@oralloy,
Quote:"The indications we have, from the reactor to radiation readings and the materials they are seeing, suggest that the core has melted through the bottom of the pressure vessel in unit two, and at least some of it is down on the floor of the drywell."
the Japanese are sufficiently alarmed to call for expertise re-enforcements.
Quote:PARIS | Wed Mar 30, 2011 10:19am EDT
(Reuters) - Areva Chief Executive Anne Lauvergeon arrived in Japan on Wednesday, broadening out a French delegation that has flown out to help Tokyo Electric Power bring its crippled Fukushima nuclear plant under control.
The head of the French nuclear reactor maker -- one of France's most powerful female executives -- traveled to Tokyo with three French experts in radioactive water contamination.
Two other Areva experts flew to Japan on Tuesday, after a request for help from Tokyo Electric Power (TEPCO), an Areva spokeswoman said.
Separately, President Nicolas Sarkozy will make a flying visit to Tokyo on Thursday, the first foreign leader to arrive since a March 11 earthquake
http://www.reuters.com/article/2011/03/30/us-japan-areva-idUSTRE72T3O920110330
@oralloy,
oralloy wrote:Mon Mar 28, 2011 9:03am EDT
TOKYO (Reuters) - Greenpeace called on the Japanese government to extend an evacuation zone around the stricken Fukushima nuclear power plant, saying it had found high radiation levels outside the zone.
The environmental group said it had confirmed radiation levels of up to 10 microsieverts per hour in Iitate village, 40 km (25 miles) northwest of the nuclear plant.
http://www.reuters.com/article/2011/03/28/us-japan-quake-greenpeace-idUSTRE72R2XV20110328
Wed Mar 30, 2011 11:05am EDT
VIENNA, March 30 (Reuters) - The International Atomic Energy Agency has told Japan that radiation levels recorded at a village near a stricken nuclear reactor are over recommended levels, a senior IAEA official said on Wednesday.
Iitate village lies 40 km (25 miles) northwest of the nuclear plant.
"The first assessment indicates that one of the IAEA operational criteria for evacuation is exceeded in Iitate village," IAEA official Denis Flory told a news conference.
http://www.reuters.com/article/2011/03/30/japan-nuclear-village-idUSWEA182620110330
@Butrflynet,
Butrflynet wrote:http://www3.nhk.or.jp/daily/english/28_33.html
Exposed workers okay
Three men exposed to high levels of radiation at the Fukushima Daiichi nuclear power plant have left the hospital with a clean bill of health.
The 3 workers left the National Institute of Radiological Sciences in Chiba Prefecture on Monday.
They had been receiving special medical treatment after having been exposed to radiation while installing power cables at the Number 3 reactor complex on Thursday.
Two of the men stood in radioactive water for about 2 hours. They were due to receive treatment for burns, but doctors at the institute found that this was not necessary.
The institute says the level of their exposure was up to 3,000 millisieverts, less than initially thought.
The 2 men reportedly show no symptoms of burns, and their internal organs were exposed to very low levels of radiation.
The institute says the third man also has no symptoms.
The 3 men will undergo checks at the institute in several days' time.
Doctor Fumiaki Nakayama of the institute says that even if the men do develop symptoms, they do not need treatment, and the symptoms will eventually disappear.
Three sieverts is quite a dose. I imagine they shortened their life a bit, although it's true that they probably don't have to worry too much about short term impact.
I think it's a given that reactor #2 has containment problems, but here's a sign that reactor #3 might also have some sort of containment difficulties:
Quote:Air may be leaking from reactors No. 2 and 3
Japan's Nuclear and Industrial Safety Agency says air may be leaking from the No 2 and No 3 reactors at the Fukushima Daiichi power plant.
The agency was responding at a news conference on Wednesday to speculation that low pressure inside the 2 reactors was due to possible damage to the reactors' pressure vessels.
It said some of their data show pressure is low, but there is no indication of large cracks or holes in the reactor vessels.
The agency said fluctuations in temperature and pressure are highly likely to have weakened valves, pipes and openings under the reactors where the control rods are inserted.
Wednesday, March 30, 2011 15:15 +0900 (JST)
http://www3.nhk.or.jp/daily/english/30_25.html
(Is that URL going to be recycled next time there is a 25th story on the 30th day of a month?)
Latest news briefs from NHK:
Radiation monitors not given to each worker
NHK has learned that Tokyo Electric Power Company, or TEPCO, has not provided every worker at the damaged Fukushima nuclear plant with radiation monitors, breaking government rules.
High levels of contamination have been detected at the Daiichi power complex following a series of hydrogen explosions that have scattered radioactive substances.
TEPCO says the quake destroyed many radiation monitors, so in some work groups only leaders have them, leaving others struggling to manage exposure.
The government requires companies to provide each individual worker with a radiation monitor when working under such conditions.
One worker who helped restore electricity to the plant, says each man must have been exposed to different levels of radiation, and that he has no idea how much contamination he was exposed to.
TEPCO says that those without monitors are assigned to low-radiation work, and that safety measures are in place.
The health ministry says exposure to large amounts of radiation is always a possibility during a nuclear power plant accident. It adds if the claims are true it is a serious problem, and that it plans to investigate the company's safety management.
Thursday, March 31, 2011 19:37 +0900 (JST)
IAEA reports high radiation outside exclusion zone
The International Atomic Energy Agency says radiation levels twice as high as its criterion for evacuation were detected in a village 40 kilometers from the troubled Fukushima Daiichi nuclear plant.
This is outside the 20 kilometer exclusion zone and the 20-to-30 kilometer alert zone where the Japanese government advises voluntary evacuation.
The nuclear watchdog reported the findings at a meeting of its members in Vienna on Wednesday.
The IAEA said its experts measured levels of Iodine 131 and Cesium 137 in soil around the plant between March 18th and 26th.
It said measurements in Iitate Village, 40 kilometers northwest of the Fukushima plant, was double the IAEA operational criteria for evacuation and that it has advised Japan to carefully assess the situation.
In Tokyo on Thursday, Japan's Chief Cabinet Secretary Yukio Edano told reporters that the government has been notified by the IAEA of its radiation findings.
Edano said the reported radiation levels in Iitate will not have an immediate impact on human health but could be harmful if exposed over a long period of time. He said the government will closely assess the long-term impact and take appropriate action.
Thursday, March 31, 2011 13:29 +0900 (JST)
Nuclear watchdog defends its decision
Japan's nuclear safety watchdog says it sees no reason to change the zone for which the government advised residents to stay indoors or evacuate voluntarily.
The Nuclear Safety Commission made the remark to reporters on Thursday, following reports by the IAEA that radiation levels twice as high as its criterion for evacuation were detected in soil at a village outside the zone.
Commission member Seiji Shiroya said evacuation criteria in Japan are decided according to how much radiation people would be exposed to, not radiation levels in the ground. He said the IAEA's findings should be used as references, but that the commission's decision on the zone is correct.
Shiroya said the commission studies various factors, including radiation levels in the air and amounts of airborne radioactive substances taken into the body through breathing and eating.
He said the IAEA probably measured radiation on a grass surface with available equipment, but that he believes the commission's figures are more accurate when considering the effect on the human body.
Thursday, March 31, 2011 19:37 +0900 (JST)
US to send emergency response unit to Japan
The US military is sending Marines specialized in responding to nuclear emergencies to Japan to help deal with the trouble at the Fukushima Daiichi nuclear plant.
Japan's Self-Defense Force Joint Chief of Staff Ryoichi Oriki announced the measure on Thursday.
Oriki said US Defense Secretary Robert Gates has approved the sending of the 140-member Chemical Biological Incident Response Force.
The unit is trained in search-and-rescue operations and clearing highly radioactive nuclear materials.
Oriki said the unit will not necessarily take immediate action, and that the Self-Defense Forces hope to share information with them and study how it can be put into use when needed.
The US military has provided a barge capable of carrying large volumes of fresh water to keep reactors at the plant cool. It has also sent nuclear experts to Japan as part of efforts to resolve the crisis.
Thursday, March 31, 2011 19:36 +0900 (JST)
@Butrflynet,
That's unforgivable. When I worked with nukes (bombs in SAC), we always wore badges to measure our exposure to radiation. They were check regularly.
@cicerone imposter,
Im thinking that the safety issues we had better address for our own nuke program is the storge of spent fuel. That stuff is stored in water pools on all our reactors and if a hurricane or tidal wave of some flood due to ice damming (Weve got 2 plants on the banks of the SUsquehanna River). Ive been seeing the effects of our recent "teeny Ice Age" and the ice damming that can occur . The pools at three mile island cpould be damaged by ice damming.
I feel a proposal (unsolicited) to Savannah River coming on.
@farmerman,
It would seem to me that the engineers would be trying to find solutions that has backup systems in place in the event there are unforeseen crisis such as in Fukushima. It may be double-kill now, but the extra cost will be worth the safety for all concerned. I was discouraged to find that the nuke plants in Japan didn't have backup energy systems to pump water to keep them cooled.
Even nuke bombs had many safety systems built into them to prevent accidents.
@Butrflynet,
Quote:The US military is sending Marines specialized in responding to nuclear emergencies to Japan to help deal with the trouble at the Fukushima Daiichi nuclear plant.
Why would there have been this delay ?
@cicerone imposter,
I agree with that - but am not sure even that would have done any good. So I started thinking of ways to protect piping et al, and I just don't know enough about the system(s) to figure how to have them have "wiggle" room.
@ossobuco,
I'm pretty sure they had diesel powered backup. Possibly it was destroyed in the initial event. At any rate, that's what they use at Palo Verde in Arizona. Not many tidal waves there, so it's probably okay.
@roger,
Didn't some water pipes break too? or valves get wonky.. not that I have any idea how to keep that from happening.
@ossobuco,
I haven't heard one way or the other, but it doesn't sound unlikely. I really don't know what forces are involved in earthquakes and tidal waves.
roger
@roger,
roger, It's a shift in the ocean floor that displaces the water above it that turns into a tsunami.
@cicerone imposter,
Very true - also see satellite picture on previous page for sinkhole on the waters - but what makes the bottom of the ocean collapse to begin with? Vaguely I understand motion of continental plates (mostly thanks to Farmerman's patient explanations over the years) but what I hope to do is predict such collapses:
http://www.satnews.com/cgi-bin/story.cgi?number=1749124299
This is from a new European satellite. Blue is very high gravity, red is very low gravity. Ships in the middle of the Indian ocean "sit" on the water so much lower than ships in the North Atlantic because of stronger gravity. The hope (a dim one, admittedly) is to track gravity shifts so as to predict earthquakes.
@High Seas,
Earthquakes are imperfect science. All we know are where the main faults are, but trying to predict the "big one" is practically impossible.
@roger,
I thought I read that, but I'm reluctant to chase it down from links on this thread or otherwise. Anyway, it mildly interests me to figure out how to protect pipes/valves/electrical connections in a way that can resist some strong forces. We used to sleeve pipes under concrete, etc., all the time, but they weren't able to take any kind of serious bending or blunt force. The usual flex type of plastic tubing would be gone in fractions of a second.
I suppose humongous concrete, but I was trying to imagine some flexible item. Obviously not my expertise if anyones.
@cicerone imposter,
Yes, that's what I just said. Earthquake prediction is an inexact science, ranking just above weather prediction and about equal to economic forecasting
@ossobuco,
That's a simple one: plumbing in nuclear plants (pipes, valves, pumps, etc) is designed to handle pure water. In Japan it's been overwhelmed by salt water.
Mind - Japan had no choice but to flood everything with salt water in order to bring temperatures in fuel pools and reactors down; the sea was all they had.
@High Seas,
Yes, I know that, but a) did any pipes break, and b, were the pipes et al sleeved in any way?
(I just added to my last post re sleeving in concrete)
I'm just fantasizing on some kind of magical material sleeve that would have protected them from the salt water.
