Japan Earthquake: Nuclear Plants at Fukushima Daiichi

[RealWing]

Really? From what I've heard of German reactors, the operating manuals are to be obeyed, and when operator manual tells you to do something - e.g. to vent - it would take government approval not to vent. The automatic pressure relief valves surely don't ask for approval.

The operating manuals in this case are the Emergency Operating Procedures. They specifically tell you to get Gov't approval to vent. When we get that approval, we vent. So yes, I agree - follow procedures.

At our reactors in Ontario, Canada, we have a huge Vacuum Building (VB) that is kept under vacuum at all times and connected to each reactor. If a major rupture occurs, the steam etc is automatically sucked into the VB and doused with water which condenses the steam. This is all passive and no power is needed. At some point after that, the pressure inside our containment structure will approach atmospheric and venting will be required - primarily to ensure that all the radioactive material goes out through a monitored, hardened and filtered vent, instead of leaking out through unmonitored pathways in the containment structure.

 

[GJBRKS]

A friend in Japan tells me the officials are very reluctant to accept foreign help because of pride. They rather build their own robots. It surely is an insult for a pride high-tech-nation like Japan, who's relying so much on nuclear power and doesn't have their own robots to deal with such a crisis. Things are quite a bit different in Japan. If you haven't been there yet, it's worth a long trip (well... pack your dosimeter...).

Let's be carefull in assuming Japan doesn't accept help just to make a point :

- The Japanese government has expressed thanks to the USA for their crisis teams
- The French Areva will supervise the construction of a water decontamination site by a UK firm
- German concrete pump trucks are being flown in using a Russian Antonov
- American robots have surveyed the plants
- A Russian decontamination vessel is being transported to the site.
- An American barge has been used to store contaminated pump water
- The NRC has been doing crisis recommendations that up to now are being followed to the letter
( http://cryptome.org/0003/daiichi-assess.pdf : read the advised steps , and see that's exactly what TEPCO does or plans to do)

I'd say it is even particularly important for the government to show they are working with the USA , in order to prevent a popular backlash towards the ( after all) American imported technology

 

[PietKuip]

There was 172,000 people in the 30 km evaluation zone, considering nearly all were in a 20 km zone and the rest was ask to stay indoors, considering current projection (by NNSA) for radiation dose for people not indoors not evacuated and staying or coming back for a year in the 30Km zone in currently around 20mSv .

Hopefully, according to current knowledge there should not be additional death due to ionization in the general population

What might be a reasonable estimate of the extra dose in Tokyo? I think 1 mSv might be a reasonable order of magnitude (about a year of 0.1 microSievert per hour, on average). With 10^7 people that gives 10^4 man-Sievert, about 100 deaths.

 

[I_P]

My apologies if I stepped on your toes. I saw PietKuip ask "Don't they want to know what it is?" And in fact they probably do not care. That guy on the loader or crane and the technician monitoring radiation know that concrete is dangerous and in their way. They are working with dose limits and if they spend time studying a particular piece of debris they will soon be useless because they will be at their limits. These workers are trying to get the job done. They may never be able to return to their homes. When the site is stabilized they may be unemployed. Put yourself in their place. There is radioactivity in the air water and soil. There is sharp metal and debris all over the place. There is more debris hanging perilously over head. It could be corium, it could be a piece of spent fuel blown out of a fuel pool. It may be a hot piece of Cesium or irradiated steel, or a spec of cobalt-60.

It seems that there are more and more people on this site that really believe TEPCO is lying about everything. That was reinforced today when the government of Japan took over the PR communications role. We'll have to wait and see if that improves anything. I am also sensitive to a tendency to project the distrust and contempt on the workers, and I may have over-reacted if that wasn't what you and Piet were saying.

NUCENG, I truly appreciate your posts and those of others who have posted here with specific industry knowledge and/or perspective. It helps keep the discussion on track and informative. That said let me respond in a general way to you as a representative of your profession. Nothing personal intended or implied.

The death toll from the quake and tsunami is around 30,000 people. The exact figure is still climbing as it has been hard to determine the number of missing given the scale of destruction. Who knows how many will die when LA or San Fransisco or Lisbon or Tokyo (etc.) is shaken by another 'big one'. Human nature and behavior intersecting with natural forces that manifest sporadically, unpredictably (regarding the precise time of an event, not necessarily it's probability) and with great force - many types of examples come to mind here. However, this is quite a different matter from the accident at Fukushima.

The attitude of the staff and management at TEPCO was that such an accident was impossible and no preparations had been made or consideration given to the possibility. Training and equipment to deal with a serious accident was not implemented or acquired, one of the rationals being that to pursue such matters would show insecurity or fear and call into question the safety of nuclear plants.

The historical and scientific knowledge about tsunamis was not properly considered given the known risks to plants on the coast. It was stated that unit 1 was constructed with an 'off the shelf' plan from GE that wasn't modified to suit the site specific risks because the engineers were not familiar enough with plant design to confidently recommend changes to it. Once the first unit was built the following units were added using the same basic format, incorporating the same site-based flaws. This was not corrected later because of cost, and as above, because the major changes required would have been acknowledgment that the original design wasn't safe.

When the accident occurred (first couple of days) the site technicians were left on their own to do the best they could while upper management was MIA. There was a fundamental misunderstanding of the seriousness of the situation (one shared by many in the nuclear power industry around the world) that resulted in hesitation to take necessary steps. TEPCO balked at venting, because of liability issues most likely, as well as the use of seawater for cooling because of concerns for their investment.

When it became clear that venting was necessary TEPCO made no attempt to re-establish the network of radiation monitors around the site perimeter that were disabled from lack of power. This violation of public responsibility and trust meant that it was impossible to adequately assess/measure risk to the public during the critical first week of the accident.

There was no system put in place to monitor conditions at the plant, given that it was too dangerous for workers on-site to do this, resulting in confusion over how the situation was progressing/deteriorating.

Offers of outside help and equipment were refused despite the fact that TEPCO lacked adequate equipment and trained personnel.

Plant workers were neither adequately trained nor equipped for safely and effectively carrying out their duties.

All of the above has led to confusion, misinformation, and an ad-hoc response that exacerbated an already terrible situation, unnecessarily endangered public safety and the safety of those tasked with working on the site. TEPCO in particular deserves neither the benefit of the doubt nor public trust. The government response, as the steward of the public interest, has not effectively mitigated TEPCO's failures. After all this the public will be asked to foot the bill for damage and cleanup and to suffer the various risks and ramifications of the accident for decades to come. [That said, there is also public responsibility in a democracy to make sure that public officials are doing their jobs, and consumers who rely on/expect 24hr electricity should understand that this requires acceptance of some risks and costs.]

 

[Samy24]

What might be a reasonable estimate of the extra dose in Tokyo? I think 1 mSv might be a reasonable order of magnitude (about a year of 0.1 microSievert per hour, on average). With 10^7 people that gives 10^4 man-Sievert, about 100 deaths.

We will never know. Even 1000 deaths will statistically never be visible. Till today most people belief only 47 man were killed in the Chernobyl accident

 

[Borek]

To all: please stop discussing politics, management and other things unrelated to the technical aspects of the Fukushima situation. Fell free to discuss these things in separate threads, but not here.

 

[clancy688]

Concrete does not get this radioactive by neutron activation.
It seems to me there must have been some corium on this piece.

So where is the rest?

Hm... I don't think that's the problem here. I'd rather ask "How did it get there?"

NHK World wrote "has been found near the reactor". So it's outside the reactor. And considering its classification as "concrete fragment", it has most likely been ejected from either Unit 3 or Unit 4.
But if there really is Corium embedded in this piece, then I have absolutely no idea how it was able to leave the reactors. Corium is flowing down, not up. But the explosions happened on top of the RPVs. Far above of the reactor fuel rods. Maybe there has been Corium. But it should be impossible for it to get ejected.

I know that TCups has a theory about the explosion at Unit 3. It's thousands of posts away, but if I remember correctly, he assumes that the Unit 3 explosion breached the SFP, boiled the water away and ejected the fuel handling machine - probably with fuel rods.
So perhaps a little chunk of fuel elements landed on a rubble part, got hot and fused with it, forming the dangerous concrete block?

What would happen, if a fuel rod would be ejected from the SFP and totally broken apart by the force of the explosion, so that all uranium pellets impact individually on site? Would they heat up and melt through the surface?

An NRC paper stated that there was highly radioactive rubble which was bulldozed over - possible fuel pellets?

 

[Caniche]

To all: please stop discussing politics, management and other things unrelated to the technical aspects of the Fukushima situation. Fell free to discuss these things in separate threads, but not here.

Which threads do you recommend?
Bit of an artificial divided though when politics dictates the bottom line and management decides cost/benefit and both control the data presentation that creates the technical pea-souper that appears here. Given those circumstances I would like to express heartfelt thanks to all those who endeavour to provide honest interpretations from restricted information,much appreciated

 

[etudiant]

The earlier reports of very contaminated material found between reactors 3 and 4 together with todays find indicate that solid pieces of nuclear material have been released, not solely gaseous or liquid emissions.
Is there any plausible source other than the SFPs, as TCups has suggested?
What are the implications if material from the SPFs is found scattered around the site?
Is there a scanning radiation meter instrument available that could survey the site and pick out radioactive hot spots similarly to the way an IR camera highlights heat leaks?

 

[MJRacer]

The earlier reports of very contaminated material found between reactors 3 and 4 together with todays find indicate that solid pieces of nuclear material have been released, not solely gaseous or liquid emissions.
Is there any plausible source other than the SFPs, as TCups has suggested?
What are the implications if material from the SPFs is found scattered around the site?
Is there a scanning radiation meter instrument available that could survey the site and pick out radioactive hot spots similarly to the way an IR camera highlights heat leaks?

X-ray film?

 

[Jorge Stolfi]

X-ray film?

You cannot focus neutrons and gamma rays to make an image on film. (X-ray imaging works because the source is point-like; there are no lenses involved in image formation.)

 

[Dmytry]

Jorge Stolfi: well perhaps you can make pinhole cam... but i don't think it'd work well. For cosmic rays, you can have several detectors and do tracks. I don't know if that would work for gamma. I think not. It'd scatter too much in the first detector.

edit: wow, see this: http://science.nasa.gov/science-news/science-at-nasa/balloon/mixe2/
but again I don't know what would be the range of that thing in air. But I think it can work.

Hm... I don't think that's the problem here. I'd rather ask "How did it get there?"

NHK World wrote "has been found near the reactor". So it's outside the reactor. And considering its classification as "concrete fragment", it has most likely been ejected from either Unit 3 or Unit 4.
But if there really is Corium embedded in this piece, then I have absolutely no idea how it was able to leave the reactors. Corium is flowing down, not up. But the explosions happened on top of the RPVs. Far above of the reactor fuel rods. Maybe there has been Corium. But it should be impossible for it to get ejected.

I know that TCups has a theory about the explosion at Unit 3. It's thousands of posts away, but if I remember correctly, he assumes that the Unit 3 explosion breached the SFP, boiled the water away and ejected the fuel handling machine - probably with fuel rods.
So perhaps a little chunk of fuel elements landed on a rubble part, got hot and fused with it, forming the dangerous concrete block?

What would happen, if a fuel rod would be ejected from the SFP and totally broken apart by the force of the explosion, so that all uranium pellets impact individually on site? Would they heat up and melt through the surface?

No, individual pellet won't melt through surface. A pile might.
Reactor core is something on order of hundred tons of uranium (ton = 1E6 grams), maybe more. Individual pellet is 10..20 grams at most by the look of it. Let's say core makes few tens megawatts of decay heat, then the individual pellet makes few watts at most, and that's shortly after shutdown.
You could read what it was like in Chernobyl if you want to know what fuel does after being blown apart.

An NRC paper stated that there was highly radioactive rubble which was bulldozed over - possible fuel pellets?

Dunno, I'd guess so, no idea what else it could've been, they don't tell how radioactive that 'highly radioactive' rubble was.

 

[tsutsuji]

To all: please stop discussing politics, management and other things unrelated to the technical aspects of the Fukushima situation. Fell free to discuss these things in separate threads, but not here.

I am leaving this forum as a protest against the censorship exerted against my last post. My last post was deleted without any prior warning or posterior explanation whatsoever. This is rude.

Someone asked me a question in reference to my last post. I was gathering information to provide an anwer to that question when I found that both my last post and the question in reference to my last post had been deleted. There is a probablility that the answer to that question, concerning the relevance of the INTRA robots, is technical.

My conviction is that decision making and technical matters are intimely intricated when a crisis like the Fukushima crisis is concerned. Dealing with the latter while ignoring the former can only provide a biased vision of the situation. Therefore I would rather leave than collaborate to a biased form of reporting.

Trying to create a "pure science" detached from men and women's lives is anti-humanist.

A 16th century writer said :

science without conscience is but the ruin of the soul

http://en.wikiquote.org/wiki/François_Rabelais

 

[com.oligarchy]

Wasn't there a set of photos showing heat more
concentrated in the center of reactor building 4?
Indicating the reactor was hot. Funny how this is
the explosion we don' have video of.

Guess the Toshiba re-shroud, doesn't work and we
will have to retire these reactors like the original
design said, after 30 years. I remember way back then
they said the concrete absorbs radiation over time and
cant be refitted, site reused. They also said they were
going to dry cask, and create a central storage location
in the shield, or something. Reptilian and sociopathic

right, sorry, no politics, just the facts now

 

[michael200]

Just because high dose material has been found on the site is not surprising. The destroyed building next to the unit 3 reactor building is the radwaste building. Also I would not be suprised if the u3 and u4 fuel pool demineralizers were damaged in the explosions. Radioactive does not mean fuel is flung around the site. It doesn't take a lot of co60 to provide a 1 sievert source.

 

[NUCENG]

NUCENG, I truly appreciate your posts and those of others who have posted here with specific industry knowledge and/or perspective. It helps keep the discussion on track and informative. That said let me respond in a general way to you as a representative of your profession. Nothing personal intended or implied.

The death toll from the quake and tsunami is around 30,000 people. The exact figure is still climbing as it has been hard to determine the number of missing given the scale of destruction. Who knows how many will die when LA or San Fransisco or Lisbon or Tokyo (etc.) is shaken by another 'big one'. Human nature and behavior intersecting with natural forces that manifest sporadically, unpredictably (regarding the precise time of an event, not necessarily it's probability) and with great force - many types of examples come to mind here. However, this is quite a different matter from the accident at Fukushima.

The attitude of the staff and management at TEPCO was that such an accident was impossible and no preparations had been made or consideration given to the possibility. Training and equipment to deal with a serious accident was not implemented or acquired, one of the rationals being that to pursue such matters would show insecurity or fear and call into question the safety of nuclear plants.

The historical and scientific knowledge about tsunamis was not properly considered given the known risks to plants on the coast. It was stated that unit 1 was constructed with an 'off the shelf' plan from GE that wasn't modified to suit the site specific risks because the engineers were not familiar enough with plant design to confidently recommend changes to it. Once the first unit was built the following units were added using the same basic format, incorporating the same site-based flaws. This was not corrected later because of cost, and as above, because the major changes required would have been acknowledgment that the original design wasn't safe.

When the accident occurred (first couple of days) the site technicians were left on their own to do the best they could while upper management was MIA. There was a fundamental misunderstanding of the seriousness of the situation (one shared by many in the nuclear power industry around the world) that resulted in hesitation to take necessary steps. TEPCO balked at venting, because of liability issues most likely, as well as the use of seawater for cooling because of concerns for their investment.

When it became clear that venting was necessary TEPCO made no attempt to re-establish the network of radiation monitors around the site perimeter that were disabled from lack of power. This violation of public responsibility and trust meant that it was impossible to adequately assess/measure risk to the public during the critical first week of the accident.

There was no system put in place to monitor conditions at the plant, given that it was too dangerous for workers on-site to do this, resulting in confusion over how the situation was progressing/deteriorating.

Offers of outside help and equipment were refused despite the fact that TEPCO lacked adequate equipment and trained personnel.

Plant workers were neither adequately trained nor equipped for safely and effectively carrying out their duties.

All of the above has led to confusion, misinformation, and an ad-hoc response that exacerbated an already terrible situation, unnecessarily endangered public safety and the safety of those tasked with working on the site. TEPCO in particular deserves neither the benefit of the doubt nor public trust. The government response, as the steward of the public interest, has not effectively mitigated TEPCO's failures. After all this the public will be asked to foot the bill for damage and cleanup and to suffer the various risks and ramifications of the accident for decades to come. [That said, there is also public responsibility in a democracy to make sure that public officials are doing their jobs, and consumers who rely on/expect 24hr electricity should understand that this requires acceptance of some risks and costs.]

I concede that everything you say about TEPCO may be true. On some of it, it is probably true about US plants, Russian plants, German plants and everywhere else. If they knew that they had underestimated the threat of seismic events, or tsunamis and did nothing about it they should be held to blame. If anything good can come from this tragedy it will be from rethinking our vulnerabilities and taking action to make our plants even safer.

i just think that right now, our concentration should be focused on what can be done to stabilize the plants and minimize the threat to the public. That is much harded than pointing fingers and criticizing the people who are there. We have no choice but to work with TEP
CO and Japanese leaders. Keep the thumbscrews and rack handy, their time will come.

 

[Fairweather]

You cannot focus neutrons and gamma rays to make an image on film. (X-ray imaging works because the source is point-like; there are no lenses involved in image formation.)

Gamma Ray detectors and imaging systems can be fabricated using tungsten collimators and detector arrays. See http://hesperia.gsfc.nasa.gov/hessi/index.html

 

[etudiant]

I concede that everything you say about TEPCO may be true. On some of it, it is probably true about US plants, Russian plants, German plants and everywhere else. If they knew that they had underestimated the threat of seismic events, or tsunamis and did nothing about it they should be held to blame. If anything good can come from this tragedy it will be from rethinking our vulnerabilities and taking action to make our plants even safer.

i just think that right now, our concentration should be focused on what can be done to stabilize the plants and minimize the threat to the public. That is much harded than pointing fingers and criticizing the people who are there. We have no choice but to work with TEP
CO and Japanese leaders. Keep the thumbscrews and rack handy, their time will come.

In that context, is there anything material that TEPCO is not doing that experts on this blog feel they need to do?

Surprisingly, the site is still very thinly staffed, about 500 people versus a normal complement of 4- 5000 reported in the Mainichi Daily News here:
http://mdn.mainichi.jp/mdnnews/news/20110325p2a00m0na014000c.html

If the site does indeed have only a skeleton staff, it surely indicates that no dramatic initiatives should be anticipated. So the facilities are expected to ride out the cyclone season largely as they are. There are not enough people to do much to help.

 

[AntonL]

On the last page of this http://www.meti.go.jp/press/2011/04/20110419002/20110419002-2.pdf" the route to transfer the highly radio active water is shown.

This route is through the turbine halls 3 and 4 and the pipes are flexible plastic pipes with metallic spiral for support.

How does plastic hold up to high radiation? will it go brittle or loose strength?

Is it wise to route highly radioactive water through what is possibly a fairly uncontaminated area, in case a leak springs. There seems to be concern regarding the couplings as they tied down and double wrapped as added precaution.

 

[robinson]

Can't verify any of this yet, but if true, quite interesting.

Japan admits daily radioactive release from Fukushima many times higher than previously announced — Nuclear commission blames calculation error

http://enenews.com/daily-radioactive-release-from-fukushima-is-150-times-higher-than-previously-announced-154-trillion-becquerels-released-everyday
http://ex-skf.blogspot.com/2011/04/fukushima-i-nuke-plant-154.html

 

[etudiant]

Can't verify any of this yet, but if true, quite interesting.

Japan admits daily radioactive release from Fukushima many times higher than previously announced — Nuclear commission blames calculation error

http://enenews.com/daily-radioactive-release-from-fukushima-is-150-times-higher-than-previously-announced-154-trillion-becquerels-released-everyday
http://ex-skf.blogspot.com/2011/04/fukushima-i-nuke-plant-154.html

The discussion on the scale of the emissions is somewhat moot, imo, because the reality of radiation cannot be hidden.
Japan is beginning to have summer weather, with inland winds and frequent rains. If the site continues large scale emissions, the Japanese authorities will need to further expand the evacuation zone.

 

[dh87]

Just because high dose material has been found on the site is not surprising. The destroyed building next to the unit 3 reactor building is the radwaste building. Also I would not be suprised if the u3 and u4 fuel pool demineralizers were damaged in the explosions. Radioactive does not mean fuel is flung around the site. It doesn't take a lot of co60 to provide a 1 sievert source.

I agree with this. TEPCO says that so far the released radioactivity is around 10,000,000 Curies (http://www.tepco.co.jp/en/nu/fukushima-np/f1/images/f12np-gaiyou_e.pdf). As I calculated a couple pages back, this 900 mSv/hr object is a few Curies. It would be stunning if there weren't things this hot. It's not an indication that the fuel has escaped.

 

[com.oligarchy]

DH87
What difference does it make
its the same effect to living things
on this planet

 

[rowmag]

NHK TEPCO says the workers were exposed to 3.17 millisieverts of radiation during the clean-up and the concrete block has been stored safely in a container with other debris.

If they take 3.17 mSv by using a "remote-controlled rubble removing equipment" the radiation in that area must be enormous.

According to Yomiuri, it was not remote-controlled equipment, it was manned equipment that was used:

http://www.yomiuri.co.jp/feature/20110316-866921/news/20110423-OYT1T00654.htm

It was discovered on the 20th, and put into the container on the 21st.

As for the source, it is thought to be related to the hydrogen explosion of Unit 3.

 

[Jorge Stolfi]

I created a rough model of Fukushima Daiichi Unit #1 using the free raytracing program POV-Ray.

http://www.ic.unicamp.br/~stolfi/EXPORT/projects/fukushima/povray/Main.html

Unit #1 was the only one for which I had some reliable blueprints. If I had blueprints of the other units, I could consider doing them too...

Enjoy.

 

[NUCENG]

In that context, is there anything material that TEPCO is not doing that experts on this blog feel they need to do?

Surprisingly, the site is still very thinly staffed, about 500 people versus a normal complement of 4- 5000 reported in the Mainichi Daily News here:
http://mdn.mainichi.jp/mdnnews/news/20110325p2a00m0na014000c.html

If the site does indeed have only a skeleton staff, it surely indicates that no dramatic initiatives should be anticipated. So the facilities are expected to ride out the cyclone season largely as they are. There are not enough people to do much to help.

At present workers are trying to cool and stabilize reactors and fuel pools.

They are exploring buildings with robots to gather information about damage.

They are clearing debris from the site that interferes with areas they will use to restore power and find out what systems may still be operable.

They are allowing time to reduce dose rates.

They are limiting the number of people on site to reduce the number of people getting emergency doses to a minimum.

They are testing remote control equipment and some methods like spraying a type of sealent to keep down dust and airborne doses.

They have issued a roadmap for future actions.

They have a lot of foreign "help" to consider.

If they were providing more information, forums such as this one might be able to provide a form of validation and technical review of that information.

Other than that I can't think of anything else they should be doing. You raise the question of cyclones. In Japan the word is taifun or typhoon. That is a legitimate concern. Torrential rain and winds could further damage the buildings and further disperse radioactivity to the environment. But until they have a better understanding of damage, it could be counterproductive to start bracing or repairing buidings. Getting debris cleared up will reduce potential missile damage.

Your question is a good one. What else should they be doing?

 

[MiceAndMen]

I created a rough model of Fukushima Daiichi Unit #1 using the free raytracing program POV-Ray.

http://www.ic.unicamp.br/~stolfi/EXPORT/projects/fukushima/povray/Main.html

Unit #1 was the only one for which I had some reliable blueprints. If I had blueprints of the other units, I could consider doing them too...

Enjoy.

Pretty good, Jorge, although I would dispute that fig_un1_pools_and_walls.png shows the correct layout of the pools. There has been no confirmation that the smallest pool in the picture actually exists separately from the SFP in any of the reactor buildings.

I was going to do a large-scale plant layout in 3D until I saw someone beat me to it.
http://www.turbosquid.com/3d-models/c4d-nuclear-power-plant-fukushima/594020
I downloaded some of the jpegs from that page and saw many inaccuracies. The overall work is good, but not precise enough for my liking. The guy even duplicated the paint scheme on the side of the buildings! For that price, I would expect near perfection, and even if everything was perfect I don't think I would pay $299 for the model

 

[rowmag]

Don't know if these have been mentioned:

"The government is considering building an underground barrier near the Fukushima No. 1 nuclear power plant to prevent radioactive material from spreading far from the plant via soil and groundwater, a senior government official said."

Reactor 1 already half-entombed with water:
"At a press conference held Friday, TEPCO said it believed pressure suppression pools at the bottom of the No. 1 reactor's containment vessel were full of water, and that the top section of the containment vessel was about half full. Under normal circumstances, the pressure suppression pools are about 50 percent full with water."

http://www.yomiuri.co.jp/dy/national/20110423dy01.htm

 

[TCups]

I agree with this. TEPCO says that so far the released radioactivity is around 10,000,000 Curies (http://www.tepco.co.jp/en/nu/fukushima-np/f1/images/f12np-gaiyou_e.pdf). As I calculated a couple pages back, this 900 mSv/hr object is a few Curies. It would be stunning if there weren't things this hot. It's not an indication that the fuel has escaped.

10,000,000 Curies?! Really? The equivalent radioactivity of ten thousand kilograms of radium?! Ten metric tonnes?!

What sort of things accumulate in precipitators? Co 60? Can someone tell us more about "radwaste buildings" please? Does contamination from the radwaste building fit with these early measurements? (see attached)

http://i306.photobucket.com/albums/nn270/tcups/4000d390.png

 

[Borek]

My conviction is that decision making and technical matters are intimely intricated when a crisis like the Fukushima crisis is concerned. Dealing with the latter while ignoring the former can only provide a biased vision of the situation. Therefore I would rather leave than collaborate to a biased form of reporting.

As I explained earlier, feel free to discuss other matters in different threads, you can start them either in Nuclear Engineering or Politics & World Affairs subforums.

It is not about censorship, it is about keeping some order in the discussion. Putting everything into one thread means mess.