Posts Tagged ‘nuclear’

Examining some old Fukushima news

Sunday, February 26th, 2012

An old news article is circulating around that states that 68 tons of fuel has melted in reactor number 1 and that it was close to breaching the bottom of the containment. The article is several months old but for some reason I have seen it pop up again on facebook so I though it is worth examining the article briefly. In particular I want to examine this statement.

Only 37 centimeters of concrete remains between the fuel and the vessel's outermost steel wall in the most damaged area, TEPCO said.

This wording is repeatedly used by anti nuclear sources to imply that a much worse disaster was very close to happening. What the articles fail to mention however is that there is A LOT more concrete between the ground and the molten core. The reactor building itself is a very thick concrete structure. Will Davis, on his excellent blog Atomic Power Review, talked about this the first time the news about the number one vessel failure showed up last November. Some of what he wrote is worth repeating and I hope he doesn't mind me repeating it here and also posting a picture from his blog.

The NHK report indicates a melt depth of about 2.1 feet(64 cm, my note /Johan). The distance to the ground is roughly eighteen times this depth from the dry well interior floor to grade. Below is a drawing from WASH-1082 which I've marked to show the distance from the dry well floor to the grade outside, which on the particular plant shown is 39' 0"(11.8 meters, my note /Johan). I do not presently know the exact measurement at Fukushima Daiichi No. 1 but it is likely within ten percent of this measurement... meaning that in the worst case that TEPCO is describing, by its own data, the core material may have melted only about as much as 5% of the distance to the grade.

I encourage everyone to read the rest of his blog as it is by far the best information source for the Fukushima accident.

 

I also want to add this picture of the mark I containment that schematically shows the thick concrete even more clearly! Picture found at the blog "The capacity factor".

So we see that there is a tremendous amount of concrete below the shell of the containment structure. The hints and suggestions that the core would only have to melt another 37 centimeters for a unnamed disaster to take place is obviously false. In reality the shell of the containment is integrated into a thick concrete structure and the molten core would have to melt through several more meters, likely around 10 meters, to get out of the reactor building itself.

The cleanup of the containment is going to be a very hard and messy job, much worse than the cleanup of TMI was. But the core is still a long long way from the ground.

 

/Johan

 

Challenge to nuclear opponents

Thursday, February 23rd, 2012

It has always mystified me (and I think I can speak for all of us in NPYP) that someone can be anti-something when it comes to energy. Lets suppose for instance that someone declares himself to be anti-chemical energy, the logical follow up question to the fellow would of course be "what kind of chemical energy?". The question is logical because there are so many different ways one can extract chemical energy, everything from burning cow dung in huts to the engine in your car to high tech gas turbines to dynamite. Our friend there probably didn't even think of those distinctions when he made his statement, but what if he did? Let's say he rebukes by stating he really means that he is anti coal. Even that statement can be challenged, it must by necessity be conditional otherwise it is moronic. If he is anti coal because of air pollution, then would he change his mind if there was a solution to the pollution? If someone developed a filter that reduced pollution levels to insignificant amount is fossil fuels then ok? Logically he should think so. If he is anti coal because of the immensely destructive coal mining, would he change his mind if environmentally sound mining practices where developed? The guy is presumably actually anti air pollution or anti dirty mines, not anti chemical energy or anti coal. He just never bothered to go through the chain of reasoning to understand what he really opposes in chemical energy.

Same can be said of any energy source, there is no rational reason to be against the energy source itself, rather one is against some undesirable effect due to the present application of the energy source. NPYP are not fans of coal by any means, but I dare say that if there was solid solutions to its problems, then none of us would oppose its use. There just isn't any justifiable reason to oppose it if the problems are solved. There is no other way to rationally look at energy production.

The advantage with digging deep and specifying exactly what one is actually opposed to means opening up to the possibility of finding solutions! If someone simply state that they are anti windmills then the discussion pretty much ends right there. If the person instead states that the noise from windmills is disturbing then the discussion can turn to possible solutions to reduce noise. Everyone wins on that! There is no reason to be horribly emotional about the whole thing and cling to an anti-something idea so hard that one blocks any fruitful discussion and becomes blind to solutions.

A discussion goes no where until one gets to the core of the argument, which is, what properties of a specific energy source makes you oppose it and and how can it be improved so you no longer oppose it?

The frustrating thing in the nuclear debate is that the discussion never seems to reach that point. Ask leading environmentalists that exact question and they will squirm like a worm on a hook.

If someone specifies that they are opposed to nuclear energy due to the waste problem. Fine we say, but what exactly do you mean by the waste problem and what effect does the waste have that you find repulsive? If you are bothered by the possibility that the waste will hurt future generations, then lets discuss how to safely dispose of the waste. If you are anti nuclear because you are bothered by the safety of nuclear installations, then specify what level of safety is safe enough (obviously there must be a level where an activity is considered safe enough, otherwise the person in question would never get out of bed to shower for fear of slipping and dying) and lets discuss how to reach that.

But the discussion always ends before reaching that point because the "anti person" generally never  seems to be interested in solutions to the posed problems and they are usually not even able to state clearly why they consider the issue as a problem in the first place. This is not only valid for the nuclear debate, one sees the same tendencies in all kinds of discussion where there is a clear anti side. Anti genetic engineering, anti cars, anti meat, anti space exploration, you name it! It seems very hard for people to go past the simple emotional attachment of being against something and instead engage into a meaningful discussion about the issues. It is too easy to just be opposed to something, it is damned much harder to actually find solutions.

So to move the nuclear discussion into a more fruitful direction it would be enlightening if some nuclear opponents could specify what conditions nuclear would have to fulfill to be an acceptable energy source. Believe it or not even we have such conditions. I don't think for instance anyone in NPYP wants to see more RBMK reactors built (the type of reactor at the Chernobyl plant) and just to speak for myself I have quite strict demands on what nuclear energy should be in the long run to be an acceptable energy source. I am not anti nuclear, but I am certainly anti towards some ways of extracting nuclear energy.

To summaries and to state the challenge again clearly.

 

What conditions would have to be fulfilled for you to consider nuclear an acceptable energy source?

 

Weekend reading

Friday, February 17th, 2012

Activity is not very high here lately so I though I would provide you all with some nice weekend reading material.

First is the article "Energy as the ultimate raw material" by the nuclear energy pioneer Alvin Weinberg. Weinberg used to think of the big picture and this article showcases that. He outlines a few approaches to a asymptotic state of civilization, a state where humanity is using resources at a rate that is practically infinitely sustainable. In such a state humanity uses a lot of energy in order to produce the necessary raw materials from common rock, seawater etc.The article is from 1959 but well worth reading even today.

The second article is a blog post from Will Davis over at Atomic Power Review, "Vogtle COL approval vote indicates perspective on "nuclear renaissance". I selected it because in it Will describes some the various reactors that where developed during the first decades of nuclear energy. In my opinion it speaks volumes of how restricted the view of nuclear energy has become, nuclear power today is pretty much identical to light water reactors, but that is just a fluke of history and some day tinkering with other designs will charge on at full speed again.

As the third article I give you Gismags "Feature: Small modular nuclear reactors - the future of energy?". Aside from a few glaring technical errors or statements that doesn't make a whole lot of sense, it gives a good overview of the developments going on with small modular reactors.

I also end the post with a small section from Freeman Dysons book "Disturbing the universe". A fantastic book by a fantastic scientist! Any spelling errors are mine since I wrote out the paragraphs below.

The fundamental problem of the nuclear power industry is not reactor safety, not waste disposal, not the dangers of nuclear proliferation, real though all these problems are. The fundamental problem of the industry is that nobody any longer has any fun building reactors. It is inconceivable under present conditions that a group of enthusiast could assemble in a schoolhouse and design, build, test, license and sell a reactor within three years. Sometime between 1960 and 1970, the fun went out of the business.

The adventurers, the experimenters, the inventors, were driven out, and the accountants and managers took control. Not only in the private industry but also in the government laboratories, at Los Alamos, Livermore, Oak Ridge and Argonne, the groups of bright young people who used to build and invent and experiment with a great variety of reactors where disbanded. The accountants and managers decided that it was not cost effective to let bright people play with weird reactors. So the weird reactors disappeared and with them the chance of any radical improvement beyond our existing systems.

We are left with a very small number of reactor types in operation, each of them frozen into a huge bureaucratic organization that makes any substantial change impossible, each of them in various ways technically unsatisfactory, each of them less safe than many possible alternative designs which have been discarded. Nobody builds reactors for fun anymore. The spirit of the little red schoolhouse is dead. That, in my opinion, is what went wrong with nuclear power.

- Freeman Dyson

 

/Johan

Sustainable energy choices for the 21st Century

Wednesday, June 29th, 2011

Barry Brooks over at Brave New Climate has created a new video that summarises the need for nuclear in 2,5 minutes. Well worth watching and spreading!

Welcome Fukushima progress

Wednesday, June 29th, 2011

We are now over 3 months into the Fukushima accident, progress is creeping along at a steady pace. Since our last update there has been lots and lots of new and I won't try to cover it all. The biggest news I want to share now is that TEPCO has gotten some kind of recirculation cooling working, it was reported today by Will Davis at Atomic Power Review(by far the best blog to keep an eye on for Fukushima news, I highly recommend to read it).

In short water is leaking out of the containment buildings into the turbine buildings, the water is pumped from the turbine buildings into the water treatment facility, then from there its pumped back into the reactor. Its like I described in the last update on may 18th (shown on the picture below) and one of the steps in the plan TEPCO released that month.

If everything goes well now the volumes of contaminated water will start to creep down, a proper toast is in order!

Another fairly recent news is that NRC announced that the spent fuel pools in Fukushima never went dry. That really calls into question Chairman Jaszco's recommendation for a larger evacuation zone for american citizens in Japan than what the Japanese authorities had decided.

There has also been a lot of bullshit flying around about the situation in Fort Calhoun due to the river flooding around the nuclear power plant. Claims about goverment cover ups, Russian authorities warning about disaster etc. I haven't bothered to look more in detail into it yet, but so far the reactor has both working diesels and connection to the external grid and quite a bit of margin before the river even comes near to flood over the flood protections. Here is a good post by Neutron Economy about the situation.

Why I'm not worrying about Fort Calhoun (and you shouldn't either)

 

Links(English)
Rod Adams Ted Rockwell - Fukushima: It's Not About Radiation, It's About Tsunamis
NEI Nuclear Notes Friday Update
World Nuclear News Fukushima cover on its way
The Neutron Economy Expected Doses Over a Year and Evacuation of Fukushima Towns
Will Davis How the Misinformation Superhighway affects Nuclear Energy
Will Davis JAIF Public Opinion Poll Data

 

Links(Swedish)
Med örat mot rälsen Kärnkraften igen
Kultur Ska vi glömma Fukushima?
Seppo Laine Mycket värre än man kunde tro

 

Status for each reactor

/Johan

Day 68: Video of work at Fukushima and a encouraging PDF

Wednesday, May 18th, 2011

TEPCO has released a video that shows work being done at the Fukushima plant. Very interesting to watch.

One gets a real sense for the devastation the tsunami inflicted while watching that clip.

TEPCO also recently released this PDF file that gives an overview of work being done. I will add some pictures from it:

In the above picture one can see how they plan to rig up the new heat exchangers for reactor 1. Within the reactor building, but outside the containment, they will put a water to water heat exchanger. They will pump water from within the containment through this heat exchanger, where it transfers the heat to a secondary circuit that in turn flows to a heat exchanger outside of the reactor building that dumps the heat to the air. This is the original plan TEPCO had before they realized the full extend of the damage to the number 1 core and containment, so it is not sure they will progress as described. But the secondary heat exchanger and its piping is already being built.

Tepco also shows the above picture on how they plan to reuse leaking water from the containment as cooling for the reactor. It is not clear how the two plans are connected to each other. I would assume the second plan is the one that is going to be used instead of the first plan. Instead of taking water directly out of the containment they will use the existing leakage paths, purify the water and pump it back into the reactor.

For the number 2 reactor shown above the main problem is to stop the leakage from the suppression pool. They plan to excavate the reactor building in order to access the room where the suppression pool is housed and then fill the entire volume with grout. Considering that (probably) the suppression pool is leaking at number one as well then maby this plan will be implemented there as well (just my speculation).

Both in unit 2 and 3 are they planning to reuse the leaking water in the same manner as in unit 1.

In the rest of the document they give some basic information on how they plan to clean the massive amounts of contaminated water that exists on the site, some details on the protective building they want to build around the reactors and how to prevent more contamination of soil, water etc. Well worth scrolling through, massive work is certainly ongoing at the site and it seems TEPCO has a solid plan that they are implementing.  Of course more surprises will without a doubt pop up during work, but it looks promising. We are still waiting for more in depth information on the situation of the number 2 and 3 reactors.

English blogs:
All Things Nuclear TEPCO Says Core of Unit 1 Melted
Atomic Power Review Fukushima Daiichi update, Weds. morning 5/18

English News:
New York Times Venting Failure in the Nuclear Reactors at Fukushima Daiichi
Reuters UK nuclear power gets green light

/Johan

 

Day 67: Complete meltdown of the number 1 core

Tuesday, May 17th, 2011

During the last days a lot of news has been released by TEPCO. TEPCO has released this presentation that gives more details of the events that took place in the number 1 reactor from the beginning of the earthquake up until now. To summarize the content of the presentation.

  • The water level gauge has been giving wrong readings, the reading has been stating that the water level is about 1.7 meters below the top of the fuel assemblies. In reality the water level has been 8 meters below the top of the fuel assemblies, this means the entire length of the fuel has been uncovered completely.
  • TEPCO now assumes the RCIC system failed after the tsunami (another news release indicates it was manually shut down!!)
  • 16 hours after the earthquake the entire core had suffered a meltdown and all of it dropped down to the lower part of the pressure vessel.
  • The temperature readings on the vessel indicate that the core is still mostly within the vessel and adequately cooled.
  • Some parts of the core is suspected to have melted small holes in the bottom of the containment, which explains why they could not increase water level despite increasing pump rate.

They don't mention the reading of the pressure gauge that indicates the vessel pressure is about 14 atmospheres. I was personally fooled by this reading and assumed the number 1 vessel is in better shape than the number 2 and 3 reactors. The question is what readings can be trusted at all.

Due to this new information on the status of the reactor TEPCO has decided to scrap the original plan to flood the containment up to the level of the fuel assemblies. Since all the fuel is now located at the bottom of the vessel there is no need to flood the containment that high.  The containment is also confirmed to be breached and water leaking out of the it like in the case with reactor number 2.

Another theory for the explosion in the number 4 reactor building has appeared. The videos from the pool show that it is largely intact and no major fuel damage can be seen. That means it seems unlikely hydrogen from a zircalloy+water reaction in the spent fuel pool can be the cause of the explosion. Instead TEPCO now believes hydrogen leaked into the number 4 building from a shared ventilation system with the number 3 reactor.

TEPCO is going to do more complete analysis of the status of reactor 2 and 3 and the information will be released within days. It will be interesting to see if the RCIC system (see this blog post for a description of the system) worked in the other 2 reactors and, if it did, to what extent it mitigated the consequences of the station blackout.

Work is progressing on all fronts to build a enclosure around the number 1 reactor, to build a water processing plant, create more redundancy in the electricity supply, clear the area of debris and to pump away the junk water from the turbine halls and trenches. IAEA as usual reports the release of radioactive material and dose rates.

The Fukushima accident has unfortunately seen its first death with a 60 year old worker that lost consciousness  while working on a drainage system to the radioactive waste storage. He was brought to a hospital but could not be revived. So far there is no report that the death was related to radiation.

 

News English:
WNN Fukushima fuel melt confirmed
WNN Theory for Fukushima Daiichi 4 explosion
WNN Revisions to Fukushima restoration roadmap

Blogs English:
Depleted Cranium Worker Dies at Fukushima Nuclear Plant
Atomic Power Review Core totally demolished at Fukushima Daiichi No. 1

Blogs Swedish:
TEM funderingar <Är kärnkraft förnybart?
Den blinde Argus Kärnkraft och rädsla
Supermiljöbloggen IPCC: Förnybart kan ersätta fossila bränslen
Fourfact Blinkar jätten?
Skattepolitik och samhällsfilosofi Inga elbilar i Sverige om Tyskland stänger kärnkraften?
Ann-Kristine Johansson Kärnkraftsdiskussion
Nina Drakfors Japan, kärnkraftshaveriet fortsätter och kräver strålningsdödstal
Supermiljöbloggen Amerikansk kärnkraft dåligt rustad för katastrofer

/Johan

Day 58: Dose rates climbing in the number 2 wetwell

Sunday, May 8th, 2011

Another week has passed and more steps have been taken to get the situation under control. Lets start with the usual reactor status table  made out of NISA data:


Reactor 1 Reactor 2 Reactor 3
Water level (meter)* -1.7 -2.1 -2.15
Flow rate(m3/min) 8 7 9
Core pressure (kPa) 1390 - -
Containment pressure (kPa) 120 60 102
Wetwell pressure (kPa) 110 - 183.2
Feedwater nozzle temp (Celsius) 119.8 115.6 202.1
Bottom head temp (Celsius) 96.9 - 151.9
Wetwell temperature (Celsius) 51.4 66.8 40.0
Containment dose rate (Sv/hour) - 22.7 12.2
Wetwell dose rate (Sv/hour) 1.1 148 0.480
*Distance from top of assembly
- broken gauges or missing data

Everything looks pretty stable except the wetwell dose rater in the number 2 reactor. It has increased to well over 100 Sv/hour from 37.1 in the last update I made (i wrongly wrote 0.371).  I haven't been able to follow the news so closely the last week so I have not seen if this has been mentioned in any TEPCO press release. Below is a graph of the increase. If anyone know of any action done on the number 2 reactor, starting the 3 or 4th of may please write a comment to this blog post.



 

A air filtration system has been connected to the reactor building of reactor number 1. The purpose of it is to get airflow through the building and clean out the air activity by filtrating the air. It is hoped that it will be enough to allow workers to enter the building and work safely without getting to much dose.

Kyodo reports that TEPCO plans to send in workers on monday in order to measure dose rates within the building. Seems strange that they would send in people when they have already used robots once for that purpose.

A longer video clip of the number 4 spent fuel pool can be seen over at Atomic Power Review. It doesn't appear to be very damaged.

The big news of the week is that the prime minister of Japan has asked Chubu electric to shut down its Hamaoka nuclear power plant. Hamaoka has 3 operational nuclear power plants, all of them quite new. Started at 1987, 1993 and 2004. The newest one is a ABWR and would presumably have state of the art eartquake protection. The reason for the prime ministers request is a estimate that the site  has a high probability to be hit by a 8.0 earthquake within 30 years. If the reactors indeed can not handle such a quake then the closure request is rational. But it does smell a bit like political posturing at this point. There is no legal precedence for such a situation and it is not clear if Chubu electric has to obey the request.

 

 

Links(English)
WNN Filters for Fukushima Daiichi 1

Blogs(English)
Atomic Power Review Japan updates: Fukushima Daiichi, Hamaoka
NEI NEI Weekly Update on Fukushima Daiichi – 5/6/1

Blogs(Swedish)
Effekt Monbiot brottas med sig själv
Genusnytt En KARL ska väl tåla lite strålning...
Forskarbloggen Hur många döda efter Tjernobyl?
inas insikter Tjernobyl idag / Fukushima imorgon?
Begrundat och Plitat Cesium och Jod verkar ge spikes i Fukushima när man gläntar på dörren ...

/Johan

Day 35: Parts of the fuel has fallen to the bottom of the vessels

Friday, April 15th, 2011

10:00(CET)/08:00(UTC)/17:00(JST)

Just a short update for today. The number 2 turbine building basement is filling up with water as quickly as TEPCO is pumping it out. No word is said about how the similar work in number 1 and 3 is proceeding. Temperatures are on a downwards trend in all reactors. Pressure in the number 1 pressure vessel continues to climb slowly, containment pressures are stable. Not much new happening on that front.

The Japanese Nuclear Society has reported that their analysis shows that parts of the fuel of all 3 reactors has melted and dropped down to the bottom of the vessels. Small parts of molten fuel has according to their analysis dropped from the rods, solidified when hitting the water and then sunk to the bottom forming small grains. The grains are easily cooled since they have large surface area to volume ratio and they don't form a geometry that is prone to re-criticality.

They also state it is unlikely that there is a large amount of molten fuel at the bottom due to the low temperature readings in the bottom head. Nothing really surprising there either and I pointed it out some time ago. None of this is really surprising.

Zeolite containing sandbags have been put outside the water intake for the number 2 reactors. Zeolite is a porous material that readily adsorbs different molecules (adsorbption is the process of molecules sticking to the surface layers of a material, as opposed to absorption that means its sucked into the material itself). It was used to clean contaminated water within the TMI power planet after the meltdown there.

TEPCO has ordered storage tanks from the US to use to store radioactive water in. IMO I think TEPCO is trying to do perfect when perhaps they should think about doing things adequate. It seems like the volume of water is so large that temporary solutions, like erecting temporary pools, should be considered. But then again it is always easy to be an armchair quarterback on opposite side of the Eurasian continent (other seems to share my general idea though). I haven't seen any new published analysis of the radionuclide content of the water in the number 2 basement, it would be interesting to see what it contains. The dose rates from the water should be going down due to the I-131 decay. Over 95% of the I-131 has decayed now.

Nitrogen injection into the number 1 containment continues, but pressure in the containment has stabilized. Meaning there must be a leakage somewhere. The leakage can't be very large however.

The radiation levels in the groundwater is increasing in the plant area. Otherwise radiation trends are all downwards around Fukushima. From IAEA

Gamma dose rates are measured daily in all 47 prefectures. The values tend to decrease over time. For Fukushima, on 13 April a dose rate of 2.0 µSv/h was reported. In the Ibaraki prefecture, a gamma dose rate of 0.14 µSv/h was reported. The gamma dose rates in all other prefectures were below 0.1 µSv/h.

Dose rates are also reported specifically for the Eastern part of the Fukushima prefecture, for distances beyond 30 km from Fukushima-Daiichi. On 13 April, the values in this area ranged from 0.2 to 26 µSv/h.

In addition to the 7 measurements referred to in yesterday's brief, (note- these measurements were made at distances of 25 km and 33 km not 32 km and 62 km as reported), 13 more measurements were made on 12 April at distances of 25 to 33 km, West and Northwest from the Fukushima Nuclear Power Plant by the IAEA team. At these locations, the dose rates ranged from 0.5 to 16.5 µSv/h. At the same locations, results of beta-gamma contamination measurements ranged from 0.05 to 2.1 Megabecquerel/m2.

Analytical results related to food contamination were reported by the Japanese Ministry of Health, Labour and Welfare on 13 April that covered a total of 98 samples taken on 4 and 11 to 13 April. Analytical results for 76 of the samples of various vegetables, pork, seafood and unprocessed raw milk in nine prefectures (Chiba, Fukushima, Gunma, Ibaraki, Kanagawa, Miyagi, Niigata, Saitama and Yamagata) indicated that I-131, Cs-134 and/or Cs-137 were either not detected or were below the regulation values set by the Japanese authorities. In Fukushima prefecture on 11 April, twenty samples of various vegetables were above the regulation values set by the Japanese authorities for Cs-134/Cs-137, and one sample of seafood (sand lance) and one sample of spinach were above the regulation values set by the Japanese authorities for both I-131 and Cs-134/Cs-137.



Links(English)
Reuters Burrial of reactors tricky

Blogs(English)
Depleted Cranium Fukushima: Now a level 7, but nothing changes
All things Nuclear What Happened at Fukushima Dai-Ichi?
Atomic Power Review Brief update: Temperatures at Fukushima Daiichi 1,2,3
Atomic Power Review Fukushima Daiichi: Reactor cores
Atomic Power Review FACTS: Decommissioning of nuclear power plants

Links(Swedish)
Newsmill Japanska strålsäkerhetsmyndighetens INES 7-gradering endast temporär
Newsmill Brittisk miljöaktivist: Antikärnkraftslobbyn har bluffat om strålningens hälsorisker
Newsmill Japans unga revolterar mot kärnkraften
DN debatt ”Vi fattar inga panikbeslut om kärnkraften”
DN debatt”Att stänga två reaktorer skadar svensk basindustri”

Blogs(Swedish)
Rättvisan framför allt Långsiktighet, var god dröj.
Lotta Olsson Energipolitik är långsiktig...
In Your Face Kan du vika tranor?
Dr Angels blog Fukushima är ännu en mardröm

Day 20 after the tsunami

Thursday, March 31st, 2011

Update 12:00(CET)/10:00(UTC)/19:00(JST)

New JAIF update for today, I will compare it with the NISA update from yesterday.

Reactor 1:
Water level in the core: 1.65 (1.60) meters below the top of fuel assemblies
Flow rate of injected water: 133 liter/minute
Core pressure: 612(592) kPa
Containment pressure: 210(230) kPa
Core temperature(feedwater nozzle): 251.2 (270.1) Celsius
Core temperature(bottom head): 130.2 Celsius
Dose rate within containment: 37.7 Sv/hour

Reactor 2:
Water level in the core: 1.5 (1.5)   meters below the top of fuel assemblies
Flow rate of injected water: 133 liter/minute
Core pressure: unknown
Containment pressure: 110 (100) kPa
Core temperature(feedwater nozzle): 174.3 Celsius
Core temperature(bottom head): Unknown
Dose rate within containment:  39.6 Sv/hour
Spent fuel pool temperature:  48 Celsius

Reactor 3:
Water level in the core: 2.3 (2.25)  meters below the top of fuel assemblies
Flow rate of injected water: 116 liters/minute
Core pressure: 121 (119)  kPa
Containment pressure: 173 (164) kPa
Core temperature(feedwater nozzle): 75.3 Celsius (under review)
Core temperature(bottom head): 116.0 Celsius
Dose rate within containment:  26.8 Sv/hour
Status with the reactors are pretty much unchanged. Work is proceeding with pumping away junk water from turbine halls so one can repair the coolant pumps. Work is slow however due to lack of any place to put the radioactive water.

IAEA released a new estimate on ground fallout yesterday and its not pleasant reading. Here is a quote:

Based on measurements of I-131 and Cs-137 in soil, sampled from 18 to 26 March in 9 municipalities at distances of 25 to 58 km from the Fukushima Nuclear Power Plant, the total deposition of iodine-131 and cesium-137 has been calculated. The results indicate a pronounced spatial variability of the total deposition of iodine-131 and cesium-137. The average total deposition determined at these locations for iodine-131 range from 0.2 to 25 Megabecquerel per square metre and for cesium-137 from 0.02-3.7 Megabecquerel per square metre.

This is Chernobyl level ground deposits of Cs-137 around the plant and indicates one might have to expand the evacuation zone around Fukushima. The basis of the IAEA estimate is from the dust samples published by MEXT.

 

Links(English)
Bloomberg Fukushima workers face risk of uncontrolled reactions
Reuters Japan under pressure to expand evacuation
Kyodo news Kan to review plan to build more nuclear power plants from scratch

Blogs(English)
MIT nuclear information hub Plutonium in the environment
Depleted Cranium Great presentation on Fukushima Daiichi
Where are the clouds Ibakari analysis for 21 march
Atomic Insights Detectable radiation versus dangerous radiation

Links(Swedish)
Expressen Vattenbombningarna kan ha skadat reaktorerna
Aftonbladet Nivån av radioaktivt jod når nya toppmätningar
DN Kärnkraftverk kan stängas för gott
SvD USA styrka skickas till Fukushima

Blogs(Swedish)
Dr Angels Redan 1999 protesterade Greenpeace mot Fukushima
Linn Tummen upp för kärnkraft
Norah4you Dags att tala klarspråk Japan