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timeasterday said:I don't think this image has been posted before but seems to show refueling operations at one of the reactors.
And in what is known?
timeasterday said:I don't think this image has been posted before but seems to show refueling operations at one of the reactors.
shadowncs said:We can only speculate but look at aerial-2011-3-30-0-50-45.jpg from 20 March... if those are tsunami runups then we have an idea.
james14 said:We have heard many times that the radiation coming from the standing water is > 1000 mSv / hr. So we don't know the actual levels, just that it's greater than the 1000. I believe some here have estimated this value to be wildly lower than the actual.
Lately there have been reports of this water being > 10,000 times the level of water normally in a reactor.
Would I be right therefore in assuming that the normal level of radiation levels of water in a reactor is approx 0.1 mSv / hr?
Basically I was wondering if the "levels > 10,000" was as limited a piece of information as the "> 1000 mSv/hr" one. Or, if we could perhaps work out an actual level of radiation from those figures of "> 10,000 times the normal level in a reactor"
timeasterday said:I don't think this image has been posted before but seems to show refueling operations at one of the reactors.
timeasterday said:I don't think this image has been posted before but seems to show refueling operations at one of the reactors.
Unit 4 did a full core offload for maintenance
83729780 said:the multiplier references radioactivity (becquerels), not radiation
there's also a need to distinguish "times normal level" from "times legal limit"
also, the >1,000 mSv/hr was a measurement taken a couple of days ago from water in the turbine building of reactor 2. The most recent measurement of "10,000 times the legal limit" was a becquerel measurement from water near reactor 1 (see AntonL's post on the previous page [https://www.physicsforums.com/showpost.php?p=3221570&postcount=2251"])
razzz said:Google Earth shows elevation where ever you point the mouse.
TCups said:Very helpful.
The approximate size and relative location of the refueling chute in the SFP is apparent.
We know that this building has the concrete superstructure, like Bldgs 3, 4.
We know that the yellow dome to the left is the drywell cap.
Does anyone know what is sitting in the corner behind the drywell cap?
TCups said:It still appears to be there, in the NW corner of Bldg 3
.
RealWing said:As a former NPP manager, I've been closely following this event from the beginning, but just found this forum yesterday. I've been trying to put myself in their shoes to better understand what they are dealing with.
I would fully expect that they are doing their best to limit doses to workers ALARA - even in these very stressful circumstances. They would not be irresponsibly simply ordering someone to go and get a sample. They would do their best to use long handled sampling, different routes etc and HP briefings to minimize dose.
PietKuip said:Now we hear how irresponsible Tepco is: they had not even brought in sufficient numners of personal dosimeters for the people working there. It is disgusting.
Reno Deano said:Do not condemn until you have walked in their shoes.
AtomicWombat said:Yes. A steam explosion can occur without air being present:
http://en.wikipedia.org/wiki/Steam_explosion"
And at high enough temperature (>1700 Celsius) zirconium also reacts explosively with steam producing hydrogen without the need for air.
Zr + 2H2O -> ZrO2 + 2H2
Of course once hydrogen escapes the containment it can also explode in air.
No. The only concern about hydrogen is deflagration or detonation. Beyond that, the concern is the degraded condition of the fuel, which no longer confines the fission products. Beyond that is the degraded condition of the reactor coolant system which provides the next barrier between fission products and the environment. Beyond that is the degraded condition of the containment system which is the third barrier between fission products and the environment.hbjon said:Any danger of the H-2 fusing together? Or at the current temp and pressure this not possible?
hbjon said:Any danger of the H-2 fusing together? Or at the current temp and pressure this not possible?
gmax137 said:That looks like a bunch of 3/8 inch stainless tubing to me. There's typically miles of that stuff in a plant, used for instrumentation.
Joe Neubarth said:It does not to me.
I see rumpled elongated narrow sheets that were made that way by physical shock, like from that explosion.
They appear to be (approximate guess) ten times to fifteen times wider than they are thick.
For them to have taken on such a rumpled shape their substance must have some malleability, much like lead.
What ever fits that description is what it is.
I think they are fuel rods that have been through one hell of an explosion.
But what the hell, I am not a nuclear engineer. I just go by what my eyes tell me.
"a thing's a phallic symbol if it's longer than it's wide" -- Melanie
Astronuc said:No. The only concern about hydrogen is deflagration or detonation. Beyond that, the concern is the degraded condition of the fuel, which no longer confines the fission products. Beyond that is the degraded condition of the reactor coolant system which provides the next barrier between fission products and the environment. Beyond that is the degraded condition of the containment system which is the third barrier between fission products and the environment.
Proton fusion has a relatively low probability even in the center of the sun with a density of 160 g/cm3, 10 times that of lead, or 160 times that of water at 1 atm and ~25°C. The sun's core temperature of 15 million K (27 million °F) keeps it in a plasma state.
Normal condition in the BWR core is a mix of saturated liquid water and steam at ~286°C, with the cladding temperatures a bit hotter, and the fuel temperatures of 350-1400°C, where the highest temperature of the fuel is the centerline. In the current situation, the fuel temperature is much low, probably on the order of 200-400°C.
jensjakob said:Leads to some very interesting questions:
1. The refueling machine has narrower width than reactor opening. (Which is square).
2. Does this mean that fuel only can be stored in the SPF pool, since the refueling machine can't move to the other side of the reactor?
3. Can the "crane" turn around and operate on the other side (e.g. if there were tracks in the reactor concrete lid so the refueling machine could be restationed to the other side?)
Curios
Jens Jakob
james14 said:I assume there is at least some connection? IE an increase in the level of radioactivity (becquerels) would normally result in a higher dose of radiation (sieverts)?
And if so, is it possible to estimate one from another, or is it just not feasable?
Bez999 said:Look again Jens, it appears this photo was taken from the SFP, with the machine standing over the reactor vessel. It looks like the perspective has you fooled, you can see the machine bridge tracks on the other side of the pool there.
Bez999 said:@Tcups: Here's how I see that photograph. Take a ruler and place it alongside the SFP edge in the left of the picture to get a feel for the perspective. You'll see that the machine is actually wider than the SFP, contrary to what Jens suggested.
Also the fact that there is a gate shows that this is the SFP, not an equipment pool. Also, it is unlikely that reactor opening is square or rectangular rather than round or hexagonal, purely from a structural perspective. Hence, what we see is the SFP in the foreground and the reactor opening behind the gate, which also lines up with your comment about about the blue light.
In this picture the equipment pool would be behind the fuel handling handling machine.
The thing in the background looks like some tool that might be used to lift something out rather than being part of the reactor. It wouldn't surprise me if it was a jig to lift the steam dryer out with, don't know. I'd assume the steam dryer itself would be pretty active, but not to the degree it can't be lifted through the air to the equipment pool. One of the nuclear engineers here may know.
razzz said:hidsuz: I'd start with a extended vacation starting immediately until they get some kind of control over the situation.
Drudge Report has a bunch of headlines up concerning the nuke situation, like...
http://chronicle.augusta.com/latest-news/2011-03-31/srs-concrete-pump-heading-japan-nuclear-site"
I'd say a 7.0 or larger quake and these boom trucks are toast if set up.
Most of the radioactivity maybe at the site, which is a problem for those at the site. The decay heat has been decreasing over three weeks, so it's not going to increase. The challenge is to remove the remaining heat so that pressure is managed, i.e. not increased.hidsuz said:Hi folks. Here in Tokyo and need to make a decision in the next few days. Stay and work but incur moving costs without knowing whether I`ll still end up having to leave, or simply quitting and starting from scratch back home. TEPCO, the govt, media, agenda based 'experts' simply cannot be trusted. Been reading this most excellent forum and, if I could oblige( I can start a different thread or try elsewhere if this is too OT), have some questions.
1)What is the worst case scenario?
2)What is most probable?
*and on what time frame to both
If I will most likely have to deal with ongoing radioactivity fears of the air, food, water and potential explosions on a day to day basis for years instead of months, it`d be an easy decision to leave. Thanks, I will try to provide any real time news.
Astronuc said:Most of the radioactivity maybe at the site, which is a problem for those at the site. The decay heat has been decreasing over three weeks, so it's not going to increase. The challenge is to remove the remaining heat so that pressure is managed, i.e. not increased.
I've not heard about the concrete system being moved from Savannah River to Fukushima. It's not enough to simply pour concrete into the SFPs or containment. If it's done incorrectly it can crack and develop porosity.
Look on http://www.mext.go.jp/english/radioactivity_level/detail/1304082.htm for readings of radioactivity. I'm still looking for more information myself.
Astronuc said:Most of the radioactivity maybe at the site, which is a problem for those at the site. The decay heat has been decreasing over three weeks, so it's not going to increase. The challenge is to remove the remaining heat so that pressure is managed, i.e. not increased.
I've not heard about the concrete system being moved from Savannah River to Fukushima. It's not enough to simply pour concrete into the SFPs or containment. If it's done incorrectly it can crack and develop porosity.
Look on http://www.mext.go.jp/english/radioactivity_level/detail/1304082.htm for readings of radioactivity. I'm still looking for more information myself.
Bez999 said:This one would be a hell of a lot easier to entomb, as there remains an external shell in place. Pretty much all they have to do is open all internal doors and pump the whole building full of concrete (with a lot of absorbing material in it), with only some of the top floors requiring additional boxing.
If done solidly, they could built new reactors right on top of the boxes thus created, well out of the flooding levels!![]()
Bodge said:
Not necessarily. It would depend on how much positive reactivity is achieved before negative reactivity - Doppler and moderator temperature - would kick in. I don't think we seen any such events.Bodge said:Decent radiation graphs:
http://fleep.com/earthquake/
Isn't predicted decay heat somewhat inaccurate if recriticalities are occurring?
Astronuc said:Most of the radioactivity maybe at the site, which is a problem for those at the site. The decay heat has been decreasing over three weeks, so it's not going to increase. The challenge is to remove the remaining heat so that pressure is managed, i.e. not increased.
I've not heard about the concrete system being moved from Savannah River to Fukushima. It's not enough to simply pour concrete into the SFPs or containment. If it's done incorrectly it can crack and develop porosity.
Look on http://www.mext.go.jp/english/radioactivity_level/detail/1304082.htm for readings of radioactivity. I'm still looking for more information myself.
javadave said:bring on the Pharaoh!
TCups said:IF it comes to that as a solution, then I think they should go with rounded or domed containments . . .
http://i.imgur.com/7MYkR.jpg
and paint them pink.
curious11 said:Or. they;re just control rods... ?
http://www.sciencephoto.com/images/download_lo_res.html?id=841700465"
I need to look further into the details. At the moment, I don't believe there will be more hydrogen release. And if the cooling is stabilized, I think the activities should further decrease. I'd like to know the source (radionuclides) producing the activities.hidsuz said:Thanks Astronuc.
So I gather that as long as they keep pouring water in, and they divert the outflow out to sea, we don`t see further explosions or large amounts of radioactive steam/gas which could form clouds and hold us at the mercy of the winds. And that it`s then a matter of time(depending on source heard weeks, months or years though) before full control, and then perhaps no need to encase? Heard from wife that some nanofilter type net has been proposed to put over the reactors.
Been monitoring using these sites:
Ibaraki govt just north of Tokyo http://www.houshasen-pref-ibaraki.jp/present/result01.html
Yokohama govt(basically Tokyo) http://www.city.yokohama.lg.jp/kankyo/saigai/
Kanagawa govt(just west of Tokyo) http://www.atom.pref.kanagawa.jp/cgi-bin2/telemeter_map.cgi?Area=yokosuka&Type=WM
Tokyo govt http://ftp.jaist.ac.jp/pub/emergency/monitoring.tokyo-eiken.go.jp/monitoring/index-e.html
Private individual Tokyo counter inside with window slightly ajar http://www.ustream.tv/channel/%E3%82%AC%E3%82%A4%E3%82%AC%E3%83%BC%E3%82%AB%E3%82%A6%E3%83%B3%E3%82%BF
Private individual Tokyo http://park30.wakwak.com/~weather/geiger_index.html(measuring inside a wooden house with good ventilation and says reading typically 20% higher outside. Reliable?)
Readings have generally been coming down last several days to basically normal which I believe is due mostly to wind direction here and at Fukushima as well as much lower gaseous output.
jlduh said:To Justguessing:
the top cover of the pressure vessel (big and yellow) shown in this video is the one of reactor No4 and there is nothing abnormal to see it here because the reactor was on maintenance, so the top cover was removed with no fuel in the core. I was talking about reactor No3 where i have the impression to see something ressembling strangely to a cover of pressure vessel.
"the top cover was removed with no fuel in the core" did i say?
(well, are we sure that there was no fuel in the core at No4 by the way? We know that it was down but if my understanding of operations is right, when refuelling they just change maybe one third of the fuel, no?
Could it be possible that there was still fuel physically in the open core when the accident happened? So in this case this fuel may be in the same situation than in the other reactor with a decay rate much more advanced of course, because shut down before tsunami. IS IT POSSIBLE? Then of course it would have been fully under the water at the moment of the tsunami but then what happened after if water leaked from pool? It could have been hot too, don't you think? Could this explain why there is so much damage on building No4, even at the low stages of the building? Didn't we conclude to quickly that the reactor was OFF while some fuel was still inside?
TCUPS: try with an other browser maybe, it works perfectly here (don't know for other members?).
Astronuc said:I need to look further into the details. At the moment, I don't believe there will be more hydrogen release. And if the cooling is stabilized, I think the activities should further decrease. I'd like to know the source (radionuclides) producing the activities.
One should limit the exposure of babies, small children, pregnant women, and women of child-bearing age.
As much as possible, drink bottled water, or use a water filter with an activated charcoal filter.
...“The bottom line is, the Japanese need this particular unit worse than we do, so we’re giving it up,” said Jerry Ashmore, whose company, Augusta-based Ashmore Concrete Contractors, Inc., is the concrete supplier for the MOX facility.
The 190,000-pound pump, made by Germany-based Putzmeister has a 70-meter boom and can be controlled remotely, making it suitable for use in the unpredictable and highly radioactive environment of the doomed nuclear reactors in Japan, he said...
...The pump was moved Wednesday from the construction site in Aiken County to a facility in Hanahan, S.C., for minor modifications, and will be trucked to Atlanta’s Hartsfield Airport, where it will be picked up by the world’s largest cargo plane, the Russian-made Antonov 225, which will fly it to Tokyo...
...Initially, the pump from Savannah River Site, and another 70-meter Putzmeister now at a construction site in California, will be used to pump water—and later will be used to move concrete.
“Our understanding is, they are preparing to go to next phase and it will require a lot of concrete,” Ashmore said, noting that the 70-meter pump can move 210 cubic yards of concrete per hour.
Putzmeister equipment was also used in the 1980s, when massive amounts of concrete were used to entomb the melted core of the reactor at Chernobyl.
In addition to the equipment now at Fukushima and the two 70-meter pumps being moved from the U.S., a contractor in Vietnam has given up a 58-meter pump so it can be diverted to Japan, and two 62-meter pumps in Germany were loaded on Wednesday for transport to Tokyo.
Ashmore officials have already notified Shaw AREVA MOX Services, which is building the MOX plant for the U.S. Department of Energy’s National Nuclear Security Administration, that the pump was being moved and will not be returned. “It will be too hot to come back,” Ashmore said...
shogun338 said:This video contains some ground level footage of the severe damage at the plant .
83729780 said:2:18 to 2:28, something is glowing orange inside the third story of reactor 4
tcups said:@bez999
my understanding is that the equipment pool is used for storage of the reactor vessel cap (not the drywell cap) during the refueling process. It has been suggested to me by astronuc the equipment on the floor at the back left corner might be the steam dryer (would that be radioactive?).