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RE: OT: Massive 8.9 quake in northern Japan
Posted: Tue Mar 15, 2011 6:46 pm
by jeffk3510
ORIGINAL: ChezDaJez
ORIGINAL: bradfordkay
Steve, I always wondered about the secondary loop in submarines. Is it seawater being pumped through? Can the trail of warmer water be used to find the sub?
I think Bullwinkle
used to be a nuke so he understands the shipboard systems far better than I do. As he says the secondary system on newer submarines is a closed loop system. On early generation Soviet nuculear submarines the secondary loop was cooled by seawater.
I know several countries including the Soviets/Russians and the US have all experiemented with ways to detect submarine heat trails using IR and blue/green laser systems over the past few decades. What progress has been made I don't know.
One of the problems with detecting the heat trail from nuclear subs is just what JWE said. The warmer water is rapidly cooled by the surrounding ocean and by the time it reaches the surface it should be about the same temperature. Also the sea surface temperature is quite variably even over short distances. Currents and wind/wave action will also help to reduce its detectability.
Chez
Used to be one or used to be on one?
RE: OT: Massive 8.9 quake in northern Japan
Posted: Tue Mar 15, 2011 6:52 pm
by Bullwinkle58
ORIGINAL: USS America
That's a very good explanation of the situation.
It is, but the situation is fast-moving and things have moved along since it was written. I see on TV that there was a fire in a spent rod continament pool in the past twelve hours, and that radioactive readings in Tokyo are elevated, but not yet dangerous.
The French, apparently with no more info than us here, are yelling that the accident is a '6', not a '5' (thanks, France, for that.) Gemrany has shut down a whole bunch of its reactors, but the story didn't say why (inspections I suspect.) And solar-related stocks are soaring, while nuclear-power-related stocks are tanking.
It does seem as if the Japanese govt and the international atomic agency guys aren't on the same sheet of music, and that there is a lot of confusion over who is giving the straight scoop to the world, let alone the Japanese public. I suspect again that there is very imperfect kowledge as a lot of instrumentation is probably wiped, and nobody is going near the containment vessels to use eyeballs.
Now is the time to have invented very good robots. We need a Wayback Machine.
RE: OT: Massive 8.9 quake in northern Japan
Posted: Tue Mar 15, 2011 7:00 pm
by Bullwinkle58
ORIGINAL: ChezDaJez
I think Bullwinkle used to be a nuke so he understands the shipboard systems far better than I do. As he says the secondary system on newer submarines is a closed loop system. On early generation Soviet nuculear submarines the secondary loop was cooled by seawater.
I used to be a pork chop ON a nuke, but I have big ears and I was always curious. We have at least one self-IDed nuke around here--Knavey.
Our subs' secondary loops are cooled by seawater in the condensers, but seawater never touches anything radioactive.
These Japanese reactors are described as boiling-water, and don't sound like they have steam generators. I haven't looked it up, but it sounds like they generate steam directly off the top of the core and take it directly to the turbines, unless the media has got it very wrong. That's cheaper and simpler, but it makes your generating gear radioactive (probably low level, but still . . .)
Naval reactors are pressurized and don't make steam; they transfer heat into steam generators which make steam. The primary coolant doesn't ever mix with secondary water, so the secondary steam can go into the engineroom and not poison the crew. Primary water never leaves the reactor compartment, and humans don't go in there except in the yards.
RE: OT: Massive 8.9 quake in northern Japan
Posted: Tue Mar 15, 2011 7:29 pm
by herwin
ORIGINAL: Bullwinkle58
ORIGINAL: USS America
That's a very good explanation of the situation.
It is, but the situation is fast-moving and things have moved along since it was written. I see on TV that there was a fire in a spent rod continament pool in the past twelve hours, and that radioactive readings in Tokyo are elevated, but not yet dangerous.
The French, apparently with no more info than us here, are yelling that the accident is a '6', not a '5' (thanks, France, for that.) Gemrany has shut down a whole bunch of its reactors, but the story didn't say why (inspections I suspect.) And solar-related stocks are soaring, while nuclear-power-related stocks are tanking.
It does seem as if the Japanese govt and the international atomic agency guys aren't on the same sheet of music, and that there is a lot of confusion over who is giving the straight scoop to the world, let alone the Japanese public. I suspect again that there is very imperfect kowledge as a lot of instrumentation is probably wiped, and nobody is going near the containment vessels to use eyeballs.
Now is the time to have invented very good robots. We need a Wayback Machine.
ORIGINAL: Bullwinkle58
ORIGINAL: USS America
That's a very good explanation of the situation.
It is, but the situation is fast-moving and things have moved along since it was written. I see on TV that there was a fire in a spent rod continament pool in the past twelve hours, and that radioactive readings in Tokyo are elevated, but not yet dangerous.
The French, apparently with no more info than us here, are yelling that the accident is a '6', not a '5' (thanks, France, for that.) Gemrany has shut down a whole bunch of its reactors, but the story didn't say why (inspections I suspect.) And solar-related stocks are soaring, while nuclear-power-related stocks are tanking.
It does seem as if the Japanese govt and the international atomic agency guys aren't on the same sheet of music, and that there is a lot of confusion over who is giving the straight scoop to the world, let alone the Japanese public. I suspect again that there is very imperfect kowledge as a lot of instrumentation is probably wiped, and nobody is going near the containment vessels to use eyeballs.
Now is the time to have invented very good robots. We need a Wayback Machine.
Robot research costs money, and the UK is getting out of that kind of research. UC Merced seems to be doing some interesting work in that direction, so I'm planning to spend the summer there.
RE: OT: Massive 8.9 quake in northern Japan
Posted: Tue Mar 15, 2011 8:35 pm
by spence
On the international scale used by experts to rank nuclear incidents, Chernobyl ranked as a “major accident” or 7, the highest on the scale. Three Mile Island was a 5, an “accident with wider consequences.” Japanese officials have said they regard the Fukushima incident as a 4, an “accident with local consequences.”
I just got done watching a news/opinion show on TV which attempted to get an expert to say what threat the problems at the reactors in Japan might pose to the U.S. The answers given were not particularly useful to anyone not actually equipped to measure radiation. The problems with the reactors were compared (as in the article) in the segment to Chernobyl and Three Mile Island. A couple of questions not asked were:
1) How does the amount of radiation leaked from the worst case "meltdown scenario" compare to the radiation created by the Hiroshima and Nagasaki atomic bombs?
2) I don't imagine the isotopes of radiative fallout from the atomic bombs were the same as might be created by one or more meltdowns at Fukushima (but perhaps they were). In any case such radiation as was created drifted across the Pacific to the U.S. much the way the "firebomb balloons" launched by the Japanese in 1944-45 did. Was it ever detected here?
3) How long did it take for those balloons to cross the Pacific and how does that time compare to the half-life of Iodine-131 which seems to be the radiation threat mentioned most often?
RE: OT: Massive 8.9 quake in northern Japan
Posted: Tue Mar 15, 2011 10:11 pm
by Chickenboy
FIL is a retired Los Alamos nuclear physicist. Helped build bombs, but spent most of his time on reactor safety issues here and abroad. In his opinion, there's not a chance in hell that this leads to a full meltdown. It may be a TMI-like partial core melt with extensive cleanup after the fact, but he's convinced that we won't be having a 'China Syndrome' in Japan.
RE: OT: Massive 8.9 quake in northern Japan
Posted: Tue Mar 15, 2011 10:16 pm
by Chickenboy
ORIGINAL: spence
On the international scale used by experts to rank nuclear incidents, Chernobyl ranked as a “major accident” or 7, the highest on the scale. Three Mile Island was a 5, an “accident with wider consequences.” Japanese officials have said they regard the Fukushima incident as a 4, an “accident with local consequences.”
I just got done watching a news/opinion show on TV which attempted to get an expert to say what threat the problems at the reactors in Japan might pose to the U.S. The answers given were not particularly useful to anyone not actually equipped to measure radiation. The problems with the reactors were compared (as in the article) in the segment to Chernobyl and Three Mile Island. A couple of questions not asked were:
1) How does the amount of radiation leaked from the worst case "meltdown scenario" compare to the radiation created by the Hiroshima and Nagasaki atomic bombs?
2) I don't imagine the isotopes of radiative fallout from the atomic bombs were the same as might be created by one or more meltdowns at Fukushima (but perhaps they were). In any case such radiation as was created drifted across the Pacific to the U.S. much the way the "firebomb balloons" launched by the Japanese in 1944-45 did. Was it ever detected here?
3) How long did it take for those balloons to cross the Pacific and how does that time compare to the half-life of Iodine-131 which seems to be the radiation threat mentioned most often?
Spence,
My understanding of the Hiroshima and Nagasaki radiation issues is that radiation there was comparatively short-lived. This may be due in part to the airburst (versus groundburst=more radioactive earth thrown up) and the fact that with explosions in the atmosphere, they tend to consume much of their energy in the production of a large nuclear fireball, heat, etc. Had there been a ground detonation, things would be worse for the long-term. Scant comfort for those exposed to the very high radiation generated by the blast, I know, but things are obviously a whole lot better within a few (comparative) years.
Dunno about a large scale nuclear explosion from a nuke plant by comparison.
RE: OT: Massive 8.9 quake in northern Japan
Posted: Tue Mar 15, 2011 11:30 pm
by witpqs
ORIGINAL: Chickenboy
Dunno about a large scale nuclear explosion from a nuke plant by comparison.
Don't worry about that. That's called a nuclear bomb, and that ain't happening. The worst potential problems involve radioactive material being made airborne by means of fire, and any explosions would come from that. The fires so far have not been nuclear materials themselves but in the outer containment (those Hydrogen gas explosions for example) and other parts of the plant.
I read a book by a journalist several years ago in which he talked about how journalists and their editors get to print (and broadcast) what they want to. They keep calling one "expert" after another until they find one you either wants to or is willing to say what they want. It's no trouble at all to make 26 or 27 phone calls or as many as they have to.
RE: OT: Massive 8.9 quake in northern Japan
Posted: Tue Mar 15, 2011 11:32 pm
by witpqs
ORIGINAL: Mynok
Where are they pumping in the seawater then?
When I first read that they gave the impression it was into the containment building itself. Now I'm not so sure as I have read that the English speaking press' translations of the Japanese press releases has been horrible and misleading.
RE: OT: Massive 8.9 quake in northern Japan
Posted: Wed Mar 16, 2011 1:24 am
by Chickenboy
ORIGINAL: witpqs
ORIGINAL: Chickenboy
Dunno about a large scale nuclear explosion from a nuke plant by comparison.
Don't worry about that. That's called a nuclear bomb, and that ain't happening. The worst potential problems involve radioactive material being made airborne by means of fire, and any explosions would come from that. The fires so far have not been nuclear materials themselves but in the outer containment (those Hydrogen gas explosions for example) and other parts of the plant.
Agreed. H explosions and steam explosions are more likely. Powerful enough to cause some questions about containment and escape of some radioactivity. FIL was somewhat comforting in saying that the reactor cores will resume ambient temperature, but it may take them 4-6 days to shed all that heat from their reaction. In other words, more time=more betta.
RE: OT: Massive 8.9 quake in northern Japan
Posted: Wed Mar 16, 2011 5:08 am
by herwin
Another explosion and the reactor staff has been pulled out of the facility. I suspect hard lessons have been learned about designing for this kind of disaster.
RE: OT: Massive 8.9 quake in northern Japan
Posted: Wed Mar 16, 2011 6:13 am
by CaptBeefheart
I think it's too bad the media conversation has drifted to the nuke plant, and the plight of numerous homeless people without power, food or water is being ignored. There's no sense of perspective--the tsunami killed one person in Oregon, which is one more person than radiation from Fukushima Daiichi will kill.
Here's another thoughtful
article on Fukushima which jibes well with what an ex-GE nuke engineer who lives in Tokyo was telling me last night. He's not leaving Tokyo, by the way.
Cheers,
CC
RE: OT: Massive 8.9 quake in northern Japan
Posted: Wed Mar 16, 2011 12:55 pm
by Cap Mandrake
I can't blame the media for covering the reactor thing. It is a major story. There is at least the potential of very significant impact. That is what the media are for. I think they are a bit premature on the "Are we safe here" stuff, but they absolutely need to cover the story. Official government releases leave something to be desired.
RE: OT: Massive 8.9 quake in northern Japan
Posted: Wed Mar 16, 2011 12:57 pm
by jeffk3510
I remember watching the news the first time and all they talked about were the Americans living in Japan....I thought how narrow minded..
RE: OT: Massive 8.9 quake in northern Japan
Posted: Wed Mar 16, 2011 1:51 pm
by The Gnome
ORIGINAL: jeffk3510
I remember watching the news the first time and all they talked about were the Americans living in Japan....I thought how narrow minded..
I get where you're going, but it is an American news broadcast trying to get info to families who have people over there. I think if you knew people there that would be your first concern as well. I'm not seeing it as an "Ugly American"ism.
RE: OT: Massive 8.9 quake in northern Japan
Posted: Wed Mar 16, 2011 1:59 pm
by jeffk3510
ORIGINAL: The Gnome
ORIGINAL: jeffk3510
I remember watching the news the first time and all they talked about were the Americans living in Japan....I thought how narrow minded..
I get where you're going, but it is an American news broadcast trying to get info to families who have people over there. I think if you knew people there that would be your first concern as well. I'm not seeing it as an "Ugly American"ism.
Fair enough.
RE: OT: Massive 8.9 quake in northern Japan
Posted: Wed Mar 16, 2011 2:22 pm
by witpqs
ORIGINAL: Cap Mandrake
I can't blame the media for covering the reactor thing. It is a major story. There is at least the potential of very significant impact. That is what the media are for. I think they are a bit premature on the "Are we safe here" stuff, but they absolutely need to cover the story. Official government releases leave something to be desired.
I don't blame them either for covering it. I do blame them for the way they have covered it, with wanton misinformation and bombastic claims (even to the point of implying or misstating facts regarding the past incidents at TMI and Chernobyl), and I do wish they would provide greater coverage of the more important, life-threatening and life-changing issues that people are facing over there right now.
RE: OT: Massive 8.9 quake in northern Japan
Posted: Wed Mar 16, 2011 2:46 pm
by witpqs
MIT NSE Nuclear Information Hub (http://web.mit.edu/nse/)
I assume they have posts going back to the beginning of these events and I plan to eventually start at the beginning and read forward.
RE: OT: Massive 8.9 quake in northern Japan
Posted: Wed Mar 16, 2011 2:55 pm
by US87891
ORIGINAL: witpqs
ORIGINAL: Cap Mandrake
I can't blame the media for covering the reactor thing. It is a major story. There is at least the potential of very significant impact. That is what the media are for. I think they are a bit premature on the "Are we safe here" stuff, but they absolutely need to cover the story. Official government releases leave something to be desired.
I don't blame them either for covering it. I do blame them for the way they have covered it, with wanton misinformation and bombastic claims (even to the point of implying or misstating facts regarding the past incidents at TMI and Chernobyl), and I do wish they would provide greater coverage of the more important, life-threatening and life-changing issues that people are facing over there right now.
They need to sell air time. Telling the truth and giving information is boring. It is more interesting to give details about four headed dogs and the end of the earth so people will be rivited to the TV when the commercial comes. It is not their fault, it is just their occupation. The worse thay can make something sound the better it is for their ratings. Some of the networks are even reporting things from conspiracy websites like abovetopsecret as factual. Like Lenin said so many years ago, the worse the better.
RE: OT: Massive 8.9 quake in northern Japan
Posted: Wed Mar 16, 2011 3:09 pm
by Cap Mandrake
ORIGINAL: witpqs
ORIGINAL: Cap Mandrake
I can't blame the media for covering the reactor thing. It is a major story. There is at least the potential of very significant impact. That is what the media are for. I think they are a bit premature on the "Are we safe here" stuff, but they absolutely need to cover the story. Official government releases leave something to be desired.
I don't blame them either for covering it. I do blame them for the way they have covered it, with wanton misinformation and bombastic claims (even to the point of implying or misstating facts regarding the past incidents at TMI and Chernobyl), and I do wish they would provide greater coverage of the more important, life-threatening and life-changing issues that people are facing over there right now.
What do you expect? The reporters are selected on the basis of the attractiveness of their hair and/or breasts, neither of which is highly associated with nuclear engineers in my experience.