RE: OT: Massive 8.9 quake in northern Japan

RE: OT: Massive 8.9 quake in northern Japan (Full Version)

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Schanilec -> RE: OT: Massive 8.9 quake in northern Japan (3/14/2011 3:45:07 PM)
Hope those idiots are consentrated on one site. Easier to keep and eye on them.

witpqs -> RE: OT: Massive 8.9 quake in northern Japan (3/14/2011 11:14:54 PM)
FYI, USGS is now calling it a 9.0 earthquake.

rtrapasso -> RE: OT: Massive 8.9 quake in northern Japan (3/15/2011 12:19:44 AM)
quote: ORIGINAL: witpqs FYI, USGS is now calling it a 9.0 earthquake. These things tend to increase over time for technical reasons... originally the Sumatra quake that produced the tsunami was called an 8.7... now up to 9.1+ depending on who you believe. It took a few years to revise the numbers. i wouldn't be terribly surprised if they end up calling the recent Japanese quake a 9.3 or 9.4 (in about 2 years).

USSAmerica -> RE: OT: Massive 8.9 quake in northern Japan (3/15/2011 1:03:00 AM)
Things are going downhill at the Fukushima Daiichi nuclear plant. [:(]

Mynok -> RE: OT: Massive 8.9 quake in northern Japan (3/15/2011 2:22:59 AM)
They need to get some power generation there ASAP so they can shut those reactors down. I fear the worst.

witpqs -> RE: OT: Massive 8.9 quake in northern Japan (3/15/2011 3:34:34 AM)
quote: ORIGINAL: Mynok They need to get some power generation there ASAP so they can shut those reactors down. I fear the worst. The reactors shut down at the first warning of the quake. Apparently the whole thing has been dealing with residual heat.

ChezDaJez -> RE: OT: Massive 8.9 quake in northern Japan (3/15/2011 11:41:56 AM)
quote: ORIGINAL: witpqs quote: ORIGINAL: Mynok They need to get some power generation there ASAP so they can shut those reactors down. I fear the worst. The reactors shut down at the first warning of the quake. Apparently the whole thing has been dealing with residual heat. The residual heat from the reactor core is the problem. I'm no expert and most of my nuclear reactor knowledge comes from submarine type reactors but the underlying principle is the same though the execution may be somewhat different. A reactor is basically nothing more than a huge pressure cooker. Within this pressure cooker, you have a primary loop that contains water under high pressure. The reactor's sole purpose is to generate the heat to turn this water into the steam that drives a turbine. It is a closed loop system and has no access to the environment unless damaged. The water in this loop is radioactive. To recondense the steam back into water, the primary loop passes through a secondary loop that receives water from a lake, river, ocean or huge cooling ponds. This secondary loop is entirely seperate from the primary loop and is open to the environment. This water is not radioactive. The water in the secondary loop is circulated by means of huge main cooling pumps. These pumps require considerable electrical power to function. It is the loss of electrical power to these pumps that is causing all the problems at Fukushima Dai-ichi. The electrical generation plant failed because the reactors scrammed after the quake as they are supposed to causing the turbines to stop. The backup diesel generators then took over. All was fine until the tsunami swamped the backup generators causing them to fail. Emergency battery back up then took over until they were depleted after about 6-8 hours. With the loss of the secondary loop, the reactors had no way to stay cool so the water inside the primary loop continued to evaporate and build up heat and pressure within the containment vessel. Think of it as a tea kettle sitting on a hot stove with no way to turn off the stove. With no operational secondary loop to cool the steam back into water, the water level in the core began to drop exposing more and more of the uranium rods. As more uranium is exposed, the temperature climbs. Uranium rods exposed to air can generate about 2200 degrees celsius but uranium begins melting at about 2100 degrees celsius. When the rods reach this temperature, you now have meltdown occuring. Hope this helps those who aren't familiar with reactor design and hopefully I don't look like to much of an idiot to those that are! Chez

bradfordkay -> RE: OT: Massive 8.9 quake in northern Japan (3/15/2011 4:51:24 PM)
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?

herwin -> RE: OT: Massive 8.9 quake in northern Japan (3/15/2011 4:55:38 PM)
quote: 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? The secondary loop is also a closed loop.

Mynok -> RE: OT: Massive 8.9 quake in northern Japan (3/15/2011 5:03:27 PM)
Where are they pumping in the seawater then?

witpqs -> RE: OT: Massive 8.9 quake in northern Japan (3/15/2011 6:03:06 PM)
quote: ORIGINAL: ChezDaJez quote: ORIGINAL: witpqs quote: ORIGINAL: Mynok They need to get some power generation there ASAP so they can shut those reactors down. I fear the worst. The reactors shut down at the first warning of the quake. Apparently the whole thing has been dealing with residual heat. The residual heat from the reactor core is the problem. I'm no expert and most of my nuclear reactor knowledge comes from submarine type reactors but the underlying principle is the same though the execution may be somewhat different. A reactor is basically nothing more than a huge pressure cooker. Within this pressure cooker, you have a primary loop that contains water under high pressure. The reactor's sole purpose is to generate the heat to turn this water into the steam that drives a turbine. It is a closed loop system and has no access to the environment unless damaged. The water in this loop is radioactive. To recondense the steam back into water, the primary loop passes through a secondary loop that receives water from a lake, river, ocean or huge cooling ponds. This secondary loop is entirely seperate from the primary loop and is open to the environment. This water is not radioactive. The water in the secondary loop is circulated by means of huge main cooling pumps. These pumps require considerable electrical power to function. It is the loss of electrical power to these pumps that is causing all the problems at Fukushima Dai-ichi. The electrical generation plant failed because the reactors scrammed after the quake as they are supposed to causing the turbines to stop. The backup diesel generators then took over. All was fine until the tsunami swamped the backup generators causing them to fail. Emergency battery back up then took over until they were depleted after about 6-8 hours. With the loss of the secondary loop, the reactors had no way to stay cool so the water inside the primary loop continued to evaporate and build up heat and pressure within the containment vessel. Think of it as a tea kettle sitting on a hot stove with no way to turn off the stove. With no operational secondary loop to cool the steam back into water, the water level in the core began to drop exposing more and more of the uranium rods. As more uranium is exposed, the temperature climbs. Uranium rods exposed to air can generate about 2200 degrees celsius but uranium begins melting at about 2100 degrees celsius. When the rods reach this temperature, you now have meltdown occuring. Hope this helps those who aren't familiar with reactor design and hopefully I don't look like to much of an idiot to those that are! Chez I also forgot to mention that much of the heat is coming from the products of the fission reaction. They are short-lived to fairly short-lived radioactive isotopes. As they decay they release heat. The amount of them present decreases as they decay, and therefore the amount of heat they release also decreases. Still, it is a lot of heat at first, then decreases fairly rapidly over hours/days/weeks. The uranium itself will be putting out some heat from its decay too, but at first the big heat producer is those short-lived isotopes.

Bullwinkle58 -> RE: OT: Massive 8.9 quake in northern Japan (3/15/2011 6:08:28 PM)
quote: 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? The secondary loop uses distilled water as well. Seawater is used in the condensate loop through the main condensers to convert used steam back to secondary loop feed water. That seawater is then tossed over the side. As to your last quesiton, the sea is large and cold, and the sub is small and only a little warm. There may be other ways to track subs from environmental effects, but I ain't discussing them here.

LargeSlowTarget -> RE: OT: Massive 8.9 quake in northern Japan (3/15/2011 6:08:35 PM)
quote: ORIGINAL: ChezDaJez The electrical generation plant failed because the reactors scrammed after the quake as they are supposed to causing the turbines to stop. The backup diesel generators then took over. All was fine until the tsunami swamped the backup generators causing them to fail. Emergency battery back up then took over until they were depleted after about 6-8 hours. If electrical power for the pumps is the problem, then something like this could be a solution? Unfortunately no turbo-electric ships that I know off remain in service - last one seems to have been SSN-685.

Bullwinkle58 -> RE: OT: Massive 8.9 quake in northern Japan (3/15/2011 6:10:50 PM)
quote: ORIGINAL: witpqs I also forgot to mention that much of the heat is coming from the products of the fission reaction. They are short-lived to fairly short-lived radioactive isotopes. As they decay they release heat. The amount of them present decreases as they decay, and therefore the amount of heat they release also decreases. Still, it is a lot of heat at first, then decreases fairly rapidly over hours/days/weeks. The uranium itself will be putting out some heat from its decay too, but at first the big heat producer is those short-lived isotopes. Press reports that the main Iodine isotope they're worried about has a half-life of eight days. I don't know the decay heat features of these reactors. I've seen elsewhere that the cores are a combo of uranium ond plutonium (about 7% of the latter.) Don't know if that's true.

JWE -> RE: OT: Massive 8.9 quake in northern Japan (3/15/2011 6:30:17 PM)
quote: 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? Technically, yes, perhaps. But the secondary loop discharge and recirc is periodic. Discharge is often over, or even under the layer, and is so dispersed that it doesn't have a 'trail' as one might suspect. IR heat detect, on the surface at least, requires a realtively large 'differential' to resolve a source. Dispersion from the sea makes that problematic for surface forces even with the requisite equipment. Beneath the surface, layering (horizontal and vertical) and current shift makes it practically impossible to track a vessel on the basis of its discharge heat signature. Water temperature and water pressure tend to collapse the discharge stream into a very narrow stream that is rotary and disperses by square law. Brother Chez may have some more practical things to say, but given what we gots now, there aint no way to get there from here unless you get real lucky.

Mynok -> RE: OT: Massive 8.9 quake in northern Japan (3/15/2011 7:28:40 PM)
Wired on the plant situation

USSAmerica -> RE: OT: Massive 8.9 quake in northern Japan (3/15/2011 8:28:49 PM)
quote: ORIGINAL: Mynok Wired on the plant situation That's a very good explanation of the situation.

ChezDaJez -> RE: OT: Massive 8.9 quake in northern Japan (3/15/2011 8:52:24 PM)
quote: 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

herwin -> RE: OT: Massive 8.9 quake in northern Japan (3/15/2011 8:56:21 PM)
quote: ORIGINAL: Mynok Where are they pumping in the seawater then? Now.

herwin -> RE: OT: Massive 8.9 quake in northern Japan (3/15/2011 8:59:58 PM)
Brother Bullwinkle is doing what he's supposed to do.

jeffk3510 -> RE: OT: Massive 8.9 quake in northern Japan (3/15/2011 9:46:59 PM)
quote: ORIGINAL: ChezDaJez quote: 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?

Bullwinkle58 -> RE: OT: Massive 8.9 quake in northern Japan (3/15/2011 9:52:48 PM)
quote: 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.

Bullwinkle58 -> RE: OT: Massive 8.9 quake in northern Japan (3/15/2011 10:00:13 PM)
quote: 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.

herwin -> RE: OT: Massive 8.9 quake in northern Japan (3/15/2011 10:29:17 PM)
quote: ORIGINAL: Bullwinkle58 quote: 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. quote: ORIGINAL: Bullwinkle58 quote: 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.

spence -> RE: OT: Massive 8.9 quake in northern Japan (3/15/2011 11:35:10 PM)
quote: 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?

Chickenboy -> RE: OT: Massive 8.9 quake in northern Japan (3/16/2011 1:11:09 AM)
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.

Chickenboy -> RE: OT: Massive 8.9 quake in northern Japan (3/16/2011 1:16:00 AM)
quote: ORIGINAL: spence quote: 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.

witpqs -> RE: OT: Massive 8.9 quake in northern Japan (3/16/2011 2:30:26 AM)
quote: 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.

witpqs -> RE: OT: Massive 8.9 quake in northern Japan (3/16/2011 2:32:34 AM)
quote: 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.

Chickenboy -> RE: OT: Massive 8.9 quake in northern Japan (3/16/2011 4:24:24 AM)
quote: ORIGINAL: witpqs quote: 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.

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