saying:

"The spent fuel pool in unit 4 is boiling, and once that starts you can't stop it," said Jim Riccio, a nuclear expert at Greenpeace. "The threat is that if you boil off the water, the metal cladding on the fuel rods that is exposed to the air, and is volatile, will catch fire. That will propel the radiation even further."
Keith: hope you get answers to your questions. where do you think most of the radiation is coming from and how short lived is it?

also, where did you get the statistic about 10 mrem dose for workers? if this is true, this is really good news. if it's false, it's going to look really bad. what is the source?

On alvarez and chernobyl, alvarez claims that the reactor core released 6 million curies. Not quite right. It released 300 million curies, half of which were xenon 133, inert gas, much of the rest the more dangerous iodine 131 and Cesium 137. Info from Garwin and Charpak, Megawatts and Megatons.

How wrong can you be in the service of creating fear?
Keith: You ineffectively addressed my concern in 30. Please consider this:The backup generators would still be running,if they get refueled at times,and if they were placed higher up in the complex at some point in the 40 years of operation. The batteries that did operate ran out of power in 8 hours.Generators could have been flown or trucked in with plenty of time to hook up to the emergency power grid in order to keep the critical circulating pumps in operation,if the connection panels were not also placed low enough in the complex to be flooded.Is there a lesson anywhere here in these backup failures.Also,
Please explain if the MOX fuelmix containing plutonium in unit 3 makes the escaping steam and particulates more dangerous to those attempting to quell the fires and those downwind.
If the situation in Japan is so safe, why don't you pack up your love ones and move next door to it?
Helicopters were attempted for water dumping but pulled back due to radiation concerns.

Anyone who says "the situation is under control" is clearly not familiar with the situation! If the situation was under control, we could leave the plant alone for a couple weeks and it would get better. At the moment doing that would result in catastrophic breaches on multiple reactors.

You speak with the confidence of a slots player who's never taken a stats class.

If the nuclear issue was the only issue, sure I'd go there with my family. The problem is that they had an earth shattering earthquake.

We can add you to the list of morons that have already posted on this page.
Kip's point (41) is very important. This event is going to have a massive impact on the future of nuclear power reaching carbon emission targets etc. It is vital to be clear about whether the main causal factors are (a) the earthqauke and the tsunami, or (b) issues with the design of old BWRs, or (c) inadequate safety planning and management. It looks very much like a combination (b) and (c).
Wow, so hydrogen explosions, cracked containment vessels, and a reading of 1000 mSv of radiation at the site and "the situation is under control" I was laughing so hard that I snorted milk out my nose. But then what do you expect from one of the unwashed and uneducated masses. Full speed ahead, nuclear gods!
--We can add you to the list of morons that have already posted on this page.--

This seems a pattern with you, Chris. So far, you have labeled two people as "morons" - who have had the good sense to point out that four severely damaged and compromised reactors, with high levels of external radiation and the best outcome as a horrendously expensieve scrapping operation as anything but "normal", "safe" or "under control".

You appear to be unabel to digest simple status charts provided by the plants' Japanese operator, the link to which I have posted, which clearly show the level of damage and extreme concern.

Your "contribution" on this thread appears to be that of a foul-mouthed simpleton, spewing childish personal tantrums in the hope of forcing the world to be more like you want it to be.
"if the cladding has been degraded (causing the caesium and iodine in the steam), is that likely to affect the fuel rod's geometry and lead to a potential criticality? "

Absolutely not, water moderated reactors are made specifically to prevent this outcome.

If the reactor is hot, water turn into steam and the reactor goes unmoderated (i.e. no neutron slowdown).

Hot reactor - Hot water steam - steam no moderation.

Any reactors, other then chernobyl type, are now build criticality temperature dependent. If the temperature goes too high, something stop the criticality.

If that were the case, you would simply ignore me. However, you've taken the time to respond to what I've said, so I've touched a nerve with you. This is good. You'll never find anywhere that I've written that what happened hear wasn't a disaster. It is a natural disaster. I feel really bad for the people of Japan. They have suffered already, and I fear it is just a beginning.

You see, the whole problem I have with people like you, is that you are going to stand on the sidelines and say "see this doesn't work!!" You've yet to offer a solution. My whole point from the beginning, and I think Keith is trying to explain, is that in light of what happened over there, the nuke plants operated relatively well.

If you disagree with that assesment, please tell me what the death toll is as a result of the "nuclear accident"??? So far, the dose rates that I've seen are negligible. You're worse off going to the beach for the day.

Our country is in a energy crisis. We are depending on foriegn oil from countries that definitely don't have our best interest in mind. Unfortunately we can't run the country on pixi dust. We need nukes!!!

I apologize to Dimitry and anyone else I called a moron, but I think spreading hysteria is a crime against this country and it's security.

I hope we don't wait until the lights go out to take action. Trying to build a nuke plant overnight would cause an accident.

This is absolutely my last post on this issue. My thoughts and prayers are with the Japanese people, and again, I apologize for my vitrial comments.


Very good article, strikes a balance, thanks for that...some questions;

1) looking at various photos of the Fukushima damage reactor three looks pretty much munted in terms of it's external structures. Much more so than the others.Where can one look in the photos to see where the spent fuel pond might have been, assuming it was on the top of the building above the reactor?

2) Do you think it may have just tipped over spilling fuel rods onto the ground or could an explosion have blown outwards spewing fuel rods all over the vicinity of the plant?

3) Correct me if I am wrong but reactor three was converted to run on a plutonium mix with help from the French who are apparently leaders in the plutonium field of nuclear power generation. is there a chance spent plutonium mix rods are lying around somewhere?

4) do spent fuel rods heat up without being submerged in water and what is the risk of spontaneous combustion of such rods?

5) I think the changeover of fuel type in reactor three occured last year...would there by any chance have been enough time to have elapsed resulting in the first of the plutonium mix rods to have been spent and transferred to storage ponds?

Many thanks

When helicopters dumping buckets of water on the reactors have to be withdrawn because of high radiation levels, I see a failure of technology.
Drones can fly long distances, yet human pilots are needed for an helicopters to lower a bucket in the ocean and lift it up a few hundred yards and dump it. With precise GPS locating capabilities and sensors that can let you know if a bucket is completely immersed, there must be a video game software engineer that can have the helicopter accomplish this task over and over automatically. It is time that robots replace people in these dangerous jobs. Maybe a scaled up version of the latest remote control video hummingbird that can suck and eject water from its tail can do this job. It is clear that all the parts exist. Welcome to the technologies of peace. generatorblue
I think this should go down as an example of how safe reactors are and well prepared the Japanese were. Here are some numbers a colleague of mine compiled to keep in mind (where possible, numbers were verified against multiple sources: IAEA, NYT, Ibaraki prefecture radiation monitoring stations south of Fukushima):radiation dose unit conversion: 1 rem 10000 micro-Sv,

1. Maximum doseyear for US rad worker: 5 rem,

2. Background radiation doseyear in US: 0.500 rem (Denver, CO: 1 rem)

For radiation dose in Japan, consider:


3. Highest measured dose rate anywhere in Ibaraki: 0.00025 remhour (Tuesday morning)

4. Highest reported dose rate at site boundary: 0.1 remhour

5. Highest reported dose rate on reactor site: 40 remhour for several hours,

Comparing this with radiation dose rate at Chernobyl on reactor site in days after explosion( http:en.wikipedia.orgwikiChernobyl_disaster ) :
6. 10 to 5000 remhour (not considering dose-on-contact of ejected reactor components),

7. Average cumulative radiation dose for Chernobyl first responders, resulting in up to 300 acute radiation deaths: 500, 000 rem.

Some news organizations keep using milli-Sv and milli-rem interchangeably, never mind the factor 100 difference.
I understand my question does not have an "exact" answer and it depends on many factors:

What would a "typical" contact dose rate be in RHR on a fuel assembly that is being removed as spent fuel a week after shutdown in a commercial BWR and in a PWR. Thanks
The country is in an energy mess, perhaps partly due to wasteful overuse of energy. You may dispute that but can the industry continue to maintain public confidence and credibility while relying on engineering system safety factors which are going to be periodically evidenced to be inadequate in dramatic public displays?

Thanks for your "hearfelt" apology. You wrote:

--I apologize to Dimitry and anyone else I called a moron, but I think spreading hysteria is a crime against this country and it's security.--

I want to remain a moron, rather than the new accusation of being a "criminal against this country and it's security" - the latter seems far more serious and probably carries a significant prison term.

My "crime" ? Well I posted a link to the TEPCO status page on their Fukushima reactor cluster. I pointed out that the information in those charts clearly state anomalous, dangerous and unsafe conditions at the plant. I also stated that those claiming that the event demonstrated the "safety" of nuclear power are likely adhering to a religious, rather than rational belief system.

Instead of dealing with the facts presented by the plant's operator, you decided it would be best to accuse me of "spreading hysteria", "standing on the sidelines" and desiring to "eat berries and twigs". For the record, I like berries but not twigs.

I don't know what is going on in your head, but I am really hoping that you are in those professional fields that benefit from a hyper-elevated emotionalism and you don't make rational, logical, technical decisions for a living.

You pointed out unsafe conditions at the plant? How is that different from the other areas of the country affected by the Earthquake.

Since you have a selective memory, here is your original post:

Dimitry at 1:06 AM on March 16, 2011:
Seems like the author's rather religious belief in "safety of nuclear power" may take a hit with the latest news and photos of the "normal" situation at Fukushima. Gives the acronym "SNAFU" all new meaning.

As you can see, there is no reference to a TEPCO status page. To me, that seemed like an emotional response. Also, you have STILL stated no facts. You did not address my main point, how is it affecting the general public???????
That's a lot of question marks there, Chris...

My very second post, linked a TEPCO page, which is really the only source of official and factual news on the matter. You are yet to digest it, apparently. Those are the FACTS, I stated, which you are apprently not able to comprenend. Much more entertaining to accuse those around you of being a "criminal" or a "moron", right?

Now, to your ill-asked question - "how is it affecting teh general public?"

Well, lets count the ways:

1. Enforced evacuation from a large area.

2. Indoor orders for a larger area.

3. Food contamination instructions for affected area.

4. Continous radiation scans of general population in affected area.

5. Evacuation of foreign nationals from a very large area around the plant.

6. Slow semi-evacuation or emptying of Tokyo.

7. Re-evaluation of many nuclear projects and policies in Europe.

8. Run on iodine pills all over US West Coast.

9. Substantial levels of radiation exposure to the immediate hundreds of workes manning the front lines. Japanese government had to increase exposure limits to 5 times that of the US standard to keep them working there. They are as much members of the general public as anyone else.

Those are just a few of things that are obvious to a rational person after a few minutes of thinking. I am sure there are more. The fact that you are unable to comprehend any of the above and are insisting by your multiple question marks that there are NO effect on the general public from this near-catastrophe, tells me that you are operating on the religious, rather than rational beliefs.

On the other hand, the nuclear industry likely considers anything short of massive die-off around the plant as "vindication of safety", a view you apparently wholeheartedly subscribe to.
Ok, maybe I didn't ask the question correctly.

How many people are dead as a result of the nuke plant failure verses the number of dead due to the earthquake and resulting tsunami?


Right, the situation is under control. Sure seems like it is ready to meltdown and looks it as well. If by under control you mean the evacuation and the "dead zone" of 10 miles or so around the site that will never be inhabited again blocked off , then YES IT IS REALLY UNDER CONTROL!
--How many people are dead as a result of the nuke plant failure verses the number of dead due to the earthquake and resulting tsunami?--

I guess you did not ask the question correctly. Your interest appears to be - is the situation at Fukushima more or less fatal at this point than the most destructive earthquake and tsunami to hit that area?

If that is your standard of judging safety, than I grant you that the Fukushima power plant is less destructive than the level 9 earthquake plus a massive tsunami.

However, civil projects are judged on a different spectrum than the giant earthquakes and tsunamis.

You see, a power plant is supposed to NOT cause deaths (several workers missing, presumed dead), massive evacuations, indoor orders, large civilian radiation sweeps and panic. While natural catastrophes do that as a matter of course.

Judging by your beam-like focus on comparing death tolls in attempt to prove "safety", you either already work or aspire to work in management. This is a very common philosphical inversion that is often used in the managerial class - the "success" and "failure" are redefined in order to accomodate the changed environment. Therefore, parts are "assumed" to work unless engineering can prove immediately that they will not, and power plants are "safe" if they are not as destructive as tsunamis.
I'm not sure what your point on all this is. Either way, I'm tired of arguing with you. You are going to believe nuclear power is not safe no matter what I or anyone that knows anything about radiation and nuclear power say.

I believe that was my original thought when I posted here. Unfortunately articles like this one are so overshadowed by misrepresentations, overreactions, and sometimes down right lies (i.e. several workers missing, presumed dead).

We should agree to come back here 3 months from now and have this same discussion.

What'd you say Dimitry, are you in?

How many deaths and damage were caused by failures at damns and refineries during the earthquake vs those a Fukushima Daiichi?

How many deaths and how much environmental damage has been caused by incidents at damns and other non-nuclear power plans vs those at nuclear power plants? Lets not even talk about refineries, mines and other facilities that produce the fuel for such plants.

Those are the relevant questions when arguing over the safety of nuclear power.
--I'm not sure what your point on all this is. Either way, I'm tired of arguing with you. You are going to believe nuclear power is not safe no matter what I or anyone that knows anything about radiation and nuclear power say.--

Do you always tell others what they 'believe' or do you actually listen? You have told me nothing about radiation or nuclear power, except to use illogical comparisons with natural disasters, ad hominem personal attacks and other childish outbursts.

--I believe that was my original thought when I posted here. Unfortunately articles like this one are so overshadowed by misrepresentations, overreactions, and sometimes down right lies (i.e. several workers missing, presumed dead).--

So your original thought is that references to plant operators' status reports are 'misrepresentations, overreactions, and sometimes down right lies (i.e. several workers missing, presumed dead)'?

The information on the missing two workers is from an IAEA report, which documents other injuries at the 'safe' power plant, which I will try to post an excerpt from.

--We should agree to come back here 3 months from now and have this same discussion.--

So you don't want to talk factually about nuclear safety now, when the topic has direct relevance, but will do so in 3 months? OK, I guess...

--What'd you say Dimitry, are you in?--

Sure, if you actually start looking at the facts, eschew weird analogies with tsunamis and behave like a gentleman.
From IAEA Report on Fukushima Injuries:

According to the report, two Tokyo Electric Power Company (TEPCO) employees suffered minor injuries; two subcontractor employees were injured, one who suffered broken legs and the other -- whose condition was unknown -- was transported to a hospital; two people have gone missing; two people were suddenly taken ill; two TEPCO employees were transported to a hospital when authorities were donning respiratory protection in the control center; four people -- two TEPCO employees and two subcontractor employees -- sustained minor injuries due to the March 11 explosion at unit 1; and 11 people -- 4 TEPCO employees, 3 subcontractor employees and 4 Japanese civil defense workers -- were injured due to the March 14 explosion at unit 3.

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Also according to IAEAs report, 17 people -- 9 TEPCO employees and 8 subcontractor employees -- suffered from deposition of radioactive material to their faces due to low levels of exposure and were not taken to a hospital; two policemen were decontaminated after being exposed to high levels of radiation; one worker suffered from significant exposure during vent work, and was transported to an offsite location; and firemen who were exposed to radioactive material are being evaluated.

--How many deaths and how much environmental damage has been caused by incidents at damns and other non-nuclear power plans vs those at nuclear power plants? Lets not even talk about refineries, mines and other facilities that produce the fuel for such plants.--

All good points. Nuclear power has additional special considerations, due to potential wisespread affected area, very long term environmental degradation and continued lack of spent fuel strategy world-wide.

Given the long term medical, environmental and political effects of many of our current power generation methods, perhaps we should be looking to improve the situation, instead of continuing to balance fatialities and environmental degradation between bad and worse options?

Is coal or nuclear our very best options going into the future? I hope neither, if the choice is spent fuel puddles near every reactor andor widespread cancer and asthma from coal.

Your original assertion was that 'several' workers are missing, presumed dead.

To me, two people does not fall into the category of several (unless you are fear mongering that is)

First, I did not see presumed dead in the IAEA report.

Second, it does not reference when they were missing or what may have caused them to come up missing (like, I don't know, maybe a massive tsunami)

Third, in general, the report is poorly written. I don't blame the IAEA for that though, it sounds as though some of the translation is being jumbled.

On the whole, it does not point to injuries related to it being a nuclear power plant.

I want to wait three months, because it is hard to tell what is exactly going on with all the mis reporting. The facts will speak for themselves after a few months. Or not. I am getting reports from NEI. It is starting to trickle out even now that every thing is under control. In my humble uneducated opinion (he he) this will seize to be an emergency once site power is restored. Then it will be a big, expensive, nasty, radiological mess to clean up. Ideal situation? No. But not having electricity is not ideal either.

Btw, I really liked your ideas for replacing power we get from coal and nuclear. Oh wait a minute, you didn't have any. :)

The two workers were in the turbine room of Reactor 4 when the large fire there occured. They have been missing ever since.

Are you always this smug with this kind of thing, or only when you 'think' you can score a cheap point at the expense of some simple 'workers', hey only two of them, right?

Your smug and self-satisfied humor at their expense is quite nauseating.

Your expectations of (he he) end of emergency when power is restored is (he he) quite misplaced. The cooling infrastructure in the 4 reactor side is likely shot due to several large explosions and fire, so it is inlikely one can simply 'reboot' the plant and hit 'cool'. Your opinion is indeed 'uneducated' - how many large civil engineering projects have you worked on in your 'professional' capacity - five classes and a senior thesis?

Again, we agree that the best scenario is 'a big, expensive, nasty, radiological mess to clean up'. And who pays for this? Why the taxpayer - certainly not the nuclear industry, which would quickly go bankrupt if it actually had to pay for the cleanup and for long-term spent fuel storage or dispositin in a really safe manner.

There are plenty of opportunities to scale up sustainable energy resources, reduce our currently profilgate use of energy and retool the currently non-sustainable methodologies toward higher safety and more sustainability. Unfortunately, with the political elites essentially purchased by the energy lobby, none of this is likely to occur.

We are looking at a future of more unsafe nuclear and dirty coal so we can "have our electricity", you are right about that. So rest assured that your industry will not suffer in profits or in clout, while proudly proclaiming safety on the radioactive ruins of Fukushima.
I guess when I point out that you mischaracterized what is going on, I'm being smug. So be it. However, you calling me uneducated would appear that you are talking down to me, not vice versa.

Large fire in Reactor room 4? Unit 4 had been shutdown for refueling. I'm just not sure what to make of that. I am not minimizing any loss of life. And I am not using the deaths of innocent to advance my agenda either. Guess who is. The nuclear proliferation movement. Not only that, but diverting attention to the real tragedy. The death count from the 'real' disaster is over 10,000.

As for this:

There are plenty of opportunities to scale up sustainable energy resources, reduce our currently profilgate use of energy and retool the currently non-sustainable methodologies toward higher safety and more sustainability.

I only have one thing to say to that. Hehe.
America may not know much about science, but they do understand trust, and they've learned over time that they should not trust nuclear engineers. This column is yet another example of overconfidence by the nuclear engineering community.
Mr Yost, are you a nuclear engineer, or an economist ? The reason I'm asking is, back on October 15, 2010, you wrote : "As economists, we are inclined to take the vantage point of..." Did you get promoted in the meantime ?
Dude... you are so wrong. The situation is much more dire than you describe. Have you heard the reports of dose levels at the site boundary? Keep watching... I bet everyone evacuates and the plant melts away.
Lot't of wasted space above. I want to hear the facts, not a lot of uninformed and biased opinions. Keith, you had a good set of questions and gave some answers that came out of the briefing. Please let us know what the facts are about the spent fuel pool. Did it lose one of it's wall's? What about the so-called zirconium fire? What is the current status?
--I guess when I point out that you mischaracterized what is going on,--

You guess wrong again, comrade. Where and what did I "mischaracterized"? The only imprecision in my posts has been the use of "several" instead of "two".

--I'm being smug. So be it.--

We agree there.

--However, you calling me uneducated would appear that you are talking down to me, not vice versa.--

Right you are. Your entire presence here has been one large uneducated blunder, with baseless accusations ('you are a moron, Dimitry!'), hysterical attacks ('you are a criminal against the country'!) and self-aggrandisement ('I know about radiation and nuclear power' - no evidence of that from your posts).

--Large fire in Reactor room 4?--

Reading comprehension and attention issues, to boot. The missing men were in the turbine room in Unit 4 - aka, the Big Fire that was all over all the news.

--Unit 4 had been shutdown for refueling. I'm just not sure what to make of that.--

I though you were the self-proclaimed expert on nuclear power and radiation. Why a fire in Unit 4 occur - perhaps the dry spent fuel pool above got a bit hot?

--I am not minimizing any loss of life.--

Sure you are. Only backtracked when got caught.

--And I am not using the deaths of innocent to advance my agenda either. Guess who is. The nuclear proliferation movement. Not only that, but diverting attention to the real tragedy. The death count from the 'real' disaster is over 10,000.--

Obviously MIT no longer takes the writing requirement as seriously as it once did. You meant to say 'nuclear non-proliferation movement', in itself a logical mistake, but given your overall communication quality, understandable. And, of course it wasn't diverting attention TO the real tragedy but FROM it.

--I only have one thing to say to that. Hehe.--

I am glad all nuclearcoal future makes you giddy with delight.

I have a counter proposal to about our 3 months discussion. Lets make it about 10 years. You will be all grown up then, would have gotten your degree, worked for a while, learned how the world really works, perhaps took on real responsibilities and learned how to communicate rationally and calmly.
What's really interesting here is that it was the loss of backup power which made the situation serious. I could find no press asking the obvious question why not fly in generators until I happened upon Heres a timeline:
"Efforts to manage Fukushima Daiichi 3
13 March 2011
Reactors 1, 2 and 3 were in operation at Tokyo Electric Power Company's (Tepco's) east coast Fukushima Daiichi nuclear power plant when the magnitude 9.0 earthquake struck. Because plant power and grid power were unavailable during the earthquake, diesel generators started automatically to supply power for decay heat removal.

This situation continued for one hour until the plant was hit by the tsunami wave, which stopped the generators and left the plant in black-out conditions.

The tsunami wave that hit the plant measured at least 7 meters in height, compared to the maximum 6.5 meter case the plant was designed to cope with.

The loss of power meant inevitable rises in temperature within the reactor system as well increases in pressure. Engineers fought for many hours to install mobile power units to replace the diesels and managed to stabilize conditions at units 2 and 3.

However, there was not enough power to provide sufficient coolant to unit 1, which came under greater and greater strain from falling water levels and steady pressure rises. Tepco found it necessary yesterday to vent steam from the reactor containment. Next, the world saw a sharp hydrogen explosion destroy a portion of the reactor building roof. The government ordered the situation brought under control by the injection of seawater to the reactor vessel."

Me (David) back.

So, it sounds like the generators they brought in just werent powerful enough.

Theres another really really tragic datapoint. On Sunday, the 13, the USS Ronald Reagan arrived offshore with the capability to supply 100MW of power to the plant. This is a normal thing a Nimitz class aircraft carrier does during humanitarian missions. It can light up a whole city.

It may very well turn out that that all the severe consequences could have been averted if the Japanese had just asked for help. Maybe this was considered and rejected for a solid technical reason, but I sure hope some investigative journalist follows up this angle and gets to the truth.

1) Interesting marketing docket peddling "fail safe" nuclear energy. I think there is nothing "fail safe" with nature and human. It is a calculated risk one need to take.

2) People do not die of radiation like they die when shot at. They die over generations. People are still dying of Bhophal Gas Tragedy. (BTW US Companies that profited and installed the leaky valve are still smiling).

3) Is there an alternative to Nuclear. Personally I do not think so unless we find a way to reduce our wants and population. I guess Nuclear is the way to save the earth as this will destroy Humans and then bring balance. So as a popular Hindi Movie Song goes "ALL IS WELL".
IAEA reports:

Japanese Earthquake Update (18 March 12:25 UTC)
Japanese authorities have informed the IAEA that, prior to the earthquake of 12 March, the entire fuel core of reactor unit 4 of the Fukushima Daiichi nuclear power plant had been unloaded from the reactor and placed in the spent fuel pond located in the reactor's building.


Contrary to several news reports, the IAEA to date has NOT received any notification from the Japanese authorities of people sickened by radiation contamination.

In the report of 17 March 01:15 UTC, the cases described were of people who were reported to have had radioactive contamination detected on them when they were monitored.

I don't know how much clearer you can get than that.
--Japanese Earthquake Update (18 March --12:25 UTC)
Japanese authorities have informed the IAEA that, prior to the earthquake of 12 March, the entire fuel core of reactor unit 4 of the Fukushima Daiichi nuclear power plant had been unloaded from the reactor and placed in the spent fuel pond located in the reactor's building.--

This has been know for days, but I am glad you are finally up the speed. Sounds like a pretty dangerous practice to unload well-spent fuel into the pool temporarily, since the pool generally has much lower levels of protection and containment, which we have just seen. The pool in Unit 4 is likely to have been damaged by the quake and subsequent fire, making the task of keeping it wet almost impossible. Since the outer containment building has been largely destroyed (clearly seen on the recent photos), we have the entire fuel load, at various level of decay essentially open to the environment and being essentially uncooled.

The real news today is:

--Tokyo (CNN) -- Japan's nuclear and industrial safety agency on Friday raised the level for the crisis at the Fukushima Daiichi nuclear plant from a 4 to 5 -- putting it on par with the 1979 incident at Pennsylvania's Three Mile Island.
According to the International Nuclear Events Scale, a level 5 equates to the likelihood of a release of radioactive material, several deaths from radiation and severe damage to a reactor core.--
Death toll due to Three Mile Island 0
New nuclear power plants since Three Mile Island: 0
Ok, no nuclear. I guess we're back to conservation. I hope that works. Rolling black outs in California didn't go over too well.
Ah, the old "TMI killed the nuclear industry" myth.

It is completely incorrect to claim that there were no new nuclear plants since TMI - considering that this dialog is clearly taking place regarding the international nuclear power industry, not just the USA. Incidentally, 53 US plants that were in progress at the time of TMI were completed and put on line.

However, this bit of misinformation makes it sound like there was an instant freeze on new reactors going online. Yes, some projects were mothballed - some that were even in advanced stages of completion.

But to assert that all we've got post-TMI are plants that were already online at the time of that accident?

Oh mention of the fact that nukes are NOT economical and even with great engineering, the Profit motive has been winning out over safety. There were obvious flaws in the nuke design in flaws that exist in several plants in the US.

No mention of the status of our NRC organization and the budget cuts and reduced staff over the years....leaving the plants increasingly self-regulated. We see where this got us in the banking industry. we need to think about our Republican and Libertarian push to downsize everything except military spending!! Self-regulated nuclear power coming to soon to a neighborhood near you!

Mr Yost,

Your silence is deafening.

Headline: US bombs Libya, Ending Japanese Nuclear Crisis
It seems that Keith's and Chris's expectations and predictions have largely failed to track reality of this continuous and evolving tragedy.
7 spent fuel pools, loaded with decades worth of spent fuel.
1760 tonnes of fresh/used nuclear fuel on site, the Chernobyl reactor had only 180 tonnes.
3 reactor units suffering melt downs, unit 4 pool with a with a full core offload (98 tonnes) of very hot MOX. The MOX zircalloy cladding has caught fire and exposing MOX fuel with no containment structure, and releasing cesium-137, Pu-239 etc etc etc.
Whole situation now totally FUBAR!
Any remaining pro-Nuke people should have their foreheads tattooed with the words "delusional personality"!

Four hundred and fifty nukes worldwide, with three major FUBARS, equals one FUBAR for every 150 reactors. What a pathetic safety record. And still lots of old/BWR time-bomb reactors still operating!
We are entering an historic moment in time now, when the green revolution to rival the industrial revolution, is about to really take off.
Nuclear energy RIP!
A correction to my last post, (which was done when I should have been in bed), The MOX fuel of course resides in the plant 3 reactor.

On further reflection, I can't believe the insanity of storing over a thousand tones of radioactive spend fuel on top of a reactor/s. Any major problem creating a radioactive environment with either, creates immense difficulty in managing the other!
The situation, from using a forty year old known dodgy GE Mark One type reactors, and building these time bombs in a known severe earthquake and tsunami area, plus a history of coverups and unsafe operations, equals a level of insanity beyond belief.
There is enough Pu-239 within the crippled #3 MOX reactor, should it all go up in a smoke with a raging inferno, and provided it gets distributed somewhat evenly around the world, to kill every man woman and child on the planet, many times over. Just look on the bright side and enjoy the remaining 20 year latency period, before the cancer appears.

Anyway, with roughly seven billion people, we are probably already overpopulated. Maybe this is the required solution to the overpopulation issue.

I might also point out, that if the situation could continues to deteriorate even further, and into a total inferno. Remembering, that given enough heat, almost anything is combustible, even steel, and don't forget the zircalloy cladding. Combine this with variable winds and you could, possibly end up with most of Japan becoming an exclusion zone. A very chilling thought indeed!

I still think that any remaining pro-nuke zealots should be identified and then have their foreheads tattooed with the words "Delusional Idiot".
I have known all my life that appropriate or realistic risk management was largely absent within large parts of the nuclear industry, and that Three Mile Island, Chernobyl and Fukushima type events were inevitable, sooner or later. And I guess, I also suspected that it would probably take three events, or maybe even four, before the slow learners pulled their heads in.
Lets face reality, it is quite obvious (read the previous posts) that if the Fukushima accident had been less severe, all the delusional idiots would still be maintaining that nukes are safe.
The world unfortunately, is full of idiots, and we ALL have to suffer the resulting consequences.
I wish we could identify them at birth, and eliminate them from the gene pool!


Just curious, where did you get your power to turn your computer on?

Hi Chris
Very valid question!
Mostly from the coal powered grid, which also includes a small mix of wind/solar, plus some hydro during peak times. I live in Australia, where we have plenty of coal, so we have no need for nuclear, but that doesn't stop the politicians from occasionally raising the possibility of nuclear, but nuclear is not economic (it always needs very large government subsidies), and it would be political suicide here anyway, and they know it.
As for me, I think coal is bad too. We are personally in the process of cutting our carbon footprint. Currently in the process of doing an energy audit, and have been actively reducing our consumption for quite some time to make our house energy efficient. This is our first step, to hopefully zero emissions eventually. Energy conservation is the easiest and most economic first step. And we use bicycles instead of our car for all our shorter trips.
We eventually intend to install solar PV panels on our roof to be connected to the grid, to generate most, if not all of our own power. More and more of our friends have already done this, as there are various generous government subsidies available. Once it has paid for itself, the energy is then free! The solar hardware is getting more and more affordable as time goes by, and of course conventional power costs are continually rising. Economics will drive the green revolution, but it won't happen overnight, but it will, and is happening, it is inevitable, it is now just a question of how quickly it happens.
We have lots of sunshine in Australia, there is no reason that we could not generate most if not all of our mainstream energy from solar and wind (plus some geothermal and Hydro etc). Any periodic shortfalls could be supplied by backup natural gas powered Jet Turbines, which is a lot greener than coal. But I am sure that technology improvements over time will enable 100 green energy nationally, and I feel confident that eventually it will be the cheapest option.
LOL. :-)
Definition of Insanity, and an accident waiting to happen.
How loony is this?
All you need is a leak!
Like in the Dirty Harry movie: "Do you feel lucky? Punk!"


Because of the unavailability of off-site storage for spent power-reactor fuel, the NRC has allowed high-density storage of spent fuel in pools originally designed to hold much smaller inventories. As a result, virtually all U.S. spent-fuel pools have been re-racked to hold spent-fuel assemblies at densities that approach those in reactor cores. In order to prevent the spent fuel from going critical, the fuel assemblies are partitioned off from each other in metal boxes whose walls contain neutron-absorbing boron.
It has been known for more than two decades that, in case of a loss of water in the pool, convective air cooling would be relatively ineffective in such a dense-packed pool. Spent fuel recently discharged from a reactor could heat up relatively rapidly to temperatures at which the zircaloy fuel cladding could catch fire and the fuels volatile fission products, including 30-year half-life 137Cs, would be released. The fire could well spread to older spent fuel. The long-term land-contamination consequences of such an event could be significantly worse than those from Chernobyl.

Thanks for the info. Can you tell us how much it is to install a solar system (without a subsidy), how much power it would produce (in kw), how much sunlight you get compared to a place like Boston (58 according to NOAA)?


I am not an expert, but in summer roughly 5 or 6 hrs of 100 rated output per day, so a one kw panel puts out 5 to 6 kw hrs per day, and in winter probably 2.5 kw hrs per day.
Ave home in Australia uses about 20 kw hrs per day, but it is better if you can to try and reduce this by half. It can be done! Solar hot water is a good start.
Solar PV panels are expensive here, they where about $10 per watt installed, but getting closer to $5 per watt now.

So, in summer, you get about 1 kw hr per day per thousand dollars that you invested, and maybe half that in winter.

America is always much cheaper than here, so you may be able to get under $5 per watt fully installed. So you might get a 4 kw system installed for maybe under $20,000.

I am waiting, because I think this will get a lot cheaper, and am investing my money and effort on power reduction at the moment. I recently bought a Samsung 40 inch LCD/LED TV, it uses 140 watts, the cheaper older model used twice as much. We use low power mood lighting in our house with strategically placed reading lights where needed, it looks great, and works well. My wife is right now sewing thermal efficient rubber backed curtains, for next winter (and summer). We also survived last summer with very minimal usage of aircon. We used overhead fans instead, and closed the curtains each day, and guess what, surprise, surprise, we did not die when the temp went a little above 20 deg C (68 deg F).
Did you know that electric hot water storage tanks leak heat, which wastes about half the power it consumes!
We are going to buy a new HW unit and put it in an insulated box. And also plan to also install a solar evacuated tube system as well to heat the water, as these are now getting more affordable.
I don't know about Boston weather, and I only use broad brush stroke figures for myself (and my DIY PV solar motor home system).
I recommend consulting a local expert and/or doing your own research. Also consider power reduction as well, or instead.

I admire what you are doing. I wish everyone could do that. But in reality, that is not the case. Most people do not have $20k (very conserviative number, even here in the US) to spend on a system that can only provide power for certain parts of the year. If anybody doubts this, use Greg's numbers against your most recent electric bill and see how many kw's you really use. The numbers speak for themselves.

I do agree everyone should cut back.

Now, where we disagree. You've recieved power from coal/hydro for probably your whole life. Not sure about Australia, but there hasn't been many new coal plants built recently. With the environmental controls and permitting, it is cost prohibitive. Instead, utilities have been dumping money into plants that are very old. Also measures to reduce load are still underway. This cannot last. New generation will have to be built.

So what do you build. My view is that you can build nuclear safely and it is enviromentally friendly (zero emissions). Yours is that it can never be safe. Time will tell. So I guess you can tatoo my forehead!! :)

I wish you good luck with your solar panels.

Until the nuclear industry genuinely holds itself accountable, no. I do not believe plants are safe.

Vermont Yankee: cooling tower falls down. "Oops. We'll use more stringent inspection methods next time."

Plant officials say there are no underground pipes with elevated levels of radiation. "Oh. Oops. Uh, there are, actually. What we said earlier was a miscommunication."

Elevated levels of cesium-137 are found. "Yeah, but that stems from old problems. It's not OUR fault."

Elevated levels of tritium are found. "Hmm. How odd. We don't know where it's coming from. Can we get back to you?"

My expectation for the design and operation of a nuclear generating station is absolute top levels of inspection and precision at all times. This doesn't appear to be the case.

The position of nuclear apologists always seems to be "yeah, well. some releases. so what. they were acceptable levels. I mean, no one died, right?"

This time.

Maybe Chris could do it better. But with his inflammatory name-calling and defensive posturing it seems he's perfect for the nuclear industry as-is.

Anonymous poster 94,

What's your idea?

Atleast Greg is putting his money where his mouth is.

What have you done? What is your idea for long term energy supply?

Yep, $20k is too expensive! But the one third Government $ subsidies here (ie in Australia), is making it work. Remember, a long journey always starts with the first step.

I remember a time when a President made a goal to land on the moon within a decade. To some it must have seemed fanciful and impossible, but with a fantastic effort it was done!

What's probably needed is an charismatic iconic leader to get the job done.

What an truly uplifting experience it would be to be to have a really worthwhile (national or worldwide) goal, and be a part of the solution!
Chris said:
We "can" build nuclear safely and it is enviromentally friendly.

But I say:
Yes, it is possible! But in the real world it won't and hasn't happened.

The nuclear industry has had over half a century to "get it right". It was widely known for 30 years that the GE Mark One type reactors (ie in Fukushima, and same as one third of current USA reactors) where not robust enough in an emergency (google it).

What nut case/s put lots of them in a known severe earthquake/tsunami area? And what nut cases neglected to do anything about it for thirty years?

Yep, it is "possible" to do lots of things in theory, but past experience proves otherwise.

Quote of the day: "Experience" is what you get, when you "didn't" get what you plan to get!

2nd quote for the day: Insanity is doing the same thing over and over, but expecting a different result each time!

PS: Chris, no tattoo for you, your too nice!
PPS: For a good feeling! Google: Wiki Sierra Sun Tower
PPPS: And if you don't want to sleep at night? Google: Wiki Davis Besse Nuclear Power Station
Anonymous at 11:46 AM on March 30, 2011:
The above post is pretty convincing. If only people were prepared to delve behind the spin and the secrets.
The info is actually there, but people just won't look, or else they just persist in deluding themselves.

Amazing that there is overwhelam ming evidence against nuclear, you only have to delve a little, but I find human nature is really strange!

Two things come to mind:

1. Non so blind as those who don't want to see.

2. "The Emperor new clothes" syndrome is alive and well today!
(Google Wiki for it).

Extract from Wikipedia:
"The Emperor's New Clothes" (Danish: Kejserens nye Klder) is a short tale by Hans Christian Andersen about two weavers who promise an Emperor a new suit of clothes that are invisible to those unfit for their positions, stupid, or incompetent. When the Emperor parades before his subjects in his new clothes, a child cries out, "But he isn't wearing anything at all!" The tale has been translated into over a hundred languages.
I thought that the Fukushima disaster would be enough to turn around all the die hard pro-nuker's.

I now have serious doubts, and am now wondering hypothetically, what it will actually take?

Scenario 1. It continues (what's new) to get a lot worse in Japan, and the fallout makes half of Japan uninhabitable? Nup?

Scenario 2. Same as above but fallout makes parts of other countries nearby uninhabitable? Nup?

Scenario 3. Creates a financial tipping point, and Japan goes into a full blown depression, with it's already insane national debt of about 200 percent of it's GDP. Nup?

Scenario 4. Japanese financial melt down creates the catalyst to cause USA with national debt 100 percent of GDP, ($13 trillion?) (and unlike Japan, it's debt is financed externally!) to go into a full blown depression. It then defaults on it's international payment obligations and sends the rest of the world the same way? Nup! (no money!)

Scenario 5. USA then can't afford to shut down or replace their nukes, so a series of melt downs start happening in the old run down cash strapped plants, contaminating more and more of Americas food bowl and cities, making them uninhabitable! Hummmm? Nup! (too late she cried!)

Maybe then we will have convinced the pro-nuker's, but now far too late to be "able" to do anything!

Ah well, the world has always had it's share of of slow learners.

Anyway, you can always look on the bright side, it will solve the world's over-population problem!

So, continue watching this space to see how things develop!

And, then every day keep asking yourself........ "Do I feel lucky today?"

And me? I'm fairly philosophical, I've had a fun ride so far, I'm not afraid of death!

I'll just accept that all of "us" dumb sh!ts probably deserved our fate!

And, the collective "us" actually includes me!
Simply because I probably could have done more too!
Have a nice day! :-)
Fukushima is not really that bad!
Our nuke's are better! It won't happen here!
It's too expensive to change.
We can't afford it!
Green power can't handle the base load!
Vested interests won't allow it!
There's no viable alternative!
Our (unsustainable?) way of life is non-negotiable!
It's just too hard!
Excuses, excuse, excuses, excuses!

Have you ever noticed, that excuses are most often just lame attempts for doing nothing and/or to avoiding inconvenient truths!

Most people perfected it during their childhood; "it's not MY fault, SHE hit me first!".

Excuses are the nails used to build a house of failure. Don Wilder and Bill Rechin
The time for action is now!

I life boat is there to use whilst the ship is sinking, not much use if (you go into denial and) you wait until after the ship sinks!

Albert Einstein
We can't solve problems by using the same kind of thinking we used when we created them.
I am also disappointed at having the MIT name associated with an article such as this. It is so obviously written by an apologist for the nuclear industry. No further comments are needed here.
"What's your idea?"

I thought I was pretty clear. Plant managers need to maintain a zero-tolerance stance on all aspects of plant operations, top to bottom. Vermont Yankee is but one example of corners being cut. There should be no corners cut, ever. That seems like a pretty simple idea.

By the way, I never said I was against nuclear power generation. In fact, I'm not. I'm just not real pleased with how it has been historically executed.

"At least Greg is putting his money where his mouth is."

Indeed. Since I pay my own utilities I voluntarily pay the premium to have my money redirected to renewable sources. Yes, I know it is one grid. Yes, I am aware that my power does not come via special "green" power lines. Sure, you can chuckle and say "how nave of you to buy into their scam". However, the only tool I have left is voting with my dollars since nothing else appears to work at any level. The more people that come forward and say "I'm willing to pay more if it means that you'll put it towards more environmentally responsible means", the more the industry will shift. They always follow the money.

I rent. But if/when I buy, you'd best believe I'd be looking very closely at my options for supplementing the energy I have to buy with other resources.

"What have you done?"

I cut my consumption every last place that I can. CFL bulbs, no air conditioner, no lights left on needlessly. Putting the heat as high as 62 is a treat. If it's yellow, let it mellow. Timed showers. I could go on and on. Sure, a lot of that is because I don't want big utility bills - but luckily it's also the right thing to do in terms of my personal energy use. Win-win.

"What is your idea for long term energy supply?"

Are you assuming that I am engineer? I depend on the scientists and utility companies for this one. See above. If the utilities smell money from renewable resources, they will find more/better ways to get them to us. They will fund research. They will get the EPA off their backs as a result. Another win-win.

Do I have the answer? Nope. I don't. I never claimed to. Your assertion that I am not permitted to criticize the nuclear industry without presenting an alternate long-term energy plan is absurd. I never said "close all plants now". But if we're going to use it, is it too much to ask that it be done right?
Anonymouos 94,

I'm glad your doing your part in conserving energy. I only called you out because you named me specifically in your post. As I said in an earlier post, conservation is defintely a good start, but it is not the answer. Nor is solar or wind. You have to have a base supply. Because when the sun ain't shining and the wind ain't blowin, the lights will go out. Not only that, wind and solar don't come close to handling the load even if there were ideal conditions.

By the way, I think there was a study done that proved that a CFL bulb consumes more energy to produce than what is saved during it's lifetime. I'll have to dig that up and share that with ya. :)

Spring break happened, and I lost interest in following the hype surrounding Fukushima. As far as I can tell, the timeline I published in my follow-up article remains accurate, and the bloviating of the media since then has just been so much hot air.

MIT NSE didn't have answers for the questions, and it will likely be a few months before we get anything definite. But, in the meantime, there remains no health risk to the public as a result of Fukushima, and the situation has been well in hand for a couple weeks now. This was an engineering success.

To be frank: I find the comment section of any website to be inane. You gentlemen are free to go back and forth all you like here, but why should I spend any time debating your flawed views? With the time I could spend trying to win over one or two internet trolls, I could write an article that gets 10,000 eyeballs.

It's not the critic of the critic who counts-- it's the critic who is actually in the arena.

If you really think you have ideas worth fighting for, then develop your writing abilities and get yourselves in the game. If you're MIT students, the opin department is always looking for fresh blood.

I am going to assume that this is actually you posting. How can you say that this situation is well in hand?

There is radioactive water all around the plant--three workers have been exposed to significant levels of radiation. There are leaks into the ocean and the sources of the leaks cannot be found.

The pumping arrangement is still temporary, and it does not appear that there will be a permanent pumping solution soon.

There is still a 12 mile evacuation zone around the plant.

So yes, if no one goes near the plant, then it is safe for the public.

My final question is when will you head to Fukushima to give on site advice, drink the water and eat the fish?
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