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zapperzero said: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 said: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.
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.And at least for me, this is the same.
It will also have international consequences I think - China has been making noises about Cesium ending up in "their" water already.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!
Caniche said:Silly sausage, nothing is set in stone. You might wish to reconsider that strange response ;all you were given was historical fact.
Caniche said:Cheers for the colourful bit ,which fact do you refute? Espionage;forced labour or slavery?
dontdomaths said:...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).
tsutsuji said: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.
zapperzero said:Way to dig one's own grave, there.
tsutsuji said: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.
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.
zapperzero said: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?
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.zapperzero said: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"?
tsutsuji said: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 ]
NUCENG said:1. Is the working group report available?
NUCENG said:Were the arguments included by the power companies based solely on cost or did they actually address the technical risk of extended SBO.
MadderDoc said: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.
zapperzero said: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 said: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.
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.
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 said:<..>
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.
zapperzero said: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?
tsutsuji said: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.