Japan Earthquake: Nuclear Plants at Fukushima Daiichi

[Most Curious]

Surely in respect of Fukushima 1;2 and 3 the term 'containment' is no longer applicable ,it does not hold water

Containment may no longer be air or water tight but it still provides a lot of shielding!

 

[LabratSR]

New video released by TEPCO

Fukushima Daiichi: Cooling water injection reliability description

http://www.youtube.com/user/AtomicPowerReview

 

[intric8]

It would seem unlikely a neutron source - spent fuel or transuranics undergoing spontaneous fission would be located outside of containment

Neutrons would account for the discrepancy with the cumulative dose as stated by tepco, since most of that dose would not be picked up by dosimeters used by subcontracted employees. And with over 3000 workers on site, the quality of some of those dosimeters may be in question, no?

Also, occupational deaths at construction sites usually have clear causes, ie falls, electrocutions, etc. The reasons for the last two deaths are somewhat vague. I do agree that radiation is highly unlikely the cause. In the event of an additional death under similar circumstances in the near future, i think there will be sufficient public pressure to discover working conditions that may be contributing to the problem, or force tepco to screen employees for pre existing health conditions more effectively.

 

[maddog1964]

Neutrons would account for the discrepancy with the cumulative dose as stated by tepco, since most of that dose would not be picked up by dosimeters used by subcontracted employees. And with over 3000 workers on site, the quality of some of those dosimeters may be in question, no?

Also, occupational deaths at construction sites usually have clear causes, ie falls, electrocutions, etc. The reasons for the last two deaths are somewhat vague. I do agree that radiation is highly unlikely the cause. In the event of an additional death under similar circumstances in the near future, i think there will be sufficient public pressure to discover working conditions that may be contributing to the problem, or force tepco to screen employees for pre existing health conditions more effectively.

Unfortunaly I do not read Japanese, and find my computor to translate in a unreliable manner, Could you please direct me to a link that has to date shown that other than Tepco being the Owner, that his Employer has done anything to cause his death. Is he even employed by the same sub-contractor as the others? The emplyees at the site are working under dire conditions.. nothing is going to make it "fully safe". People get sick at work and die for many reasons. The one who passed away before its my understanding was a heart attack, the other was acute lukemia, both may have happened if they never set foot on the site.
Worked on a job were one had a heart attack, a second employee survied because the EMS was able to bring him out of a "diabtic" reaction... he was minutes from not coming back his blood sugar levels were so low.
(if my math is right,its late) Let's look at the numbers.. 3000 emp working approx 5 hours a day, guessing 6 days a week/4 weeks a month..that equates to 360,000. manhours worked in a month..we know the injury/death rate is not going to be zero! So what do you consider the acceptable %, before""public pressure" to discover "contributing factors.." and FORCE Tepco to better screen for pre-exsiting conditions? "
But I belive, and sorry if I read your first post wrong, that you are trying to assume that it was something but an unfortune incident. Let's see what releases come out in the coming days, that are credible.
Also it would be very likely for a person wanting to work there, to NOT be honest about pre-existing conditions. With this said Tepco and its subs sould review and may be (info not avalible to us) reviewing procedures to assist with the health. It is standard to do a investigation after the injury/death of an employee.
Sorry if on the wrong thread.

 

[Rive]

Neutrons ...

Forget the neutrons. The neutron emission of practically anything is pretty low. You need a really big pile of (power-plant kind) fissile materials (under water) to get dangerous levels of neutron emission (through criticality).

At some point in the next months they will start messing with U3 top. That will be dangerous - but not because of the radioactivity.

 

[maddog1964]

Forget the neutrons. The neutron emission of practically anything is pretty low. You need a really big pile of (power-plant kind) fissile materials (under water) to get dangerous levels of neutron emission (through criticality).

At some point in the next months they will start messing with U3 top. That will be dangerous - but not because of the radioactivity.

You are abosolutly correct, it will be very dangerous, and very challaging, but the radioactivity will be one saftey item that can be address and controlled easier than the removal of rubble. What many may not understand is that since nothing is as it was engineered, as they start to move the rubble it will only be a assumption as to the responce of the material and system stresses/movment as they proceed.

 

[gmax137]

... occupational deaths at construction sites usually have clear causes, ie falls, electrocutions, etc. ...

Source please? In my experience they are all heart attacks. Purely anecdotal, but over 30 years I've worked on sites with maybe 5 fatalities, they were all heart attacks.

 

[tsutsuji]

http://www3.nhk.or.jp/news/genpatsu-fukushima/20111010/index.html The pipe cutting works on two locations at unit 1 took five and a half hours and were completed on the same day, on 9 October.

http://www.jiji.com/jc/c?g=soc_30&k=2011101100316 Together with the roadmap update on 17 October, Tepco will provide a new estimate of the radioactive releases, and an operation plan for the water treatment facility.

http://www.rbbtoday.com/article/2011/10/11/81904.html Plans for 11 October. Dust sampling over Fukushima Daiichi unit 3. Start of replacement of one of the seven monitoring posts surrounding Fukushima Daini (during replacement, readings will be available from the remaining 6 monitoring posts only).

 

[Rive]

http://www.tepco.co.jp/en/nu/fukushima-np/images/handouts_111011_03-e.pdf"

Are they on the 4th floor, shooting upward? I can't recall a survey map about that floor of U1.

 

[tsutsuji]

http://www.tepco.co.jp/en/nu/fukushima-np/images/handouts_111011_03-e.pdf"

Are they on the 4th floor, shooting upward? I can't recall a survey map about that floor of U1.

In a previous press release, Tepco referred to the location as

*From 11:44 am to 2:03 pm on October 7, we conducted dust sampling at
Opening section for equipment hatch and truck bay door of Unit 1 Reactor
building.
http://www.tepco.co.jp/en/press/corp-com/release/11100712-e.html

 

[Rive]

In a previous press release, Tepco referred to the location as...

So most likely it's from the first floor, with some tricky lights. Thanks :-)

 

[tsutsuji]

http://www3.nhk.or.jp/news/genpatsu-fukushima/20111012/index.html On 12 October an emergency drill simulating a magnitude 8 earthquake near Fukushima Daiichi will be carried out. 30 workers will be employed to install fire trucks and hoses to pump seawater in order to confirm that the cooling of the reactors can be restored within 3 hours.

 

[tsutsuji]

http://www3.nhk.or.jp/news/genpatsu-fukushima/20111013/0500_kunren.html The drill assumed that tanks and pumps had been broken by an earthquake. 40 people installed fire trucks and 300 m of hoses, so that cooling was restored to one reactor in 1 hour 10 minutes. In the future Tepco will perform other drills assuming a tsunami with debris spread on roads, and occurrences at times when gathering people is more difficult, such as on holidays and during the night.

 

[Edano]

http://www3.nhk.or.jp/news/genpatsu-fukushima/20111013/0500_kunren.html The drill assumed that tanks and pumps had been broken by an earthquake. 40 people installed fire trucks and 300 m of hoses, so that cooling was restored to one reactor in 1 hour 10 minutes. In the future Tepco will perform other drills assuming a tsunami with debris spread on roads, and occurrences at times when gathering people is more difficult, such as on holidays and during the night.

and a station blackout ?

 

[maddog1964]

and a station blackout ?

I will have to go back and reread the info Tsutusji has been so wonderful to provide us with, but I believe one of the main "assumption" of the drill is that they ARE in "station blackout"

Please stay factual on this PF. thread. There are other threads related to sarcasim!

The drill being done in the manner stated in the above quote makes complete logical sense. Identifiy what does not work well first (base line), correct, then add the variables one at a time so that a correct and effective procedure can be developled/refined and "taught to the employees". Thats why they do drills!

 

[tsutsuji]

and a station blackout ?

My understanding is that it is assumed by the drill that the present equipment is inoperative (either materially broken or out of electric power), and a whole new diesel powered equipment must be installed quickly enough.

http://www3.nhk.or.jp/daily/english/13_14.html (in English) says the drill is performed using a "mock facility" [it is probably what is shown on http://www.tepco.co.jp/en/news/110311/images/111012_05.jpg ]

http://www.tepco.co.jp/en/nu/fukushima-np/images/handouts_111012_02-e.pdf pictures of the drill (large size pictures at http://www.tepco.co.jp/en/news/110311/index-e.html )

 

[Edano]

My understanding is that it is assumed by the drill that the present equipment is inoperative (either materially broken or out of electric power), and a whole new diesel powered equipment must be installed quickly enough.

http://www3.nhk.or.jp/daily/english/13_14.html (in English) says the drill is performed using a "mock facility" [it is probably what is shown on http://www.tepco.co.jp/en/news/110311/images/111012_05.jpg ]

http://www.tepco.co.jp/en/nu/fukushima-np/images/handouts_111012_02-e.pdf pictures of the drill (large size pictures at http://www.tepco.co.jp/en/news/110311/index-e.html )

thank you for your links. still, the factual information tepco provides on this drill, is poor.

 

[nikkkom]

I guess in the grander scheme of things it is futile to expect that station personnel will always react properly to large emergencies. It's just too different from their day-to-day job. People are going to be shocked, mentally unprepared. Scared. Etc. And make mistakes.

I bet you can train Fukushima people (because they have a very good reason to take this training very seriously), but on other stations, especially in other countries, their readiness will be about the same as on Fukushima pre-disaster.

Maybe we need to have mobile team(s) _specially_ trained to deal with NPP accidents? They can have helicopters, air-mobile generators and pumps, battery-backed portable lights, etc, but more importantly, their full time job would be to be trained and ready to react to serious accidents on NPPs in their region. I think a team like this could have saved F1, by restoring electric power to cooling systems.

 

[jim hardy]

""I think a team like this could have saved F1, by restoring electric power to cooling systems.""
my own opinion is only an ounce of prevention could have saved that plant. The electrical system needed to be made submersible. Once it gets wetted you are in for weeks of manual cleanup.
the seawater has to be washed out of the electric system, corrosion fixed, and all the motors dried out. That's slow, tedious work. Alternative is build a new electric system and that's huge.


now , to surround the electrical rooms with basically a submarine hull is more like a pound of prevention
but just look at the tons of cure going on now.

some poor fellow someplace is rue-ing the day he didn't act on those mid 1990's geology reports of probable big tidal waves. i have to believe the executives would have acted had they known.

 

[Rive]

...now , to surround the electrical rooms with basically a submarine hull is more like a pound of prevention ...

There was three different issue with the power backup:

- the water damaged the equipment itself
- the water damaged the cooling of the equipment (water outlets and pumps near the sea).
- the water damaged the fuel reserves of the equipment

I would prefer simply to move the equipment and its fuel reserves a different place, hillside: and modify it for air cooling.

 

[nikkkom]

some poor fellow someplace is rue-ing the day he didn't act on those mid 1990's geology reports of probable big tidal waves. i have to believe the executives would have acted had they known.

I think it's exactly executives who squashed flat any suggestions that F1 is unsafe. In the name of saving a few tens of millions dollars. Engineers tend to be much more honest (they know that laws of nature can't be overruled). In both Challenger and Columbia disasters engineers felt that something is definitely not right, were begging their bosses to do something, and were overruled.

 

[zapperzero]

I guess in the grander scheme of things it is futile to expect that station personnel will always react properly to large emergencies. It's just too different from their day-to-day job. People are going to be shocked, mentally unprepared. Scared. Etc. And make mistakes.

I bet you can train Fukushima people (because they have a very good reason to take this training very seriously), but on other stations, especially in other countries, their readiness will be about the same as on Fukushima pre-disaster.

Maybe we need to have mobile team(s) _specially_ trained to deal with NPP accidents? They can have helicopters, air-mobile generators and pumps, battery-backed portable lights, etc, but more importantly, their full time job would be to be trained and ready to react to serious accidents on NPPs in their region. I think a team like this could have saved F1, by restoring electric power to cooling systems.

Well, Japan didn't even invest in specialized robots, let alone a SWAT team.

There should be equipment on hand, but to be honest, I don't think such a specialized team is needed, or indeed desirable. Just think - if such a team had been established when F1-1 was built, it would have had 50 years to ossify into incompetence and complacency.

There should be a team of bureaucrats tasked with management and logistics and provided with very wide-ranging administrative powers in an emergency, a la FEMA, but the actual responders should be trained plant operators who are kept on call, on a rotation basis, just like a militia.

Every X years, or upon entering the profession, people would have to pass a training course, do some practice exercises and be ready to deal with any real emergency that might occur, for a given period.

This has double benefit - you can have many more competent responders for when things go really, really bad, plus you instill a healthy fear of the unknown and maybe a few good practices into, essentially, all the personnel of all the plants.

The team that is on-site when the unthinkable occurs should be treated as victims regardless of their physical status - i. e. evacuated ASAP and replaced with new, rested people with zero preconceptions.

 

[NUCENG]

Well, Japan didn't even invest in specialized robots, let alone a SWAT team.

There should be equipment on hand, but to be honest, I don't think such a specialized team is needed, or indeed desirable. Just think - if such a team had been established when F1-1 was built, it would have had 50 years to ossify into incompetence and complacency.

There should be a team of bureaucrats tasked with management and logistics and provided with very wide-ranging administrative powers in an emergency, a la FEMA, but the actual responders should be trained plant operators who are kept on call, on a rotation basis, just like a militia.

Every X years, or upon entering the profession, people would have to pass a training course, do some practice exercises and be ready to deal with any real emergency that might occur, for a given period.

This has double benefit - you can have many more competent responders for when things go really, really bad, plus you instill a healthy fear of the unknown and maybe a few good practices into, essentially, all the personnel of all the plants.

The team that is on-site when the unthinkable occurs should be treated as victims regardless of their physical status - i. e. evacuated ASAP and replaced with new, rested people with zero preconceptions.

IAEA is talking about fielding an ERO team they would deploy to direct emergency response at future accidents. This concerns me because it may actually reduce effective response. The discussion of the external support teams you are discussing is also a concern if it seeks to remove plant staff from the response. Okay, here is a short description of typical emergency response processes at US nuclear power plants. This discussion is my opinion that any changes need to support existing staff and response, not replace it.

Licensed operators receive continuous refresher training on emergency procedures including use of large control room simulators with impressive fidelity to the real plant. Crews are typically on a rotating shift schedule and have a shift rotation each cycle in training. They are periodically given knowledge examinations, plant walkthroughs, and graded simulator exercises as a part of maintaining their licenses. This training is conducted at the plant but is monitored and inspected by the NRC.

All licensed operators and most radiological workers at US nuclear power plants are assigned to duties in the Emergency Response Organization. During an emergency there is an on-site Technical Support Facility with extensive communications capability to NRC state and local emergency response organizations. The plants are capable of manning this facility around the clock for an extended period of time. In addition there is an offsite Emergency Operating Facility, including capabilities for briefing the press. This facility takes over operational control from the TSC after it is manned. Again this facility has extensive communications capabilities.

Plant technicians and maintenance workers also gather at a designated facility or location to perform duties as assigned. Radiation monitoring and plume tracking teams are dispatched both onsite and offsite to monitor a potential release. There is also onsite, TSC, and EOF meteorological monitoring teams that run plume prediction models and provide data to support evacualtion and sheltering recommendations.

Emergency response organization is typically exercised about 4 times per year and periodically includes response by state, local, and NRC organizations. Recently, the industry has also included exercises of response to security events such as terrorism. Once per year a plant receives a graded inspection by NRC during an ERO exercise. Non-security results are discussed in inspection reports which are available as public documents.

The idea of having an external agency that can come into a plant and take over emergency response sounds good but may not be achievable. The level of training such a team could have will never be as complete as the people who operate and maintain a specific plant. The real motivation for this proposaL may be the mistrust and misinformation we have seen with TEPCO. Fixing that does not require a team to replace or override the plant staff.

There may be some specific support functions from external responders that could be incorporated into emergency response. External generators and repair teams for off-site power lines is one. Right now plants would typically call on the utility and have written agreements from the utility and from the grid operators to restore power to nuclear plants as a high priority.

Another area involves the evacuation plans. These plans are not exercised to the same levels as plant operations. That is natural, because it would be a severe impact and expense to basically shut down normal activities in a 10 mile zone around a plant. However, with the increased threat of terrorism (even if not aimed at a nuclear plant) it seems to me that some exercises need to be run to validate plans and to provide lessons learned to any type of evacuation event.

The support of unmanned aerial drones and exploratory robots may be another useful capability that is a prospect for shared cost and implementation as an external support team.

To summarize: I believe that the EROs at US nuclear power plants would probably perform better than the Fukushima plant staff and management did. However, there are certainly lessons to be learned and incorporated in US plants based on the Fukushima accident. This also applies to local and state emergency responders and the NRC. The real challenge for the future is to get every plant across the world ready to respond to the level of performance and trust we wish had been there in Japan. I just don't think you do that by basically telling the industry that if they screw up they will be relieved of their responsibility by an external organization.

 

[nikkkom]

The idea of having an external agency that can come into a plant and take over emergency response sounds good but may not be achievable.

I do not propose that they completely take over the plant. I propose that the emergency team brings in known-working emergency-grade equipment and supplies, along with their expertise.

The key points here are

(1) The equipment is not on site during the event which caused emergency. It *can't* be damaged (flooded/burned/sabotaged/...) because it is physically not at the plant.
(2) The equipment is highly mobile (air-mobile). It will be delivered even if roads are flooded, blocked, or destroyed.
(3) The equipment includes items which may be unavailable on the plant because they are not needed during normal plant operation, or because they may be broken/lost/inoperable because they are usually not needed during normal plant operation. Potassium iodine pills, battery-backed lights (what F1 personnel BADLY needed!), flexible water hoses, robots, satellite communications, etc...

The level of training such a team could have will never be as complete as the people who operate and maintain a specific plant.

IIRC there were cases when "people who operate a specific plant" did not know how to operate emergency valves on their own plant, or even did not know where those valves are!
The "red team" by the nature of its mission *will* have these docs at hand (because every NPP will be obliged to provide them).
Again, there is no need to send plant personnel home when "red team" arrives. They can (and should!) work together.

The real motivation for this proposal may be the mistrust and misinformation we have seen with TEPCO.

Thinking that Tepco is a pinnacle of arrogance and incompetence and everybody else are much, much better may turn out a dangerous self-delusion. Call my cynic, but I don't think we can assume that no other operator is equally bad.

 

[NUCENG]

I do not propose that they completely take over the plant. I propose that the emergency team brings in known-working emergency-grade equipment and supplies, along with their expertise.

The key points here are

(1) The equipment is not on site during the event which caused emergency. It *can't* be damaged (flooded/burned/sabotaged/...) because it is physically not at the plant.
(2) The equipment is highly mobile (air-mobile). It will be delivered even if roads are flooded, blocked, or destroyed.
(3) The equipment includes items which may be unavailable on the plant because they are not needed during normal plant operation, or because they may be broken/lost/inoperable because they are usually not needed during normal plant operation. Potassium iodine pills, battery-backed lights (what F1 personnel BADLY needed!), flexible water hoses, robots, satellite communications, etc...



IIRC there were cases when "people who operate a specific plant" did not know how to operate emergency valves on their own plant, or even did not know where those valves are!
The "red team" by the nature of its mission *will* have these docs at hand (because every NPP will be obliged to provide them).
Again, there is no need to send plant personnel home when "red team" arrives. They can (and should!) work together.



Thinking that Tepco is a pinnacle of arrogance and incompetence and everybody else are much, much better may turn out a dangerous self-delusion. Call my cynic, but I don't think we can assume that no other operator is equally bad.

We appear to be in violent AGREEMENT about bringing in emergency equipment and supporting recovery.

Your last two paragraphs are where we differ. The need for a "red team" is not a substitute for making sure the in-plant staff know their business. I worked at one nuclear plant as an engineer for 15 years. I had access to all the drawings and precedures and even a library of photographs of major components. I performed walkdowns to support modifications and often spent a lot of time finding and verifying a specific valve or small component. Whenever I could I asked for support from an operator, who was experienced in startup valve and component checks, because it speeded up the process tremendously. That same difference would exist with your "red team" concept. The solution is to make sure the in-plant staff is fully trained and exercised to perform required actions in an emergency. I repeat, my belief is that you will never be able to train a "red team" to that level across the various plant designs.

As to self delusion, I am unapologetic in my support for safe and continued operation of nuclear power plants. Go back and look at my initial posts on this forum and you will see the tone shift from a general defense that the TEPCO team was probably doing their best. I was astounded to see some of the facts emerge about basic issues like knowing where their emergency procedures were, how they had to get permission to vent containment, how they allowed containments to overpressurize, deliberate misinformation and suppression of information, and many more. I could not fathom how a regulator could have allowed them to ignore updates to the seismic and tsunami risk.

to paraphrase, "Thinking that Tepco is a pinnacle of arrogance and incompetence and everybody else are much, much better may turn out" to be ACCURATE. Many of the lessons learned may actually confirm the wisdom of doing this differently in the US. That doesn't mean we won't find things we can do better, or justify sitting on our laurels. I am more of a realist than a cynic and am willing to bet that you are too. I want you to keep questioning and watching and discussing issues that you see. You may not accept this on faith, but that is the way most nuclear employees and managers, in my experience, approach their jobs.

 

[jim hardy]

one needs to be cautious. Bureaucracy becomes a self feeding monster.

if i remember correctly, the morning after TMI our NRC sent in a team to "take over".
That lasted about an hour - the reaction when they entered the control room was basically "wtf are all these gages?" and they promptly turned things back over to the utility.


you don't want to create another FEMA.

imho there should be onsite provisions for last ditch emergency connections of water and power -
and the workingmen should be trained as to their locations and function...
"Pressure washer goes here to keep pump seals cool
hook the welder to this outlet right here to keep up station battery
and that secondhand locomotive engine up on top of the hill gets connected to this motor junction box using this spool of cable right here for AC to pump seawater for ultimate heatsink..."
and tried out a couple times a year in e-drills.


"""I think it's exactly executives who squashed flat any suggestions that F1 is unsafe. In the name of saving a few tens of millions dollars. Engineers tend to be much more honest ""

in the utility i worked for they intentionally alternated levels of management. If you walked vertically up the organization chart you'd encounter an engineer then an up-through-the-ranks fellow who they'd sent to school for an MBA. That layering went clear to the top. It gave the company a healthy balance. Seems not a bad idea for a company that operates machinery to have some machinery people in the chain of decisionmaking.

i don't know that engineers are any more "honest" in an ethical sense but they do tend to be practical and risk averse. Comes from getting humiliated so often by Mother Nature and her boyfriend Edsel Murphy.

old jim

 

[tsutsuji]

A robot has entered Fukushima Daiichi unit 1 first floor again yesterday and measured the radiation as the same place where steam had been found in June. Although unit 1's temperature has declined from 100°C to 70°C and steam was not observed again, the radiation remains extremely high with 3000 ~ 4700 mSv/h. It is planned that the construction of unit 1's cover will be completed today.

http://www.tepco.co.jp/en/nu/fukushima-np/images/handouts_111014_03-e.pdf "Survey results of pipe penetration on 1st floor of Unit 1 reactor building of Fukushima Daiichi Nuclear Power Station"

http://www.tepco.co.jp/en/nu/fukushima-np/images/handouts_111014_02-e.pdf "Completion of installing the roof panel of the cover for the reactor building at Unit 1, Fukushima Daiichi Nuclear Power Station"

 

[nikkkom]

As to self delusion, I am unapologetic in my support for safe and continued operation of nuclear power plants. Go back and look at my initial posts on this forum and you will see the tone shift from a general defense that the TEPCO team was probably doing their best. I was astounded to see some of the facts emerge about basic issues like knowing where their emergency procedures were, how they had to get permission to vent containment, how they allowed containments to overpressurize, deliberate misinformation and suppression of information, and many more. I could not fathom how a regulator could have allowed them to ignore updates to the seismic and tsunami risk.

to paraphrase, "Thinking that Tepco is a pinnacle of arrogance and incompetence and everybody else are much, much better may turn out" to be ACCURATE.

In other words, you propose to accept the theory that all other NPP operators in the world are much better than Tepco.

Sorry, I simply can't do that. I could possibly buy it after Chernobyl, by saying that it was an outlier data point. But it happened *again*. Another NPP operator, in another country, but similar symptoms of not treating safety seriously enough.

Apparently, the system needs serious fixing. I propose a fix which adds another layer of accident response, one decoupled from NPP operator and its possible arrogance/stupidity/greediness/lapses in preparedness.

What do you propose? Basically nothing apart from minor patching-up of some safety rules?

Many of the lessons learned may actually confirm the wisdom of doing this differently in the US.

Speaking of US. Are emergency vents of US plants also have *no filters at all*, like Fukushima's ones didn't have?
Meaning: they will also vent Cs-137 and Cs-134 if, God forbid, it would ever come to venting of overheated reactor? How much adding filters to those lines would cost? I bet a few orders of magnitude less than $200bn for cleanup which Japan will need to spend now...

 

[NUCENG]

In other words, you propose to accept the theory that all other NPP operators in the world are much better than Tepco.

Sorry, I simply can't do that. I could possibly buy it after Chernobyl, by saying that it was an outlier data point. But it happened *again*. Another NPP operator, in another country, but similar symptoms of not treating safety seriously enough.

Apparently, the system needs serious fixing. I propose a fix which adds another layer of accident response, one decoupled from NPP operator and its possible arrogance/stupidity/greediness/lapses in preparedness.

What do you propose? Basically nothing apart from minor patching-up of some safety rules?



Speaking of US. Are emergency vents of US plants also have *no filters at all*, like Fukushima's ones didn't have?
Meaning: they will also vent Cs-137 and Cs-134 if, God forbid, it would ever come to venting of overheated reactor? How much adding filters to those lines would cost? I bet a few orders of magnitude less than $200bn for cleanup which Japan will need to spend now...

No, I cannot speak for all countries. But I can speak from experience in the US. If you can't do the same then perhaps your opinion may be just that - opinion, and uninformed at that.

Proposing a fix that works is good, but I have explained why that fix may not be what you are asking for. Instead of discussing the reasoning I provide you imply that I am justifying doing nothing. Nothing could be further from the truth. I agreed with the concept of some external response teams to support emergency response in my initial response. But I am convinced that your more expansive red team needs a lot more discussion.

So if you will stop dismissing my motives and twisting my position we can carry on a reasonable discussion including venting capabilities. If not, you can reinforce your opinion without my help.

 

[Bodge]

Not the first time I've said it, but its (way past) time to decommission all NPPs that over ~35 years old. More 'unforseen' events WILL occur, a combination of time, luck, human error and chaos theory will ensure it.

Also,

4 generator failures hit US nuclear plants [AP] http://www.guardian.co.uk/world/feedarticle/9886829

...Four generators that power emergency systems at nuclear plants have failed when needed since April, an unusual cluster that has attracted the attention of federal inspectors and could prompt the industry to re-examine its maintenance plans...

"Three diesel generators failed after tornadoes ripped across Alabama and knocked out electric lines serving the Tennessee Valley Authority's Browns Ferry nuclear plant in April. Two failed because of mechanical problems and one was unavailable because of planned maintenance.

Another generator failed at the North Anna plant in Virginia following an August earthquake. Generators have not worked when needed in at least a dozen other instances since 1997 because of mechanical failures or because they were offline for maintenance, according to an Associated Press review of reports compiled by the U.S. Nuclear Regulatory Commission.

"To me it's not an alarming thing," said Michael Golay, a professor at the Massachusetts Institute of Technology who studies risk at nuclear plants. "But if this trend were to continue, you'd certainly want to look into it."...