Japan Earthquake: Nuclear Plants at Fukushima Daiichi

AI Thread Summary
The Fukushima Daiichi nuclear plant is facing significant challenges following the earthquake, with reports indicating that reactor pressure has reached dangerous levels, potentially 2.1 times capacity. TEPCO has lost control of pressure at a second unit, raising concerns about safety and management accountability. The reactor is currently off but continues to produce decay heat, necessitating cooling to prevent a meltdown. There are conflicting reports about an explosion, with indications that it may have originated from a buildup of hydrogen around the containment vessel. The situation remains serious, and TEPCO plans to flood the containment vessel with seawater as a cooling measure.
  • #7,801
Rive said:
'Radiation hardened cameras' (google it) are available for nuclear industry. But Westfield is right, no use for such cameras now, they have to bring the reactors in cold shutdown first, and then secure everything before visually checking the internals of the containment/RPV. Such pictures will be needed only for the decommissioning, which will not happen in the next few years.



It was on outage, so no SCRAM was needed?? :-)

You are right but I was looking for a SCRAM signal which should still have been generated and for the time the diesels tripped. Unfortunately in at least that data set the information is missing. I don't suspect a conspiracy here, They pulled this data together to meet government demands and I'm sure they didn't take their top people off there work to compile this data. The data includes photocopies of the recorder strip charts so I still may find the data I'm looking for on that site.
 
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  • #7,803
pdObq said:
On some pages it says "-99 = Missing control rod position". Don't know how to interpret that.

Go to page 4 of that file. You see the Seismic Trip and SCRAM signals at 14:46:46 to 14:46:58. At 1447 you see All CR Full In. That signal requires all rods to be fully inserted.
 
  • #7,804
A half-off sidenote: http://www.technologyreview.com/blog/arxiv/26773/

NUCENG said:
You are right but I was looking for a SCRAM signal which should still have been generated and for the time the diesels tripped.
So the SCRAM signal should be there even if the reactor is not in active state. Interesting :-) Thanks.
 
  • #7,805
A few contaminated water management updates :

Instead of trying to move all the water as originally planned, TEPCO officials have decided to move only enough water so that it does not overflow from the trench.

(...)

TEPCO officials said work to install a temporary tank for the contaminated water by mid-July is continuing.
http://www.asahi.com/english/TKY201105180147.html

jensjakob said:
Pictures from when the Tsunami hit Fukushima:
http://www.bt.dk/udland/her-rammer-tsunamien-atom-kraftvaerket

A lot of new pictures I haven't seen - shows the extent of the flooding

Thanks. Some explanations about this picture release are provided by http://www3.nhk.or.jp/daily/english/19_24.html
 
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  • #7,806
Unit #6 is leaking also:
Transferred stagnant water on the basement floor of the reactor building to
the Radioactive Waste Treatment
May 10th 11:00 ~ 12:30
May 11th 11:00 ~ 12:30
May 12th 10:30 ~ 12:30
May 13th 11:30 ~ 12:15
http://www.nisa.meti.go.jp/english/files/en20110519-1-2.pdf

Explanation #1: RPV is leaking.
Explanation #2: SFP is leaking.
Explanation #3: Waterproof systems are not working and groundwater is leaking into the reactor building.

The greatest danger lies in the explanation #3. If it's happening in the unit #6 it can also happen in the units #1 - #5. It water can come in it can also go out.

Then I also noticed:
Why are they not updating the temperature/radiation/pressure charts?

For instance, the last one working for unit #3 (temperatures) is from 16th of May:
http://www.tepco.co.jp/nu/fukushima-np/f1/images/032_1F3_05160600.pdf

These ones are not working at the current moment (17th of May and 18th of May):
http://www.tepco.co.jp/nu/fukushima-np/f1/images/032_1F3_05170600.pdf
http://www.tepco.co.jp/nu/fukushima-np/f1/images/032_1F3_05180600.pdf
 
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  • #7,807
I don't know if this has been posted already. I had been looking for the pollution maps http://www9.nhk.or.jp/kabun-blog/200/79839.html (Fukushima I Survey Maps).

This folder presently includes 10 maps dated from March 23rd to May 18th.

~kujala~ said:
Unit #6 is leaking also:

http://www.nisa.meti.go.jp/english/files/en20110519-1-2.pdf

Explanation #1: RPV is leaking.
Explanation #2: SFP is leaking.
Explanation #3: Waterproof systems are not working and groundwater is leaking into the reactor building.

The greatest danger lies in the explanation #3. If it's happening in the unit #6 it can also happen in the units #1 - #5. It water can come in it can also go out.

What about #4 : Unit 6 hit and flooded by a tsunami ?

~kujala~ said:
Then I also noticed:
Why are they not updating the temperature/radiation/pressure charts?

For instance, the last one working for unit #3 (temperatures) is from 16th of May:
http://www.tepco.co.jp/nu/fukushima-np/f1/images/032_1F3_05160600.pdf

These ones are not working at the current moment (17th of May and 18th of May):
http://www.tepco.co.jp/nu/fukushima-np/f1/images/032_1F3_05170600.pdf
http://www.tepco.co.jp/nu/fukushima-np/f1/images/032_1F3_05180600.pdf

What about http://www.tepco.co.jp/nu/fukushima-np/f1/images/11051906_temp_data_3u-j.pdf ?
 
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  • #7,808
Gary7 said:
Just regarding the USS Ronald Reagan, I looked for information regarding the ballistic radiation readings and subsequent food contamination and three-day emergency, but I could not find any. There was an early report of radioactivity in the drinking water, which was later shown to be a false positive. There is an excellent AP article that describes events on the Ronald Reagan here.

http://www.1310news.com/news/world/article/202681--uss-ronald-reagan-fought-contamination-amid-effort-to-aid-disaster-stricken-japan?ref=topic&name=index.php&title=

More details here

http://waronterrornews.typepad.com/home/2011/03/japan-uss-ronald-reagan-update.html

Furthermore, all of this transpired on the 13th of March (Sunday). If I recall correctly, the explosion at Unit #3 occurred on Monday the 14th. So the radiation that the USS Ronald Reagan encountered had to have come from Unit #1.

What transpired on the Reagan was a few hours after the explosion of #3, which happened on the morning of the 14th in Japan, which is the evening of the 13th in the United States.

If you don't believe me, find the records from UTC and we can translate. It's a fact, I listened to it, real-time. I'm not exactly sure why the hard core spin machine is moving to divert everything away from reactor #3, but whatever it is cannot be good.

The article you point out tells the story. I'm unable to now find the blogs from sailors who said the entire ship was near panic, but read between the lines in this story and you can tell:

http://www.1310news.com/news/world/article/202681--uss-ronald-reagan-fought-contamination-amid-effort-to-aid-disaster-stricken-japan?ref=topic&name=index.php&title=
 
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  • #7,809
tsutsuji said:
What about #4 : Unit 6 hit and flooded by a tsunami ?

The water levels have been rising in (5 and) 6.

The company says water levels are also rising in the Number 5 and 6 turbine buildings.

http://www3.nhk.or.jp/daily/english/21_03.html
 
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  • #7,810
Bodge said:
You read my mind.

What isotopes were in that cloud?

Additionally, where is the film footage of the minutes and hours after the explosion at three?

We have all seen the infamous video of the mushrooming debris cloud ascending to 1km+, what happened next?

There is so much data withheld that the question has to be WHY aren't many simple questions already answered?

If news is positive I'd expect it to be released.

They probably won't release the records for many years, but I to look at people's actions in these situations, which tell the story:

Here's what they did immediately following.

1. The USS Ronald Reagan diverted a major disaster recovery mission and steamed the other direction for several hours. They announced they had received a "minor exposure" to radiation, however an aircraft carrier battle group almost never diverts a mission. They scrubbed the entire ship and still some "hot spots" remained. Read the article posted above.

2. In the next two days, the United States took an unusually almost confrontational position with the government of Japan. They imposed a larger evacuation zone for US personnel, and strongly urged the Japanese government to expand theirs.

3. The US military began moving families out of Japan to Korea.

4. The USS George Washington left a port south of Tokyo while it was still under repair, and all navy and family members were issued iodine pills.
 
  • #7,811
As there is no safe level of radiation, any radioactive release is going to be dealt with seriously. Especially if you have the luxury of not being the nation affected, and therefore able to provide a duty of care to your people that goes beyond what the host nation can provide for their millions of citizens.

Nobody disputes that a large amount of radioactivity escaped the site. The question is quite how much. Given that the official version already involved levels that would cause the US military to take action, the actions of the aircraft carrier add nothing to this picture, do not provide indication that something on a much larger scale occurred, do not support your crackpot theories, and are a further waste of this thread.

I am no fan of the way the Japanese handled their evacuation stuff, and levels of contamination have clearly spread further than they wanted to admit in the early days. But this is not at all the same as covering up a radioactive release that was orders of magnitude higher than they have admitted to. The solid data collected from a variety of locations in Japan speaks for itself.
 
  • #7,812
An interview with former Fukushima plant manager:

http://spectrum.ieee.org/tech-talk/...echalert&utm_medium=email&utm_campaign=051911

Interesting as it provides some sense of what someone very familiar with the plant was thinking when they watched the disaster unfold on tv.

Not a lot of technical specifics, apart from this answer about what safety upgrades were done there in the past:

IEEE Spectrum: Were there safety upgrades while you were head of Fukushima Dai-1?
Futami: In the 1990s, countermeasures against severe accident were taken reflecting NRC and Japanese authorities’ regulations. They included the installation of recirculation pump trips (RIP) and alternate rod-injection systems (ARI) for an event known as anticipated transient without scram (ATWS), installation of automatic depressurization systems (ADS) for the reactor pressure vessels, installation of alternate water injection lines to the reactors and primary containment vessels, and installation of primary containment vessel vents.
 
  • #7,813
tsutsuji said:
What about http://www.tepco.co.jp/nu/fukushima-np/f1/images/11051906_temp_data_3u-j.pdf ?

Thanks, all temperatures now fine, that's the main thing. :smile:
I leave explanations to others.
 
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  • #7,814
I want to come back to what the state of the reactors may be and what this means for the further development of the situation.

It seems that all three RPVs are broken, probably the core melted through their steel already in the first hours after the power loss. It is possible, for me quite sure, that the hot mass dropped from the RPV into the lower structures and started burning through them. Due to the changed geometry and the heat causing steam pillows water can not cool the mass very effectively.

I was deeply impressed by the speed of a core melting through thick concrete I saw in the simulation documents posted here before. We had many hours without cooling at all and after this more than two months of questionable cooling.

It seems that the cores had the chance -- in a bad case scenario, that seems not unrealistic to me -- to escape the containment.

I read some time ago that such a core could only melt some meters into ground, but who cares, as it could never burn the concrete basement. The studies seen here prove this wrong.

Are there any simulations what happens in such a scenario?
 
  • #7,815
New images of the tsunami hitting the plant

https://www.youtube.com/watch?v=GzvTQ5CIQSE

and of workers in unit 2

https://www.youtube.com/watch?v=xzY3VsJ_eW8

I note the workers have also entered unit 3 today. I await the reading as taken and the announcement of the conditions of each core. I suspect they have been preparing for the worst news - but we shall see what's released Friday!
 
  • #7,816
SteveElbows said:
An interview with former Fukushima plant manager:

http://spectrum.ieee.org/tech-talk/...echalert&utm_medium=email&utm_campaign=051911

Interesting as it provides some sense of what someone very familiar with the plant was thinking when they watched the disaster unfold on tv.

Not a lot of technical specifics, apart from this answer about what safety upgrades were done there in the past:


WAIT!

Did you notice this sentence from the former plant manager:

TEPCO's civil engineering group estimates the maximum tsunami risk and maximum earthquake risk for each power plant site. I was informed the maximum tsunami at the Fukushima Dai-1 site might be 10 meters


As we know, the official run up assessment by Tepco (recalculated in 2010) was... O.P.+5,7m!

http://www.netimago.com/image_201642.html

Does this guy actually says that in fact Tepco internally was talking about a maximum 10m high run up possible at Daichi plant whereas their official calculation was concluding O.P. + 5,7m ?

This is an important statement!

Let's re-read this part of the interview:

1) As a former plant manager of the Tepco Daichi Plant (1997-2000), he was concerned about the loss of power that could result if the diesel generators were put out of order in case of a tsunami:

IEEE Spectrum: While you were head of Fukushima Dai-1, did you worry about a possible tsunami?
Futami: Yes, I worried about earthquakes and tsunami. When I was superintendent, I thought the worst events that could happen were a fire in a radiation control area and station black out (SBO) if there was a loss of external electricity and the diesel generators failed.

All Japanese nuclear power plants use seawater as the final heat sink to cool steam and remove residual heat, so important equipment is located on the power plant's seaside yard. I worried about the loss of that equipment following a tsunami.

2) But why was he concerned by this risk as Tepco evaluated, and re-evaluated in 2010, the maximum run-up at +5,7m, giving a confortable (in apparearance) 4,3 m safety margin as the buildings were on a platform at +10m (and +13m fr N°5 and N°6)? Why was he concerned whereas Tepco conclusions were:

"We assessed and confirmed the safety of the nuclear plants"?

3) the reason comes with the quoted sentence:

TEPCO's civil engineering group estimates the maximum tsunami risk and maximum earthquake risk for each power plant site. I was informed the maximum tsunami at the Fukushima Dai-1 site might be 10 meters.

Of course with this 10 meters possiblity know internally it seems, and the buildings at +10m (with the EDG in the basements!), we understand he could have been concerned

(even if he adds in the interview
The turbine buildings and the reactors were built 10 meters above the sea level, so it is beyond my imagination that seawater flowed into the turbine buildings of all units, and that facilities on the basement floor were flooded.
)

If this statement was repeted in front of a court in a trial, i guess Tepco would have ahard time to explain the reason of this inconsistency of numbers...

Was the study done by Tepco arranged to end up with an official safe number of +5,7m to fit the existing situation of the plant layout, but knowing that it may well be wrong and underestimated?

Is it what the former plant manager is meaning when he adds later on in the interview:

But TEPCO should have taken more serious countermeasures against tsunami.
 
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  • #7,817
pdObq said:
...
See also here, http://www.bt.cdc.gov/masscasualties/blastessentials.asp , under primary blast injuries:
Injury from over-pressurization force (blast wave) impacting the body surface: TM rupture, pulmonary damage and air embolization, hollow viscus injury.​
I am not really familiar with all that "medical slang" but that sounds a lot like "internal bleeding" would summarize it reasonably well for medical laymen like me.

Yes, hollow viscus injury essentially means internal bleeding. The other terms are other stuff.
 
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  • #7,818
SteveElbows said:
An interview with former Fukushima plant manager:

http://spectrum.ieee.org/tech-talk/...echalert&utm_medium=email&utm_campaign=051911

Interesting as it provides some sense of what someone very familiar with the plant was thinking when they watched the disaster unfold on tv.

Not a lot of technical specifics, apart from this answer about what safety upgrades were done there in the past:

Also of interest:

Futami: I did not experience serious operational problems. Instead of that, I was fighting against stress corrosion cracking of internal components in the reactor pressure vessels. Those components are highly radioactive and are inside the reactor pressure vessels. However it was necessary to work inside the reactor pressure vessels in order to replace a component called a shroud, although we used remote and automatic equipment as much as possible. I led the shroud replacement program of unit 1, 2, 3 and 5 and completed the world’s first shroud replacement in 1998.

Stress corrosion cracking is an aging problem. Some Fukushima Dai-1 reactors exceeded 30 years while I was a superintendent. I put my best effort into replace aging equipment based on preventive maintenance philosophy.

IEEE Spectrum: Can you explain what a shroud is?
Futami: The shroud is a large component inside the reactor pressure vessel. It's a very large cylindrical form made of stainless steel. In the space between the shroud and the reactor pressure vessel's outer walls, the water flows down from the top to the bottom of the reactor vessel. Then in the reactor core, which is inside the shroud, the water flows from the bottom to the top. We found many stress corrosion cracks on the shroud’s welding lines, so we decided to replace the shrouds. We had to stop the plant about a year, and it cost about 8 billion Yen. Coincidentally, at the number 4 reactor unit at Fukushima Dai-1 they were just replacing the shroud in this year’s annual inspections. That’s why all the core fuel was removed from the reactor pressure vessel, and installed in the spent fuel storage pool. That may have generated more heat than is usual at the spent fuel pools, and may have contributed to the fires that broke out around the spent fuel pool in the number 4 building

I like also this small extract, which is very illustrative of the inconscious psychology of many people working in this industry where the reality and the "ideal reality" are often mixed together (note the contradiction!)

IEEE Spectrum: Do you think the other nuclear plants in Japan are safe enough?

Futami: Yes. I am sure that Japanese nuclear power plants will become safe enough by modifications and countermeasures against tsunami based on the lessons learned on 3-11.

If they "will become", then the answer to the actual question asked is NO!

Ok, some will say... it's a translation mistake? :wink:
 
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  • #7,819
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  • #7,820
imandylite said:
I note the workers have also entered unit 3 today. I await the reading as taken and the announcement of the conditions of each core. I suspect they have been preparing for the worst news - but we shall see what's released Friday!

I am not sure that we should expect the same info to come from humans going into reactor buildings 2 & 3 as happened with reactor 1. The core news from reactor one was due to them recalibrating a water level sensor, and it has not been mentioned whether such work has been attempted at 2 & 3.

All we may get is a general description of working conditions, and radiation dose rates from a few different areas of the buildings.

For example here is the latest reactor 3 news I saw:

http://www3.nhk.or.jp/daily/english/19_23.html

Workers have entered the Number 3 reactor building at the Fukushima Daiichi nuclear plant for the first time since a hydrogen explosion 3 days after the March 11th quake and tsunami.

Tokyo Electric Power Company says 2 workers in protective suits and carrying air tanks went inside for about 10 minutes from 4:30 PM Wednesday to check radiation levels.

TEPCO says the workers measured radiation of 160 to 170 millisieverts per hour around the door of the containment vessel.

The utility says it would be difficult to start work on injecting nitrogen gas needed to prevent a hydrogen blast into the containment vessel under such high radiation levels.
 
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  • #7,821
And here is the news from the reactor 2 walkabout:

http://www3.nhk.or.jp/daily/english/19_40.html

The utility says the workers measured levels of radiation in the air as they walked around the containment vessel, and came up with readings ranging from 50 millisieverts per hour to less than 10.
The workers found three pools of water on the floor, and saw water dropping down from above in some places.
 
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  • #7,822
mikefj40 said:
Just picked this up on the Twitter... Purportedly new images of tsunami flooding from TEPCO http://www.tepco.co.jp/tepconews/pressroom/110311/index-j.html

TEPCO slideshow: http://cid-0b14c7ab35e39ebd.photos.live.com/play.aspx/%5ENFNPP1%20Tsunami%20Flooding

Forgive me if these have already been posted. They're new to me.

Thank you, the long discussed scaffold, aka "the green box", can be seen from this angle:

v3ep8y.jpg


And some black smoke somewhere near the turbine buildings on the last pic.
 
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  • #7,823
ihatelies said:
...they are designed to complete their mission under the harshest conditions.
Nope. They were designed to fight and win wars. They are out there for only one reason: by capable of releasing complete mayhem they are meant to prevent any stupid military action by anybody else.

Any other mission is possible/acceptable only if their primary reason for existence is not in risk.

Just the risk of contamination is more than enough to send them to safe waters. The battlegroup must be kept ready for action. It's military, man! Not some red cross charity ship.

ihatelies said:
However at the time, Fukushima needed electricity, manpower, nuclear expertise, and possibly diesel fuel.
A carrier battlegroup can supply only a limited amount of food, fuel and carrying capacity - nothing what cannot be supplied by ground based forces. They had no real use there.

Ps.: ooops, Am I right that the original post is gone? Then feel free to remove this one too. Thanks/sorry :-)
 
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  • #7,824
Rive said:
Nope. They were designed to fight and win wars. They are out there for only one reason: by capable of releasing complete mayhem they are meant to prevent any stupid military action by anybody else.

Any other mission is possible/acceptable only if their primary reason for existence is not in risk.

Just the risk of contamination is more than enough to send them to safe waters. The battlegroup must be kept ready for action. It's military, man! Not some red cross charity ship.


A carrier battlegroup can supply only a limited amount of food, fuel and carrying capacity - nothing what cannot be supplied by ground based forces. They had no real use there.
-+

Since my message has been removed, I guess the mods didn't think this discussion to be in line with the intent of whoever sponsors this forum

However I will correct you. I've been on aircraft carriers, in fact I've been on the Reagan. Yes they are the most formidable fighting machines man has created, but they rarely do that. Most of the time they practice, and occasionally they are used for other missions.

That carrier was headed there because it had exactly what they needed at Fukushima - in the quantities needed.

You guys want to divert the conversation away from the facts fine.
 
  • #7,825
ihatelies said:
They probably won't release the records for many years, but I to look at people's actions in these situations, which tell the story:

Here's what they did immediately following.

1. The USS Ronald Reagan diverted a major disaster recovery mission and steamed the other direction for several hours. They announced they had received a "minor exposure" to radiation, however an aircraft carrier battle group almost never diverts a mission. They scrubbed the entire ship and still some "hot spots" remained. Read the article posted above.

2. In the next two days, the United States took an unusually almost confrontational position with the government of Japan. They imposed a larger evacuation zone for US personnel, and strongly urged the Japanese government to expand theirs.

3. The US military began moving families out of Japan to Korea.

4. The USS George Washington left a port south of Tokyo while it was still under repair, and all navy and family members were issued iodine pills.

I think that's a pretty skewed and deceptive narrative. The reality -- as closely followed by those of us who live here and are involved to various degrees with the US base at Yokosuka-- was much more nuanced. I apologize for not having all the supporting evidence at hand right now however. Midnight here in Yokohama...

1. The Reagan got some radiation, but not to a degree worrisome to health. But it was enough to posssibly skew readings on sensitive equipment for detecting nuclear activity in the region, specifically North Korea. So they got outta there. Of course I'm not surprised that crew members said they'd never experienced real radiation before. Most of them weren't born when Chernobyl blew, much less TMI. One important point is that the "Nukes" at Yokosuka -- the nuclear service guys -- never broke a sweat during the whole ordeal. They were not worried about health issues. Equipment calibration, yes.

2.Yes, the US implemented a wider recommendation zone. At the time they made it clear that this was through "an abundance of caution." All sorts of people, from US journalists to NGO's to people driving trucks full of food and clothing, remained active within the 50 mile zone and closer, and we have yet to hear of suspected health threats incurred by them. US military and DOE readings showed that increased radiation levels extended to the NW beyond the Japanese evacuation zone, and that seems to be the reason for the call, and high radiation readings in several villages outside the Japanese 30k perimenter subsequently vindicated the caution but still have not demonstrated threats to health (exceeded warning levels, yes, but that's not the same as threat to health). Keep in mind that other governments -- German, French -- were advising their nationals to evacuate Tokyo and leave the country if possible. The US and UK responses were much more measured and ultimately have proven more sound in my opinion. (just my opinion, OK?)

3. The movement of US dependent families was a VOLUNTARY EVACUTION! The US Govt didn't move anyone who didn't ask to be moved. The brass seem to have regretted issuing the order immediately. There was never any radiation at US bases that appoached the level of threat to health. There were tons of rumors however. Good article from Stars and Stripes from April 2:

http://www.stripes.com/news/rumors-fueled-fear-for-days-after-earthquake-in-japan-1.139835

Basically, voluntary evacuation was approved because family members were demanding it. People were deluged with emails and phone calls from people back home who were watching the most preposterously alarmist stateside news about the disaster and insisting they evacuate. So the military agreed to let them go, gave everyone who wanted it a round trip ticket and a per diem, and allowed them to come back in mid April, a month ago. With that deal I would have gone to visit relatives myself.:

http://www.stripes.com/news/dod-lif...ut-some-plans-for-families-to-return-1.141240

4. As for KI pills, again it was for people who wanted it. There was never a recommendation that people take it. Distribution stopped in mid April :

http://www.stripes.com/news/pacific...ng-iodide-pills-to-citizens-in-japan-1.141349

To summarize, I think the US military and US Embassy actions reflected a fine balance between actual threat to health and operational efficiency (never very high beyond the immediate vicinity of the reactors) and perceived danger on the part of US nationals (many people freaking), especially in light of much greater freakouts on the part of other governments. And FWIW, while many Embassies --again Germany stands out -- issued mandatory evacuation orders for dependents and inessential staff, many of them moving the embassies themselves to Nagoya or Osaka, with the corollary effect of many German (and Dutch, and Belgian, and French) companies imposing evacuation orders on their employees and families as well, the US embassy actually increased its staff in Tokyo during the crisis period. We longtimers told each other that when the US bases themselves and the US embassy evacuated, and the NIKKEI stock exchange in Tokyo was closed, then we should worry.

Yes, we all watched as sailors had their leaves canceled and streamed back to the George Washington. But like so many things during this crisis, even though things were never very dangerous beyond the immediate vicinity of the reactors, we were all extrapolating the possible vectors the disaster might take, and anticipating various worse situations that might develop, even if unlikely. When we evaluate the actions of the US military, we should probably interpret them as the brass anticipating unlkely but potentially disturbing scenarios, and trying to stay ahead of them.
 
  • #7,826
jlduh said:
Does this guy actually says that in fact Tepco internally was talking about a maximum 10m high run up possible at Daichi plant whereas their official calculation was concluding O.P. + 5,7m ?

If the interview was conducted in Japanese, we'd need to see the original Japanese text of the interview.

I am not sure if he meant much more than being happy with the O.P. + 10 m ground floors at units 1 to 4.

The general tone of that interview is "Tepco did everything fine in the past and will go on doing everything fine in the future". The only part that sounds to my ears a little bit bold or original is the part about the contaminated water discharge into the sea https://www.physicsforums.com/showthread.php?p=3310797#post3310797 and the quote I made yesterday about spent fuel pools : https://www.physicsforums.com/showthread.php?p=3307151#post3307151.

Astronuc said:
Picture are release

http://www.tepco.co.jp/en/news/110311/ Two sets of images. 2011.5.19
tsunami hit the shore 03:42 pm and was moving back out 03:44 - only two minutes!

Also for perspective
http://www.world-nuclear-news.org/RS_Images_show_tsunami_inpact_1905111.html

Some explanations about these pictures are also provided in the NHK link I mentioned at https://www.physicsforums.com/showthread.php?p=3310792#post3310792
 
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  • #7,827
Uagrepus said:
...And some black smoke somewhere near the turbine buildings on the last pic.
That looks like some debris in the air, out of focus, close to the lens rather than smoke in the distance. It's completely gone in the next image (both images at 3:44pm):
http://www.tepco.co.jp/en/news/110311/images/110519_1_7.jpg
 
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  • #7,828
tsutsuji said:
If the interview was conducted in Japanese, we'd need to see the original Japanese text of the interview.

I am not sure if he meant much more than being happy with the O.P. + 10 m ground floors at units 1 to 4.

The general tone of that interview is "Tepco did everything fine in the past and will go on doing everything fine in the future". The only part that sounds to my ears a little bit bold or original is the part about the contaminated water discharge into the sea https://www.physicsforums.com/showthread.php?p=3310797#post3310797 and the quote I made yesterday about spent fuel pools : https://www.physicsforums.com/showthread.php?p=3307151#post3307151.
Some explanations about these pictures are also provided in the NHK link I mentioned at https://www.physicsforums.com/showthread.php?p=3310792#post3310792

Just for your information, and as i found this point very important, i just sent a mail to the author of this interview to try to clarify this sentence:

"TEPCO's civil engineering group estimates the maximum tsunami risk and maximum earthquake risk for each power plant site. I was informed the maximum tsunami at the Fukushima Dai-1 site might be 10 meters".

as it was declared in this interview.

By the way, what he is saying in this interview is somewhat different than what he declared a few weeks ago here, saying: "When I was in charge, the thought of a
tsunami never crossed my mind."

http://thescotsman.scotsman.com/world/39The-thought-of-a-tsunami.6741474.jp

Of interest in this second article, this extract with obviously one mistake:

After an advisory group issued non-binding recommendations in 2002, Tokyo Electric Power Company (Tepco), the plant owner and Japan's biggest utility, raised its maximum projected tsunami at Fukushima Dai-ichi to 18.7ft - considerably higher than the 13ft-high land on which it stands. Yet the company appeared to respond only by raising the level of an electric pump near the coast by 8in.

18.7 ft is 5.7m for the max projected tsunami so it's consistent with Tepco study.

But "13 ft high land on which it stands" is non sense as the platform is 10m high...
 
  • #7,829
StrangeBeauty said:
That looks like some debris in the air, out of focus, close to the lens rather than smoke in the distance. It's completely gone in the next image (both images at 3:44pm):
http://www.tepco.co.jp/en/news/110311/images/110519_1_7.jpg

To me, this is dirt on the lens, not smoke.
 
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  • #7,830
English diagram of what they found in reactor 2 building, including location of water puddles and matching of photos to location:

http://www.tepco.co.jp/en/nu/fukushima-np/images/handouts_110519_01-e.pdf

This comes from what I believe to be new section of TEPCO website as they continue to improve the way they are releasing information. There is nothing else noteworthy in this section yet:

http://www.tepco.co.jp/en/nu/fukushima-np/handouts/index-e.html

Can I also take this opportunity to thanks NUCENG for the detailed thoughts on all the 11th march reactor data.
 
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  • #7,831
StrangeBeauty said:
That looks like some debris in the air, out of focus, close to the lens rather than smoke in the distance. It's completely gone in the next image (both images at 3:44pm):
http://www.tepco.co.jp/en/news/110311/images/110519_1_7.jpg

Yes, the foto seems to be from behind a window (see the grid?), so an insect on it is possible also between 6 of 17 at 15h44 (1) and 7 of 17 at 15h44 (2). I agree, no smoke on the water ...
 
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  • #7,832
http://www.asahi.com/national/update/0518/TKY201105180230.html provides a diagram with a scenario for unit 1's hydrogen explosion. Hydrogen runs through a damaged part of the RPV into the containment vessel, then through a crack in the containment vessel.

On March 11th, 9:51 PM workers were forbidden to enter the reactor building because of the 290 mSv/h radiation there.

jlduh said:
But "13 ft high land on which it stands" is non sense as the platform is 10m high...

13 rhymes with the O.P. +13 m ground floor height at units 5 & 6.
 
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  • #7,833
tsutsuji said:
http://www.asahi.com/national/update/0518/TKY201105180230.html provides a diagram with a scenario for unit 1's hydrogen explosion. Hydrogen runs through a damaged part of the RPV into the containment vessel, then through a crack in the containment vessel.

On March 11th, 9:51 PM workers were forbidden to enter the reactor building because of the 290 mSv/h radiation there.



13 rhymes with the O.P. +13 m ground floor height at units 5 & 6.

Yes, except it's foots and not meters...
 
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  • #7,834
The latest map of radiation detected on site is out. How interesting it is probably depends on when you last looked at it, I was slightly out of date as the last time I looked this map was getting too busy, its a fair bit cleaner again now.

http://www.tepco.co.jp/en/nu/fukushima-np/f1/images/f1-sv-20110519-e.pdf

Latest additions are from area near reactor 1, various points along the waste water transfer pipes, and areas near the sea.
 
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  • #7,835
Does anyone have any thoughts and/or data that might provide insights re: the possible state(s) of the fuel?

I have heard there is a possibility that when the zircaloy cladding burned, the fuel pellets may have dropped to the floor of the RPV, but are more likely to be spread out, rather than in a molten lump.

Any informed thoughts on this? Thanks.
 
  • #7,836
SteveElbows said:
An interview with former Fukushima plant manager:

http://spectrum.ieee.org/tech-talk/...echalert&utm_medium=email&utm_campaign=051911

Interesting as it provides some sense of what someone very familiar with the plant was thinking when they watched the disaster unfold on tv.

Not a lot of technical specifics, apart from this answer about what safety upgrades were done there in the past:

In this interview Tsuneo Futami does little more than parrot the official TEPCO company line. He says he oversaw core shroud replacement
Tsuneo Futami said:
However it was necessary to work inside the reactor pressure vessels in order to replace a component called a shroud, although we used remote and automatic equipment as much as possible. I led the shroud replacement program of unit 1, 2, 3 and 5 and completed the world’s first shroud replacement in 1998.

Stress corrosion cracking is an aging problem. Some Fukushima Dai-1 reactors exceeded 30 years while I was a superintendent. I put my best effort into replace aging equipment based on preventive maintenance philosophy.

Perhaps he did put his best effort into the replacement projects once they were underway, but saying the replacements were "based on a preventive maintenance philosphy" is not truthful.

Standard TEPCO public relations policy calls for them to claim they undertook core shroud replacement programs as a matter of "preventive maintenance". Yet, the big scandal in 2002 went directly to TEPCO covering up information that the core shrouds in several of their reactors were cracked. They knew about it for years and told no one. After a whistleblower complained to METI, they embarked upon an investigation (in conjunction with TEPCO and after TEPCO fired the whistleblower) that showed several core shrouds were, indeed, cracked. In the end, even that report downplayed the severity of the cracks in the Fukuchima Dai-ichi Unit 2 reactor.

http://cnic.jp/english/newsletter/nit92/nit92articles/nit92coverup.html

It has been confirmed that there are 29 cases of falsification, which were related to damage in many parts of the reactor pressure vessel such as core shroud, jet pump, access hole cover, feed water spurger, on-core monitor housing and others. The NISA and the TEPCO published interim reports on September 13 and 17 respectively, which addressed the 29 suspected cases in more detail. Regarding the cracks detected in the core shroud, according to the report, they had been already found at Fukushima I Unit-1 and Unit-4 in 1993, where the cracks in the middle part of the shroud at Fukushima I Unit-2 in 1994 were reported officially as the first case. The magnitude of the cracks in Fukushima I Unit-2 turned out to be far greater and more serious than the ones announced by the official report. It has also become clear that reactors in Fukushima I Unit 1, 3, and 5 have cracks in each shroud, so the claim that no cracks were found in the core shrouds and that they were replaced as a “preventive measure” is completely false.

(Bolded emphasis mine.)

That is just one website where details of the safety report falsification scandal can be found. There are many others that corroborate essentially the same story.

Whenever I see reference to TEPCO's "preventive measures" claiming some sort of credit or praise for the company in their quest for safety that involves their core shroud replacement program, I have to laugh and dismiss the source. In light of this I heavily discount anything Tsuneo Futami has to say. He is, IMO, a TEPCO stooge.
 
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  • #7,837
Uagrepus said:
Thank you, the long discussed scaffold, aka "the green box", can be seen from this angle:

v3ep8y.jpg


And some black smoke somewhere near the turbine buildings on the last pic.

diesel exhaust?
 
  • #7,838
NUCENG said:
diesel exhaust?

Some debris or dirt on the lens. I'm a photographer and am used to seeing this.
 
  • #7,839
ihatelies said:
What transpired on the Reagan was a few hours after the explosion of #3.

The article you point out tells the story. I'm unable to now find the blogs from sailors who said the entire ship was near panic, but read between the lines in this story and you can tell:

http://www.1310news.com/news/world/article/202681--uss-ronald-reagan-fought-contamination-amid-effort-to-aid-disaster-stricken-japan?ref=topic&name=index.php&title=
It would be interesting to know what nuclides were detected by the radiation people on the Reagan. A US citizen might try to obtain the data by a Freedom of Information request.
 
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  • #7,840
I am many pages behind in reading, but I am wondering whether I am correct that there has been only one publicized reading of radioactive materials in the Great Turbine Lakes in late March. The (corrected) numbers from #1 (low), #2 (very high, near 30 Sv/hr), and #3 (high, 750 mSv/hr) were reported by NISA. It seems to me that these are important numbers to monitor over time (except for the lethal doses of radiation received by the monitors) to determine whether more radioactive material is leaking from the reactors and where it's going. TEPCO might want to have these numbers to understand the scale of the problem.
 
  • #7,841
For those with some Japanese, I highly recommend this NHK documentary which screened this week "ネットワ―クで作る放射能汚染地図" - Network Mapping Radiation Contamination".

Part 1 http://www.youtube.com/watch?v=BUltgqsTTGg&feature=related
Part 2 http://www.youtube.com/watch?v=J7dfoqCj5BA&feature=related
Part 3 http://www.youtube.com/watch?v=6H30i_jI_Ys&feature=related
Part 4 http://www.youtube.com/watch?v=bUA6BueVBR8&feature=related
Part 5 http://www.youtube.com/watch?v=lX-in2-KisA&feature=related
Part 6 http://www.youtube.com/watch?v=XPXprWgh5Wk&feature=related
Part 7 http://www.youtube.com/watch?v=stDYKdPUqtY&feature=related

It has some very interesting footage taken, riding along with Environmental Radiation academics who swing into action after the Fukushima accident to take samples and start mapping fallout ahead of official government efforts and before the 20km closure.

Some interesting explanations about the interaction of local geography and weather conditions which shaped the contamination area, including some narrow valleys to the north-west which collected contaminated snow creating some very hot spots.

Part 4 from 5.30 on:

142h8jt.jpg


There is some interesting equipment used, including a portable computer unit which overlays a live digital video camera feed with live gamma radiation spectra. Used from a moving car, the unit is used to get some detailed data on the spread of different contaminants.

Part 4 @ 2.30 minutes:

2iut1lx.jpg


The one thing I noticed overall - while there are many scenes of detailed spectrographic analysis being performed, the only isotopes mentioned are those of iodine and cesium. Even the NHK graphics suggest information on 9 isotopes are being collected at each point via soil analysis, however the other 6 are never named. Anyone able to fill in the gaps?

Part 1 @ 9 minutes:

2qav9zn.jpg


dyk9wp.jpg
 
  • #7,842
ihatelies said:
What transpired on the Reagan was a few hours after the explosion of #3, which happened on the morning of the 14th in Japan, which is the evening of the 13th in the United States.

If you don't believe me, find the records from UTC and we can translate.
The article I linked to earlier clearly states the decontamination occurred on Sunday, two days after the earthquake. Also, the New York Times reported on Sunday March 13th that USS Ronald Reagan encountered radiation. If the events on the USS Ronald Reagan transpired a few hours after the explosion of #3, the New York Times could not have reported on this on the 13th.

http://www.nytimes.com/2011/03/14/world/asia/14plume.html?_r=1

To put this in even finer detail: The explosion at #3 occurred at about 11:01 am on Monday the 14th (Japan time). This would be 9:00pm on the night of the 13th, EST. Given the time it takes for the helicopter to travel to the aircraft carrier, get decontaminated, and then for the aircraft carrier to reposition itself, and then for that information to get to the reporter, and to have him write the copy and send it to the editors for publishing, it would seem that the only way the New York Times could have reported on this on the 13th would be if they were in possession of a time machine.

Since I think this is of some relevance to the explosion at #3, I have invested a bit of time in the details. However, since it has very little value in helping understand the physics of the event, I will be more than happy if the moderators see fit to delete any and all discussion of the so-called "ballistic radiation levels" and "contaminated food and water" of the USS Ronald Reagan.
 
  • #7,843
NUCENG said:
Very important: If level 0-reference is Top of Active Fuel Unit 3 core uncovery began at about 1600 on 3/11. Because multiple SRVs were cycling and HPCI apparently did not start, the coolant discharged through SRVs was more than RCIC could make up so level continued to drop after RCIC started. It would be assumed they were able to recover level after the time of these graphs or it would have been unit 3 needing to be vented first.

I think you are referring to page 1 of this:

https://www.physicsforums.com/newreply.php?do=newreply&p=3310549

That caught my eye at first too, but then I looked at the following:

http://www.tepco.co.jp/nu/fukushima-np/plant-data/f1_2_Chart3.pdf

If you look at pages 3 and 4, you can see what looks like the same
behavior being recorded by a different sensor (?) on a paper strip
chart that has been scanned in. There are two scales at the bottom,
which differ in both offset and scale factor:

原子炉水位 (広帯域) [mm] = Reactor water level (wideband) [mm]
and
原子炉水位 (燃料域) [mm] = Reactor water level (fuel region) [mm]

The zero offsets are different, and I am guessing that the second one
is the one with zero referenced to the tops of the fuel rods. (That
would match TEPCO's labels elsewhere where they report that.)
I think what was shown in the first link above is the "wideband"
(wide area?) scale, whatever that is.

If this is correct, then the Unit 3 fuel rods did not get exposed
on the 11th, at least as far as these charts show.

What do you think?
 
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  • #7,844
rowmag said:
The zero offsets are different, and I am guessing that the second one is the one with zero referenced to the tops of the fuel rods. (That would match TEPCO's labels elsewhere where they report that.) I think what was shown in the first link above is the "wideband" (wide area?) scale, whatever that is.

If this is correct, then the Unit 3 fuel rods did not get exposed on the 11th, at least as far as these charts show.

What do you think?

This may or may not be relevant, but the attached diagram shows typical GE BWR instrumentation levels. Notice there is a level called "Instrument 0" and all other measurements are relative to that reference level. In this particular diagram "Instrument 0" is not the same as the top-of-fuel level.

The full-size diagram is found on page 117 of this GE BWR Tech Manual:
http://atominfo.ru/files/fukus/023020088.pdf

instr_levels.png


The right side shows a "narrow range" gauge and a "wide range" gauge. Maybe a similar measurement arrangement is used by TEPCO.
 
  • #7,845
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  • #7,846
SteveElbows said:
The latest map of radiation detected on site is out. How interesting it is probably depends on when you last looked at it, I was slightly out of date as the last time I looked this map was getting too busy, its a fair bit cleaner again now.

http://www.tepco.co.jp/en/nu/fukushima-np/f1/images/f1-sv-20110519-e.pdf

Latest additions are from area near reactor 1, various points along the waste water transfer pipes, and areas near the sea.

This map shows that some concrete was measured max 400 mSv/h, and some iron pipes 100 to 230 mSv/h. In a former post (last one I could find was from Astronuc) it was explained that maybe rebars (or whatever) could "catch" I and Cs.

Is it plausible that some material (like concrete and iron) get some I and Cs "on" it, being exposed to radioactive steam before explosions? Why in this case don't we read much more rubbles with these levels of radiation around reactor #3 or 1? If not, where these parts could come from?
 
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  • #7,847
rowmag said:
I think you are referring to page 1 of this:

https://www.physicsforums.com/newreply.php?do=newreply&p=3310549

That caught my eye at first too, but then I looked at the following:

http://www.tepco.co.jp/nu/fukushima-np/plant-data/f1_2_Chart3.pdf

If you look at pages 3 and 4, you can see what looks like the same
behavior being recorded by a different sensor (?) on a paper strip
chart that has been scanned in. There are two scales at the bottom,
which differ in both offset and scale factor:

原子炉水位 (広帯域) [mm] = Reactor water level (wideband) [mm]
and
原子炉水位 (燃料域) [mm] = Reactor water level (fuel region) [mm]

The zero offsets are different, and I am guessing that the second one
is the one with zero referenced to the tops of the fuel rods. (That
would match TEPCO's labels elsewhere where they report that.)
I think what was shown in the first link above is the "wideband"
(wide area?) scale, whatever that is.

If this is correct, then the Unit 3 fuel rods did not get exposed
on the 11th, at least as far as these charts show.

What do you think?


My comment was based on the first page of:
http://www.tepco.co.jp/nu/fukushima-np/plant-data/f1_6_Katogensho3.pdf

On that chart there is no mistaking the scale.

In plants I have worked at there may be as many as four different zero references.

The first is the elevation (above sea level).
The second is AVZ (Above vessel zero) which measures from the bottom inside of the RPV
The third is TAF which sets 0 at the Top of Actve Fuel.
The fourth is AIZ (Abave Instrumrnt Zero) which basically references level (positive and negative) from the midpoint between the top 2 instrument taps.

The human factors lessoned learned after TMI2i ncluded control room modifications to use one reference. However some plants picked a different one.

So I looked for clues for which one this is. In a typical US plant the top two instrumment taps are around 10 feet apart or about 3000 mm. , that would measure levels between +1500 mm and -1500 mm. F1-3 is slightly bigger so +1800 mm to -1800 mm makes sense. Narrow Range in the graphs then is being based on only the positive half above instrument zero. and they weren't close to core uncovery.

Physically, TAF would typically be around 10 feet or more below this instrument zero reference. Again, -4000 mm on the Wide Range Instrument makes sense for a bigger plant.

I think you are right that they weren't close to TAF yet.

I am still stuck with why F1-3 had so much SRV activity compared to F1-2. It has to be the delay in getting RCIC started. I need to go back and read some of the early press releases. I now remember reading that F1-3 had HPCI running and later tried to switch to RCIC but were unsuccessful.

That too makes more sense now. SRVs were taking more coolant out than RCIC could make up, so they would have switched to the bigger HPCI pump to recover level. HPCI is usually 4-5 times higher capacity. But HPCI uses more steam. As pressure dropped they would want to use the smaller pump to prolong makeup flow.

Anyway, thanks for the catch.
 
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  • #7,848
MiceAndMen said:
This may or may not be relevant, but the attached diagram shows typical GE BWR instrumentation levels. Notice there is a level called "Instrument 0" and all other measurements are relative to that reference level. In this particular diagram "Instrument 0" is not the same as the top-of-fuel level.

The full-size diagram is found on page 117 of this GE BWR Tech Manual:
http://atominfo.ru/files/fukus/023020088.pdf

View attachment 35729

The right side shows a "narrow range" gauge and a "wide range" gauge. Maybe a similar measurement arrangement is used by TEPCO.

Nice find. You got it!
 
  • #7,849
MiceAndMen said:
This may or may not be relevant, but the attached diagram shows typical GE BWR instrumentation levels. Notice there is a level called "Instrument 0" and all other measurements are relative to that reference level. In this particular diagram "Instrument 0" is not the same as the top-of-fuel level.

The full-size diagram is found on page 117 of this GE BWR Tech Manual:
http://atominfo.ru/files/fukus/023020088.pdf

View attachment 35729

The right side shows a "narrow range" gauge and a "wide range" gauge. Maybe a similar measurement arrangement is used by TEPCO.

WATER LEVELS:

Something is unclear (at least comparing it to data from Daichi) in this manual for reactor water levels I think as they say that for reactors other than BWR/4 model, the "fuel zone range" for reactor water level uses Top OF Fuel (TAF) point as instrument zero (which is what we see in the measurements: 0 is TAF and - is below top of fuel), instead of the "instrument 0" that your refer. This is explained page 112 of the above manual.

In other words:

for BWR/4 ->> Instrument 0 is defined as 516 3/4 inches (13,12m) "above vessel zero" (AVZ) which measures from the bottom inside of the RPV. This "Intrument 0" is then located in an area close to steam dryer at the very top of the vessel (see page 107)

for other models: -->> instrument 0 = Top of Fuel (TAF) FOR READINGS IN THE "FUEL RANGE" (only)

Unit 1 is BWR/3 , Units 2,3,4,5 are BWR/4 and Unit 6 is BWR/5 (with Mark II containment).

But it seems that all the readings we have for all reactors (including BWR/4) use TAF as zero? Which is not consistent with the manual you listed i think?

But maybe they just changed this since the manual was written to have some uniformity between the reactors (that would be a good idea for the operators!).

So be careful, there are maybe other differences between the manual and what is implemented at Daichi?

DETECTION OF HEAD FLANGE LEAK: It seems there is a system to detect the presence of water i between the two O'rings that seals the flange (RPV head/ RPV). There should be an alarm when detected or even a measurement of the leakage (which is collected to a drain). See page 122 of the pdf. But it is indicated page 106 that using this procedure to read the leak rate steam cuts further the inner seal making the leak even worse! Great system...

I don't know but maybe you will see some parameter somewhere in the buch of data showing this information, indicating some possible leakage at the flange...

Do you think there could be a "kind of similar" detection of leakage of steam+H2 from the top cover of the containment vessel?
 
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  • #7,850
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