Japan Earthquake: Nuclear Plants at Fukushima Daiichi

In summary: RCIC consists of a series of pumps, valves, and manifolds that allow coolant to be circulated around the reactor pressure vessel in the event of a loss of the main feedwater supply.In summary, the earthquake and tsunami may have caused a loss of coolant at the Fukushima Daiichi NPP, which could lead to a meltdown. The system for cooling the reactor core is designed to kick in in the event of a loss of feedwater, and fortunately this appears not to have happened yet.
  • #10,466
Atomfritz said:
Do they really expect a makeshift cooling bypass made of plastic tubes for the broken intake pump to last that long?

Perhaps their attention focused so much on Fukushima 1, units 1-4 that unit 5 and 6 (and perhaps Fukushima 2) don't get as much attention as they still deserve. "Cold shutdown" is not a state that you once achieve but that has to be actively maintained.

Units 5 and 6 survived because one of the diesels at unit 6 was air cooled, so losing the sea water pumps didn't kill it. Other than that single diesel, units 5 and 6 still depend on either the grid or truck-mounted generators. I have not heard anything about moves to replace the dead diesels.

The plastic pipe incident shows that the sea water pumps still haven't been restored. The whole "cold shutdown" setup for units 5 and 6 seems very temporary still.
Atomfritz said:
And this pic was taken long time after explosions. That time the explosion site already looked quite "clean" compared to earlier, less detailed images/videos.
And indeed, not only small debris seems to have been wiped off, larger pieces also. Sometimes I had the feeling that they also may have used the Putzmeister guns for "cleaning" the remains of the roof/top floor.
Maybe this even would make sense, as this would prevent dry dusty debris being eroded and taken away by wind?

I doubt they would want to wash contaminated dust onto the surrounding of the reactor building. Unit 3 was the most serious source of scattered highly active debris, because of its unique combination of a large explosion and large amount of radioactivity leaked. Unit 1 had a milder explosion and a lot less radioactivity. Unit 2 had somewhat more radioactive release but a largely intact building. Unit 4 had a smaller explosion and the least amount of radioactive contamination. Removing hotspots of several hundreds of mSv/h was very important for being able to get any work done near unit 3.

Atomfritz said:
And, they seem to be more eager to vacuum the lower floors than to find out what is going on the floors above.

That's because they don't have to go upstairs right now to get the nitrogen injection going, which is their first priority. The heat exchanger for the unit 3 SFP is already hooked up working, which was the primary reason to go upstairs in unit 4.

Atomfritz said:
Maybe the accident site would already have been cleaned up if the s**t had happened in the Soviet Union where people are not so panicky about radiation?

Maybe it would, if you had volunteered ;-)
 
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  • #10,467
nikkkom said:
What exactly can you possibly want to achieve by cleaning up the site to "green grass" state?

Even after thermal output will fall to levels which can be dealt with air cooling, central parts of these ruins will contain HIGHLY radioactive corium and residue from evaporated highly radioactive water.

This stuff, even if removed, needs to be stored somewhere; and after it is removed, steel and concrete of reactor pit will be radioactive anyway. If you'd want to dismantle the site, you'd need to remove and store them too, as medium-level waste, for many decades.

IOW: dismantling F1 ruins will definitely have astronomical cost, will possibly require some people to absorb a few more rems, and will still require storage for the radwaste.

The better idea, then, is to threat F1 as *the* storage for its radwaste. Total dismantling is not necessary. After 6-12 more months, remove top part of the buildings. Install heap pipes and radiators for heat conduction from ruined reactor cores and their passive air cooling. Fill reactor pit and torus with concrete. Remove fuel from SFPs. Possibly use Fukushima-1 in the future as the dry cask storage site - it will be slightly radioactive anyway for the next 100+ years, people won't live closer than about 5 km to it.

I don't disagree with your suggestion of using F1 as a dry cask storage site, provided tsunami defenses are beefed up sufficiently first. However, I disagree with leaving the corium in there for longer than a number of decades. This kind of waste needs to be stored for millennia in geologically stable formations, not in a building on a tsunami-swept sea shore never intended to be used for more than 40 years that has already suffered a major accident.

I am not a geologist, but in my opinion the safest storage site for Japanese nuclear waste may not even be found in Japan, which gets 20% of the world's earthquakes (and for that reason alone probably should never have built nuclear power stations in first place). The final storage problem would be solved better through international cooperation. Some countries have more suitable formations than others and if something goes wrong, the radioactive plume will does not stop at national borders and 12 nautical mile zones, as we have found out with Chernobyl and the Fukushima disaster.
 
  • #10,468
http://www.asahi.com/national/jiji/JJT201107040042.html At 9 PM on 3 July, The flow of water injected into unit 1 began to slowly decrease from the 3.5 ton/hour flow, although the pump was running normally. At 8:13 AM on 4 July, the flow reached 3 ton/hour, causing an alarm to ring.

Viewing that the cause of the problem might be the presence of a foreign body blocking the water, Tepco temporarily pushed the flow of water to 7.5 ton/hour and this action was successful in achieving the restoration of a 3.8 ton/hour flow at 8:50 AM.

The foreign body is believed to have come from the filtrate water from the dam.

http://www.nikkei.com/news/headline...19490E2E6E2E2E18DE2E6E2E5E0E2E3E39F9FE2E2E2E2 As a consequence of the sea water PVC hose failure yesterday, Tepco plans to change every PVC hose by something stronger. Tepco has yet to check all the locations where these hoses are used, but this concerns mostly the piping between the water treatment facility and the reactors.

In order to prevent the megafloat from pitching, the water must be injected into different chambers to ensure some balance. For that reason, injection was stopped on 3 July while the injection location is being switched to another chamber. It will resume on 4 July afternoon. Did you know that while it is meant to be multi-purpose, the most famous purpose intended for the megafloat was to make an extension to Haneda airport, but it was refused in 2010?

Tepco is installing shields to protect workers from radiations in unit 3's reactor building. The purpose is to be able to start nitrogen injection on 8 July.
 
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  • #10,469
I originally posted this on the TEPCO Management and Government Performance Thread and the Other Political thread. It hasn't generated any discussion there. There was a lot of speculation early on about how much NRC knew. These references are interesting reading because it looks almost like we were as well informed as they were. Also of interest is how their different ideas and speculations mirrored what went on here.

For anyone interested in NRC contacts with Japan in the early days

FYI NRC has responded to FOIAs

FOIA/PA 11-0118, 0119, and 0120

http://www.nrc.gov/reading-rm/foia/japan-foia-info.html

Rough count is way over 1000 pp.
 
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  • #10,470
Thanks for that, NUCENG. I was in the habit of checking that FOIA page from time to time, but after a couple months just assumed there would be some kind of "emergency" exception that prevented their release.
 
  • #10,471
NUCENG said:
I originally posted this on the TEPCO Management and Government Performance Thread and the Other Political thread. It hasn't generated any discussion there. There was a lot of speculation early on about how much NRC knew. These references are interesting reading because it looks almost like we were as well informed as they were. Also of interest is how their different ideas and speculations mirrored what went on here.

For anyone interested in NRC contacts with Japan in the early days

FYI NRC has responded to FOIAs

FOIA/PA 11-0118, 0119, and 0120

http://www.nrc.gov/reading-rm/foia/japan-foia-info.html

Rough count is way over 1000 pp.

I think there's been some interest, just not many comments. I, for one, haven't yet found the time to do much more than a quick skim-through.

EDIT: the idea of printing out e-mails, then collating them in a scanned PDF? Who came up with that one? There's zero excuse here - while I can understand why rules and regulations would have treeware master copies, this is just stupid, verging on willfully incompetent.

If I sound frustrated, it's 'cause I am. I have good text processing, indexing and search tools at my disposal - and none of them work!
 
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  • #10,472
http://pbadupws.nrc.gov/docs/ML1117/ML11175A296.pdf

pp 113:

water level and pressure graphs for a hypothetical long-term station blackout at Peach Bottom NPP. Looks quite familiar.

EDIT: and by familiar, I mean similar to actual plots of Fukushima Dai-ichi Unit 2 data.
 
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  • #10,473
joewein said:
I don't disagree with your suggestion of using F1 as a dry cask storage site, provided tsunami defenses are beefed up sufficiently first.

I do disagree. If life gives you lemons, you should return them and ask for a refund. But seriously, it's not such a good place to store lots of radwaste. There's a city nearby and the site geology is real bad.
 
  • #10,474
tsutsuji said:
At 9 AM on 3 July, The flow of water injected into unit 1 began to slowly decrease from the 3.5 ton/hour flow, although the pump was running normally. At 8:13 AM on 4 July, the flow reached 3 ton/hour, causing an alarm to ring.

Viewing that the cause of the problem might be the presence of a foreign body blocking the water, Tepco temporarily pushed the flow of water to 7.5 ton/hour and this action was successful in achieving the restoration of a 3.8 ton/hour flow at 8:50 AM.

I trimmed the quote, but my intent is to thank you, tsutsuji, for your continued valuable contributions.
 
  • #10,475
Has this been discussed already and I missed it? Arnie comments on the old SFP3 underwater video, thanking Ian Goddard for pointing out that one fuel bundle appears to be visible in the corner. After reminding everyone that reactor 3 is the one that was "blown to smithereens," he implies that the rest of the fuel has vanished from the pool, but just says,"Where are the other bundles?"

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

Comments?
(Just in case anyone has doubts, I think Gunderson is a self-promoting bundle of smarm and falsehood)
 
  • #10,476
I read this thread for good science, not "green" editorializing or politics. Those belong elsewhere, IMHO. Not that I am without opinions too, just prefer a thread that is nearly pure science and engineering.

I really value the opportunity to read the thoughts of very well qualified individuals who have first hand knowledge of the processes and systems - the engineers, operators, physicists and others with direct experience in the real world. Yes, some is over my head but I am here to learn and do a lot of that in reading the good science here.

Were I interested in conservation, politics of waste disposal or appropriateness of nuclear power I would search out and read threads dealing with those issues. (Not likely to waste my time on ANY "green" crap, however.)
 
  • #10,477
Azby said:
Has this been discussed already and I missed it? Arnie comments on the old SFP3 underwater video, thanking Ian Goddard for pointing out that one fuel bundle appears to be visible in the corner. After reminding everyone that reactor 3 is the one that was "blown to smithereens," he implies that the rest of the fuel has vanished from the pool, but just says,"Where are the other bundles?"

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

Comments?
(Just in case anyone has doubts, I think Gunderson is a self-promoting bundle of smarm and falsehood)
I would not speak ill of the man as I believe he is well intentioned. Still, when I saw that video, I wondered if that was an area of the SFP that only had one assembly in it. If the pool blew all to hell, where did all the assemblies go? I do not see the circular rods lying about the grounds. Besides in an earlier video of the Number 3 SFP, it looked to me like there were a whole lot of assemblies under water. Though the SFP has a lot of debris in it, I expect that most of it is still there. If it had exploded as Arnie postulated, I doubt that it would still be holding water.
 
  • #10,478
Azby said:
Comments?
(Just in case anyone has doubts, I think Gunderson is a self-promoting bundle of smarm and falsehood)

Azby,

I'd agree with you there. He and a few others I can think of have been promulgating very poor and inaccurate scientific information.

They are just media whores of the first order.

Greg
 
  • #10,479
Joe Neubarth said:
I would not speak ill of the man as I believe he is well intentioned. Still, when I saw that video, I wondered if that was an area of the SFP that only had one assembly in it. If the pool blew all to hell, where did all the assemblies go? I do not see the circular rods lying about the grounds. Besides in an earlier video of the Number 3 SFP, it looked to me like there were a whole lot of assemblies under water. Though the SFP has a lot of debris in it, I expect that most of it is still there. If it had exploded as Arnie postulated, I doubt that it would still be holding water.

Yes, I spoke inappropriately. I will rephrase it as,"I have rarely found anything Gunderson has said in the past to be accurate or backed up by solid evidence, so I discount most of what he says in this video."

As for what may have happened in the pool, does anyone else think it's possible that one or more bundles may have been dislodged and forced upward, while the others remain in place below the rubble?
 
  • #10,480
Arnie Gundersen has one unchallengeable point that we cannot deny. Fukushima is a nuclear reactor accident that shouldn't have happened. Its consequences are still unfolding, but are devastating in cost, health and social impact.

It galls me to the core that this accident could have been prevented. I am trying hard not to let my anger and embarrassment prevent me from seeing that opponents like Arnie may have some valid points. As long as he has the media spotlight he is influencing public opinion. The only effective way to deal with that is to expose his misinformation, errors and faulty conclusions with facts, corrections, and logic. But that will be an uphill battle against the images of Fukushima, Chernobyl, and TMI2. Name-calling and blanket judgements based on our perception of his motives only reinforce impressions of arrogance on our part.

Time will reveal where he is wrong, and we can speed that process along the way, but we can't afford to ignore where he is right.
 
  • #10,481
NUCENG said:
Arnie Gundersen has one unchallengeable point that we cannot deny. Fukushima is a nuclear reactor accident that shouldn't have happened. Its consequences are still unfolding, but are devastating in cost, health and social impact.

It galls me to the core that this accident could have been prevented.

Mr. Nuceng,

Thank you for your informative posts on this thread.

Would

a)a higher seawall

and/or

b) waterproofing diesels and electric distribution have sufficed to prevent this in the face of earthquake followed by tsunami ? I understand that integrity of various RPV penetrations were compromised by earthquake alone, and disaster of some flavor might still have ensued even without tsunami.

sigyn
 
  • #10,482
It may be too early for Tepco to even know exactly what went wrong and when. It does seem obvious that even a 30 meter wall wouldn't have prevented the immense pressure to the intake/outflow areas, the pipes that actually have to be directly connected to the ocean for cooling.

The turbine rooms and other areas may still have failed even if somehow they had a wall high enough to stop the ocean. From careful observation of the tsunami waves, it isn't just a matter of stopping the waves. The intakes have to be connected to the ocean. A wall would have stopped the damage to the buildings, but not to the intakes and where they connect to.

Loss of cooling may still have happened, both to the diesels and the reactors. It's an issue that probably wasn't planned for at all.
 
  • #10,483
placing electrical switchgear down in the basement with diesels made it safe from tornadoes and falling airplanes
but in retrospect it needed a submarine hull around it.

to my mind one's diesels should be stand-alone, that is able to start and run independent of switchgear and intake structures. Had they been up on top of the hill and cooled by radiators things could have gone a lot better.

Our plant had two that were so cooled, compressed air start and shaft driven cooling fans for the radiators. If you had DC from battery they'd go.

old jim
 
  • #10,484
Joe Neubarth said:
I do not see the circular rods lying about the grounds. Besides in an earlier video of the Number 3 SFP, it looked to me like there were a whole lot of assemblies under water. Though the SFP has a lot of debris in it, I expect that most of it is still there. If it had exploded as Arnie postulated, I doubt that it would still be holding water.

I don't think TEPCO has posted any other videos of SFP 3, only of SFP 4. That's the one you may be thinking of when you talk about seeing lots of assemblies under water.

Here's a Youtube posted version of the the complete TEPCO video for #3 from which Gundersen shows a clip. The handle can be seen in the top right corner between 1:55 and 2:02:


Later, around 2:12 you see what may be empty racks at a different spot.

FWIW, in the https://www.physicsforums.com/showpost.php?p=3382117&postcount=10379" we don't see any isolated, single fuel assemblies, though we see racks in which a single row (10x1 assemblies) is populated.
 
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  • #10,485
sigyn said:
Mr. Nuceng,

Thank you for your informative posts on this thread.

Would

a)a higher seawall

and/or

b) waterproofing diesels and electric distribution have sufficed to prevent this in the face of earthquake followed by tsunami ? I understand that integrity of various RPV penetrations were compromised by earthquake alone, and disaster of some flavor might still have ensued even without tsunami.

sigyn

Understanding that a 5.7 m design basis tsunami was insufficient basd on scientific evidence and historical evidence prior to 1896 would have been the start. It should have initiated a detailed review and may even have shown that a 15 m tsunami was possible. If a design could not be found to mitigate that risk, the plants should have been shut down.

However, I believe that a risk analysis and design basis review would have pointed to increasing the floodwall height, strengthening and water-proofing buildings, protecting the seawater pumps by building a strengthened pump house, providing additional air cooled backup power sources. Reviwing severe accident procedures might have provided additional coolant makeup sources or questioned the initiation pressure for containment venting and potential delaysfrom needing government approval to vent. And there are more options that I haven't thought of. Even if an accident still occurred it could have been less severe.

If wishes was fishes we could feed the world! That didn't happen and now there is both a need to deal with Fukushima as it is and a need to make sure it doesn't happen somewhere else.
 
  • #10,486
NUCENG said:
Arnie Gundersen has one unchallengeable point that we cannot deny. Fukushima is a nuclear reactor accident that shouldn't have happened. Its consequences are still unfolding, but are devastating in cost, health and social impact.

It galls me to the core that this accident could have been prevented. I am trying hard not to let my anger and embarrassment prevent me from seeing that opponents like Arnie may have some valid points. As long as he has the media spotlight he is influencing public opinion. The only effective way to deal with that is to expose his misinformation, errors and faulty conclusions with facts, corrections, and logic. But that will be an uphill battle against the images of Fukushima, Chernobyl, and TMI2. Name-calling and blanket judgements based on our perception of his motives only reinforce impressions of arrogance on our part.

Time will reveal where he is wrong, and we can speed that process along the way, but we can't afford to ignore where he is right.

NUCENG, you are one of the bright lights in this thread. It has been said that a man's ability to understand something is directly affected by his paycheck depending on him not understanding it. You have consistently shown a willingness to be open-minded and willing to suffer the slings and arrows of some of the more anti-nuclear people who show up here from time to time. If the industry as a whole had people like you leading it we would all be in a far better place than we are today. (I am no fan of Arnie Gunderson, but you are right IMO with respect to some of his points.) Kudos to you, sir.
 
  • #10,487
MiceAndMen said:
NUCENG, you are one of the bright lights in this thread. It has been said that a man's ability to understand something is directly affected by his paycheck depending on him not understanding it. You have consistently shown a willingness to be open-minded and willing to suffer the slings and arrows of some of the more anti-nuclear people who show up here from time to time. If the industry as a whole had people like you leading it we would all be in a far better place than we are today. (I am no fan of Arnie Gunderson, but you are right IMO with respect to some of his points.) Kudos to you, sir.

Thanks, I hope you are wrong about the paycheck motivation. The way I looked at it my paycheck has always been based on finding truth about whatever I am working on and solving problems based on that truth. If I was correct then the problems stayed solved. My success came from the fact that I did better than the defifintion of an engineer. (Engineer: a person, who, given a 50/50 chance, is only wrong 90% of the time.)

If I can't be right 100%, then Arnie can't be wrong 100%. ;-p
 
  • #10,488
joewein said:
I don't think TEPCO has posted any other videos of SFP 3, only of SFP 4. That's the one you may be thinking of when you talk about seeing lots of assemblies under water.

Here's a Youtube posted version of the the complete TEPCO video for #3 from which Gundersen shows a clip. The handle can be seen in the top right corner between 1:55 and 2:02:


Later, around 2:12 you see what may be empty racks at a different spot.

FWIW, in the https://www.physicsforums.com/showpost.php?p=3382117&postcount=10379" we don't see any isolated, single fuel assemblies, though we see racks in which a single row (10x1 assemblies) is populated.

The video you listed is the one I was referring to. I did not know that Arnie was taking a portion of that video to show one fuel assembly top. In the opening seconds of the entire video when the bubbles are coming up and blocking the image you can briefly see a regular pattern that could be the top of the fuel assemblies. To do so, you have to look around the bubbles, preferably to the top and left.

Starting at about second 25 do a series of stops and starts to capture stills of the video. Granted there is lots of debris blocking the image, but I can see some fairly consistent regularity to the patterns partially visible underneath the debris. I believe that to be the top of the fuel assemblies.

All of that debris is sitting on top of something flat down there. NOW, what I can not tell you is the state of the fuel rods that extend down from the assemblies tops. All I can see is a fleeting pattern that suggests the fuel assembly tops are down there under a dozen feet or more of water.
 
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  • #10,489
NUCENG said:
Thanks, I hope you are wrong about the paycheck motivation. The way I looked at it my paycheck has always been based on finding truth about whatever I am working on and solving problems based on that truth. If I was correct then the problems stayed solved. My success came from the fact that I did better than the defifintion of an engineer. (Engineer: a person, who, given a 50/50 chance, is only wrong 90% of the time.)

If I can't be right 100%, then Arnie can't be wrong 100%. ;-p

Funny, when we went through Nuclear Power School in the Navy we always used to say that the proof of a true Navy Nuc was that when given a Fifty Fifty chance, He'd blow it EVERY time.
 
  • #10,490
NUCENG said:
If wishes was fishes we could feed the world! That didn't happen and now there is both a need to deal with Fukushima as it is and a need to make sure it doesn't happen somewhere else.

Wrong, the need to make sure it doesn't happen was there even before Fukushima! The fact that Fukushima happened only finally made it nearly impossible to deny that.

And yet, so far I saw only Japanese admitting their NPPs need work in increasing safety. Not one single other country yet admitted that in light of Fukushima, they found something in need of improvement in their NPPs. (Unless I missed some news, in which case feel free to post URLs). Not NRC, nor French or Russian regulators came forth with concrete measures they found in need of implementing right away.

Yes, there is talk about the need of unspecified improvements in safety nearly in every meeting of nuclear regulators. It fails to reassure me. I fear we will see too little and too late of said improvements.
 
  • #10,491
jim hardy said:
placing electrical switchgear down in the basement with diesels made it safe from tornadoes and falling airplanes
but in retrospect it needed a submarine hull around it.

to my mind one's diesels should be stand-alone, that is able to start and run independent of switchgear and intake structures. Had they been up on top of the hill and cooled by radiators things could have gone a lot better.

Our plant had two that were so cooled, compressed air start and shaft driven cooling fans for the radiators. If you had DC from battery they'd go.

old jim
Fukushima One's first four reactors were just one tsunami away from destruction from the first day they put number One in operation about 40 years ago.

Consider this:

1. When they lost one Utility Power Line leading to the plant, there was no backup source of commercial electricity. (Was this the case for 40 years and nobody realized what a serious error it was in site design?)

2. If anybody can see a real sea wall in the photos of Fukushima, I have yet to see it. The actual Tsunami was 4.2 meters in height. As we all know from seeing the ocean, a swell at sea can be two feet high but when it crashes onto the shore, the run up from that swell (wave) can be considerably higher than two feet. An approximate rule of thumb (This is not engineering practice) would be to take the height of the expected Tsunami and move the decimal point one place to the right to determine the height in feet for a wall to protect the plant. Thus the expected 4.2 meter tsunami at sea would require a 42 foot sea wall. I do not see a 42 foot sea wall at Fukushima.

At San Onofre where the projected worse case scenario would have a Three meter tsunami, (3 Meter Swell => 30 Foot Wall) the sea wall was built 30 feet high. San Onofre made an attempt to estimate run up from the swell. Fukushima site engineers blew it out their arse. It almost looks like the engineering firm gave it no consideration. Maybe they did not know what a Tsunami was in Japan. Most unusual considering that it is a Japanese word.

3. Emergency Diesel Generators, Electrical Connection Boxes, Motor Controllers, Pump Controllers, Power Cables and Data Cable Runs were all built in places where they could be swamped and flooded by a wave washing over the essentially non existent sea wall at Fukushima.

4. The steam shut off valves leading to the towers failed shut upon loss of electric power. The Japanese engineers had not designed an easy means of reopening that valve manually from a safe distance. Thus when they needed to manually reopen it to prevent Hydrogen Gas from escaping inside the reactor plant building and exploding, they could not reopen it because the steam was radioactive and exceeded the limits for the man who was frantically trying to reopen the valve (or valves in question.)
 
  • #10,492
I would say 100% many Japanese (and the rest of the world) actually had no scientific understanding of what a tsunami actually is like. Most still don't.

For example, there is no run up like a regular ocean wave has. And there is also no run out after the wave. They are not like ocean waves at all actually.
 
  • #10,493
robinson said:
I would say 100% many Japanese (and the rest of the world) actually had no scientific understanding of what a tsunami actually is like. Most still don't.

For example, there is no run up like a regular ocean wave has. And there is also no run out after the wave. They are not like ocean waves at all actually.

Surely, you jest. Tsunamis are very much like ocean waves. They are usually far larger, and they are broader, but their action is exactly like a wave washing up on the beach. Because of breadth they can appear to be in slow motion, but they can do an awful lot of damage. I do not know where you get such a silly notion. Wave dynamics are wave dynamics. They wash up and they wash back out again, just like a wave on a beach and you can see it on any video footage you want. If you watch wave action on any beach you will see that to be a wave the water does not have to curl and roll over on itself. It just needs to roll up on the beach and then flow back out again, creating a wave in the near opposite direction.

Webster's dictionary defines a wave as "a disturbance or variation that transfers energy progressively from point to point in a medium and that may take the form of an elastic deformation or of a variation of pressure, electric or magnetic intensity, electric potential, or temperature."

The most important part of this definition is that a wave is a disturbance or variation which travels through a medium. The medium through which the wave travels may experience some local oscillations as the wave passes, but the particles in the medium to not travel with the wave. The disturbance may take any of a number of shapes, from a finite width pulse to an infinitely long sine wave.
 
  • #10,494
Joe Neubarth said:
Surely, you jest. Tsunamis are very much like ocean waves. They are usually far larger, and they are broader, but their action is exactly like a wave washing up on the beach.

OK I had to stop right there. That is exactly what I am talking about. The closest thing to understanding a tsunami would be a tidal bore, except that it is moving upriver very very fast, and is much larger than any known tidal bore ever recorded.

The term "tidal" wave actually describes the effect, as if a monster high tide is approaching very fast. This no doubt needs a topic. So I will not sidetrack this thread further.
 
  • #10,495
nikkkom said:
Wrong, the need to make sure it doesn't happen was there even before Fukushima! The fact that Fukushima happened only finally made it nearly impossible to deny that.

And yet, so far I saw only Japanese admitting their NPPs need work in increasing safety. Not one single other country yet admitted that in light of Fukushima, they found something in need of improvement in their NPPs. (Unless I missed some news, in which case feel free to post URLs). Not NRC, nor French or Russian regulators came forth with concrete measures they found in need of implementing right away.

Yes, there is talk about the need of unspecified improvements in safety nearly in every meeting of nuclear regulators. It fails to reassure me. I fear we will see too little and too late of said improvements.

You are right that the need was there, and it wasn't done. Wishing won't fix that - as I said. So what was wrong?

Now, you have made the assumption that the same vulnerability exists in US plants, French Plants or Russian Plants. I can't speak for the French (outside of lessons learned from Blaiais flooding event. I hope the Russsians learned from Chernobyl.

On this forum I have pointed out a statement to the Convention on Nuclear Safety that the Japanese did not review plant design bases after a plant was built unless there was a new plant being built. That is one tremendous difference in the US. We are expected to work on design bases validation every time we conduct inspections, design modifications and review operating experience from other plants. Reviews have been initiated and NRC is preparing generic guidance requirements. I have posted links to those reviews performed at every US plant and available on the NRC website. NRC Commissioners have indicated they probably will require additional protection for backup power sources and coping with station blackouts. We have discussed clear indications of both government and management negligence in Japan.

All you are offering in rebuttal is your fear and opinion. You apparently have missed or ignored or disbelieved my posts and the links I have already provided. Feel free to go back and review and come up with something concrete to discuss. It still takes an honest effort to learn. Show me that further effort on my part won't waste my time.
 
  • #10,496
Joe Neubarth said:
Funny, when we went through Nuclear Power School in the Navy we always used to say that the proof of a true Navy Nuc was that when given a Fifty Fifty chance, He'd blow it EVERY time.

That is known as the Rickover effect. No matter how hard you work, you could work harder. No matter how right you are you can still learn more, so you are still wrong.
 
  • #10,497
NUCENG said:
You are right that the need was there, and it wasn't done. Wishing won't fix that - as I said. So what was wrong?

Now, you have made the assumption that the same vulnerability exists in US plants, French Plants or Russian Plants. I can't speak for the French (outside of lessons learned from Blaiais flooding event. I hope the Russsians learned from Chernobyl.

On this forum I have pointed out a statement to the Convention on Nuclear Safety that the Japanese did not review plant design bases after a plant was built unless there was a new plant being built. That is one tremendous difference in the US. We are expected to work on design bases validation every time we conduct inspections, design modifications and review operating experience from other plants. Reviews have been initiated and NRC is preparing generic guidance requirements. I have posted links to those reviews performed at every US plant and available on the NRC website. NRC Commissioners have indicated they probably will require additional protection for backup power sources and coping with station blackouts. We have discussed clear indications of both government and management negligence in Japan.

All you are offering in rebuttal is your fear and opinion. You apparently have missed or ignored or disbelieved my posts and the links I have already provided. Feel free to go back and review and come up with something concrete to discuss. It still takes an honest effort to learn. Show me that further effort on my part won't waste my time.

While the guidance requirements seem to be pretty effective, they are not totally robust.
If memory serves, the Besse Davis reactor vessel had the head almost corroded through, as no one asked where the copious rust in the water was coming from. More seriously, slowly emergent problems such as the risks posed by overfilled spent fuel pools do not seem to be surfaced very effectively. Is there an industry mechanism to help bring such generic problems to the foreground?
 
  • #10,498
Joe Neubarth - a nice summary you put up above at 2:25. Thanks for your kindness.

I have to believe that, after that 1995-ish report of potential for huge tsunamis, had somebody made those TEPCO executives aware of their plant's vulnerability to inundation they'd have spent the money to fix it.
Quality is a cornerstone of Japanese business culture. [Google Demming]
Usually the folks at the bottom have to point out weaknesses for after all they are the ones best positioned to discover it. Smart managers encourage that, and listen.

"For want of a nail a shoe was lost..."
 
  • #10,499
jim hardy said:
<...>[Google Demming]<...>

Jim, I have no need to Google him.

W Edwards Deming. A physicist at Bell Labs that had to travel all the way to Japan to find an audience that was willing to listen. And when they listened they learned, and they were able to transform their way of industry to become one of the world leaders. The foundations Deming laid see Toyota as one of the top selling car manufacturers in the USA.

Sadly his own countrymen didn't listen, much to their own loss.

To bring this back on topic, I think the data (evidence) based culture that Japan has as a result is why they don't want to interpolate. TEPCO simply say that (for instance)
At approximately 6:00 am on March 15, an abnormal noise began emanating
from nearby Pressure Suppression Chamber and the pressure within the
chamber decreased.

Interpolation of this data - that an explosion blew a hole in the SC - is entirely natural to us and our journalists. But the evidence (data) is exactly as stated by TEPCO.

This gives rise to frustration and the opinion in some minds that TEPCO are witholding information. In fact, TEPCO are only witholding interpolation and opinion. Rightly in my mind.
 
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  • #10,500
NUCENG said:
You are right that the need was there, and it wasn't done. Wishing won't fix that - as I said. So what was wrong?

You said:
Reviwing severe accident procedures might have provided additional coolant makeup sources or questioned the initiation pressure for containment venting and potential delays from needing government approval to vent. ... That didn't happen and now there is both a need to deal with Fukushima as it is and a need to make sure it doesn't happen somewhere else.

What is wrong with it? Wrong that you regret that *after this disaster* (word "now" in the above quote has that meaning), there is a "need to make sure it doesn't happen somewhere else". Which is WRONG, THIS NEED WAS THERE EVEN BEFORE THE DISASTER. Waiting for a disaster to happen in order to start looking at the problems seriously is WRONG.

How can I say this even more clearly?

Now, you have made the assumption that the same vulnerability exists in US plants, French Plants or Russian Plants. I can't speak for the French (outside of lessons learned from Blaiais flooding event. I hope the Russsians learned from Chernobyl.

On this forum I have pointed out a statement to the Convention on Nuclear Safety that the Japanese did not review plant design bases after a plant was built unless there was a new plant being built. That is one tremendous difference in the US. We are expected to work on design bases validation every time we conduct inspections, design modifications and review operating experience from other plants. Reviews have been initiated and NRC is preparing generic guidance requirements. I have posted links to those reviews performed at every US plant and available on the NRC website. NRC Commissioners have indicated they probably will require additional protection for backup power sources and coping with station blackouts. We have discussed clear indications of both government and management negligence in Japan.

All you are offering in rebuttal is your fear and opinion. You apparently have missed or ignored or disbelieved my posts and the links I have already provided. Feel free to go back and review and come up with something concrete to discuss.

Wrong again. I don't have to prove that plants are unsafe. It's the other war around - the nuclear industry must prove to the satisfaction of the people that they are safe.

There is a direct parallel with Challenger disaster. Engineers who voiced concerns about O-ring erosion were asked to provide a proof that O-rings can be breached. Rogers Report specifically points out that managers were dead wrong about it. Shuttle can be launched not when engineers can't prove it's unsafe to do so, it can be launched only if engineers are sure that it is reasonably safe to do so!

Your believe that everything is shiny in France, Russia and US just because this disaster happened in Japan, not those countries. I am not so sure about it.

I read post-disaster reports after both Shuttle disasters, I know how stubborn people may be in (self)deception about safety when it comes to multi-billion projects. NASA managed to self-hypnotize itself into believing Shuttles are safe even after NASA itself dramatically proved it's not true.

We are basically in port-Challenger state right now in regards to NPPs, and unless we start to do something differently now, we are going to get Columbia.

The reaction of worldwide nuclear community up to now is mostly PR. PR is not going to convince me. I need to see deeds, not words.

"For a successful technology, reality must take precedence over public relations, for nature cannot be fooled", said Richard Feynman, and I fully agree with him.
 
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