Fukushima Fukushima Management and Government Performance

[tsutsuji]

I could not find a Japanese version exactly similar to the English article. The closest Japanese article is http://www.bloomberg.co.jp/news/123-LVFBSX1A1I4H01.html published on the same day, by the same reporters. The word "sanction" is not used in http://www.bloomberg.co.jp/news/123-LVFBSX1A1I4H01.html . http://www.bloomberg.co.jp/news/123-LVFBSX1A1I4H01.html says 口頭で注意した (he was verbally warned).

http://www.bloomberg.com/news/2011-11-30/leader-of-tepco-fukushima-fifty-steps-down.html mentions http://www.yomiuri.co.jp/atmoney/news/20110608-OYT1T01036.htm as it source, which talks about Tepco's president Shimizu summoning Yoshida to Tokyo on 6 June for a verbal warning for not having reported the facts for more than two months, but where 人事上の処分には当たらないとしている means "He said that this is not a basis for a disciplinary sanction".

In May, before Yoshida went to Tokyo, the Asahi said:

However, TEPCO officials are considering disciplinary action against Yoshida because he kept quiet about what actually happened for more than two months.

"It is difficult to understand why several days had to pass before revising the facts of a previous announcement," said Kenji Sumita, professor emeritus of nuclear engineering at Osaka University. "Repeated changes to announcements will affect the process of examining the accident. It would be natural to suspect the reliability of other records."
http://ajw.asahi.com/article/0311disaster/fukushima/AJ201105270252

 

[NUCENG]

I am a bit confused. If Yoshida was responsible for the deliberate decision to ignore scientific findings about the seismic and tsunami risk, then he should be held responsible. If however, he was the guy in charge on the worst day nucklear power ever saw, and he was trying everything he knew to combat the accident, is it reasonable to expect every decision to be correct? If they can demonstrate negligence, they should file that case. If all he did was withhold information from the people that were really to blame (TEPCO and the Japanese Regulators), I think he may end up as the hero along with the rest of the "Fukushima Fifty" in this story.

My problem is that we don't know enough to judge Yoshida, and we shouldn't. We do know that some people had knowledge of the risk and could have taken action to prevent or lesson the severity of this accident and they didn't. Why isn't that at the top of the page in every newspaper?

 

[zapperzero]

My problem is that we don't know enough to judge Yoshida, and we shouldn't. We do know that some people had knowledge of the risk and could have taken action to prevent or lesson the severity of this accident and they didn't. Why isn't that at the top of the page in every newspaper?

Thank you for articulating my concerns. I was, for once, at a loss for words.

 

[Astronuc]

Japan May Declare Control of Reactors, Over Serious Doubts
http://www.nytimes.com/2011/12/15/w...re-control-over-damaged-nuclear-reactors.html

“The government wants to reassure the people that everything is under control, and do this by the end of this year,” said Kazuhiko Kudo, a professor of nuclear engineering at Kyushu University. “But what I want to know is, are they really ready to say this?”

. . . .
“Claiming a cold shutdown does not have much meaning for damaged reactors like those at Fukushima Daiichi,” said Noboru Nakao, a nuclear engineering consultant . . . .

. . . .

 

[Astronuc]

More on the jumpers. Article claims cumulative exposures are not tracked.
http://www.thestar.com/news/world/a...clear-gypsies-face-peril-at-power-plants?bn=1

Assuming that the article is acurate, it is disgraceful. In the US, such of practice of not accounting for exposure, and essentially falsifying records, would be illegal.

On the other hand, while working summer construction jobs during my university years, I watch similar practices with illegal aliens in Texas, but at non-nuclear sites. One of the nations largest construction companies brought truckloads of illegal aliens on-site, and if they were injured on the job, they were dismissed. They received no benefits, such as insurance, accumulated no social security, and earned less than the legal minimum wage.

 

[NUCENG]

Assuming that the article is acurate, it is disgraceful. In the US, such of practice of not accounting for exposure, and essentially falsifying records, would be illegal.

On the other hand, while working summer construction jobs during my university years, I watch similar practices with illegal aliens in Texas, but at non-nuclear sites. One of the nations largest construction companies brought truckloads of illegal aliens on-site, and if they were injured on the job, they were dismissed. They received no benefits, such as insurance, accumulated no social security, and earned less than the legal minimum wage.

One immediate red flag about the article: TLD's are passive dosimeters for measuring cumulative doses. And electronic dosimeters I have used don't have on/off switches. If they were to be turned off and lost the initialization for the worker and his dose limits, they would alarm on exit.

 

[Astronuc]

One immediate red flag about the article: TLD's are passive dosimeters for measuring cumulative doses. And electronic dosimeters I have used don't have on/off switches. If they were to be turned off and lost the initialization for the worker and his dose limits, they would alarm on exit.

That's a good and important point. I had read that to mean they just leave them behind or place them in their lunch box or in some situation where the dosimeters were not exposed.

Whenever I worked in a hot area, I check out a dosimeter and checked it back in after leaving the hot area. The cumulative doses were reported at the end of the year, IIRC.

No one was allowed in a hot area unless they were wearing a dosimeter.

 

[NUCENG]

!

That's a good and important point. I had read that to mean they just leave them behind or place them in their lunch box or in some situation where the dosimeters were not exposed.

Whenever I worked in a hot area, I check out a dosimeter and checked it back in after leaving the hot area. The cumulative doses were reported at the end of the year, IIRC.

No one was allowed in a hot area unless they were wearing a dosimeter.

The more I reflect on this there are problems. First the discussion quotes a worker who only worked until the earthquake and tsunami. This may not be accurate for current practice due to all the flack TEPCO took over the lack of dosimetry right after the accident.

Second They quote a politician and a year-old study by a "watchdog" group. Wouldn't be a bad idea to question potential bias there!

Third, they quote the author of "The Lie of Nuclear Power." Obvioulsly an objective commentor (NOT).

They quote Kim Kearfott of the University of Michigan who does have good credentials, but only on how they recruit workers, not about training or use of dosimetry.

Finally they quote Kristin Shrader-Frechette of Notre Dame. She is a strident anti-nuclear critic as a part of her advocacy for "Environmental Justice."

All in all, I rate this article as about a 2 out of 10 for believability.

 

[NUCENG]

Japan May Declare Control of Reactors, Over Serious Doubts
http://www.nytimes.com/2011/12/15/w...re-control-over-damaged-nuclear-reactors.html

Source:

http://www.gainesville.com/article/20111214/API/1112140576?tc=ar

It appears they will use the term "stability" vs. "cold shutdown." IMHO, That is a much more accurate description.

 

[W7VOA]

I am looking to do a telephone interview for our radio newscasts (and web site) with a nuclear engineer about the Japanese prime minister's announcement (which will occur in a few hours) that Fukushima-1 has achieved "conditions" akin to a "cold shutdown." If anyone is available, please PM me.

-- Steve Herman
VOA Northeast Asia Bureau Chief
Twitter @w7voa

 

[W7VOA]

We've got someone. Thanks.

 

[zapperzero]

http://www.asyura2.com/11/genpatu19/msg/378.html

Apparently NISA has decided to let TEPCO off the hook for any past, present or future releases of contaminated water into the ocean, reason cited being "emergency".

How can this be?

link via ex-skf

 

[NUCENG]

http://www.asyura2.com/11/genpatu19/msg/378.html

Apparently NISA has decided to let TEPCO off the hook for any past, present or future releases of contaminated water into the ocean, reason cited being "emergency".

How can this be?

link via ex-skf

It is consistent with the earlier decision that TEPCO does not own, nor is responsible, for land contamination. I don't think anyone on this forum found that to be proper. And at least for me, this is the same. What are they going to be held responsible for? Will the next release be that the government wants evacuees to refund their compensation back to TEPCO? This is getting a little bit BIZARRE!

 

[zapperzero]

It is consistent with the earlier decision that TEPCO does not own, nor is responsible, for land contamination. I don't think anyone on this forum found that to be proper.

Umm.. that was just TEPCO's contention in court - it was rejected by the judge.

And at least for me, this is the same.

It is similar indeed and gives us a clue as to the earlier incident you mention - the brazen attitude from TEPCO seems now grounded in previous experience with toothless industry regulators - a run-of-the-mill judge proved to be less inclined to... accommodate.

What are they going to be held responsible for? Will the next release be that the government wants evacuees to refund their compensation back to TEPCO? This is getting a little bit BIZARRE!

It will also have international consequences I think - China has been making noises about Cesium ending up in "their" water already.

 

[dontdomaths]

Enjoying the great conversations on this issue on pf.

Silly sausage, nothing is set in stone. You might wish to reconsider that strange response ;all you were given was historical fact.

Just signed up to say your colourful narrative is not "historical fact".

 

[Caniche]

Cheers for the colourful bit ,which fact do you refute? Espionage;forced labour or slavery?

 

[dontdomaths]

Cheers for the colourful bit ,which fact do you refute? Espionage;forced labour or slavery?

Thanks for not taking it as a troll attempt :)

I'm not refuting the specifics actually. Factually, feudalism can always be stretched to slavery, at some stage someone is going to be forced work. Yes there were prisoners and they might have been put to work and not paid. Espionage is common if not inherent function of all governments, after all not all of their activities can be overt. Obviously some of the most famous images of spys have been ninjas..

However- I'm arguing against this sort of simplicity. Summarily picking a few historical points in summary doesn't equate to "historical fact" in the way you were representing because it's neither balanced or encompassing. It's a coloured narrative because it's highlighting what suits to paint a certain characteristic to explain aspects of contemporary work practices.

This is of course only my opinion but since there were no other disenting views, and NUCENG seemed to be debating with you having accepted your point I thought I'd chime in.

I think the answer is simpler, and not racially or culturally based. People need money. You'll find the same thing happens in every country.

If that point doesn't make sense perhaps an inversion might demonstrate the point- Are you American? If so do you draw the same parallels to contemporary work practice in the US because America was in many ways built on slavery, espionage and forced labour? Probably not- because this too would be 3 things that are factual but not characteristic of the US (well apart from the slavery which as I understand it is something that culturally is still an issue).

 

[gmax137]

...Are you American? If so do you draw the same parallels to contemporary work practice in the US because America was in many ways built on slavery, espionage and forced labour? Probably not- because this too would be 3 things that are factual but not characteristic of the US (well apart from the slavery which as I understand it is something that culturally is still an issue).

You left out the genocide of the previous indigenous cultures.

Actually I'm agreeing with your point, I think it's well taken

 

[tsutsuji]

http://www3.nhk.or.jp/news/genpatsu-fukushima/20120508/index.html A 17 year old boy was employed for 6 days at Fukushima Daiichi in April 2011, installing pipes, in violation of the law banning workers younger than 18 in nuclear power plants, and received a 1.92 mSv dose. This was found on 7 May 2012 by checking this worker's identity and age. Among the 23,000 who have worked at Daiichi since the accident, the identity of 6000 of them has not been confirmed yet, and more workers younger than 18 might be found among them.

 

[tsutsuji]

http://www3.nhk.or.jp/news/genpatsu-fukushima/20120516/index.html [from Tepco's press conference on 15 May 2012] At a study meeting in 2006, 2 years after the Sumatra tsunami, gathering the NISA, power companies and other participants, it was said that if a 14 m tsunami strikes Fukushima Daiichi, water would enter buildings through doors and service entrances and "there is a possibility that electric power supply equipments lose function". The NISA issued instructions such as making the seawater pumps watertight, and Tepco took this and other countermeasures but did not study countermeasures against water flowing into the buildings. Tepco comments that "as there was no certain evaluation that tsunamis higher than 10 m would strike, it was not followed by a study of countermeasures". Calculated estimates of tsunamis around 10 m high were also obtained during the three years that preceded the accident. It is becoming clear that several opportunities to revise countermeasures against tsunamis were missed.

http://www.tepco.co.jp/nu/fukushima-np/images/handouts_120516_05-j.pdf documents from the 2006 study meeting

http://www.japantimes.co.jp/text/nn20120516a5.html "NISA, Tepco knew in '06 of Fukushima tsunami threat"

http://mainichi.jp/english/english/newsselect/news/20120515p2a00m0na007000c.html "TEPCO was warned of possible power loss from tsunami at nuclear plants in 2006"

 

[tsutsuji]

http://www.ustream.tv/recorded/22600907 Video of Tepco's press conference, 15 May 2012
http://genpatsu-watch.blogspot.com/2012/05/20125151800.html Transcript of Tepco's press conference, 15 May 2012

Matsumoto:

The next item: there have been news reports today of yesterday's Diet's investigation committee session, suspecting for example that although we had been warned by the NISA in Heisei 18 (2006) of the risk of tsunami-caused full loss of electric power, Tepco did not take the necessary countermeasures.

On this matter, let me narrate the factual relationships that we checked. As, retrospectively, not being prepared enough resulted in a major accident caused by this tsunami, we present our sincere apologies, but let me explain the situation at that time.

First of all, from January to July 2006, the NISA and JNES organised a floods study group. It was attended by the Federation of Electric Power and by electric power companies including Tepco in quality of observers.

That study group examined questions such as the vulnerability of the design of nuclear power plants in the United States against internal inundations, or the accident where a seawater pump at an Indian nuclear power plant was inundated due to the Indian Ocean off the coast of Sumatra tsunami.

Then, this brings us to October 2006, the NISA held a preliminary meeting on the planning of earthquake resistance back-checks to be imposed on the Federation of Electric Power, and during that meeting, the NISA presented instructions on how to deal with tsunamis.

It was said that the Society of Civil Engineers' method being conservative enough, there is no problem in using that method. However, concerning tsunamis, as we are dealing with a natural phenomenon, one must think that phenomenons beyond design basis are possible, and in the case the design basis is exceeded, emergency seawater pumps lose function, resulting in core damage, so we received a demand to take concrete countermeasures at the plants where the margin against tsunamis is small.

Later, this brings us to April 2007, the Federation of Electric Power replied to the aforementioned NISA's requests, and we at Tepco submitted a report mentioning that according to the Society of Civil Engineers' method, the margin of Fukushima Daiichi's emergency seawater pumps against tsunamis is extremely small and saying that we will take voluntary countermeasures.

Concretely, we reported that we would study the watertighting of motors and electric operated equipments. At that time we did not receive additional instructions from the NISA, but in continuation, from that time on, both we and the NISA were aware that it was necessary to make a probabilistic evaluation of tsunami heights and to study the tsunami hazard.

The factual relationships being as I explained, at that time at the floods study group we did not study only the emergency seawater pumps but also an hypothesis where the buildings' site is inundated.

Of course, if the buildings' site is inundated, water flows in through entrances, and the electric supply equipments located inside the buildings get inundated and lose function. Well, in some sense it is an obvious result, and it does not constitute a new knowledge of a new risk that would have been pointed out by the NISA.

For us, it was an obvious awareness that we were holding. The study contained in that report consisted in examining what happens if a tsunami exceeds the buildings' ground level, regardless whether it is possible with a real tsunami or regardless the probability of such an event.

Concerning the elevation of the plant, we performed the study in accordance with the Society of Civil Engineer's tsunami evaluation method, and both the NISA and we evaluated that the approach with this evaluation guideline was conservative enough. For that reason, with this result of tsunami height evaluation[1], we thought at that time that safety was being secured.

However, at that time in October 2006, a protective wall was surrounding the motors of the emergency seawater pumps located at an elevation of 4 m at Fukushima Daiichi, but as the margin against the design basis tsunami of 5.7 m was small, we received a demand from the NISA to take concrete countermeasures, and we began to study the watertighting of the electric operated equipments.

As a result, we do not confirm the news reports that say that we received a written instruction from the NISA or that the NISA requested that we take countermeasures against the risk of full loss of AC electric power resulting from an inundation of the buildings. That's all from me for today.

[1]The evaluation according to the Society of Civil Engineer's method is O.P. + 5.6 m for Fukushima Daiichi unit 5, according to the last column of the table at the bottom of http://www.tepco.co.jp/nu/fukushima-np/images/handouts_120516_05-j.pdf page 3/3.

 

[zapperzero]

Of course, if the buildings' site is inundated, water flows in through entrances, and the electric supply equipments located inside the buildings get inundated and lose function. Well, in some sense it is an obvious result, and it does not constitute a new knowledge of a new risk that would have been pointed out by the NISA.

For us, it was an obvious awareness that we were holding. The study contained in that report consisted in examining what happens if a tsunami exceeds the buildings' ground level, regardless whether it is possible with a real tsunami or regardless the probability of such an event.

Concerning the elevation of the plant, we performed the study in accordance with the Society of Civil Engineer's tsunami evaluation method, and both the NISA and we evaluated that the approach with this evaluation guideline was conservative enough. For that reason, with this result of tsunami height evaluation[1], we thought at that time that safety was being secured.

However, at that time in October 2006, a protective wall was surrounding the motors of the emergency seawater pumps located at an elevation of 4 m at Fukushima Daiichi, but as the margin against the design basis tsunami of 5.7 m was small, we received a demand from the NISA to take concrete countermeasures, and we began to study the watertighting of the electric operated equipments.

Way to dig one's own grave, there.

 

[tsutsuji]

http://www.ustream.tv/recorded/22621594 Video of Tepco's press conference, 16 May 2012
http://genpatsu-watch.blogspot.com/2012/05/20125161800-414-1880bqkg.html Transcript of Tepco's press conference, 16 May 2012

Matsumoto:

Next item: we have distributed to you a series of documents [ http://www.tepco.co.jp/nu/fukushima-np/images/handouts_120516_05-j.pdf ]. One of them is about the floods working group and the situation of the response to it, and the other one consists in an A3 colour copy entitled "Results of the studies of the external flood working group".

Yesterday we explained the factual relationships in answer to the news reports that followed the suspicions at the day before yesterday's Diet investigation committee session, such as the suspicion that we did not take enough countermeasures against the flood situation in 2006 (Heisei 18). But that was an oral explanation, and today we can provide this explanation as a document.

In combination, as the NISA allowed us to do so, we can provide you with the last documents that we received at the floods working group.

First, please have a look at the A4 document. The floods working group was held from January to July 2006 by the NISA and JNES and it was about topics such as the vulnerability problems of nuclear power plants in the United States, or the flooding of seawater pumps at a nuclear power plant in India during the off the coast of Sumatra tsunami of that time. The Federation of electric power and the the power companies attended as observers.

The next paragraph is about the situation of the studies at the working group. The assumption was a flooding of 1 m above ground for an unlimited time. As a consequence, needless to say, when the grounds and the buildings are flooded, the result obtained is that water flows in through building entrances, and electric power supply equipments lose function.

However, this was not based on probabilities or on the possibility of occurence of such a tsunami in real life. Our opinion is that this was nothing more than a check of consequences performed as a study. The result of the study is provided in the A3 document for Fukushima Daiichi unit 5 and Tohoku Electric's Tomari units 1 and 2 as representative cases.

In the conditions of the study, it is noted for Fukushima Daiichi unit 5 that the water intake area, near the water intake is at an elevation of O.P. 4.5 m, and that the level, above that, of each service building, of the turbine building and the reactor building is O.P. 13 m.

In Table 1, as I previously said, when a 1 m above ground tsunami is assumed (for Fukushima Daiichi unit 5, that makes an O.P. 14 m assumed tsunami) the seawater pumps, the reactor building, the turbine building and the service buildings each receive an an x-mark [used to indicate an incorrect answer in a test, etc.].

Also, for Tomari units 1 and 2, as you can see, as the ground floor is at 10 m, adding 1 m makes a T.P. 11 m tsunami, and the situation is that the recirculation pump buildings, the reactor buildings, and the turbine buildings etc. receive an x-mark.

In the right half of the page we attached the pictures made at the time of the study concerning the facts checked at Fukushima Daiichi unit 5 and Tomari unit 1.

On the back of the page, it is about an examination of the situation in the case water actually enters into the buildings. Both at Fukushima Daiichi unit 5 and at Tomari units 1 and 2, in the case buildings are flooded, if water enters through the service doors for large equipments, those areas get flooded.

Results obtained for each electric power company have been summarized in Table 2 in the bottom right part of the page under the title "Consequences on outdoor equipments of a grounds level + 1 m, beyond expectation tsunami". The results marked with ※ are those of bad consequences on electric supply equipments in the case of a tsunami unlimited in time at Tomari units 1 and 2, Onagawa unit 2, Fukushima Daiichi unit 5 and Hamaoka unit 4.

Let's go back to the A4 sheet. Such a floods working group was organized, and when, in October 2006, the NISA held a preliminary meeting on the planning of earthquake resistance back-checks, it was said that for tsunamis, being conservative enough, the Society of Civil Engineer's method was OK.

First there was a talk about the Society of Civil Engineer's method. However, after that, we received a request to study concrete countermeasures for the plants where the margin against tsunamis, high waves and backwashes is small, because when the level obtained by the Society of Civil Engineer's method is exceeded, the emergency seawater pumps that are located in low locations lose function and cause core damage. Also, at that time, the Federation of electric power was orally told to additionally transmit this request to each company's top ranking management.

At Tepco, as it was requested by the NISA, this information was shared up to the head of the Nuclear Power & Plant Siting Division. However our understanding was that this request concerned the flooding of emergency seawater pumps, and not the flooding of the buildings or the measures that could have prevented the different consequences of the present [11 March 2011] tsunami.

Now the last paragraph: All the tsunami heights were to be evaluated using the Society of Civil Engineer's method, this was to be reflected in the earthquake resistance back-checks and it was approved by the NISA.

As a consequence, in application of the Society of Civil Engineer's method, we conducted a conservative evaluation, and at that time we thought that the nuclear power plant's safety was being secured.

Also, the above being explained, the opinions of the Headquarters for Earthquake Research Promotion [ http://www.jishin.go.jp/main/index-e.html ] and the publications about the Jogan earthquake were concurring on the necessity of a new wave source model, and we worked on responses such as a revision of the Society of Civil Engineer's method in parallel with the study of the watertighting of emergency seawater pumps.

This was the explanations provided yesterday summarized again today in the form of documents. Thank you.

 

[Yamanote]

Way to dig one's own grave, there.

Right.

Thanks tsutsuji-san for translating!
Nature doesn't care about man-made papers and what Tepco thought or not. They can discuss this forth and back - it is too late now, they saved the money for making the plant tsunami-proof and now they have to face the consequences. And hiding behind papers doesn't even fix a single problem.

 

[zapperzero]

However, this was not based on probabilities or on the possibility of occurence of such a tsunami in real life. Our opinion is that this was nothing more than a check of consequences performed as a study.

[...]

At Tepco, as it was requested by the NISA, this information was shared up to the head of the Nuclear Power & Plant Siting Division. However our understanding was that this request concerned the flooding of emergency seawater pumps, and not the flooding of the buildings or the measures that could have prevented the different consequences of the present [11 March 2011] tsunami.

Tsutsuji, how does this work in Japanese? Would you say the man is arguing for institutional blindness? That it is a normal condition? Am I correct in summarizing what he said as "we saw the possibility of a flood only as a paper exercise with no real-life consequences and furthermore we only cared about the pumps"?

 

[zapperzero]

With apologies for those of you who have seen this before:

Improvement of Environment around Monitoring Post of Fukushima Daiichi Nuclear Power Station (Result Report)
http://www.tepco.co.jp/en/nu/fukushima-np/images/handouts_120420_07-e.pdf

Measures are implemented so that each MP shows less than 10 μSv/h.
Regarding MP-2 that has relatively high radiation dose, the trees within 30 m radius from the MP are trimmed and surface
soils are removed. Regarding MP-3~5 that has relatively low radiation, the trees within 20 m radium from each MP are
trimmed and surface soils within its fence are removed. Regarding MP-6~7, the trees within 20 m radium from each MP are
trimmed and surface soils within its fence are removed, and shield walls are installed around each detector, because removal
of surface soil and tree trimming could be widely implemented. Regarding MP-8, tree trimming is not implemented because
there is few nearby forest, and surface soils within its fence are removed, and a shield wall is installed. Regarding MP-1, we
decided not to implement any countermeasure because the MP showed 4 μSv/h.

This is all done, presumably, to reduce background "noise". I wonder, though, how one can compare readings from detectors which are shielded differently. What is the point at which detectors cease detecting anything useful, if one continues to add shielding?

Why, if the idea is to measure the air and ONLY the air, is there not a mobile sampling unit used, instead of fixed detectors?

 

[MadderDoc]

With apologies for those of you who have seen this before:

Improvement of Environment around Monitoring Post of Fukushima Daiichi Nuclear Power Station (Result Report)
http://www.tepco.co.jp/en/nu/fukushima-np/images/handouts_120420_07-e.pdf



This is all done, presumably, to reduce background "noise". I wonder, though, how one can compare readings from detectors which are shielded differently. What is the point at which detectors cease detecting anything useful, if one continues to add shielding?

Why, if the idea is to measure the air and ONLY the air, is there not a mobile sampling unit used, instead of fixed detectors?

This is perhaps a bit too technical to be on topic, however since it could leave some with doubts of radiation monitoring management I hope mentors will allow it or move post to the more appropriate tehcnical thread.

The monitoring posts are there strictly to be able to detect whether radiation dose increases abnormally at the boundary of the site. The idea is to be able to detect abnormal emissions from the plant. In the present context, that implies being able to detect radiation dose variations down to about 1 microSv/h. However some of the instruments of the monitoring posts were in a 100 microSv/h environment due to deposition, and a change of 1 microSv/h would be within the imprecision of their readings. IOW, as it were, the instruments were useless for their purpose, while after the intervention, they are now able to serve it. With all due respect to results of mobile units, having useful fixed measuring points is a technical must, as is your ability to transmit a message about it to the public and be credible.

 

[tsutsuji]

Tsutsuji, how does this work in Japanese? Would you say the man is arguing for institutional blindness? That it is a normal condition? Am I correct in summarizing what he said as "we saw the possibility of a flood only as a paper exercise with no real-life consequences and furthermore we only cared about the pumps"?

I translate another bit of the same press conference. Matsumoto insists that all tsunamis higher than the seawater pumps do not necessarily rise so high that even the air-cooled generators are unusable. It sort of means that the air-cooled generators provided a [false?] sense of safety for the case when the seawater pumps are drowned.

http://genpatsu-watch.blogspot.fr/2012/05/20125161800-414-1880bqkg.html Transcript of Tepco's press conference, 16 May 2012

Freelance journalist Kino:

Is that to say that as it [how information is shared with higher ups] is decided on a case by case basis, in that case, the countermeasures including sealing [the seawater pumps ,etc.] were not important enough to be shared with the company president ?

Matsumoto:

Rather than "important", I think the point is that the problem could be solved within the Nuclear Power & Plant Siting Division. Also if you let me say a few words about Fukushima Daiichi, as you know, there are two air-cooled diesel generators located at 10 m on the units 1,2,3,4 side. Also at units 5 and 6 which were the topic of the study, there is also one air-cooled diesel generator.

For that reason, we were judging that even in the rare event when seawater pumps are flooded and become unusable, in the case when a tsunami does not reach the buildings' ground level as in the present [March 2011] tsunami, blackout does not occur as a consequence of the availability of air-cooled diesel generators. In that situation, we were not thinking that the sealing of electric operated equipments was a matter that had to be solved within one or two years.

 

[tsutsuji]

http://www3.nhk.or.jp/news/genpatsu-fukushima/20120604/index.html full translation

Blackout safety guideline: shelved "making them write"

The Tokyo Electric Power Company Fukushima Daiichi Nuclear Power Plant accident turned out to have been a problem of long time blackout, but it was found that a little more than 20 years ago, when studying a revision of the blackout safety guideline, a government's Nuclear Safety Commission's working group made the power companies write the reason why taking no countermeasures is acceptable, wrote a report based on that document, and shelved the revision.

In 1991 the Nuclear Safety Commission created a working group concerning the safety guideline that says that thinking about nuclear power plants' long time blackouts is unnecessary, studied a revision during closed door meetings, and finally did not issue a revision.

By October 2011, the Nuclear Safety Commission had publicly released the meeting documents of that time, and clarified the sequence of events leading to the non issuance of the revision, but as a result of new investigations requested by the National Diet of Japan Fukushima Nuclear Accident Independent Investigation Commission, a document showing the exchanges between the power companies and the Nuclear Safety Commission was found.

According to that document, at that time, saying "we don't think the risk is especially high", the power companies vigorously resisted against [1] the idea of augmenting [2] the blackout guideline. After receiving that reaction, in October 1992, the working group sent the power companies a written instruction via its executive office at that time, the Science and Technology Agency: "Please write a note explaining the reason why not taking countermeasures is acceptable".

Then, the working group wrote a report incorporating the power companies' reply almost without change, and shelved the guideline revision saying "It is unnecessary to think about blackouts lasting for a long time in nuclear power plants".

Concerning the fact that the shelving of a guideline concerning nuclear power plants' safety was done after receiving the views of the power companies, the head of the Nuclear Safety Commission, Haruki Madarame said: "In the present case, as has become clear, having the draft of the report be written by the power companies is clearly not appropriate and I am terribly sorry".

[ See also Masao Hasegawa http://japandailypress.com/weekend-editorial-the-darkside-of-japanese-nuclear-politics-262696 (May 26 2012) about other recent developments concerning the ties between NSC and power companies ]

Edits:
[1] "reacted" → "resisted"
[2] "creating" → "augmenting"

 

[NUCENG]

http://www3.nhk.or.jp/news/genpatsu-fukushima/20120604/index.html full translation

Blackout safety guideline: shelved "making them write"

The Tokyo Electric Power Company Fukushima Daiichi Nuclear Power Plant accident turned out to have been a problem of long time blackout, but it was found that a little more than 20 years ago, when studying a revision of the blackout safety guideline, a government's Nuclear Safety Commission's working group made the power companies write the reason why taking no countermeasures is acceptable, wrote a report based on that document, and shelved the revision.

In 1991 the Nuclear Safety Commission created a working group concerning the safety guideline that says that thinking about nuclear power plants' long time blackouts is unnecessary, studied a revision during closed door meetings, and finally did not issue a revision.

By October 2011, the Nuclear Safety Commission had publicly released the meeting documents of that time, and clarified the sequence of events leading to the non issuance of the revision, but as a result of new investigations requested by the National Diet of Japan Fukushima Nuclear Accident Independent Investigation Commission, a document showing the exchanges between the power companies and the Nuclear Safety Commission was found.

According to that document, at that time, saying "we don't think the risk is especially high", the power companies vigorously reacted to the idea of creating a blackout guideline. After receiving that reaction, in October 1992, the working group sent the power companies a written instruction via its executive office at that time, the Science and Technology Agency: "Please write a note explaining the reason why not taking countermeasures is acceptable".

Then, the working group wrote a report incorporating the power companies' reply almost without change, and shelved the guideline revision saying "It is unnecessary to think about blackouts lasting for a long time in nuclear power plants".

Concerning the fact that the shelving of a guideline concerning nuclear power plants' safety was done after receiving the views of the power companies, the head of the Nuclear Safety Commission, Haruki Madarame said: "In the present case, as has become clear, having the draft of the report be written by the power companies is clearly not appropriate and I am terribly sorry".

[ See also Masao Hasegawa http://japandailypress.com/weekend-editorial-the-darkside-of-japanese-nuclear-politics-262696 (May 26 2012) about other recent developments concerning the ties between NSC and power companies ]

1. Is the working group report available? Were the arguments included by the power companies based solely on cost or did they actually address the technical risk of extended SBO.

2. The Hasegawa article is extremely interesting including a reference to editorials that are calling for reorganization but not blame. While I am still supporting the work and actions taken by plant workers and operators, I am more convinced than ever that they were placed in a no-win situation by utility engineers, management, and regulators. Every example of deliberate foot-dragging, ignoring risks even when warned, the clearly inadequate regulatory performance, and the terrible record of misinformation that has been discussed here needs to be investigated. If negligence or misconduct is found, the courts must determine if it was criminal.

 

[tsutsuji]

1. Is the working group report available?

Yes. It is here: http://www.nsc.go.jp/info/20110713_dis.pdf

and all the documents of each of the 12 SBO working group meetings, from 1991 to 1993 are available on http://www.nsc.go.jp/senmon/shidai/zenkouryu_WG.htm and some related documents are also available on: http://www.nsc.go.jp/senmon/shidai/zenkouryu_WG_kanren.htm

Were the arguments included by the power companies based solely on cost or did they actually address the technical risk of extended SBO.

I can't answer as I have not started reading it. Wikipedia says "it reported the probability of SBO in Japan is less than other countries" ( http://en.wikipedia.org/wiki/Japanese_Nuclear_Safety_Commission )

See also http://www.asahi.com/english/TKY201107150338.html "Nuclear safety group in 1993: Power losses no big threat" by Jin Nishikawa 2011/07/16

 

[zapperzero]

Thank Freya for paper trails, at least. But, how can the Japanese commission have come to a conclusion so different from the one of others around the world? While I was trawling through the NRC archive, I found many documents and references to SBO. I think I remember also seeing official documents from Canada. Doesn't the IAEA monitor such topics? Aren't there international meetings at which they are discussed?

 

[zapperzero]

This is perhaps a bit too technical to be on topic, however since it could leave some with doubts of radiation monitoring management I hope mentors will allow it or move post to the more appropriate tehcnical thread.

The monitoring posts are there strictly to be able to detect whether radiation dose increases abnormally at the boundary of the site. The idea is to be able to detect abnormal emissions from the plant. In the present context, that implies being able to detect radiation dose variations down to about 1 microSv/h. However some of the instruments of the monitoring posts were in a 100 microSv/h environment due to deposition, and a change of 1 microSv/h would be within the imprecision of their readings. IOW, as it were, the instruments were useless for their purpose, while after the intervention, they are now able to serve it. With all due respect to results of mobile units, having useful fixed measuring points is a technical must, as is your ability to transmit a message about it to the public and be credible.

In the meantime, readings from these posts are reported as-is. No distinction is made, you will never see it reported in the media that these "air monitors" actually monitor the activity of the air itself and fresh fallout (by a strange, roundabout method).

It is what cued me to search for this report in the first place - some media report which talked about dose rates at the plant boundary being in the (tens of) microsievert range, which is obviously wrong.

This is also the case for monitoring posts further inland (as has been discussed here before). While it IS important to monitor fresh fallout, I'd say that the citizens in the affected areas would be better served by an estimate of total dose rate - which cannot be easily derived from the instruments' readings, as given, because of the extensive cleanup and shielding.

Sticking a counter on a pole is a singularly roundabout way of measuring airborne contamination and fallout, is it not? It would seem much better to use HEPA filters to measure particulates, scintillation chambers to get an idea of the activity of the air and so on. This is what I meant when I talked about mobile monitoring - any half-decent mobile monitoring rig, such as the M93 Fox, can do all these things and more.

 

[MadderDoc]

In the meantime, readings from these posts are reported as-is. No distinction is made, you will never see it reported in the media that these "air monitors" actually monitor the activity of the air itself and fresh fallout (by a strange, roundabout method).

Well, bad reporting in the media is one thing, but as regards Tepco,the difference in the data is clearly declared. What bothers me somewhat is that graphically the data from the cleaned up MPs are reported together with data from a non-cleaned up measuring point at 0.3 mSv/h, essentially drowning out in the graph any variation there might be at the MPs that allegedly measure air dose rate.
http://www.tepco.co.jp/en/nu/fukushima-np/f1/images/2012monitoring/f1_lgraph-e.gif

It is what cued me to search for this report in the first place - some media report which talked about dose rates at the plant boundary being in the (tens of) microsievert range, which is obviously wrong.

Yes, if that is being reported, it is wrong. Perhaps it is the effect of infiltration of the new mode, of looking 'forward' as regards controlling emissions from the plant: the criterium that _additional_ emission may not elevate the dose rate received at the site boundary by more than 1 mSv/year.

This is also the case for monitoring posts further inland (as has been discussed here before). While it IS important to monitor fresh fallout, I'd say that the citizens in the affected areas would be better served by an estimate of total dose rate - which cannot be easily derived from the instruments' readings, as given, because of the extensive cleanup and shielding.

Sticking a counter on a pole is a singularly roundabout way of measuring airborne contamination and fallout, is it not? It would seem much better to use HEPA filters to measure particulates, scintillation chambers to get an idea of the activity of the air and so on. This is what I meant when I talked about mobile monitoring - any half-decent mobile monitoring rig, such as the M93 Fox, can do all these things and more.

I certainly agree, but the site MPs are not there for the purpose of measuring the dose rate people may receive further inland by whatever amount of radioactive material which is present there at some point in time. They would in any case be better served by local measurements.

The MPs are there to detect abnormal variation of emissions from the plant. If I should qualm about anything in relation to those cleaned up MPs it is the apparent lack of definition of 'abnormal'. We've seen within day significant variations up to ~20% (or ~0.4 microSv/h in absolute figures) in the data, but no announcements of abnormalities have been made afaik, so that much would seem to be taken as normal under the present circumstances. However, compare to pre-accident when the MPs were at about 0.05 microSv/h with only a few nanoSv/h variation.

 

[zapperzero]

What bothers me somewhat is that graphically the data from the cleaned up MPs are reported together with data from a non-cleaned up measuring point at 0.3 mSv/h, essentially drowning out in the graph any variation there might be at the MPs that allegedly measure air dose rate.

I am sure that is just an unfortunate oversight. Or not, as the case may be.

Yes, if that is being reported, it is wrong. Perhaps it is the effect of infiltration of the new mode, of looking 'forward' as regards controlling emissions from the plant: the criterium that _additional_ emission may not elevate the dose rate received at the site boundary by more than 1 mSv/year.

But the total dose rate at site boundary is no longer being measured! The monitors have been re-purposed!

If I should qualm about anything in relation to those cleaned up MPs it is the apparent lack of definition of 'abnormal'. We've seen within day significant variations up to ~20% (or ~0.4 microSv/h in absolute figures) in the data, but no announcements of abnormalities have been made afaik, so that much would seem to be taken as normal under the present circumstances. However, compare to pre-accident when the MPs were at about 0.05 microSv/h with only a few nanoSv/h variation.

The fallout is not actually measured at all. It would be a simple matter - stick some filter paper out, wait an hour, put it in a scintillation detector, rinse, repeat. Why is it not done? Instead, the monitoring car drives around and measures gamma and neutrons. Neutrons! Feh.

 

[MadderDoc]

<..>
The fallout is not actually measured at all. It would be a simple matter - stick some filter paper out, wait an hour, put it in a scintillation detector, rinse, repeat. Why is it not done? Instead, the monitoring car drives around and measures gamma and neutrons. Neutrons! Feh.

Tepco is also measuring radioactivity in air, i.e. in the unit Bq/cm3, albeit reporting (only ) nuclides Cs134, Cs137, and I131, as per authority instruction (and these measurements are generally <DL these days). I'm sure there is a regulatory thing about all this measuring at the 'barn door', which is perhaps getting a bit absurd under the present circumstances, now when the horse has already bolted large scale. I am not sure what use it would be to have on top of that also fall out rates at the site boundary, they would expectedly change with the wind and seasons, and construction work at the plant, essentially just telling what is known already, that the contamination is high and the stuff is moving about, dispersing, as is its nature -- nobody is going to live at the site boundary anyway in the foreseeable future.

 

[tsutsuji]

The report of 11 June 1993 by the SBO working group of the Nuclear Safety Commission is not a very long one (28 pages without attachments). To begin with, here are the contents :

http://www.nsc.go.jp/info/20110713_dis.pdf 2/96

- Contents -

1. Foreword
2. Positioning of full AC electric supply loss events (SBOs) in foreign countries and present status, etc.
2.1. Positioning and management of SBOs in foreign countries' regulations, and present status of plant design in foreign countries
2.2. AC electric supply loss precedents in foreign countries, etc.
2.3. Assessment of reliability against SBOs etc. in foreign countries
3. Positioning and management of SBOs in our country and present status, etc.
3.1. Positioning and management of SBOs
3.2. Present status of plant design regarding SBOs
3.3. Status of plant operation management performance
3.4. AC electric supply loss precedents etc.
3.5. Assessment of reliability against SBOs etc.
4. Assessment of guidelines and safety securing countermeasures against SBOs
5. Conclusion
5.1. Summary of investigation results
5.2. Questions to be treated in the future concerning SBOs
6. Attachments

Here is a translation of part 5 (Conclusions)

http://www.nsc.go.jp/info/20110713_dis.pdf 29/96

5. Conclusion
5.1. Summary of investigation results
The following is the result of investigations on full AC electric supply loss events based on past operational achievements in our country's nuclear power plants or on reports from foreign countries that we referred to.

① There has not been any SBO precedent in Japan's nuclear power plants until now. However, as they constitute the main SBO precedents occurring in foreign countries, we investigated the 3 cases that occurred at light water reactors in the USA. Although it is difficult to study by direct comparison because the situation of design and operational management is not necessarily the same as in Japan, the points from those precedents that are to be reflected in Japanese nuclear power plants, as general lessons whose awareness must be renewed, are ① the importance of countermeasures against human errors (training of operators, etc.) and ② adequate inspections during nuclear reactor shutdowns, of the facilities whose purpose is to secure the safety of nuclear reactor facilities including electric supply equipments, and the importance of conservative design.

② In our country, the frequency of external power loss is low at about 0.01 /Reactor*Year, and in all precedents that occurred at nuclear power plants, the time taken to restore external electric power was 30 minutes or less. This is a high reliability compared with the United States' external power loss frequency of about 0.1 / Reactor*Year and external power restoration time's mean value of about 30 minutes, the longest being about 19 hours (statistics compiled until 1989).

③ Over the past 10 years, the emergency diesel generators (EDG)'s starting failure rate has been about 6x10^-4/demand in Japan. Compared with the United States' 2x10^-2/demand, our country's EDG reliability is high.

④ DC supply (emergency batteries, etc.) is especially important should a SBO happen. The capacity of emergency batteries in nuclear power plants in our country is 5 hours or more (on the basis where some of the loads are switched off). Also, as there is no precedent of failure of emergency DC supply system batteries, etc., it can be thought that reliability is maintained at a high level. In the United States, however, failures of DC supply emergency system batteries, etc. have been reported. Also, for example at Surry the capacity of emergency batteries, in the case where some of the loads are switched off, is estimated to be about 4 hours.

⑤ So, it can be thought that in our country, the reliability of external power systems, EDGs and emergency DC power system's emergency batteries etc., is good and SBOs are hard to be generated. Also, some nuclear power plants are designed to supply the emergency electric power system from a [third] power transmission system independent from the two circuits required by the guidelines, and some are designed to supply electric power from a neighbouring nuclear power plant.

⑥ If we try to evaluate plant resistance during SBO on the basis of the United States' RG1.155, the resisting time that is required is 4 hours. Against that requirement, the resisting time against SBOs of representative nuclear power plants in Japan is 5 hours or more with the response procedures already incorporated in manuals such as switching off some of the battery loads, so that the United States' NRC's SBO regulation is satisfied.

⑦ According to the Probabilistic Safety Analysis (PSA) results obtained in our country's representative nuclear power plants with internal causal factors alone, SBO-caused core damage frequencies are low, and they are also low in comparison with the United States' NRC's NUREG 1032 medium value of 10^-5/Reactor*Year. The total core damage frequencies, including this, are also low.

⑧ Concerning regulatory requirements against SBOs in the major foreign countries, the United States and France have regulatory requirements against SBOs (including prolonged SBOs). The United Kingdom and Germany have regulatory requirements that are nearly similar with the Japanese ones.

5.2. Questions to be treated in the future concerning SBOs

The present good operational management, maintenance and margin-allowing design being continued, in order to enhance safety to a higher level, the following additional steps are desirable:

① In order to enhance the Japanese nuclear power plants' safety against SBOs to a higher level, it is obvious that a situation where the operators are sufficiently trained with the manual must be maintained, but in the case new knowledge is obtained it is necessary to make efforts to appropriately reflect that new knowledge in design, operation, maintenance and manual, etc..

② The core damage frequency obtained in the probabilistic safety analysis results of nuclear power plants representative of our country are not especially high, but while conducting studies, etc. of the SBO core damage frequency by probabilistic safety analysis at individual plants, it is important to make efforts to conduct the studies that will pave the way toward a higher efficiency level of preparatory measures such as accident management.

③ While maintaining the present situation of good operation and maintenance in our country's nuclear power plants, in view of the fact that in probabilistic safety analysis the collection of the data of our country's nuclear power plants is important, it is desired that in the future the data concerning the reliability of EDGs when they are started, and the reliability of their continuous operation after starting are collected and arranged, and that they are studied and reflected in analysis of failure rates and in probabilistic safety analysis.

 

[tsutsuji]

Thank Freya for paper trails, at least. But, how can the Japanese commission have come to a conclusion so different from the one of others around the world? While I was trawling through the NRC archive, I found many documents and references to SBO. I think I remember also seeing official documents from Canada. Doesn't the IAEA monitor such topics? Aren't there international meetings at which they are discussed?

What the SBO working group seems to say in conclusion ⑧ is : we are not going to do like the USA and France which have regulations against prolonged SBOs, but we'll do like the UK and Germany which don't. I don't know if it was actually the case in 1993 in those countries, but that's what the report seems to be saying, if my fragile understanding happens to be correct.

 

[nikkkom]

Hilarious and atrocious.

 

[zapperzero]

What the SBO working group seems to say in conclusion ⑧ is : we are not going to do like the USA and France which have regulations against prolonged SBOs, but we'll do like the UK and Germany which don't. I don't know if it was actually the case in 1993 in those countries, but that's what the report seems to be saying, if my fragile understanding happens to be correct.

I would not qualify your understanding as "fragile". It seems to me from what you have translated that the commission felt stations were sufficiently safe against prolonged blackouts that they recommended only "further study" as a mode of action.

Again from your translation, it would seem that the commission did not consider external causes for an SBO, other than simply losing power from the grid for a limited period of time. Complex modes such as what actually happened seem to have never been considered. A failure of the imagination, if you will.

 

[tsutsuji]

Some more translation of the same report:

http://www.nsc.go.jp/info/20110713_dis.pdf 3/96

1. Foreword

Full AC electric supply loss events (Station Blackout, noted below as "SBO") are the "simultaneous occurrence of external AC electric supply loss and the loss of the plant's internal emergency AC electric supply" (Note).

In other words, SBOs are compound events generated when the external power supply is fully lost, and for example all the emergency diesel generators (noted below as "EDG") fail from starting. It can be thought that their frequency is extremely low.

To be prepared should a SBO occur, nuclear power plants are designed so that, against the occurrence of short time SBOs, the reactor is safely shut down and cooling can be secured after shut down. However, in the hypothetical case where AC power cannot be restored within a short time and the SBO is prolonged, because emergency batteries run out, the operation monitoring and control functions, etc. are lost and core cooling can no longer be maintained, so that it is thought that the possibility emerges that it leads to major results such as core damage. However, in recent years, probabilistic safety analysis (noted below as "PSA") which quantitatively analyses and estimates the probability for example of core damage in all accident scenarios that can be presumed, including events whose frequency is thought to be extremely low such as SBOs, has been performed in many countries.

① Reflecting for example the fact that, short time ones though they are (within the limits of the present study the longest one is 36 minutes), SBO precedents have been reported in foreign countries;

② Reflecting for example that it has been reported, according to PSA results in representative American nuclear power plants, that there are nuclear power plants where SBO is an important contributory factor to core damage; and

③ Reflecting for example the fact that in recent years, in the United States, regulatory measures have been taken against SBOs,

as developed below, the present working group investigated and compiled findings mainly on the present status of SBO regulatory requirements, accident and malfunction precedents at nuclear power plants in Japan and abroad.

Note: In our country's "safety design examination guideline for electricity-generating light water nuclear reactor facilities" [ online version: http://www.nsc.go.jp/shinsashishin/pdf/1/si002.pdf ], it is called "full AC electric power supply loss event".

 

[tsutsuji]

Let's have a look at this "safety design examination guideline(s) for electricity-generating light water nuclear reactor facilities" [ online version: http://www.nsc.go.jp/shinsashishin/pdf/1/si002.pdf ].

It is made of two parts. From page 1 to 13 you can find the regulation's main text:

-----
I. Foreword
II. Positioning and application domain of the present guideline(s)
III. Definitions (1)...(20)
IV. Nuclear power plant in general (Guideline 1... Guideline 10)
V. Nuclear reactor and nuclear reactor shutdown system (Guideline 11... Guideline 18)
VI. Reactor cooling systems (Guideline 19... Guideline 27)
VII. PCV (Guideline 28... Guideline 33)
VIII. Safety securing systems (Guideline 34... Guideline 40)
IX. Central control room and emergency facilities (Guideline 41... Guideline 46)
X. Measurement/controls and electric systems (Guideline 47... Guideline 48)
XI. Fuel handling systems (Guideline 49... Guideline 51)
XII. Radioactive waste treatment facilities (Guideline 52... Guideline 55)
XIII. Radioactive exposure management (Guideline 56... Guideline 59)
-----

Then, from page 14 to 27, are the "explanations" that apply to a selection of definitions and guideline numbers.

SBOs are mentioned in Guideline 27, page 7:

-----
Guideline 27. Design considerations against electric supply loss
Against short time full AC electric power supply loss at nuclear reactor facilities, the design shall ensure that reactor is safely shut down, and that cooling can be secured after shutdown.
-----

They are mentioned again in the explanation for guideline 27, page 22:

-----
Guideline 27. Design considerations against electric supply loss
As the restoration of electric transmission lines or the repair of the emergency AC electric supply equipments can be expected, it is not necessary to consider prolonged full AC electric power supply loss.
In the case where the degree of reliability of emergency AC electric supply equipments is sufficiently high due to the system's construction or use (for example by having it normally running), it is not necessary for design to assume full AC electric power supply loss.
-----

 

[zapperzero]

-----
Guideline 27. Design considerations against electric supply loss
As the restoration of electric transmission lines or the repair of the emergency AC electric supply equipments can be expected, it is not necessary to consider prolonged full AC electric power supply loss.
-----

I really don't think that follows. Nice catch, anyway.

 

[tsutsuji]

It was already quoted in the Asahi article linked a few posts above: ( Discussions for the NSC's safety-design guidelines for nuclear power plants set in 1990 reached a similar conclusion. "There is no need to consider a situation in which all alternating currents are lost for a prolonged period because power cables and emergency alternating current equipment are expected to be restored," according to the guidelines. ) http://www.asahi.com/english/TKY201107150338.html

The other Asahi quote (The group concluded that the "chances of losing all alternating currents are slim" and that "a reactor will unlikely enter a serious situation since outside and other power sources can be expected to return in a short period of time.") translates the last sentence of part 4 of the 11 June 1993 report by the SBO working group of the Nuclear Safety Commission, http://www.nsc.go.jp/info/20110713_dis.pdf page 25 (27/96).

 

[NUCENG]

Thank Freya for paper trails, at least. But, how can the Japanese commission have come to a conclusion so different from the one of others around the world? While I was trawling through the NRC archive, I found many documents and references to SBO. I think I remember also seeing official documents from Canada. Doesn't the IAEA monitor such topics? Aren't there international meetings at which they are discussed?

Before 11 Mar 2011, extended SBO was considered to be of very small probability due to multiple power sources from offsite power (minimum of two independent sources) and redundant onsite emergency AC. The external events (e.g., sesmic or flooding) that could generate failures loss of area grid supplies were supposed to have been evaluated and be of very low probabilities. The potential for these events to also cause failure of onsite emergency AC sources were supposed to be vanishingly small.

I am certain that you have seen NRC documents estimating probabilities near 1 in a million. Yet the extended SBO has repeatedly been the highest risk of consequences including massive property and health consequences.

So they looked at this as a high consequence, low probability event. They missed a chance to consider flooding due to tsunami effects much higher than previously evaluated. That turned this into a hich consequence high probability event with a frequency equal to the seismic event frequency.

The mayor of Fudai remembered the effects of a 1933 tsunami and built a floodwall that protected his town. It was expensive but successful. Yet at TEPCO, warnings based on previous tsunami events were ignored, probably for economic reasons. This contrast shows they could have (actually should have) protected the site from flooding. In that case we might have had damage similar to the KK reactors in a previous earthquake.

So what was the real story here? You have a company with a "natural" desire to maximize profit looking at data that has a high risk of consquences and at the same time a high cost. This is exactly the place where regulatory agencies need to be effective. In Japan, the company was allowed to interpret the new tsunami risk as "beyond design basis" because they could point out that their risk assessment met the "approved" methodology. We have seen postings that the Japanese regulators did not require plants to update risk assessment or implement changes in design basis unless a new plant was being built. There was revolving door movement from plant executives through regulatory agencies and back. The regulatory structure was complex and fragmented and even during the accident it was difficult to figure out who was in charge. The regulatory guides I have read were more advisory than regulatory. There was clearly a complacency issue that resulted in examples where Japanese regulators told IAEA that they didn't need to implement anti-terrorism protection because Japan "is a stable society" (despite nerve gas attacks on the subway).

Yet the least reported or considered aspect of this accident seems to be changes in regulatory independence, structure, and authority. Company executives have resigned. Investigations are underway. Even here, the typical post has vilified TEPCO. There is much to learn there, but I am worried that without drastic changes in the Japanese regulatory agencies, it could happen again. In the US, there is a lot of work ongoing to improve technical protection of plants, Is that hiding other issues? Every regulatory agency in the world needs to be looking at this accident with a mirror as well as a magnifying glass.

 

[zapperzero]

I am certain that you have seen NRC documents estimating [SBO] probabilities near 1 in a million.

Yes, I have. It has struck me as wishful thinking, in the near-absence of statistical data. Worse, SBOs were used as a sort of a proxy for many types of accidents and incidents. Even worse, the NRC documents only go as far as stating "at this point, a meltdown occurs" and there are only loose guidelines as to how to proceed when such an outcome becomes clear, in a crisis, the so-called SAMGs.

I read through those, and they produced in me the effect of a plane's operating manual stating, after consuming reams of paper to describe the proper way to start the APU or move fuel from one tank to the next, something along the lines of "Also, try to remember that, if the engine goes out in a steep dive, you're a goner. Sure, you might try to pull back on the stick a bit, maybe the thing'll end up landing on its belly, but don't hold your breath about it."

So they looked at this as a high consequence, low probability event. They missed a chance to consider flooding due to tsunami effects much higher than previously evaluated. That turned this into a hich consequence high probability event with a frequency equal to the seismic event frequency.

I think you are being too specific here. Flooding is not the only common mechanism by which all of the EDGs at Fukushima Dai-ichi might have stopped during a grid failure. They might have been improperly refurbished, or replaced with defective ones, or improperly tested, all at once; as we have learned, shorting just one junction box per reactor is enough to effectively isolate the EDGs from their intended consumers. And so on.

Many things are supposed to be designed to fail gracefully. Not so with the vast majority of existing nuclear power plants (although there is some hope for the future).

So what was the real story here? You have a company with a "natural" desire to maximize profit looking at data that has a high risk of consequences and at the same time a high cost. This is exactly the place where regulatory agencies need to be effective. In Japan, the company was allowed to interpret the new tsunami risk as "beyond design basis" because they could point out that their risk assessment met the "approved" methodology. We have seen postings that the Japanese regulators did not require plants to update risk assessment or implement changes in design basis unless a new plant was being built. There was revolving door movement from plant executives through regulatory agencies and back. The regulatory structure was complex and fragmented and even during the accident it was difficult to figure out who was in charge. The regulatory guides I have read were more advisory than regulatory. There was clearly a complacency issue that resulted in examples where Japanese regulators told IAEA that they didn't need to implement anti-terrorism protection because Japan "is a stable society" (despite nerve gas attacks on the subway).

Yet the least reported or considered aspect of this accident seems to be changes in regulatory independence, structure, and authority. Company executives have resigned. Investigations are underway. Even here, the typical post has vilified TEPCO. There is much to learn there, but I am worried that without drastic changes in the Japanese regulatory agencies, it could happen again. In the US, there is a lot of work ongoing to improve technical protection of plants, Is that hiding other issues? Every regulatory agency in the world needs to be looking at this accident with a mirror as well as a magnifying glass.

You're right, I think, to place part of the blame on the shoulders of society at large. It's clear that regulators didn't regulate, inspectors didn't inspect and analysts didn't analyze properly. It is also clear that TEPCO in particular and Japanese industry in general has a long and shameful history of hiding health&safety related problems and incidents. That this behaviour was allowed to continue speaks of greed and corruption at all levels of government, in the media and in what is supposed to be a competitive industry but is actually a cartel, as well.

I have little hope that such issues can ever be resolved.

 

[tsutsuji]

http://www3.nhk.or.jp/news/genpatsu-fukushima/20120604/index.html Blackout safety guideline: shelved "making them write"

Fuji-Sankei Business-i provides a few additional details:

http://www.sankeibiz.jp/compliance/news/120604/cpb1206041134001-n1.htm

Apart from expert committee members, Tepco, Kepco and Japan Atomic Energy Research Institute attended as external parties.

[The members' list (5 members + 4 external cooperators) is available on http://www.nsc.go.jp/info/20110713_dis.pdf page 29 (31/96). ]

At the meeting, saying "reflecting it in the guideline is going too far" (Kepco), and "we don't think the risk (of severe accident) is especially high" (Tepco), the power companies resisted.

In October 1992, the working group requested Tepco and Kepco: "please write down the reason why not considering prolonged SBOs is acceptable".

In November, Tepco answered such things as "Japanese nuclear plants' design provides margins against the American standards, so that sufficient safety is secured".

 

[tsutsuji]

Some more translation. http://www.nsc.go.jp/info/20110713_dis.pdf page 2-4 (4/96-6/96).

2. Positioning of full AC electric supply loss events (SBOs) in foreign countries and present status, etc.

2.1. Positioning and management of SBOs in foreign countries' regulations, and present status of plant design in foreign countries

2.1.1. United States

(1) Positioning and management of American SBO regulations

The Reactor Safety Study published in 1975 showed that SBO is an important contributor to core damage frequency, and made clear that the reliability of American emergency AC generators was not as high as had been presumed until then.

For that reason, in 1979, the Nuclear Regulatory Commission (NRC) designed SBO as Unresolved Safety Issue (USI) A-44, and started in July 1980 to study whether new regulatory requirements must be carried out.

In June 1988, the NRC published NUREG-1032, containing a technical evaluation of SBOs with evaluations of loss of offsite power frequency and duration, emergency AC generating systems' reliability, etc.. In it, it was said that it was desirable to keep SBO generated core damage frequencies below 10^-5/Reactor*Year and concluded that each nuclear power plant should possesses enough resistance so that a 2～8 hour long SBO would not lead to core damage. In reaction, adding 10CFR50.63 : "Loss of all alternating current power" (mentioned below as "SBO") to the Code of Federal Regulation, the NRC made a legal requirement to assess if enough resistance is provided against SBO, or if countermeasures such as installing backup AC power supplies are necessary. Also, the Regulatory Guide 1.155 (mentioned below as "RG1.155"), which details how the NRC staff concretely assesses resistance against SBO, was published in August 1988.

On the other hand, the Nuclear Utility Management and Resources Council (NUMARC) which is a federation of power companies and reactor makers, compiled NUMARC-8700 containing an assessment procedure even more detailed than RG1-155. The NRC staff reviewed NUMARC-8700 and approved the method contained in it.

Using the NUMARC-8700 procedure, each nuclear power plant owning American power company submitted an SBO assessment to the NRC by 17 April 1989. These were reviewed by the NRC which approved the companies' plans to change equipments or manuals at about one half of the plants, instructing them to do so within two years. Eventually, the equipment and manual changes should be completed by the end of 1994.

(2) Outline of present status of American plant design and operational management

The construction of American nuclear power plants' power supply systems varies from plant to plant, but basically they are as shown on figures 2-1 and 2-2 [http://www.nsc.go.jp/info/20110713_dis.pdf 32/96-33/96].

Many American plants are connected to the grid via two different voltage transmission lines. In normal time, onsite loads are supplied via auxiliary transformers connected to the main generator. When the reactor is started and shut down, they are supplied via the start transformers (also called shutdown transformers or backup auxiliary transformers). The safety related systems and equipments are supplied according to the operators' choice between the onsite auxiliary transformer, the start transformer or the EDGs. In the case where for example the main generator trips and power cannot be supplied by the onsite auxiliary generator, the safety related systems and equipments are automatically switched to the start transformer or EDG. The priority between start transformer and EDG varies between plants. In the case where there are several start transformers, that too becomes backup. In the case where all offsite power is lost, EDGs start automatically, and safety realted systems and equipments are supplied.

In the case the resistance against SBO specified in RG1.155 is not met, the compulsory installation of backup AC power supply specified in SBO regulations consists of an onsite AC generator or one which can be supplied from a location close to the plant. Concretely, it is as shown in the following examples: on single reactor sites, they install an EDG not belonging to the emergency partition, or power equipments receiving power from an offsite thermal or hydraulic power plant. On multiple reactor sites, there is a cross tie between emergency busses. Examples are shown on figures 2-3 and 2-4 [http://www.nsc.go.jp/info/20110713_dis.pdf 34/96-35/96].

The operation management of American nuclear power plants is regulated by the technical specifications. We present below the outline of operation management of electric systems as regulated in standard technical specifications for an undetermined plant.

1) EDG surveillance

① starting test without load
It consists of verifying that the specified revolution speed, generated voltage, frequency are secured 10 seconds after a manual start signal or a mock-up loss of offsite power signal.

② continuous test with load
Performed without break after the starting test, it consists in verifying that synchronization and specified voltage are secured within 60 seconds and that it can keep running that way for at least 60 minutes.

③ EDG test frequency
The frequency of starting tests without load and continuous tests with load depend on past test results. If the past 100 tests generated 0 or 1 malfunction, tests are performed at least once every 31 days. In the case of 2 malfunctions, at least once every two weeks, In the case of 3 malfunctions, at least once every week. In the case of 4 or more malfunctions, at least once every 3 days.

④ EDG tests during reactor shutdown
In addition to the above mentioned starting tests without load and continuous tests with load, some tests must be performed at least once every 18 months during reactor shutdown. The main ones are a 24 hour test with load, a breaking test with load verifying the circuit breaking capacity, an automatic introduction test verifying load break and connection by a load sequencer during loss of offsite power, etc. Moreover, a simultaneous start test verifying the separation and independance of 2 EDGs is performed at least once every 10 years. 2) Inspection of DC power supplies such as batteries
The following inspections are performed on 250/125 V batteries and battery chargers:

① Inspection performed at least once every week
check of electrolyte surface in representative cells, voltage check, specific gravity measurement.

② Inspection performed at least once every 92 days
check of electrolyte surface in every cells, voltage check, specific gravity measurement, mean temperature of 6 cell electrolytes, voltage inspection of the battery as a whole, electric current inspection during floating charge.

③ Inspection performed at least once every 18 months
visual inspection of every battery cell, terminal board, rack, etc., visual inspection and measurement of resistance of connection lines between cells, 8 hour long charging test.

④ Inspection performed at least once every 18 months during reactor shutdown
8 hour long connection to real load to test electric power supply capacity.

⑤ Inspection performed at least once every 60 months during reactor shutdown
Discharge test.

2.1.2. Germany

 

[tsutsuji]

2.1.2. Germany [http://www.nsc.go.jp/info/20110713_dis.pdf 6/96]

As its occurrence frequency is thought to be low, SBO is not a design standard item. Also no clear regulatory requirement is specified. However, as a design requisite for electric supply systems, the safety technical regulations set by the nuclear technical commission (KTA) stipulate about the electric supply of safety systems that ① the onsite auxiliary transformer from the main generator, ② two offsite auxiliary power supplies ③ the onsite independent emergency power supply must be usable.

In German nuclear power plants, safety related systems and equipments are supplied in normal time by the onsite main generator, but in emergencies they receive power by a connection to the outside power supplies. As shown in table 2-5 [http://www.nsc.go.jp/info/20110713_dis.pdf 36/96], a power equipment concept diagram, connection is possible with at least two power systems (the main power line (380 kV) and the backup power line (110 kV)).

When power cannot be supplied by outside power sources, emergency power facility 1 is started, consisting of 4 EDGs each with 50% capacity (5 MW each), and power is supplied. In the newest plants, an emergency power facility 2, consisting of 4 EDGs (1 MW each) is added. Should a SBO happen, power is supplied by power cables laid underground around the site. Also, in a SBO, batteries have a capacity to supply power to the necessary loads for at least 2 hours.

During a loss of offsite power, the core cooling function of PWRs is maintained by securing water supply to the steam generators (SG) via the start/shutdown feed water equipment powered by the emergency power facility 1. If that equipment fails, water is fed to the GS by 4 systems of emergency feed water systems. Their electric power is supplied by the emergency power facility 1 or 2. Besides, as part of accident management, core damage is avoided by implementing primary circuit and secondary circuit feed and bleed. In BWRs too, as part of accident management, water is passively injected to the RPV from the feed water tank, and it is also possible to perform water injection, etc. from the demineralized water tank via the fire fighting pump.

2.1.3. France

In French nuclear power plants, concrete design requisites for electric power equipments, etc. depend on the fundamental safety regulations (RFS) set by the nuclear industry safety directorate (DSIN) (handling permits and licenses, it is placed below both the Trade and Industry Ministry and the Environment Ministry), and a number of guidelines sent by the Trade and Industry Minister to the French public electric utility EdF's president (mentioned below as "guidelines").

According to the survey done until now, the situation is as follows. In a July 1977 guideline, a global probabilistic safety assessment target was set for nuclear plants. It concludes that "the design of nuclear facilities must ensure that the total probability of occurrence of intolerable result does not exceed 10^-6/Reactor*Year. Also, individual events provoking intolerable results with a probability higher than 10^-7/Reactor*Year must be considered in design"; moreover, it requires that "the probability of occurrence of several events including SBO, and their results must be studied".

Later, the DSIN required from EdF to propose design changes and operational procedures to reduce the SBO risk. Also, in an October 1983 guideline, design considerations for a new 1400 MWe plant were required. In response to this, EdF created operational procedure H3 for existing plants, which includes the use of additional equipments, received the approval of the DSIN, and concerning the new 1400 MWe plant, responded in the design phase.

In 1985, the fundamental safety regulations were revised, appending the 1983 guideline and requiring SBO countermeasures in the design phase.

It must be noted that the fundamental safety regulations require power to be supplied to nuclear power plants by 4 independent systems, that is 2 power transmission systems and 2 onsite EDGs, each with 100% capacity. A 900 MW PWR is shown as example on figure 2-6 [http://www.nsc.go.jp/info/20110713_dis.pdf 37/96].

On multiple reactor sites, it is possible to connect to a neighbouring bus. Furthermore, at some plants a 100% capacity gas turbine that can be connected to the emergency bus is installed on site. Also, in a SBO, batteries have a capacity to supply the necessary loads for 4 hours, but as they can be charged by a backup steam turbine generator using the steam from the steam generators, DC power can be secured for 3 days.

Concerning the core cooling function during SBO, there is an auxiliary feed water equipment based on a turbine driven pump using the condensate tank as source. Furthermore, in order to secure the cooling function for a prolonged time, the condensate tank can be fed by gravity transfer from the demineralized water tank, or by a mobile fire fighting diesel pump, etc. With these measures, the core cooling capacity during SBO is 3 days.

2.1.4. England

 

[Astronuc]

Of course, this is well after the fact - the disaster - which could have been prevented if TEPCO (and regulators) had been proactive.

Former Tepco chief to be grilled over Fukushima disaster
http://news.yahoo.com/former-tepco-chief-grilled-over-fukushima-disaster-023043571--finance.html