Japan Nuclear Crisis Part III

[Ed Lizard]

The reactor is scrammed...the controls rods are fully inserted in all 4 reactors.

I sort of doubt this is occuring, but if the melting point of the fuel rods is significantly lower or higher than the control rods, there could be a molten puddle of fuel on the floor of the reactor building, or empty channels where the rods were.

I kind of doubt it. I'm pretty sure without water the reactors we had in the Navy wouldn't go critical even if the rods were fully withdrawn, due to lack of a moderator. As I mentioned above, U-235 has a capture cross section, measured in a unit called Barnes, and a low energy neutron has a much higher probability of being captured and inducing fission than a fast neutron. I don't know about plutonium as reactor fuel, as far as whether it needs a moderator or not. And this is a BWR, not a PWR, so my knowledge base is limited.

Of course, nuclear weapons work without water. Briefly.

[Mt.Zoniac]

A nuclear reactor on a boat (ship) is a bitty thing with caps on energy levels, NOT the same thing a reactor on land for regional power. Boats are closed systems and are regulated by fuel and methodology these days. This is a not a SNAFOO............this is FUBAR. You can't compare apples and walnuts.

I sort of doubt this is occuring, but if the melting point of the fuel rods is significantly lower or higher than the control rods, there could be a molten puddle of fuel on the floor of the reactor building, or empty channels where the rods were.

I kind of doubt it. I'm pretty sure without water the reactors we had in the Navy wouldn't go critical even if the rods were fully withdrawn, due to lack of a moderator. As I mentioned above, U-235 has a capture cross section, measured in a unit called Barnes, and a low energy neutron has a much higher probability of being captured and inducing fission than a fast neutron. I don't know about plutonium as reactor fuel, as far as whether it needs a moderator or not. And this is a BWR, not a PWR, so my knowledge base is limited.

Of course, nuclear weapons work without water. Briefly.

[Mt.Zoniac]

So someone claims. Radiation is still spewing out.....high energy protons...enough that at least 13 proton beams were detected. There is still a reaction occurring.

The reactor is scrammed...the controls rods are fully inserted in all 4 reactors.

[OSUmetstud]

A nuclear reactor on a boat (ship) is a bitty thing with caps on energy levels, NOT the same thing a reactor on land for regional power. Boats are closed systems and are regulated by fuel and methodology these days. This is a not a SNAFOO............this is FUBAR. You can't compare apples and walnuts.

Right, but I'm not sure a reactor could go critical at all with very little water. The fuel enrichment is only 3-5% and you would need a ton of uranium in a correct configuration for it to become critical.

The control rods being fully inserted from the bottom and the lack of water should mean the chance at recriticality is remote if possible at all.

[OSUmetstud]

So someone claims. Radiation is still spewing out.....high energy protons...enough that at least 13 proton beams were detected. There is still a reaction occurring.

lol I'm pretty sure people would know if the control rods weren't inserted...the reactor would have been ****ed last week.

yeah, reactions still occur when the fuel is just sitting there...it doesn't mean it's critical. It's neutron beams...at least try to get the terminology correct.

[Dunkman]

Some small amount of fission is not the same thing is a nuclear chain reaction.

[SP]

is not the question more about the pressure levels inside the vessel and the potential risk associated with the inability to relieve them vs venting which in itself releases radiation? also, not sure what if any integrity issues any of the vessels in play may suffer from and to what extent.

how long can you maintain a scrammed reactor with minimal water or pressure management?

[SuperNET]

Good Read.....

Whatever one thinks about the near-criminal strategy taking place behind the scenes as to how Japan is handling the bailout, one thing is certain: the 50 Tepco workers who are currently laboring at Fukushima, doing all they can to restore the plant back to life, even at the cost of their own lives, are doing a tremendous service to their fellow citizens (futile or otherwise), and deserve to be called heroes. The Mail has compiled what little information is available about these impromptu martyrs, of whom five are believed to have already died and 15 are injured while others have said they know the radiation will kill them, in a piece that everyone should read, especially those who are wondering just who it is that is doing everything in their power to offset Hitachi's criminal conduct in the construction of the power plant as disclosed earlier. "The darkness is broken only by the flashing torchlight of the heroes who stayed behind. These first images of inside the stricken Fukushima Dai-Ichi power plant reveal the terrifying conditions under which the brave men work to save their nation from full nuclear meltdown. The Fukushima Fifty - an anonymous band of lower and mid-level managers - have battled around the clock to cool overheating reactors and spent fuel rods since the disaster on March 11."

http://www.zerohedge.com/article/fukushima-fifty

[Ed Lizard]

For size reasons, the uranium on the ship was nuclear weapons grade, 97% enriched 235. Commercial reactors refuel every few years, ship reactors refuel every 20 or 30 years. Part of that is the ship is rarely at full power when at sea, and the plants were shut down in the home port. But still, you want the most bang for the buck, as it were. (Not shut down for most of the fun ports, where 4160 volt shore power for the reactor coolant pumps wasn't readily available. Cubi Point NAS installed the transformers, as it was considered a working port, but then the NPA, the Maoist guerillas of the day started bombing transmission lines, so we always kept at least one reactor up. It affected the Machinist Mates the hardest, they had the biggest differential between watch stations (where someone had to work, it was called 'standing watch') between shut down and at power. The reactor operators for a time had 2 off/1 on liberty versus 3 on/1 off liberty in the reactor was up or down, the machinests went on 'port and starboard' liberty if a reactor was running.

But I digress.

500 plus Mw isn't some college research reactor, BTW, speaking of 'bitty things'.

[Ed Lizard]

Some uranium U-235 will, on its own, spontaneously split and burp put some neutrons. In the oil field, Am-Be sources are used as a source of neutrons for 'neutron porosity logging'. And some of the other fission products will burp out neutrons.

Which is why "seeing" the nuclear reaction beginning happens much quicker in a reactor that has just been shut down a day or two before versus a reactor that has been shut down for months. The control rods are moved very slowly, 3 seconds out, 57 seconds wait, if neutron levels were below the detectable limits, to avoid adding too much reactivity and having the reactor go 'super critical' before the power was detectable, maybe many decades per minute, and reach damaging power levels before it could be scrammed.

Actually, if the reactor is running steady state, it is critical, if the power level is increasing, it is super-critical, but just a little, if its controlled, If reactor power is being decreased, it is 'sub-critical'.

[Clinch Leatherwood]

I'm as rightwing as they come, well, not quite, but that BBN link has stories about the New World Order and stuff, and well, working in a nuclear plant for 4 years, I never heard of a neutron beam. A shutdown reactor wouldn't be emitting many neutrons, and I have no idea how it'd form a 'beam'.

BBN appears to be beyond World Net as a not exactly reliable source.

Some uranium U-235 will, on its own, spontaneously split and burp put some neutrons. In the oil field, Am-Be sources are used as a source of neutrons for 'neutron porosity logging'. And some of the other fission products will burp out neutrons.

Which is why "seeing" the nuclear reaction beginning happens much quicker in a reactor that has just been shut down a day or two before versus a reactor that has been shut down for months. The control rods are moved very slowly, 3 seconds out, 57 seconds wait, if neutron levels were below the detectable limits, to avoid adding too much reactivity and having the reactor go 'super critical' before the power was detectable, maybe many decades per minute, and reach damaging power levels before it could be scrammed.

Actually, if the reactor is running steady state, it is critical, if the power level is increasing, it is super-critical, but just a little, if its controlled, If reactor power is being decreased, it is 'sub-critical'.

The neutron beam stuff was right on kyodo's site. Very low levels. I guess they were observed at previous partial meltdowns as well.

[Scott747]

'Katz' is a Japanese fella that has been translating the TEPCO and other Japanese agency news conferences on USTREAM. This is from someone that was listening to the Katz translation, so take it loosely.

The 4 a.m. TEPCo news conference information - in response to reporters' questions, and as translated by 'katz' - is that the atmospheric radiation in or around Unit 3 (where the workers are in its turbine building?) is at 0.5 millisieverts/hour, but that the surface of the six inches of water in the turbine building was measured to be 400 millisieverts/hour. The three workers were in that water - which was not there the day before - for about 40-50 minutes between 10:30 a.m. and noon on Thursday, when they were connecting power in the turbine building. One worker wore boots, two did not. All three are licensed radiation engineers, one with 4 years, one with 11 years, and one with 14 years of experience. Not all are direct TEPCo employees, but work for partner companies or contractors. Also, the radioactive components in the water seem to be 10,000 times higher than would be expected from normal operations - indicating a fuel rod source (core or spent fuel pool) for the contamination. The actual source is unknown by TEPCo. Still no word, that I've heard, on the status of any spare parts needed ASAP before a restoration of core cooling at Units 1-3 can begin. [if we now know the precise temperature of the SFP in Unit 4, that seems to indicate that some measuring devices are working again, thanks to the restoration of power.

[ArtRosen]

http://www.cnn.com/2011/WORLD/asiapcf/03/24/japan.nuclear.seawater/index.html?eref=rss_latest&utm_source=dlvr.it&utm_medium=twitter&utm_campaign=topnewsfeeder

Salt buildup likely to harm pumping system before reactor, expert says

(CNN) -- While the buildup of salt from seawater pumped in to cool reactors at Japan's Fukushima Daiichi nuclear plant may become a concern, it is likely to affect the pumping system itself before it affects the fuel rods, one expert said Thursday.

"In the core, it's probably not that great of a concern because it's going to be pretty hot in there," and the salt is likely to melt before the core reaches a dangerous temperature, said Gary Was, a nuclear engineering expert at the University of Michigan.

Seawater has been used as an emergency measure after the tsunami that followed the March 11 earthquake left the plant crippled.

When salt water boils and evaporates, it leaves the salt behind. There are some concerns that those salt crystals could adhere to the fuel rods -- insulating them against future efforts to cool them, allowing the temperature to rise and possibly resulting in overheating.

[LovintheWhiteFluff]

NEWS ADVISORY: Reactor vessel of Fukushima plant No. 3 unit may have been damaged: Gov't panel

http://english.kyodonews.jp/

[LovintheWhiteFluff]

According to Asahi Shimbun which is quoting the Japan NRC, the Fukushima event has just surpassed Three Mile Island in terms of seriousness, and has been upgraded from Level 5 "Accident with Wider Consequences" to Level 6 "Serious Accident." Only Chernobyl is a Level 7 event.

Read more: http://www.businessinsider.com/fukushima-raised-to-level-6-on-ines-scale-now-officially-more-serious-than-3-mile-island-2011-3#ixzz1HZjlr6Rw

[Ed Lizard]

http://www.asahi.com/english/TKY201103240190.html

Water is becoming an issue.

[johnc]

I dozed off during the 12pm news but I think I heard them say that the pumps are damaged by seawater and they might be getting new pumps from the US.

Other news of the day is that the #1 building's control room has lights now... radiation higher than the legal limit was found on a vegetable in Tokyo... and tap water in another city has radiation above the legal limit.

[LovintheWhiteFluff]

Fukushima radioactive fallout nears Chernobyl levels

Japan's damaged nuclear plant in Fukushima has been emitting radioactive iodine and caesium at levels approaching those seen in the aftermath of the Chernobyl accident in 1986. Austrian researchers have used a worldwide network of radiation detectors – designed to spot clandestine nuclear bomb tests – to show that iodine-131 is being released at daily levels 73 per cent of those seen after the 1986 disaster. The daily amount of caesium-137 released from Fukushima Daiichi is around 60 per cent of the amount released from Chernobyl.

The difference between this accident and Chernobyl, they say, is that at Chernobyl a huge fire released large amounts of many radioactive materials, including fuel particles, in smoke. At Fukushima Daiichi, only the volatile elements, such as iodine and caesium, are bubbling off the damaged fuel. But these substances could nevertheless pose a significant health risk outside the plant.

http://www.newscientist.com/article/dn20285-fukushima-radioactive-fallout-nears-chernobyl-levels.html

[Scott747]

Operations at reactors 1, 2 and 3 have been temporarily suspended because of 'radiation in the water' from a brief update on CNBC.

[Scott747]

Edano is calling for a voluntary evacuation out to 30 km now with an official request possibly coming soon. Reasoning is logistics and not radiation fallout.

http://www3.nhk.or.jp/daily/english/25_20.html

[LovintheWhiteFluff]

(Reuters) - China found two Japanese travellers arriving with high radiation levels Friday in the latest consequence of contamination from a crippled nuclear plant two weeks after the Asian nation's devastating earthquake and tsunami.

China's customs body said the pair had medical treatment for radiation levels "seriously" over the limit, but they did not present a risk to others after flying to Wuxi in the east.

Until now no one in Japan except workers at the stricken plant has been found with seriously elevated radiation levels, and Japan's foreign ministry noted that as of March 18 the International Civil Aviation Association had declared that screening of airline passengers from Japan was not necessary.

[LovintheWhiteFluff]

Ticker on BBC News 24 saying at the moment "Officials at Fukushima nuclear plant suspect a reactor core could be breached"

[LovintheWhiteFluff]

Reuters - TEPCO says it is hard to determine the source of radiation in the water in reactor 3, and that it could have come from the cooling pool. It says it considering bailing water out of reactors as the radiation is high.

[Sunny and Warm]

It's been apparent for several days now that the Americans and the Int'l nuclear watchdog group were being the honest purveyors of info all along. It appears the Japanese are willing to risk the health of their citizens in order to calm the waters in the face of this disaster. I wonder at what point we start to hear the slow drumbeat internationally for a Chernoble-type cure as a testing of the waters so to speak. The alternative of trying to fix this thing leads to long term contamination at this plant. I can't see how they'll even be able to shut this plant down permanently for some time.

[SP]

It's been apparent for several days now that the Americans and the Int'l nuclear watchdog group were being the honest purveyors of info all along. It appears the Japanese are willing to risk the health of their citizens in order to calm the waters in the face of this disaster. I wonder at what point we start to hear the slow drumbeat internationally for a Chernoble-type cure as a testing of the waters so to speak. The alternative of trying to fix this thing leads to long term contamination at this plant. I can't see how they'll even be able to shut this plant down permanently for some time.

careful.....japan is also dealing with two other catastrophic events which alone create an environment which maintaining some level of governing and law difficult. While I do agree with some of what you stated, there might be a point, at least locally, when too much info could create hysteria levels to which few if any options exist in managing.

You can also get into the cultural aspects of the process of controlling the evolution of the various crisis which are consuming at least portions of Japan, though as risk expands into the more progressive and modernized regions of Japan its citizenry will begin to create a stir which con not be contained.

[SP]

http://www.cnn.com/2...n=topnewsfeeder

Salt buildup likely to harm pumping system before reactor, expert says

(CNN) -- While the buildup of salt from seawater pumped in to cool reactors at Japan's Fukushima Daiichi nuclear plant may become a concern, it is likely to affect the pumping system itself before it affects the fuel rods, one expert said Thursday.

"In the core, it's probably not that great of a concern because it's going to be pretty hot in there," and the salt is likely to melt before the core reaches a dangerous temperature, said Gary Was, a nuclear engineering expert at the University of Michigan.

Seawater has been used as an emergency measure after the tsunami that followed the March 11 earthquake left the plant crippled.

When salt water boils and evaporates, it leaves the salt behind. There are some concerns that those salt crystals could adhere to the fuel rods -- insulating them against future efforts to cool them, allowing the temperature to rise and possibly resulting in overheating.

Apparently, the US Navy is sending in several barges with pure water on them to flush out the pumps and also flood the cores/pools.

[Sunny and Warm]

careful.....japan is also dealing with two other catastrophic events which alone create an environment which maintaining some level of governing and law difficult. While I do agree with some of what you stated, there might be a point, at least locally, when too much info could create hysteria levels to which few if any options exist in managing.

You can also get into the cultural aspects of the process of controlling the evolution of the various crisis which are consuming at least portions of Japan, though as risk expands into the more progressive and modernized regions of Japan its citizenry will begin to create a stir which con not be contained.

I am also struck by the lack of calls from most in the international community for Japan to be more transparent. I read early on that China asked for a more honest assessment, but things quieted after that. If this were Russia or China, the American MSM would be all over them like flies on doodoo. The hypocrisy is striking.

Just a passing comment about not feeding the citizens too much info or they'll go all nuts. While true to an extent, isn't it better to inform people as a way to lessen rumors and hysteria rather than hide info from them, which in the end leads to greater anxiety and commotion? There are people in Japan who at this moment are likely being harmed to some degree by radiation. However, that is better than allowing them better info so that they can decide to move away from it. Is that correct?

[SP]

Another day of bad news. So now they are concerned about units 3's core vessel integrity, which btw is the mox reactor. There is a lot we do not know as of yet, where exactly were the workers when this water was found and how many possible water sources could have delivered it (basic process of elimination). Vessel, plumbing to and from, pool.

I guess though power has been restored to the location of these reactors they have yet to take measures for monitoring them 24/7 by using the power to provide 24/7 lighting, monitoring equipment including various detectors and video surveillance? Now if they did do these things, they would likely know exactly what occurred and where it came from.

Now its time to take a step back and review the current status. Before unit 3 was labeled to have a potential integrity problem with the vessel or pool, others already bore that distinction. What is the big picture for all 6 reactors and has the tipping point been reached to begin to take swift yet crude actions to begin containment, as in Chernobyl? If there is a potential for another explosion on any of these units, certainly unit 3 and those which surround it, someone likely has to make a bold decision very soon.

[SP]

I am also struck by the lack of calls from most in the international community for Japan to be more transparent. I read early on that China asked for a more honest assessment, but things quieted after that. If this were Russia or China, the American MSM would be all over them like flies on doodoo. The hypocrisy is striking.

Just a passing comment about not feeding the citizens too much info or they'll go all nuts. While true to an extent, isn't it better to inform people as a way to lessen rumors and hysteria rather than hide info from them, which in the end leads to greater anxiety and commotion? There are people in Japan who at this moment are likely being harmed to some degree by radiation. However, that is better than allowing them better info so that they can decide to move away from it. Is that correct?

I hear what you are saying but there also comes a point where you look at the bullet list of "thing we can do" and the options all suck. This is why I stated, if/when the risk spreads into the Tokyo region all bets are off.

Those who can, have moved away within the guidelines of the govts warning, which has been expanded to about 19-20 miles now. Its voluntary because depending upon where you are....is train service operational, buses, cars air? Where are you going beyond family resources which might very well be very localized?

Not sure what the total population of the evacuation zone is now but that would be an interesting number.

[das]

Does anyone have a good 7-day wind forecast for the area? My last attempt with WeatherBug didn't verify too well.

Here you go:

http://ready.arl.noa...-bin/trajsrc.pl

Sendai's WMO code is "RJSS". Plunk it in and select which model you'd like to output and follow the prompts.

Edited to add, here's a direct Google Earth .kmz output for the 384hr GFS:

http://ready.arl.noaa.gov/hysplitout/HYSPLITtraj_17121.kmz