Japan Earthquake: Nuclear Plants at Fukushima Daiichi

[ivars]

https://www.physicsforums.com/newreply.php?do=newreply&noquote=1&p=3225300"

Tokyo Electric Power Co. took steps to encase the fracture in concrete as an emergency measure but the utility said later that the amount of leakage was unchanged even after the measure was taken.

The utility, known as TEPCO, said the pit is connected to the No. 2 reactor's turbine building and a tunnel-like underground trench, in which highly radioactive water has been spotted so far.

It will try to block leakage of such water by injecting polymeric material into the trench on Sunday and use additional concrete to fill the crack in the 2-meter deep pit measuring 1.2 meters by 1.9 meters.

The tainted water about 10 to 20 centimeters high was found at the bottom of the pit at around 9:30 a.m. Saturday and was leaking to the sea from the crack.

The first detection of tainted water flowing out into the Pacific Ocean could force the government and the operator to limit further expansion of radioactive contamination, likely hampering efforts to restore the crippled cooling functions at the complex.

 

[hbjon]

You can develop cancer if only one side is compromised. In transcription, only one side of the DNA is used, called the template strand. If this strand has one or more base pair substitutions/deletions/etc., it could code for the wrong amino, making an incorrect protein (proteins are the major regulatory mechanism of cells). Also if a start or stop codon is compromised, you could have an incorrect protein made (or no protein made at all) as well. Lentiviruses work in this manner to cause cancer as well. If they incorporate into the DNA in the right area (which for unknown reasons, viruses will incorporate themselves into active genes) , they can cause cancer to develop as a result.

Isn't it true Kate that human physiology utilzes methods and chemical reactions that will be mysteries for years to come? The human cell at an individual level seems to have an innate understanding of how to go about it's activity with the best chance of optimum survival. Cancer may be the best outcome with a high dose of radiation as the suppressor.

 

[hbjon]

Isn't it true Kate that human physiology utilzes methods and chemical reactions that will be mysteries for years to come? The human cell at an individual level seems to have an innate understanding of how to go about it's activity with the best chance of optimum survival. Cancer may be the best outcome with a high dose of radiation as the suppressor.

Just to briefly follow a tangent from my last post on human cells and cancer. In the complex algorithms of cellular repair, a decision seems to be made to take the choice of the lessor of two evils. Cancer or death. Perhaps the organism thinks it may be able to work with the cancer and convert it back to "self" at some point in the future. Just an idea.

 

[TCups]

Just to briefly follow a tangent from my last post on human cells and cancer. In the complex algorithms of cellular repair, a decision seems to be made to take the choice of the lessor of two evils. Cancer or death. Perhaps the organism thinks it may be able to work with the cancer and convert it back to "self" at some point in the future. Just an idea.

Not to get lost in a lot of complexity of radiation biology here, the main points are:

1) there are effective biologic mechanisms for cellular repair of repetitive, sub-lethal doses of radiation.

2) the effects of intermediate and long term accumulated lifetime doses are not the same as the same cumulative dose received in a single exposure.

3) the interpolative methods that are used to arrive at the radiation safety recommendation that "there is no safe, low dose of radiation" is just that, an interpolation of incomplete data.

4) the risk of radiation induced cancer, at whatever limits of exposure that occurs, is a relative risk, and the relative risk of radiation exposure must always be weighed against other potential risks and benefits (eg. the risk of radiation induced cancer may go up from a single transcontinental airline flight, yes, but the risk of injury or death from driving from New York to Los Angeles is much higher, and there may also be a significant benefit in getting to LA a few days earlier.

And yet, as a worker in the field of radiation, this I can tell you as absolute fact: There is an irrational fear of radiation by those who are told "even one piece" (piece?) of radiation might cause a cancer.

 

[razzz]

Didn't I just get done telling them not cover over the damage without knowing where it is first?

You have a crack in a box culvert so you know it is structurally compromised, so what do they do, add dead weight to it. Not only that, they can't see the crack anymore to observe and monitor it. If this is how conditions are going to be responded to, then things can only get worse.

Polluting the Pacific is a given for the immediate future, pretending to stop the pollution with superficial actions is fallacy.

Didn't I read a press release issued by the company that readings from samples would no longer be reported unless the readings were higher than recent past samplings? As they raise the background thresholds they also reserved to determine what they are. Sly.

 

[trinon]

CTBT measurements of iodine 131 concentration in air released by bfs.de [PLAIN]http://www.bfs.de/de/ion/aktivitaetskonzentrationen_jod.jpg

The numbers are in logarithmic scale of Bq/m^3. In the legend are the http://www.bfs.de/de/ion/animation.gif" of the CBTB measurement grid given. The slashed line corresponds to the historically highest measured value in Munich after the Chernobyl accident.

Also the norwegian NILU-ATMOS institute is forecasting release dispersals. You can choose the region and a animated forecast is computed for the next 3 days:
http://transport.nilu.no/products/fukushima"
It is based but not identical to ZAMG data

And I think a whole http://eurdepweb.jrc.ec.europa.eu/PublicEurdepMap/Default.aspx" covering real-time data from all european states was also not yet posted here.

 

[jensjakob]

Is there a dead worker in a white protection suit along the bottom middle of the shot in the beginning? That was very unsettling when I saw that.

Propably not. If it were - I guess they wouldn't have released that clip.

But it could look like it...

 

[timeasterday]

Propably not. If it were - I guess they wouldn't have released that clip.

But it could look like it...

Hopefully it's just some other stuff creating the illusion. But I noticed videos released later always cut out that part.

 

[ZZR Puig]

Your comment is appreciated and educational. The fact remains that ONE piece of radiation is all it takes to start a cancer growing and cancer kills millions annually. Yes, both strand sides of DNA have to be damaged for a permanent change to occur, but that can happen from one ray. Though it is most likely that it would take two rays to damage the DNA stand about the same time, it is still one ray that does the final damage. If it is the second one, so be it. If you never were exposed to it you would not have the cancer. Such is life, and death.

Reality is not that clear at all.

Large evidence exists about positive health effects of different kinds as a result of low radiation doses, independently of the possibility of radiation induced cancer without threshold dose. Therefore even if what you say was true, the slight increase in cancer risk could be overcome by strengthened immune system response, for instance, resulting in an overall average increase in life expectancy. The location of the optimum between positive effects and cancer risks is uncertain, but significant evidence points to a non-zero dose value.

This is an interesting piece of evidence that might induce some reflection:
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2477708/"

 

[Joe Neubarth]

You can develop cancer if only one side is compromised. In transcription, only one side of the DNA is used, called the template strand. If this strand has one or more base pair substitutions/deletions/etc., it could code for the wrong amino, making an incorrect protein (proteins are the major regulatory mechanism of cells). Also if a start or stop codon is compromised, you could have an incorrect protein made (or no protein made at all) as well. Lentiviruses work in this manner to cause cancer as well. If they incorporate into the DNA in the right area (which for unknown reasons, viruses will incorporate themselves into active genes) , they can cause cancer to develop as a result.

Thanks, KateB. Gosh, I am learning so much today. I knew that viruses could cause cancer. What is that one, the Papilloma virus or something spelled like that that causes cervical cancer? I did not know until now that one of the ways that a virus can cause cancer was by splicing itself into the DNA of humans. Amazing!

Thanks to people like you, this board has become the most informative board I have ever visited.

 

[M. Bachmeier]

Borek, I am going to disagree with you on this. I am convinced that any radiation in excess of normal background exposure is not good for you and can kill you. It only takes one gamma ray to damage a DNA string in a cell in your skin, lungs, marrow or whatever to start a cancer cell growing.

The first gamma ray to hit you can trigger cancer growth or the Tenth-Trillion one can. Mathematically we have the same chance no matter which gamma ray it is. I have four skin cancers that are more than likely related to solar radiation, but could be from gamma or Beta radiation from my reactor plant operating days. There is no way of knowing which strike of radiation caused the DNA damage that created the cancers. I also have three tumors growing in my body (Well, one might be dying as the surgeons blocked off the arteries feeding the tumor.). That one was on my Kidney, the other two are on my adrenal gland and my diaphragm area. According to the doctors all are benign. One of the skin cancers is aggressive and was removed yesterday amidst a lot of blood. Those suckers grow roots in multiple directions.

Knowing what I know now, I would have stayed away from nuclear power in my youth. I am 63 now and was last in an operating plant in 1973. Nearly forty years from my last exposure to radiation that was not necessary in normal life. I advise anybody and everybody if you do not need the radiation exposure to survive, stay away from it.

The moral to the story is to avoid any extra exposure to radiation if you can. The life you save may be your own.

Joe, I'm not going to disagree with you about potential, but I'd like to add perspective. Radiation above background 'may' be beneficial. Transient radiation from a source not embedded within the biological system, while not dismissible, would require you to win the, (short story) lottery to have consequences, (also not unreasonable to dismiss based on our exposure... to other environmental toxins. I'll bet my two best friends that particulate (radioactive) substances that can both spread and incorporate into living systems are the priority now. If were going to have a valid discussion on this emergency situation it should focus, not on simple radiation readings, but absorption of the more dangerous isotopes.

Joe I'm about to undergo injection 'radiological', as I believe (may be wrong) you have of tc-99 for health assessment. I'm not afraid of the consequences even though it's being physically added biologically.

One word conclusion..., "PERSPECTIVE"

 

[jensjakob]

This picture worries me:
http://english.kyodonews.jp/photos/2011/04/82781.html

If the military takes these precautions - why do we still see workers on the ground in lot less protection?

 

[M. Bachmeier]

BUT, even then I do not always trust them.

I'll give your bonus points on that. Statistics artifacts are misleading, little outside experimental investigation and or social impact. Odds of winning the lottery don't match the winning.

 

[Borek]

To all: please don't continue discussion on the radiation/health issues here. It can be worth its own thread in Medical Sciences, feel free to start one there, but let's concentrate on technical aspects of the Fukushima here.

 

[Bob S]

Astronuc will the radiation meters the workers have detect if they walk near neutron beams? What is your opinion of the neutron beams that was reported earlier at the plant ?

Neutrons and neutron "beams" are very hard to detect with portable instruments. The most common portable instruments
are gas proportional counters using thermal neutron capture in BF₃ (boron tri-fluoride) or He³ gas.
Proportional counters saturate (paralyze) at high counting rates, so are not good in high radiation areas.

http://www.orau.org/ptp/collection/proportional counters/bf3info.htm

http://www.gepower.com/prod_serv/products/oc/en/oilfield_technology/drilling_measurements/he3_neutron.htm

I have used GM tubes wrapped with thin silver foil (Ag¹⁰⁷ activation with 2.3 min lifetime) to detect pulsed neutron beams.
Tissue-equivalent (Shonka) ionization chambers with suitable neutron moderator and gas (ethene) give a good Sievert (rem) response
to mixed (beta gamma neutron) response, even in high radiation fields (when properly designed). See

http://www.orau.org/ptp/collection/ionchamber/shonkatissueequivalent.htm

High energy neutrons produce proton recoils in a hydrogenous gas (like ethene or ethane) in an ion chamber.

Focusing neutrons is like herding cats. Neutrons are produced isotropically. Neutrons diffuse through shielding, and may leak through cracks,
but since they are uncharged, they can be moderated but cannot be focused.

Bob S

 

[M. Bachmeier]

Propably not. If it were - I guess they wouldn't have released that clip.

But it could look like it...

His head gear would not be white. Artifact. digital ?

 

[hbjon]

To all: please don't continue discussion on the radiation/health issues here. It can be worth its own thread in Medical Sciences, feel free to start one there, but let's concentrate on technical aspects of the Fukushima here.

Well then, let me throw this one at you. Is there any fission occurring anywhere in and around the plants in Fukushima? Is there danger of a chain reaction to start going on? There was talk of neutron beams and daughter products in the vicinity of the plant. I think a lot of people want to know if the explosions could have somehow cause the fuel to form a critical mass? What's the danger of having so much fuel in such close quarters? We know that fission needs to have an efficiency of over 1, what is the current efficiency in and around the 4 separate reactors?

 

[sigyn]

From

http://www.nisa.meti.go.jp/english/files/en20110402-2-3.pdf

I see several tens of sieverts/hr in the drywells of 1-3. I think this is about the same as you would get from 5 meter away from BWR fuel rods after 20,000-30,000 MWday/MT burnup from fig 3 in

http://www.osti.gov/bridge/servlets/purl/10137382-BSfGip/native/10137382.pdf

Any guesses on how much of the core is in the drywells ? Either as corium or dissolved in water leaks from the pressure vessel ?

 

[timeasterday]

A couple of construction videos of Fukushima just popped up:

 

[robinson]

1:48 of the second YouTube video of the plant, a good look at the fuel pool/reactor connection. There is a certain sort of horror watching those videos, knowing what we do now.

 

[TCups]

REGARDING THE SPENT FUEL POOLS AT UNIT 4

@michael200
Re: Your post #2535
about this blog:
http://atomicinsights.com/2011/04/fukushima-nuclear-accident-exceptional-summary-by-murray-e-miles.html

I think I follow your post, but please let me make sure.

1) The article you reference has, in your opinion, a factual error in that it suggests that the Mark 1 BWR has only one, not two SFP's. You confirm that there are indeed two SFP's and, further,

2) You suggest it was a critical operator error not to have considered restoring cooling water by any means possible to the SFP's in Bldg 4 as great a priority as restoring cooling water to the cores of Units 1, 2, and 3. Correct?

And to make sure I understand the points, this Mark 1 BWR floor plan:

http://i306.photobucket.com/albums/nn270/tcups/TopFloor-Floorplan.jpg

. . . drafted from this Mark 1 BWR schematic:

http://i306.photobucket.com/albums/nn270/tcups/Picture63.png

is correct, showing the two SFP's (one large, one small, both in blue) as they are located in Units 3 and 4 at Fukushima. Correct?

And the article you reference seems to indicate that the smaller of the two SFP is damaged and spilled hot fuel rods. Has this been confirmed?

Thanks.

 

[shogun338]

Concrete fails to plug leak at Fukushima nuclear plant http://www.latimes.com/news/nationworld/world/la-fg-japan-quake-20110403,0,2146668.story

 

[M. Bachmeier]

With respect, I'd like to make a few observations.

Time line post earthquake, re: 12 hrs. after, where is there concise data about initial measures?

What choices were made, or possible concerning emergency shutdown (borax re:variants, fill)?

Why are such an intelligent group of people concentrating the intellect on partial data instead of a proper forensic analysis of pre/post conditions at the time of this most unfortunate event.

To me the first few seconds of data has more value than supposition upon supposition of 'non-data'. The following 12 hrs. is the basis of a doctoral dissertation.

Challenge: Show me the TEPCO hard data. And, if you tell me it wasn't ported to an external server (run-time, which would be unthinkable) I'd say we've been chasing shadows... but shadows are evident.

A more knowledgeable analysis is in order.

I'm not looking for culpability, but can not escape a educated layman's perspective analysis of a percipient lack of hard data concerning initial conditions.

 

[turbo]

http://i306.photobucket.com/albums/nn270/tcups/Picture63.png

is correct, showing the two SFP's (one large, one small, both in blue) as they are located in Units 3 and 4 at Fukushima. Correct?

And the article you reference seems to indicate that the smaller of the two SFP is damaged and spilled hot fuel rods. Has this been confirmed?

Thanks.

The pool with the thicker walls and floor are for spent fuel. The pool on the opposite side is for contaminated equipment, like perhaps the top of the reactor vessel when removed for re-fueling.

 

[ZZR Puig]

To all: please don't continue discussion on the radiation/health issues here. It can be worth its own thread in Medical Sciences, feel free to start one there, but let's concentrate on technical aspects of the Fukushima here.

I understand and it is convenient to separate discussions about different topics, however is important to offer a short general reference about how worrying are really the technical issues being discussed about this accident. Especially if some Japanese people follow this forum too. Radiation may be dangerous, but fear-fed stress and ill-founded decisions certainly are.

Well then, let me throw this one at you. Is there any fission occurring anywhere in and around the plants in Fukushima? Is there danger of a chain reaction to start going on? There was talk of neutron beams and daughter products in the vicinity of the plant. I think a lot of people want to know if the explosions could have somehow cause the fuel to form a critical mass? What's the danger of having so much fuel in such close quarters? We know that fission needs to have an efficiency of over 1, what is the current efficiency in and around the 4 separate reactors?

There shouldn't be any fission reactions at the plant, other than spontaneous fissions (very low rates), and there seems to be no sign in the available data pointing in that direction. It is also worth to take in account that the fuel assemblies geometry is not only designed to allow a good cooling of the hot fuel, but to achieve a geometry that is nearly optimal from the point of view of fuel-moderator ratio and therefore maximum effective multiplication coefficient. With low-enriched fuel, a more compact geometry, that could conceivably be obtained with molten fuel at the bottom of the reactor is not necessary likely to reach criticality, as it would lack proper neutron moderation. Additionally, it would also be polluted with many other materials present in the reactor, possibly even boron from the control rods. And that would be in the event that the core has undergone extensive meltdown, which is not at all clear right now. Extensive damage is almost granted, but not necessarily significant meltdown.

 

[TCups]

The pool with the thicker walls and floor are for spent fuel. The pool on the opposite side is for contaminated equipment, like perhaps the top of the reactor vessel when removed for re-fueling.

@turbo-1:
Please read again, look at the diagram more carefully --there are 3 pools in the diagram and on my floor plan -- and then let me know the answer. I know about the equipment pool and its location. I am trying to pin down the location of the third pool. Thanks.

 

[M. Bachmeier]

I understand and it is convenient to separate discussions about different topics, however is important to offer a short general reference about how worrying are really the technical issues being discussed about this accident. Especially if some Japanese people follow this forum too. Radiation may be dangerous, but fear-fed stress and ill-founded decisions certainly are.


There shouldn't be any fission reactions at the plant, other than spontaneous fissions (very low rates), and there seems to be no sign in the available data pointing in that direction. It is also worth to take in account that the fuel assemblies geometry is not only designed to allow a good cooling of the hot fuel, but to achieve a geometry that is nearly optimal from the point of view of fuel-moderator ratio and therefore maximum effective multiplication coefficient. With low-enriched fuel, a more compact geometry, that could conceivably be obtained with molten fuel at the bottom of the reactor is not necessary likely to reach criticality, as it would lack proper neutron moderation. Additionally, it would also be polluted with many other materials present in the reactor, possibly even boron from the fuel rods. And that would be in the event that the core has undergone extensive meltdown, which is not all all clear right now. Extensive damage is almost granted, but necessarily significant meltdown.

You speak from, both a lack of data and desire for amortization, I don't advocate rash choices, but consider the human cost in decisions made. Precaution is both expensive and warranted in this case. Unknowns equal unacceptable risks for me and mine.

 

[NUCENG]

That has been suggested. Even so, to transmit the blast force downward with sufficient force to blow almost all of the walls one level below the top of the SFP4, and several wall panels two levels below, and yet leave most of the superstructure of the roof girders intact, and even have the north wall of the top floor collapse inward speaks to me of a very different kind of explosion, doors opened or closed. A lot of the damage is isolated around the northeast corner of Bldg 4.

I can maybe get to that kind of damage if hot fuel drops through the bottom of one or the other pools in the top floors and causes and additional lower level blast that spreads outward around the reinforced inner walls of the primary containment. But I just can't wrap my arms around the open door theory.

The reactor building in a BWR has a large open shaft from the refuel floor down to the ground floor. This shaft allows large loads including fuel shipping and storage casks to be lifted to the refuel floor. During outages this is widw open. During operation there may be tarps or safety nets on the openings at each floor, but it is not air-tight.

The secondary containment (reactor building) is designed to be kept at a negative pressure by normal ventilation during normal operations and by the Standby Gas Treatment System during accidents. The building is not compartmentalized like a submarine so take that for what i may mean during san explosion.

 

[turbo]

@turbo-1:
Please read again, look at the diagram more carefully --there are 3 pools in the diagram and on my floor plan -- and then let me know the answer. I know about the equipment pool and its location. I am trying to pin down the location of the third pool. Thanks.

The "third" pool appears to be a reservoir in which the dry fuel cask can be placed until it is opened and the fuel assembly is removed from the cask for transfer to the reactor. The water is required for shielding when the assembly is out of the cask.

 

[shogun338]

Could this be melted spent fuel 2 flowing out of 1 in this pic of Reactor #4 ?

 

[Dotini]

Challenge: Show me the TEPCO hard data. And, if you tell me it wasn't ported to an external server (run-time, which would be unthinkable) I'd say we've been chasing shadows... but shadows are evident.

A more knowledgeable analysis is in order.

I'm not looking for culpability, but can not escape a educated layman's perspective analysis of a percipient lack of hard data concerning initial conditions.

http://www.nytimes.com/2011/04/03/science/03meltdown.html

http://www.docstoc.com/docs/75223364/fukushima-areva <--the Areva slideshow

 

[shogun338]

This should be helpful to the workers dealing with the situation. QinetiQ North America today announced that the government of Japan has accepted its offer to provide unmanned vehicle equipment and associated training to aid in Japan’s natural disaster recovery efforts. QinetiQ North America’s technology and services will allow Japan’s response teams to accomplish critical and complex recovery tasks at a safer distance from hazardous debris and other dangerous conditions.

The equipment being staged in Japan for rapid, on-call deployment includes QinetiQ North America’s Robotic Appliqué Kits, which turn Bobcat loaders into unmanned vehicles in just 15 minutes. The kits permit remote operation of all 70 Bobcat vehicle attachments, such as shovels, buckets, grapples, tree cutters and tools to break through walls and doors. The unmanned Bobcat loaders include seven cameras, night vision, thermal imagers, microphones, two-way radio systems and radiation sensors, and can be operated from more than a mile away to safely remove rubble and debris, dig up buried objects and carry smaller equipment. http://www.qinetiq-na.com/a07ccafe-0488-4f5b-9121-969e8c8d356a/news-and-events-latest-news-detail.htm

 

[hoyrylollaaja]

Could this be melted spent fuel 2 flowing out of 1 in this pic of Reactor #4 ?

and defy gravity?

 

[TCups]

REGARDING SECONDARY CONTAINMENT VENTILATION SYSTEMS

The reactor building in a BWR has a large open shaft from the refuel floor down to the ground floor. This shaft allows large loads including fuel shipping and storage casks to be lifted to the refuel floor. During outages this is widw open. During operation there may be tarps or safety nets on the openings at each floor, but it is not air-tight.

The secondary containment (reactor building) is designed to be kept at a negative pressure by normal ventilation during normal operations and by the Standby Gas Treatment System during accidents. The building is not compartmentalized like a submarine so take that for what i may mean during san explosion.

Negative pressure . . . interesting. Does the external venting and filtration ultimately exit through the tower between Units 3 and 4? But would the ventilation system and negative pressure be operational during complete loss of power? Hard to imagine that power would have been restored to the ventilation systems and yet not to the water cooling and circulation, although it takes a lot more power to run water pumps than fans, I suppose.

 

[Joe Neubarth]

Could this be melted spent fuel 2 flowing out of 1 in this pic of Reactor #4 ?

Boy, once you plant the thought in my mind, it does look like melted lead flowing over the debris.