Japan Earthquake: Nuclear Plants at Fukushima Daiichi

Click For Summary
The Fukushima Daiichi nuclear plant is facing significant challenges following the earthquake, with reports indicating that reactor pressure has reached dangerous levels, potentially 2.1 times capacity. TEPCO has lost control of pressure at a second unit, raising concerns about safety and management accountability. The reactor is currently off but continues to produce decay heat, necessitating cooling to prevent a meltdown. There are conflicting reports about an explosion, with indications that it may have originated from a buildup of hydrogen around the containment vessel. The situation remains serious, and TEPCO plans to flood the containment vessel with seawater as a cooling measure.
  • #4,651
Guest Member said:
(NHK) TEPCO: Highly radioactive concrete fragment found

The operator of the damaged Fukushima Daiichi nuclear power plant says that concrete debris emitting a high level of radiation has been found near the Number 3 reactor.

http://www3.nhk.or.jp/daily/english/24_01.html

What inventory has such a high radiation in a power plant?
The size of the plate found was 30x30x5 cm. For fuel assemblies the size does not fit even if they are broken during the explosion of unit 3.
 
Last edited by a moderator:
Engineering news on Phys.org
  • #4,652
Guest Member said:
(NHK) TEPCO: Highly radioactive concrete fragment found

The operator of the damaged Fukushima Daiichi nuclear power plant says that concrete debris emitting a high level of radiation has been found near the Number 3 reactor.

http://www3.nhk.or.jp/daily/english/24_01.html

"the concrete block has been stored safely in a container with other debris"

Don't they want to know what it is?

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?
 
Last edited by a moderator:
  • #4,653
PietKuip said:
"the concrete block has been stored safely in a container with other debris"

Don't they want to know what it is?

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?

I did not thought about that. You are right, the fragment found could only have a very small piece of radioactive material on the surface.
 
  • #4,654
Samy24 said:
I did not thought about that. You are right, the fragment found could only have a very small piece of radioactive material on the surface.

This chunk was emitting 900 mSv per hour. Workers received 3.17 mSV getting it into a container. This thing was DANGEROUS. It hasn"t been lost. They know where it is.

They were trying to clear debris near the switchyard, probably so they can continue restoring power to equipment that still may be operable and can help stabilize the plant. Our wishes for more information pale in importance to what they are trying to do. With junk like this lying around these people are risking their lives. Give them a break.

Perspective, please!
 
  • #4,655
NUCENG said:
This chunk was emitting 900 mSv per hour. Workers received 3.17 mSV getting it into a container. This thing was DANGEROUS. It hasn"t been lost. They know where it is.

They were trying to clear debris near the switchyard, probably so they can continue restoring power to equipment that still may be operable and can help stabilize the plant. Our wishes for more information pale in importance to what they are trying to do.

There is more of this lying about. They need to know what it is. That is why one has robots, to look at stuff before a worker would handle it.
http://amptek.com/x123cdte.html" has been on Mars (and it is not expensive). It could have diagnosed what it was, what the dangers of this place are.
 
Last edited by a moderator:
  • #4,656
NUCENG said:
This chunk was emitting 900 mSv per hour. Workers received 3.17 mSV getting it into a container. This thing was DANGEROUS. It hasn"t been lost. They know where it is.

They were trying to clear debris near the switchyard, probably so they can continue restoring power to equipment that still may be operable and can help stabilize the plant. Our wishes for more information pale in importance to what they are trying to do. With junk like this lying around these people are risking their lives. Give them a break.

Perspective, please!

We got the info that this could not have been volatile iodine or cesium , so the explosions have ejected highly radioactive content , from core or spent fuel pool.

As the NRC has stated before
 
Last edited:
  • #4,657
NUCENG said:
This chunk was emitting 900 mSv per hour. Workers received 3.17 mSV getting it into a container. This thing was DANGEROUS. It hasn"t been lost. They know where it is.

They were trying to clear debris near the switchyard, probably so they can continue restoring power to equipment that still may be operable and can help stabilize the plant. Our wishes for more information pale in importance to what they are trying to do. With junk like this lying around these people are risking their lives. Give them a break.

Perspective, please!

I'm quite sure you misunderstood me. I do not want to engage any worker at the site. Most of them do likely know at what danger they are even if TEPCO told them there is no health risk.
So what do you mean with "Perspective, please" (English is not my native language)

We want to analyse what this piece is and where it is from. Normaly concrete is not radioactive in a "normal" power plant. That's it.
 
  • #4,658
PietKuip said:
[...]That is why one has robots.[...]
Problem is, they lack highly specialised robots for this sort of work, or even an onsite lab. And this is not going to change anytime soon.
Even if they wanted to, they can't, unless they finally decide to accept foreign help.
So, there's only more of this to come, people being accidently exposed by pieces of "something" lying around. 900mSv/h by concrete is so weird, wherever this came from, there is likely something even more active, rather close. Will Tepco finally admit that things got out of control?
 
  • #4,659
PietKuip said:
"the concrete block has been stored safely in a container with other debris"

Don't they want to know what it is?

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?

I think that vaporized Cs or CsI could be deposited on concrete at very high levels. The numbers provided are hard to interpret without a distance and without isotopic composition.

If this were all I-131, and it were a point source, and they measured it from 10 cm, I calculate that it would correspond to 4.5 Curies of I-131 (based on 1mCi of I-131 giving 2.2 R/hr at 1 cm from here: http://www.stanford.edu/dept/EHS/prod/researchlab/radlaser/RSDS_sheets/I-131_Inorganic.pdf).
 
Last edited:
  • #4,660
NUCENG said:
...
This forum is interesting and informative. If we can all keep the rhetoric down and respect each other we will have a much better chance of making this forum useful. We’ve already seen one thread shutdown, we all lose when that happens. You seem to see things so clearly, but you lose any chance of persuasion when you belittle others or call them stupid, or liars. Come on in, the water is fine, even if it glows in the dark. Peace?

Bravo! I wish more people on this planet would think the way you do. Very well said.
 
  • #4,661
GJBRKS said:
We got the info that this could not have been volatile iodine or cesium , so the explosions have ejected highly radioactive content , from core or spent fuel pool.

As the NRC has stated before

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.
 
  • #4,662
GJBRKS said:
Has anyone heard an official explanation for the <1 atm pressures ?

Perhaps, but I am not aware of it.

My guess is that at some point the RPV had steam in its top part, water below, water in the drywell, and a leak between the two somewhere below the water line. As water was pumped into the RPV, some of the steam condensed, and the water lvel inside the RPV rose above that in the drywell.

But I do not know where the sensors are actually placed, so I would not bet a cent on this.

GJBRKS said:
[..] the sensors are encased by condensed salt deposits.

AFAIK no active electronics are working anywhere near the reactor. I guess that the "pressure sensors" are merely tubes that extend from the reactor/containment (possibly through some sort of membrane that transmits pressure but not gas) to mechanical meters, located where they can be safely read (perhaps at the fire extinguisher line inlet -- anyone knows where that is?)

Ditto for the CAMS radiation meters --- AFAIK they are pipes that suck air samples from the reactor and take them to an external radiation counters. And I suppose that the temperature sensors are just thermocouples or temperature-sensitive resistors, each with two wires leading out of the reactor.

Can anyone confirm this?
 
  • #4,663
NUCENG said:
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.

I feel your concern towards the workers and I share your sentiments in this.
I don't think Piet meant to imply more than his own interest into this new piece of information.
You are probably right that this is not the first such an amount of debris that had to be handled to safety.
I guess I was somehow surprised by the amount of detail on this news item.
 
  • #4,664
Samy24 said:
I'm quite sure you misunderstood me. I do not want to engage any worker at the site. Most of them do likely know at what danger they are even if TEPCO told them there is no health risk.
So what do you mean with "Perspective, please" (English is not my native language)

We want to analyse what this piece is and where it is from. Normaly concrete is not radioactive in a "normal" power plant. That's it.

Perspective is assigning importance only to the most important things. This thread and a lot of the media have focused attention on the nuclear disaster. But over a thousand Japanese were killed in the original earthquake and more than 20,000 were killed in the tsunami. The three deaths at Fukushima were due to earthquake and tsunami.

We have been debating what might have been done to prevent the accident. But that is hindsight - taking credit for knowledge of what did happen, where the only real accomplishment would have been figuring out what could happen before it did.

The easy answers are usually wrong. That is what I mean by perspective. Please don't apologize for your knowledge of English, it is my native language and sometimes I can't figure out what to say or how to say it.

I was stationed in Japan in the US military for three years. I wish there was more that I could do to help them out. They may have made some mistakes. Some of them may have deliberately lied. Hey, they are human. And right now they really don't need criticism as much as they need support.
 
  • #4,665
NUCENG said:
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.

What I was trying to say is that Tepco should want to know what the debris is. The workers should have been instructed to leave material alone that is making their < 1000 mSv/h dose meters almost go off scale. Such stuff should not be handled by humans.

I pity the workers. I have contempt for the Tepco upper management. They even cut the wages of the workers, because the Fukushima Daiichi plant is not making a profit.
 
  • #4,666
Jorge Stolfi said:
AFAIK no active electronics are working anywhere near the reactor. I guess that the "pressure sensors" are merely tubes that extend from the reactor/containment (possibly through some sort of membrane that transmits pressure but not gas) to mechanical meters, located where they can be safely read (perhaps at the fire extinguisher line inlet -- anyone knows where that is?)

In that case it might be that the 'calibrated' side of the membrane has been compromised by an overpressure , reducing the readings of the 'inner' side's pressure ...
Thanks for that update
 
  • #4,667
NUCENG said:
Perspective is assigning importance only to the most important things. This thread and a lot of the media have focused attention on the nuclear disaster. But over a thousand Japanese were killed in the original earthquake and more than 20,000 were killed in the tsunami. The three deaths at Fukushima were due to earthquake and tsunami.

We have been debating what might have been done to prevent the accident. But that is hindsight - taking credit for knowledge of what did happen, where the only real accomplishment would have been figuring out what could happen before it did.

The easy answers are usually wrong. That is what I mean by perspective. Please don't apologize for your knowledge of English, it is my native language and sometimes I can't figure out what to say or how to say it.

I was stationed in Japan in the US military for three years. I wish there was more that I could do to help them out. They may have made some mistakes. Some of them may have deliberately lied. Hey, they are human. And right now they really don't need criticism as much as they need support.

No problem I'm not so sensetive about a good discussion.

If you delete all the speculation in this thread, only half a dozend posts would be left :)

If you permit a more private question? You mentioned in one of your posts that you were exposed to about 75 mSv. Was this by an accident? Normally workers should not get that dose.
 
  • #4,668
PietKuip said:
What I was trying to say is that Tepco should want to know what the debris is. The workers should have been instructed to leave material alone that is making their < 1000 mSv/h dose meters almost go off scale. Such stuff should not be handled by humans.

I pity the workers. I have contempt for the Tepco upper management. They even cut the wages of the workers, because the Fukushima Daiichi plant is not making a profit.

You are right. I would also like to know what it is. I overreacted and apologize for thinking you were criticizing the workers. Normally I edit my posts offline and have a chance to tone them down before I send them. I should go back to that routine.

The Wall Street Journal had a front page story today that Operators wanting to start depressurizing the Unit 1 containment before it overpressurized had to get permission from TEPCO management and they had to get high level government permission. Maybe it isn't TEPCO management to blame, but a culture in Japan which discourages individial initiative and decision-making.
 
  • #4,669
Below is the recorded sprayings to the spent fuel pool of unit 4 (data from Tepco press releases). The intensity of topping the pool appears to have increased lately. Similar data regarding the other SFPs can be found at:
http://www.gyldengrisgaard.dk/fuku_docs/fuku_sfp_sprayings.html

SFP4:
Concrete pump 23 April 2011 12:30-?
Concrete pump 22 April 2011 17:52-23:53
Concrete pump 21 April 2011 17:14-21:20
Concrete pump 20 April 2011 17:08-20:31
Concrete pump 19 April 2011 10:17-11:35
Concrete pump 17 April 2011 17:39-21:22
Concrete pump 15 April 2011 14:30-18:29
Concrete pump 13 April 2011 00:30-06:57
Concrete pump 9 April 2011 17:07-19:24
Concrete pump 7 April 2011 18:23-19:40
Concrete pump 5 April 2011 17:35-18:22
Concrete pump 3 April 2011 17:14-22:16
Concrete pump 1 April 2011 08:28-14:14
Concrete pump 30 March 2011 14:04-18:33
Concrete pump 27 March 2011 16:55-19:25
Injection of seawater through FPCFS 25 March 2011 06:05-10:20
Concrete pump 25 March 2011 19:05-22:07
Concrete pump 24 March 2011 14:35-17:30
Concrete pump 23 March 2011 10:00-13:00
Concrete pump 22 March 2011 17:20-20:30
Water spray by the Self Defence Force 21 March 2011 06:37-08:41
Water spray by the Self Defence Force 20 March 2011 08:21-09:40
Water spray by the Self Defence Force 20 March 2011 18:45-19:45
Explosion at unit 4 15 March 2011 06:00 appr.
Temperature in pool is 84 C 14 March 2011 04:08
 
  • #4,670
NUCENG said:
Perspective is assigning importance only to the most important things. This thread and a lot of the media have focused attention on the nuclear disaster. But over a thousand Japanese were killed in the original earthquake and more than 20,000 were killed in the tsunami. The three deaths at Fukushima were due to earthquake and tsunami.
That is because this thread is not about drowning in tsunamis, or about civil engineering to diminish the impact of tsunamis.

The nuclear accident has made the coastal part of the prefecture unsuitable for habitation and agriculture. It has exposed many Japanese to increased levels of radiation. I have not seen any estimates yet of man-Sieverts, but I guess that calculations will show at least hundreds of deaths. As a comparison: Chernobyl is calculated to have given 5 000 man-Sievert in Sweden alone. Multiply that by 0.02 and it will give you an estimate of the number of Chernobyl casualties in Sweden.
 
Last edited:
  • #4,671
Samy24 said:
No problem I'm not so sensetive about a good discussion.

If you delete all the speculation in this thread, only half a dozend posts would be left :)

If you permit a more private question? You mentioned in one of your posts that you were exposed to about 75 mSv. Was this by an accident? Normally workers should not get that dose.

The first submarine I was on had had an air accident which involved inadvertently adding a lot of air under pressure into the reactor while it was shutdown. I reported aboard shortly after that accident happened. There was no damage to the core or equipment but the air caused a significant pH transient which reeleased a lot of corrosion products from the walls of the vessel and piping and some of the oxide from the outside of the core. A lot of that contamination collected in the plants ion exchanger resin. Much of my exposure was during routine inspections and maintenace near the ion exchanger over a three year period. We had to deal with that until the submarine went into refueling and the ion exchanger resin was changed out.
 
  • #4,672
ascot317 said:
They had been offered help from e.g. France and Germany, which they rejected. That and the problems that follow this decision can surely be critisized.
The local tech guys are surely doing everything they can within their capabilities (or even more), but I'm not so sure about the management. In Japan, pride plays a huge role. Imagine yourself in the role of a crisis manager (and I guess you're qualified to do that), would you have rejected the offer of such a highly specialised company like KHG?
People aren't so much worked up about the possibility of Tepco not telling the truth, they're more upset about them doing "stupid things" due to other reasons.
Incompetence, pride etc.

Either Tepco has, so far, released everything they know (which wouldn't be much), or they're holding things back.

Look at the little things we know and how much speculation this results in. Tepco could provide more information. They're not. This is making the industry look very bad.

OK let's look at this in terms of trying to influence someone into accepting help. I can walk up to you and say, "You are to stupid to do this right and you are lying if you disagree. I am here to help so go stand in the corner and stay out of my way." Should I exppect you to let me help you?

Alternatively I can say, "I know you are up to your neck in alligators, so I'll be brief. I have this alligator proof dredger. You can use it and Ill train your people to operate it. Here are the specs. Check it out when you have a chance. Let me know if there is anything else you need and I'll try to find it."

Is there valid criticism for TEPCO and Japanese ministries? YES. Is now the time to rub their nose in it? In my opinion, NO. Does that mean you are wrong? NO. It just means that I think there will be time for this after we drain the swamp.
 
  • #4,673
NUCENG said:
You are right. I would also like to know what it is. I overreacted and apologize for thinking you were criticizing the workers. Normally I edit my posts offline and have a chance to tone them down before I send them. I should go back to that routine.

The Wall Street Journal had a front page story today that Operators wanting to start depressurizing the Unit 1 containment before it overpressurized had to get permission from TEPCO management and they had to get high level government permission. Maybe it isn't TEPCO management to blame, but a culture in Japan which discourages individial initiative and decision-making.

I wondered about the approval hierarhy back when it ruptured. I don't know the US Regs, but in Canada in an post-accident event where you have to start a radioactive release to control pressure - it requires government approval. The utility does not have the authority to do this.
In this case, depressurizing meant they would have to release radioactivity to the environment at the same time and thus seemed to require higher level approvals? Due to compromized communications and maybe LTA emergency preparedness - it simply took too long to get approval?

If so, it would have been incredibly difficult to be the plant operators/managers sitting there watching the pressure rise waiting for the @#$%^ approval to come through!
 
  • #4,674
NUCENG said:
If the pool becomes acidic Iodine gas will re-evolve and be released to the atmosphere. In other words it is not likely to go very far.

The concern that the water will become acidic has been raised several times in this thread, because acidic pH's would speed the oxidation of iodide to iodine, which is fairly volatile. If the water is acidic, the biggest problem may be dissolution of the concrete used to build almost everything at the reactor. Some people have also said that the use of seawater (pH around 8.0) will prevent this from happening.

First, I doubt that seawater is sufficiently buffered to prevent pH changes if there are acid- or base-generating reactions. Second, the chemistry suggests that there should be much more concern about very high pH than about low pH. One of the principal reactions that's occurred is oxidation of Zr by water, releasing hydrogen. ZrO2 is not very soluble in water. (In contrast, metallic Cs undergoes the same reaction with water, making Cs2O. Cs2O reacts with water, making CsOH, which is a powerful base.) ZrO2 could react with chloride in the water, making ZrCl4, which is soluble, and releasing hydroxide, raising the pH a lot. I suspect that this reaction was a much more serious issue when temperatures in the reactors were higher four weeks ago.
 
  • #4,675
PietKuip said:
Such stuff should not be handled by humans.

According to http://www.asahi.com/national/update/0423/TKY201104230396.html , after the discovery, the personnel was reduced to one man who used a "heavy machine" to take the radioactive debris to the container.

Perhaps that "heavy machine" is the "remote-controlled rubble removing equipment" shown on http://cryptome.org/eyeball/daiichi-npp6/daiichi-photos6.htm
 
Last edited by a moderator:
  • #4,676
tsutsuji said:
According to http://www.asahi.com/national/update/0423/TKY201104230396.html , after the discovery, the personnel was reduced to one man who used a "heavy machine" to take the radioactive debris to the container.

Perhaps that "heavy machine" is the "remote-controlled rubble removing equipment" shown on http://cryptome.org/eyeball/daiichi-npp6/daiichi-photos6.htm

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.
 
Last edited by a moderator:
  • #4,677
Samy24 said:
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.

My guess is that they took 3.17 mSv before finding the debris.
 
  • #4,678
PietKuip said:
I have not seen any estimates yet of man-Sieverts.

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
 
  • #4,679
RealWing said:
I wondered about the approval hierarhy back when it ruptured. I don't know the US Regs, but in Canada in an post-accident event where you have to start a radioactive release to control pressure - it requires government approval. The utility does not have the authority to do this.
In this case, depressurizing meant they would have to release radioactivity to the environment at the same time and thus seemed to require higher level approvals? Due to compromized communications and maybe LTA emergency preparedness - it simply took too long to get approval?

If so, it would have been incredibly difficult to be the plant operators/managers sitting there watching the pressure rise waiting for the @#$%^ approval to come through!

The Wall Street Journal article addressing hierarchy/protocol for venting in Japan and in the US can be accessed here:
http://online.wsj.com/article/SB10001424052748703922504576273234110896182.html?KEYWORDS=fukushima
 
  • #4,680
Since April 1st Tepco has conducted sprayings to bind radioactive dust in certain problem areas. The efforts have been concentrated on the mountainsides behind the two buildings 'across the street' from unit 3 (the Common Spent Fuel Pool (CSFP) and the Medium Voltage Switchyard (MSV) respectively), and to the area around the Central Radwaste Treatment Facility (CHWTF), situated to the south of unit 4. (see attached annotated map)

21 April 2011: 1300 m² mountain side at the CSFP
21 April 2011: 5100 m² mountainside at MVS
20 April 2011: 1900 m² around the CHWTF
18 April 2011: 1200 m² at the CHWTF
17 April 2011: ? m² at the CHWTF
16 April 2011: 1800 m² mountainside at the CSFP
15 April 2011: 1900 m² mountainside at the CSFP
13 April 2011: 1600 m² mountainside at the CSFP
11 April 2011: 1200 m² mountainside at the CSFP
8 April 2011: 680 m² mountainside at the CSFP
5 April 2011: 550 m² east and south mountainside at the CSFP
1 April 2011: 500 m² mountainside at the CSFP
 

Attachments

  • antidustspraying.jpg
    antidustspraying.jpg
    61.7 KB · Views: 455

Similar threads

  • · Replies 12 ·
Replies
12
Views
49K
  • · Replies 41 ·
2
Replies
41
Views
5K
  • · Replies 2K ·
60
Replies
2K
Views
451K
  • · Replies 5 ·
Replies
5
Views
6K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 6 ·
Replies
6
Views
20K
  • · Replies 763 ·
26
Replies
763
Views
274K
  • · Replies 38 ·
2
Replies
38
Views
16K
Replies
6
Views
4K
  • · Replies 4 ·
Replies
4
Views
11K