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Japan Nuclear Situation – 14 March updates

Update #1: TEPCO reactor by reactor status report at Fukushima (PDF file):

Update #2: New technical analysis here

Update #3: A 2nd explosion (apparently another hydrogen explosion) has occured at Unit #3. Yukio Edano says that water injection at Unit 3 is reported to be continuing, the indications are the containment vessel is still safe. More here:

Another hydrogen explosion has rocked the Fukushima Daiichi nuclear power plant, this time at the third reactor unit. Initial analysis is that the containment structure remains intact.

The blast that occurred at 11.01am today was much larger than the one seen at unit 1 two days ago. An orange flash came before a large column of brown and grey smoke. A large section of the relatively lightweight roof was seen to fly upwards before landing back on other power plant buildings.

Chief cabinet secretary Yukiyo Edamo appeared on television shortly afterwards to identify the blast was a hydrogen explosion. He said contact had been made with the plant manager whose belief is that the containment structure, important to nuclear safety, remains intact. The rationale for that statement, Edamo said, was that water injection operations have continued and pressure readings from the reactor system remained within a comfortable range.

Pressure and radiation readings

Pressure readouts from the period after the explosion were within a relatively normal range: 380 kPa at 11.13 and 360 kPa at 11.55am. These compare with comfortable levels yesterday of 250 kPa, reference levels of 400 kPa, and a high of 840 kPa recorded at unit 1 on 12 March.

Radiation readings on site remained low after the blast, albeit elevated from normal operation. In the service hall the reading was 50 microSieverts per hour. At the entrance to the plant the figure was 20 microSieverts per hour.

At 12:30pm, the radiation dose measured at a monitoring point on the Fukushima Daiichi site indicated a level of 4 microSieverts per hour. However, a subsequent reading at 1:55pm showed a reading of 15 microSieverts per hour but an increase of radioactive material was not confirmed. A monitoring post at the Fukushima Daini plant – some 10 kilometres south of the Fukushima Daiichi plant – indicated no change in the radiation dose there.

Cooling and pressure control

Fukushima Daiichi 3 was yesterday the subject of sustained efforts by engineers working to ensure that adequate cooling water was available for decay heat removal. Seawater was being injected into the reactor vessel and pressure had been relieved to comfortable levels.

A statement from Tepco shortly after the blast said that pressure had risen again to 530 kPa by 6.50am. The company determined this was ‘abnormal’ at 7.44am and declared the matter officially to government. It began to gradually relieve the pressure, and carried out a “tentative evacuation” of the site, until it reached a level of 490 kPa at 9.05am.

From Kyodo News:

Chief Cabinet Secretary Yukio Edano said the plant operator Tokyo Electric Power Co. confirmed that the 11:01 a.m. blast did not damage the container of the No. 3 reactor, allaying concerns that the explosion may have caused a massive release of radioactive substance. TEPCO said three workers, including its employees, were injured by the blast. All of them suffered bruises. ”According to the plant chief’s assessment, the container’s health has been maintained,” Edano told a press conference.


Here are some of the best updates available on the Japanese nuclear power plant situation (14 March 2011), following the massive earthquake and subsequent tsunami. In short, the nuclear reactor situation at Fukushima units #1 and #3 has stabilised with full containment intact (see below), and all other plants in the affected area are in cold shutdown.

This morning I talked to Channel 9’s “Today” program (3 min video — alas MSN don’t allow vid embedding so click on the picture to go to the off-site stream)

An excellent ‘Frequently Asked Questions’ document has been prepared by the Nuclear Energy Institute with 19 questions and answers (download 7-page PDF here). Definitely read this. A further news stream is here:

A very clear and readable statement (see 3 page document here) is also available, from the Federation of Electric Power Companies of Japan. Again, very worthwhile.

World Nuclear News provides a regularly updated commentary: Efforts to manage Fukushima Daiichi 3. The bottom line:

Unit 1: Seawater injection continues and it is thought the reactor core is now sufficiently cool. Safety regulators consider reactor pressure of 353 kPa an indication of a stable condition.

Unit 2: The normal reactor core isolation cooling system is in use. Fuel rods are covered by about 3.8 metres of water.

Unit 3: Operations to relieve pressure in the containment of Fukushima Daiichi 3 have taken place after the failure of a core coolant system. Seawater is being injected to make certain of core cooling. Malfunctions have hampered efforts but there are strong indications of stability.


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. Three other reactors were already shut for inspection but all three operating units underwent automatic shutdown as expected. 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 metres in height, compared to the maximum 6.5 metre 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 stabilise 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.

Depleted Cranium reflects on how this situation must be explained to the public: This is Our Generation’s Three Mile Island – Lets Not Screw it Up

Of course, newspapers are already speculating on the implications of these events for nuclear power in places like Australia: Meltdown fears spark ‘turning point for world’ — the closing comments were from me:

Professor Barry Brook, an environmental scientist at the University of Adelaide, said the effect on the Australian debate depended on whether it would be ”argued on a rational basis or an irrational basis”.

A rational debate would acknowledge that Japan’s largest recorded earthquake produced an incident at a 40-year-old reactor that was ranked at a level less than the Three Mile Island emergency, he said. ”I think the nuclear reactors have come through remarkably well.”

Over the coming days and weeks, there will need to be a detailed and clear-headed analysis of exactly what happened (as further information emerges), and the short- and long-term implications. I will endeavour to cover these issues in detail, from many angles, on

By Barry Brook

Barry Brook is an ARC Laureate Fellow and Chair of Environmental Sustainability at the University of Tasmania. He researches global change, ecology and energy.

150 replies on “Japan Nuclear Situation – 14 March updates”

@ Tatu – Industrial accidents happen all the time, all over the world, Emergency crews lay their lives on the line every day, and I suspect in Japan over the last 72 hrs there have been hundreds of untold stories of heroes putting themselves at great personal risk beyond this small corner where the reactors are.

Your attempt at painting the workers at the plants as victims of nuclear energy is both pathetic, and disrespectful of all those putting themselves on the line, all over Japan at this time.


As I understand it (and your commentary here has been instrumental along those lines), three of the six reactors at Fukushima were offline for inspections when the earthquake hit. The primary problem now, it seems, is that the primary cooling systems are not working because they are not powered and so emergency measures are being employed.

How long does it take to bring a reactor online? Could (one of) the other three reactors which were largely inert during this crisis be brought back online to power the cooling systems?


The best quackery I hear from media and some panic stricken individuals is: “1 million people” will eventually die as a result of what happened at Chernobyl. This figure is completely wrong! Far more people will “eventually” die, but it will not be from radiation, it will be from old age.
World Health Organization is closely monitoring aftermath of Chernobyl and there is no evidence that people are dropping like flies before their time.
The bottom line is: The low level radiation is not as deadly as some doomsday propagandists would like to make us believe.


The Japanese government has asked the IAEA for experts to come in and help. Does this mean they’ve reached a stage where they can do no more on their own? What would the situation have to have become for Japan’s own experts to seemingly “give up” and ask for help?


NYT “45 minutes ago”

“… acute crisis developed late Monday at reactor No. 2 of the plant, where a series of problems thwarted efforts to keep the core of the reactor covered with water — a step considered crucial to preventing the reactor’s containment vessel from exploding and preventing the fuel inside it from melting down.

The plant’s operator, Tokyo Electric Power, said late Monday that repeated efforts to inject seawater into the reactor had failed, causing water levels inside the reactor’s containment vessel to fall and exposing its fuel rods. After what at first appeared to be a successful bid to refill the vessel, water levels again dwindled, this time to critical levels, exposing the rods almost completely, company executives said.

Workers were having difficulty injecting seawater into the reactor because its vents — necessary to release pressure in the containment vessel by allowing radioactive steam to escape — had stopped working properly, they said.

The more time that passes with fuel rods uncovered by water and the pressure inside the containment vessel unvented, the greater the risk that the containment vessel will crack or explode, creating a potentially catastrophic release of radioactive material into the atmosphere — an accident that would be by far the worst to confront the nuclear power industry since the explosion of the Chernobyl nuclear power plant 25 years ago.

In reactor No. 2, which is now the most damaged of the three at the Daiichi plant, at least parts of the fuel rods have been exposed for several hours, which also suggests that some of the fuel has begun to melt. If more of the fuel melts before water can be injected in the vessel, the fuel pellets could burn through the bottom of the containment vessel and radioactive material could pour out that way — often referred to as a full meltdown.

“They’re basically in a full-scale panic” among Japanese power industry managers, said a senior nuclear industry executive late Monday night. The executive is not involved in managing the response to the reactors’ difficulties but has many contacts in Japan. “They’re in total disarray, they don’t know what to do.” ….


Click to access petrulemaking262011.pdf

“In October 2010, Oak Ridge National Laboratory released ―Electromagnetic Pulse: Effects on the U.S. Power Grid,‖ a series of comprehensive technical reports for the Federal Energy Regulatory Commission (FERC) in joint sponsorship with the Department of Energy and the Department of Homeland Security. These reports disclose that the commercial power grids in two large areas of the continental United States are vulnerable to severe space weather. The reports conclude that solar activity and resulting large earthbound Coronal Mass Ejection (CME), occurring on average once every one hundred years, would induce a geomagnetic disturbance and cause probable collapse of the commercial grid in these vulnerable areas. Excess heat from induced currents in transmission lines would permanently damage approximately 350 extra high voltage transformers. The replacement lead time for extra high voltage transformers is approximately 1-2 years. As a result, about two-thirds of nuclear power plants and their associated spent fuel pools would likely be without commercial grid power for a period of 1-2 years.
Commercial grid outage of 1-2 years far exceeds the current design criteria for nuclear power plants and associated spent fuel pools. Accordingly, the NRC should adjust design criteria for nuclear power plants and associated spent fuel pools ….”


And yes, a solar flare (or high altitude nuclear explosion) _can_ take out diesel generators–thus the petition to add protection for the backup pumps on nuclear plants and pump-cooled storage pools:

“It was Test 184 that caused most of the problems with the civilian infrastructure in Kazakhstan. Other tests, though, apparently caused some problems — such as those experienced with military diesel generators. The diesel generator problems usually occurred some time after the detonations due to dielectric breakdown in the generator windings. Loborev said, “The matter of this phenomenon is that the electrical puncture occurs at the weak point of a system. Next, the heat puncture is developed at that point, under the action of the power voltage; as a result, the electrical power source is put out of action very often.”

Point being–this quake-and-tsunami is one way, but not the only way, to cause problems at all fission power plants and all the backup power systems over a large area, all at once. The preparations for power failure seem to have been for one or two failures at a time, assuming there would be redundant sources nearby not damaged.

A solar flare will do the same sort of thing over a larger area.

Preparation warranted.


Oops. Someone pointed to this earlier without saying what’s in it:

Containment venting as a mitigation technique for BWR MARK I plant

“The venting of primary containment after reaching 75 psia (0.52 MPa) is found to result in the release of the vented steam inside the reactor building, and to result in inadequate Net Positive Suction Head (NPSH) for any system pumping from the pressure suppression pool. CONTAIN code calculations show that personnel access to large portions of the reactor building would be lost soon after the initiation of venting and that the temperatures reached would be likely to result in independent equipment failures. It is concluded that containment venting would be more likely to cause or to hasten the onset of severe fuel damage than to prevent or to delay it.”
It’s a study of a different situation I think (“without SCRAM”) but may be cautionary, since I recall early mention of radiation keeping workers from reaching one of the valves on the first reactor the first day, and we’ve been hearing about more and different equipment failures preventing things from being done.


Hank Roberts writes,

… this quake-and-tsunami is one way, but not the only way, to cause problems at all fission power plants and all the backup power systems over a large area, all at once. The preparations for power failure seem to have been for one or two failures at a time, assuming there would be redundant sources nearby not damaged.

A solar flare will do the same sort of thing over a larger area.

Preparation warranted

Dr. Dan Meneley was on the radio this morning and pointed out that when the water came in, the generators’ diesel tanks floated away.

The irony of nuclear installations depending on this fossil fuel kit has struck me in the past. Why wouldn’t they depend on small standby nuclear generators?


In my old days in steam engineering we were using steam driven injectors to deliver water into boilers as a permanent water feed mechanism or as back up to some more efficient mechanical pump. The injectors work on principle of mass inertia, hence it is possible to deliver water into the boiler at higher pressure than is present in boiler steam pressure itself. I believe the same device could be used to feed water into nuclear reactor by utilizing the steam generated by reactor from decay heat. This would be only good to supply water for evaporation for as long as the heat energy would exceed the demand for water.
The volume of water needed to remove residual decay heat by evaporation from 3 million kw thermal energy reactor (1Gwe, gigawatt electric) with residual decay heat of 3%, 90,000kw thermal decay right after shut down, is about 122,290 liters per hour.
Advantage of the water injector is that it has no moving parts, therefore it is a bulletproof device for emergency water feed.
I don’t know what the thermal output of those BWR in Japan is, however, the above example will give you the idea how much water is needed to remove residual decay heat by evaporation. Removing the heat by water cooling alone would take approximately 10times as much water volume or more, depending on cooling water temperature rise.


@ Barry,
I think you deserve a right of reply to the ABC. Sir Christopher Busby was a maniac this morning and said the words ‘possibility of an atomic explosion’ or ‘nuclear explosion’ about 4 times in the short time he had on the radio.


NEWSFLASH: Giant Radioactive Ducks spotted over Tokyo!

Giant Radiactive Ducks were spotted terrorising the Japanese coastline, and are probably in the vicinity of Tokyo from previous bearings! In other news, Sir Christopher Busby announces high risk of ‘atomic explosion’ at the reactors, and says the words ‘nuclear explosion’ 4 times in a short radio interview on the ABC this morning. Most of us thought these were nuclear power plants, not bombs, but in a world with the Giant Ducks of Doom about to descend on the Japanese people, anything is possible!

More seriously now — 10 thousand people may have been killed by this Tsunami. Do we really need to add to Japanese public trauma by terrifying them with reports of impossible threats of ‘nuclear explosions’ from power plants? This is one of the most uninformed, unscientific media frenzies I’ve ever witnessed, far worse than that ‘climategate’ fizzer.


I agree with Peter Lang that nuclear safety is overblown in certain areas, hence it contributes to no additional safety, however, despite all the safety hype, there was one serious mistake made at the dawn of nuclear industry and that mistake remained to this day due to political reasons. Total reliance on electrical pumps and electric back up did not meet the natural safety criteria. It was known at the time and some engineers voiced their concern. Alvin Weinberg, the inventor of light water reactor, was fired from his job because he voiced his concerns over safety. Nevertheless, the politics prevailed thus electric system was adopted as standard and it was copied due to monkey see monkey do copycat attitude, or “It was always done this way” mentality.
Recent events in Japan showed that mother nature easily outsmarted the electric system because there was no natural line of defense that nature would have to cooperate with. Nature is completely ruthless, however, it will always obey it’s own physical laws, so those laws must be incorporated in any design as much as possible.
Long ago the mistake was recognized, hence all new reactor designs utilize passive natural reactor cooling system of some sort.
Nevertheless, as always, people have to live with political consequences of the past. Nuclear peaceful energy is somewhat forgiving even under the most severe conditions. The biggest mistake of all would be to abandon this fantastic form of energy, best energy nature has to offer.


Evacuating nearby citizenry, or repositioning carriers based on wind patterns would be appropriate in a very wide range of conditions, from relatively low-risk to relatively high-risk.

It is possible for some generally reasonable people to read “impending doom” from those activities, as well as for others to see “prudent additional precautions”.

However, people with more expertise, more information, and much more to lose are making those calls, and I see little reason for them to falsely-minimize the danger in hopes of … what? Hoping no one will notice if they’re wrong?!


Prime minister Naoto Kan has begun his address to the nation by asking people to listen to his message calmly.

According to the translation by broadcaster NHK he warned: “Radiation has spread from these reactors and ‘the reading of the level seems high’. There’s still a very high risk of further radioactive material coming out.”

He has asked anyone remaining in the 20km evacuation zone around the number 1 plant and the 10km zone around the number 2 plant to leave. Hundreds of thousands have already been evacuated.

He a said workers were “putting themselves in a very dangerous situation” to try to contain the problems. He again requested people to remain calm.


Yukio Edano, the government’s chief spokesman, is now on.

He’s saying there’s a fire in the number four unit. There are no fuel rods in there but it still contains spent fuel rods. (The unit was under renovation at the time of the quake and tsunami).

He says there seems to have been a hydrogen explosion (as at units 1 and 3) in that unit too. There were not previously thought to be problems with unit 4.


Edano: The blast from Unit 2 followed the Unit 4 problems. There appears to be a release of steam from number two. This could be hydrogen he says. They are continuing to inject water at units 1 to 3

As of 10.20am (Japanese time), they have taken readings which indicate levels of radiation that could impact human health. Edano has asked them to “embrace the information calmly”.


“The readings were taken near the area where we believe the release of radioactive substances is taking place. The further away you are, the more values should go down.”

He says beyond the 20km radius the level should be reduced to one where harm to human health would be minimal or non-existent. But he says that spread will of course depend on wind speeds and direction.

He asks people to remain indoors so they are not exposed to any radiation that may come their way.


I put some attempt to transcribe in the older topic, ending with the measurements:
Interview with Chief Cabinet Secretary
Radiation measured at 10:20am
30 millisieverts at No. 1
Around No. 3 400 millisieverts
Around No. 4 100 millisieverts
“much higher than microsieverts” — this is seriously bad.


Barry, the helicopters are flying relief missions to the land; I’d think they’d move the ships so the path the helicopters fly does not cross downwind of the plants, to avoid the need to decontaminate them.

And with the new readings, this is serious.

The news is telling people not to allow air exchange between indoors and outdoors, in the 20-30km radius zone. Close the windows, do not take your laundry in if it is hanging outdoors, do not hang laundry outdoors, if you are outside right now please evacuate to a nearby building, make sure that you dust off your jacket and anything in your hair and then go indoors.

This is because of the fire at Reactor No. 4, apparently because debris falling onto the top damaged something involving the spent fuel cooling pool up there.

The speaker at the site (live stream) is saying the water cooling system for the spent fuel pool on top of No. 4 may have been damaged by stuff falling from the other explosions, and discusses the possibility both of hydrogen building up in the top of that building, and of the water level going down to expose the spent fuel in the time since the first two explosions.


The TV is now steadily repeating how to avoid carrying fallout indoors, leave laundry and jackets and shoes outside, close windows, do not use ventilation.

This means, with no electricity, no heat, and they’re predicting rain and temperatures falling toward freezing.

“400 millisieverts” is the peak reported at the site.


In several of the photos there would appear to be steam issuing from the central portion of reactor 3, does this not mean the calandria is venting? The japanese media are now reporting a “failure” in the torus at the bottom of unit 2, but with few specifics.


Radiation 33 times normal level measured in Utsunomiya, Tochigi. This is ~50 miles SW of the site.

(How long till this whole page gets pulled?)


I read this morning that some American officials are critical of Japan’s handling of the nuclear situation. Good grief! And this from a country that completely fouled up the response to a relatively simple hurricane disaster in New Orleans!

Japan was hit by one of the most powerful earthquakes in recorded history and a massive tsunami which destroyed entire towns, roads, communications, utilities (electricity, water, sewer, etc.), mass transit, airports, etc. Japan also has a volcanic eruption on its hands as well. Thousands of people are dead. Crews are searching for possible survivors and collecting thousands of drowned bodies from beaches. They are checking people for radiation exposure and in the process of moving half a million people to safety in shelters should the triple meltdown occur. Food is not getting through. It’s very cold and people are without power for hours on end due to rolling blackouts. Access to water is a problem for many. What about bathing facilities? Clothing and bedding for people who lost everything? Medical care for the sick and injured? Prescription medication for those who lost theirs in the tsunami? The despair and pain of those who have lost family members, friends and possessions? No time for grief counselling here.

And Americans (who still have not repaired the damage wrought by Katrina) have the gall to criticize? Japan just happens to be much more organized and better at emergency response than the US. Check the record. And by the way, there are over 200 radioactive leaks from nuclear power stations in the US EVERY DAY. You’re not informed about it, so I guess it doesn’t exist.


Barry, thanks so much for your scientific enlightening to a largely misinformed public. I’d like to hear you perspective and opinion of the HTR (High Temp Gas Cooled Reactors). They are supposed to be the answer to safer and easier to manage nuclear power generation. Is this what they refer as Gen IV and is the technology there yet to build a full-scale reactors of this type being that many smaller (proto-types) have already been built in Japan, China, S Africa, and elsewhere? My understanding is that these plants can’t be subject to a meltdown from an earthquake,tsunami, or any other natural disaster.

By the way your readers might be interested in reading this:

Nuclear Power Plant High-Temperature Gas-Cooled Reactor with Spherical Fuel Elements – A German Development Implemented Abroad



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