Japan Earthquake: Nuclear Plants at Fukushima Daiichi

[83729780]

http://www.dailymail.co.uk/news/art...side-Japans-stricken-nuclear-power-plant.html

Five are believed to have already died and 15 are injured while others have said they know the radiation will kill them.

is this corroborated by other sources? Is there public information on levels of exposure?

 

[|Fred]

NISA it updating this every day several time a day.. I don't know where the press get there "stuff", I thought they were long gone from Japan ..



2. Exposure of workers
(1) As for the 18 workers conducting operations in Fukushima Dai-ichi NPS, results of measurements are as follows;
One worker: At the level of exposure as 106.3 mSv, no risk of internal exposure and no medical treatment required.
Other workers: At the level of no risk for health but concrete numerical value is unknown.
(2) As for the 7 people working at the time of explosion at around the Unit 3 of Fukushima Dai-ichi NPS who were injured and conscious, 6 out of 7 people were decontaminated by an industrial doctor of the clinic in Fukushima Dai-ni NPS, and confirmed to have no risk. The other one was decontaminated at the clinic and the medical treatment was completed.

3. Others
(1) Fukushima Prefecture has started the screening from 13 March. It is carried out by rotating the evacuation sites and at the 12 places (set up permanently) such as health offices. The results of screening are being totalled up.
(2) 5 members of Self-Defence Force who worked for water supply in Fukushima Dai-ichi NPS were exposed. After the work (March 12th), 30,000 cpm was counted by the measurement at Off site Centre. The counts after decontamination were between 5,000 and 10,000 cpm. One member was transferred to National Institute of Radiological Sciences. No other exposure of the Self-Defence Force member was confirmed at the Ministry of Defence.

(3) As for policeman, the decontaminations of two policemen were confirmed by the National Police Agency. Nothing unusual was reported.

<Situation of the injured (As of 19:00 March 23rd)>

1. Injury due to earthquake
- Two employees (slightly)
- Two missing (TEPCO’s employee, missing in the turbine building of Unit 4)
- One emergency patient (According to the local prefecture, one patient of cerebral infarction was transported by the ambulance).
- Ambulance was requested for one employee complaining the pain at left chest outside of control area (conscious).
- Two employees complaining discomfort wearing full-face mask in the main control room were transported to Fukushima Dai-ni NPS for a consultation with an industrial doctor.
2. Injury due to the explosion of Unit 1 of Fukushima Dai-ichi NPS
- Four employees were injured at the explosion and smoke of Unit 1 around turbine building (non-controlled area of radiation) and were examined by Kawauchi Clinic.
3. Injury due to the explosion of Unit 3 of Fukushima Dai-ichi NPS
- Four TEPCO’s employees
- Three subcontractor employees
- Four members of Self-Defence Force (one of them was transported to National Institute of Radiological Sciences considering internal possible exposure. The examination resulted in no internal exposure. The member was discharged from the institute on March 16th.)
4. Other injuries
- A person who visited the clinic in Fukushima Dai-ni NPS from a transformer sub-station, claiming of a stomach ache, was transported to a clinic in Iwaki City, because the person was not contaminated

 

[PietKuip]

NISA it updating this every day several time a day.. I don't know where the press get there "stuff", I thought they were long gone from Japan ..

2. Exposure of workers
(1) As for the 18 workers conducting operations in Fukushima Dai-ichi NPS, results of measurements are as follows;
One worker: At the level of exposure as 106.3 mSv, no risk of internal exposure and no medical treatment required.
Other workers: At the level of no risk for health but concrete numerical value is unknown

That is ridiculous! Were these workers not carrying dosimeters?

 

[rhody]

For a true appreciation: the scope of devastation caused by the tsunami,
covering almost 200 miles of the Japanese coast, take a look at http://www.abc.net.au/news/events/japan-quake-2011/beforeafter.htm":
and http://www.abc.net.au/news/events/japan-quake2011/beforeafter2.htm" , there are two parts...

Mouse over each photo (right to left and vice versa) before and after...

Rhody...

P.S. I just reviewed both pages, slowly... this is a sample of the havoc wrought by the waves.
Obviously the low lying areas took it the worst.

 

[PietKuip]

from Kyodo:

Electric Power Co. said Wednesday it has observed a neutron beam, a kind of radioactive ray, 13 times on the premises of the Fukushima Daiichi nuclear plant after it was crippled by the massive March 11 quake-tsunami disaster.

TEPCO, the operator of the nuclear plant, said the neutron beam measured about 1.5 kilometers southwest of the plant's No. 1 and 2 reactors over three days from March 13 and is equivalent to 0.01 to 0.02 microsieverts per hour and that this is not a dangerous level.

Not trying to flame the fire here. The rad levels are low and I'm hoping TEPCO continues to make progress controling the site but the neutron beam got me thinking about reactor integrity. Neutron beams are product of fission correct? Would this finding confirm reactor damage even if it's just a pin hole?

Are these fast neutrons or slow, moderated neutrons?

Slow neutrons do not carry significant energy, it is not really ionizing radiation, microSieverts does not seem an adequate measure for a flux of thermal neutrons.

So I conclude that these are fast neutrons. They do not need holes. Neutrons are not shielded by lead or steel.

One would expect some delayed neutrons from fission products, but neutron decays have short half lives. Can this level of neutrons be due to delayed neutrons? I suppose there is always some fission too, far below levels for criticality.

 

[jensjakob]

163.000 becquerels in soil northwest of Fukushima NPP:
http://www3.nhk.or.jp/daily/english/23_28.html

That is quite bad.?

 

[83729780]

http://en.wikipedia.org/wiki/Solubility" degree C is 60g/100 liters or 600g per m3 of water
(or about 40g/100 l at room temperature thus we need to evaporate 90% of seawater for
crystallization to take place at room temp)

Therefore, to have a homogeneous solution of salty coolant we need:
21216/0.6 = 35360m3 of water

Does the addition of boron to the coolant water significantly affect NaCl solubility?

 

[Borek]

Does the addition of boron to the coolant water significantly affect NaCl solubility?

Most likely not. But i am just guessing. There is no obvious reason (like a common ion or possible precipitate) and usually there are no significant effects till concentrations get really high, much closer to saturated solutions (and we are far from that with sea water).

 

[Bob S]

from Kyodo:

Electric Power Co. said Wednesday it has observed a neutron beam, a kind of radioactive ray, 13 times on the premises of the Fukushima Daiichi nuclear plant after it was crippled by the massive March 11 quake-tsunami disaster.

TEPCO, the operator of the nuclear plant, said the neutron beam measured about 1.5 kilometers southwest of the plant's No. 1 and 2 reactors over three days from March 13 and is equivalent to 0.01 to 0.02 microsieverts per hour and that this is not a dangerous level.

http://search.japantimes.co.jp/cgi-bin/nn20110324a6.html

Hard to believe. Where would the neutrons come from if the reactors are off? The nuclear collision length for high energy neutrons is about 60 grams per cm²; 1.5 km of air is about 180 grams per cm². This does not include any shielding like the reactor pressure vessel, and concrete shield wall. Below ≈100 KeV, the neutron scattering (and thermalization) increases dramatically. The only neutron sources in the buildings are probably PuBe, PoBe, and AmBe (americium-beryllium) neutron calibration sources for radiation detector calibration.

Focusing neutrons is like herding cats; 1/R² at 1.5 km is huge.

Bob S

 

[jensjakob]

Images from inside the Fukushima controlroom - after the Tsunami:
http://ekstrabladet.dk/nyheder/krigogkatastrofer/article1524724.ece

 

[curious11]

Hard to believe. Where would the neutrons come from if the reactors are off? The nuclear collision length for high energy neutrons is about 60 grams per cm²; 1.5 km of air is about 180 grams per cm². This does not include any shielding like the reactor pressure vessel, and concrete shield wall. Below ≈100 KeV, the neutron scattering (and thermalization) increases dramatically. The only neutron sources in the buildings are probably PuBe, Po,Be, and AmBe (americium-beryllium) neutron calibration sources for radiation detector calibration.

Focusing neutrons is like herding cats; 1/R² at 1.5 km is huge.

Bob S

Perhaps the sources were more local ? but I guess if this was the case they would be less likely to emit a focussed beam?

 

[Arcer]

Puzzling that there's plenty of damage as evidence of explosions and even possibly an earthquake but so far not much to say there's been tsunami water inside the main area of the site, that is the area to the west of the long turbine generator buildings and yet the tsunami is claimed to have been 10 metres and even 14 metres high - the height of say a 3 to 5 storey building - and if it was like the tsunami in other places it would be carrying tonnes and tonnes of debris along with it.

Looking at the close ups of the building surfaces there's no staining or anything. The water must have been very clean.

 

[jensjakob]

More images:
http://ekstrabladet.dk/template/v3-0/direct/article/picProxy.jsp?url=http://multimedia.ekstrabladet.dk/archive/00647/Japan_Earthquake_647291o.jpg&iw=925&ih=646&secid=1250&cbw=1210&cbh=818

 

[Borek]

if it was like the tsunami in other places it would be carrying tonnes and tonnes of debris along with it.

Not necessarily. At the coast - where the plant is located - water is clean, it collects debris as it flows over the land. Debris can be also left when water goes back to the sea, but there is an elevated land behind the NPP - so there was no water getting back through the plant area.

 

[jensjakob]

More images from the work @ Fukushima:
http://www.b.dk/billedeserier/her-arbejder-de-mod-tiden-paa-fukushima

@Arcer: Take a look at some of the early pictures, you will see cars, containers and other large items swept as debris against the earth-berm. QUite powerfull it must have been

 

[PietKuip]

from Kyodo:

TEPCO, the operator of the nuclear plant, said the neutron beam measured about 1.5 kilometers southwest of the plant's No. 1 and 2 reactors over three days from March 13 and is equivalent to 0.01 to 0.02 microsieverts per hour and that this is not a dangerous level

I now looked at the logs on http://www.tepco.co.jp/en/nu/monitoring/

In the recent logs I can only find entries that the neutron signal is "under 0.01 μSv/h".

In the March 13 logs, it says mostly "under 0.001μSv/h" at the main gate, but sometimes "under 0.002".

Tepco has a weird way of communicating their data.

PS: http://www.tepco.co.jp/en/nu/monitoring/11031401a.pdf gives some readings as "under 0μSv/h". Idiots.

 

[83729780]

Today is the 11th day since sea water injection started and let's assume another two days
till pumps start working

--> 13 x 24hours x 2m3/hour x 34kg = 21216 kg salt

another estimate:

Richard T. Lahey Jr., who was General Electric’s chief of safety research for boiling-water reactors when the company installed them at the Fukushima Daiichi plant, said that as seawater was pumped into the reactors and boiled away, it left more and more salt behind. He estimates that 57,000 pounds of salt have accumulated in Reactor No. 1 and 99,000 pounds apiece in Reactors No. 2 and 3, which are larger.

http://www.nytimes.com/2011/03/24/world/asia/24nuclear.html?_r=1&hp
press date 24/03

 

[jlduh]

The TEPCO document on tsunamis that i posted confirm that the plant itself is built on a platform which is 10 to 13 meters higher than sea level. So in case of a wave whose height is around 14 meters, only the very top of the tsunami (which is not -relatively- a very big amount of water: 1 to 4 meters ) have entered the buildings location. This was enough unfortunately to damage the diesel generators which are in the first line (close to the sea). But it's not a so big amount for the buildings because most of the energy of the wave has been dissipated hitting the 10 to 13 meters height of the platform.

To come back on the subject of the neutron beams (up to 1,5 kms long) that tepco reported, can somebody tell me how this phenomenon was detected? Is it something you can see visually or was it through detectors?

thanks.

 

[jensjakob]

another estimate:



http://www.nytimes.com/2011/03/24/world/asia/24nuclear.html?_r=1&hp
press date 24/03

And - scary to read that cooling pumps at #5 has stopped...

 

[Arcer]

Not necessarily. At the coast - where the plant is located - water is clean, it collects debris as it flows over the land. Debris can be also left when water goes back to the sea, but there is an elevated land behind the NPP - so there was no water getting back through the plant area.

Thanks for your response.

There's plenty of damage shown as the tsunami flowed over the constructions and surfaces (extending over about 100 metes) to the east of the long turbine generator buildings back to the breakwater/harbour/coast - that's evident from the satellite images. Maybe that debris is partly piled up against the east face of those turbine buildings. Maybe some of it went out with the tsunami.

Even so I would have expected a 10 - 14 metre tsunami to take a lot of the debris around the north and south ends of the turbine buildings and between those buildings and some of it to be deposited to the west and also deposited to the west as it went back out. If it was 10 to 14 metres high I would have expected far more damage to the low level buildings to the west of the turbine buildings and there's little or none although there seemed to be some cars moved around from the satellite images.

As far as I'm aware the entire plant area is pretty flat and the only elevated land is about 100 metres to the west of the turbine buildings and that is about 60 metres to the west of the reactor buildings - the embankments for that elevated land are evident from the satellite images and are shown on the image below.

Those embankments would act as a barrier to further inland flow of the tsunami but wouldn't have stopped the tsunami getting back out through the plant area.

http://ekstrabladet.dk/template/v3-0/direct/article/picProxy.jsp?url=http://multimedia.ekstrabladet.dk/archive/00647/Japan_Earthquake_647291o.jpg&iw=925&ih=646&secid=1250&cbw=1210&cbh=818

On that image (or any other Fukushima image for that matter) where's the staining from a 10 - 14 metre high tsunami on the walls that even clean water would show just carrying a bit of surface debris and dirt just from the roads. It's just a bit puzzling that apart from it totalling the entire power plant operation so far the images show relatively little sign of such a huge tsunami at least to the west of the site.

edit: jlduh's response above clarifies that there's a change in level on the site near the line of turbine buildings.

 

[PietKuip]

To come back on the subject of the neutron beams (up to 1,5 kms long) that tepco reported, can somebody tell me how this phenomenon was detected? Is it something you can see visually or was it through detectors?

There are no neutrons as far as I can see. The word "beam" seems to be an error of translation - "ray" would be better.

The plant has a neutron monitor at the gate, and they are just reporting readings around zero. (Yes, even sometimes below zero.)

 

[Arcer]

More images from the work @ Fukushima:
http://www.b.dk/billedeserier/her-arbejder-de-mod-tiden-paa-fukushima

@Arcer: Take a look at some of the early pictures, you will see cars, containers and other large items swept as debris against the earth-berm. QUite powerfull it must have been

Thanks for your response.

Yes I've seen them. jlduh has clarified the lack of damage as apparently there'a large step in the site (not evident on the images I've seen published so far) somewhere near the turbine buildings that reduced the affect of the tsunami as that would mean it was much shallower as it progressed towards the west of the site.

 

[jlduh]

I want to report here that the french IRSN made a significant move this Wednesday in their daily report concerning reactor 3. The previous days they were still considering that the confinement could be ok on this one, but they changed their mind in the last two days. You can see the reports on this page: http://www.irsn.fr/FR/Actualites_presse/Actualites/Pages/201103_situation_au_japon.aspx#1

Translation for the forum:

21st of March: "The steam produced in the reactor vessel at the fuel contact is transferred to the confinement vessel that seems to be still intact.

22 nd of MArch: "The steam produced in the reactor vessel at the fuel contact is transferred to the confinement vessel that seems to be still intact (to be confirmed taking into account the steam plumes and the variations of pressures in this vessel)"

23 rd of March: ""The steam produced in the reactor vessel at the fuel contact is transferred to the confinement vessel that seems to be leaking based on pressure readings; this lack of integrity would be the origin of the continuous radioactive leakage in the environment (non filtered and not controled). A slight rise of the water temp in the reactor has also been observed"

I personnally feel since i saw the explosion on TV that this N°3 reactor got an explosion (in fact 3 almost simultaneous) very different than the first one, much more "deeper" with this specific black plume of dust and big debris rising vertically... This looked much more serious than the other one.

I repost here an image that i found (i think) on this thread, which shows it seems an original map in japanese with measured radioactivities around the reactors:

http://www.monsterup.com/upload/1300925395929.jpg

Obviously reactor 3 seems to concentrate much higher levels of radioactivity...

 

[Arcer]

The TEPCO document on tsunamis that i posted confirm that the plant itself is built on a platform which is 10 to 13 meters higher than sea level. So in case of a wave whose height is around 14 meters, only the very top of the tsunami (which is not -relatively- a very big amount of water: 1 to 4 meters ) have entered the buildings location. This was enough unfortunately to damage the diesel generators which are in the first line (close to the sea). But it's not a so big amount for the buildings because most of the energy of the wave has been dissipated hitting the 10 to 13 meters height of the platform.

To come back on the subject of the neutron beams (up to 1,5 kms long) that tepco reported, can somebody tell me how this phenomenon was detected? Is it something you can see visually or was it through detectors?

thanks.

Thanks for your response.

The plant being built on a platform helps to explain the puzzle and I assume that must apply to all the buildings/plant to the west of the turbine buildings area.

Many thanks.

 

[jlduh]

I extracted a "print screen" of the page of interest of the Tepco document with their screwed calculations and conclusions of max wave at 5,7m and a schematic representation of the plant on the platform. T/B is for turbine building, R/B for reactor building. S/B is... i don't know! Safety Buildings (generators)? This will clarify the configuration of the global layout i think.

http://www.monsterup.com/upload/1300925990704.jpg

 

[AntonL]

10 cubic meters of salt would mean about 0.4 m of sediment layer if it were to settle (which it will not).
As long as it is sloshy it can be moved by water pressure which is good.

If the main inlet to the PV is free of compact salt crystals (my guess is it will be) then they
can pump in fresh water and steadily dissolve the salt by pumping in more water. No idea what
they will do with the discharged water - they can't recirculate it and it is bound to be contaminated, heavily at first.

it is returned to the ocean

If that is the case than the discarded sea water would carry away much of the
concentrated NaCl from reactors which should make subsequent pumping less prone to failure.

No ways will water from within the reactor with damaged reactor core, be discharged into the sea!

 

[83729780]

No ways will water from within the reactor with damaged reactor core, be discharged into the sea!

several news sources give such an account; this the NY Times:

The Japanese have reported that some of the seawater used for cooling has returned to the ocean, suggesting that some of the salt may have flowed out again rather than remaining in the reactors.

we have to account for over [STRIKE]a cubic kilometer[/STRIKE] 1000 cubic meters of water

 

[Reno Deano]

Yes they would discharge seawater used to cool the reactor back to the sea or somewhere (sea better choice). They cannot allow the reactor vessel to go solid with liquids, especially with the continued heating from the degraded core.

They must have a crude recirculation path either to the Dry Well (blanketing the exterior of the reactor vessel with cooling liquid) or via the Feed Water path to inside the reactor vessel and the core.

 

[AntonL]

we have to account for over 1000 cubic meters of water

boiled away in the reactor and condensed somewhere else, presumably mostly in the torus and vented to the atmosphere.

 

[AntonL]

Yes they would discharge seawater used to cool the reactor back to the sea or somewhere (sea better choice). They cannot allow the reactor vessel to go solid with liquids, especially with the continued heating from the degraded core.

They must have a crude recirculation path either to the Dry Well (blanketing the exterior of the reactor vessel with cooling liquid) or via the Feed Water path to inside the reactor vessel and the core.

wishful thinking,

[/PLAIN]
Richard T. Lahey Jr., who was General Electric’s chief of safety research for boiling-water reactors when the company installed them at the Fukushima Daiichi plant, said that as seawater was pumped into the reactors and boiled away, it left more and more salt behind. He estimates that 57,000 pounds of salt have accumulated in Reactor No. 1 and 99,000 pounds apiece in Reactors No. 2 and 3, which are larger.

and presumably he knows what he is talking about and the capabilities of BWR

You could also study http://www.nrc.gov/reading-rm/basic-ref/teachers/03.pdf".