Posted on 03/15/2011 8:13:35 AM PDT by SE Mom
Latest news from Japan:
From the BBC-
1456: Tepco says it may start pouring water from a helicopter over Fukushima Daiichi's reactor four in the next few days, to cool the spent-fuel pool.
1439: A 30km (18 mile) no-fly zone is in place around Fukushima, says the IAEA.
1436: The IAEA says Monday's blast at Fukushima may have affected the integrity of the containment vessel - there are fears of more serious radioactive leaks if happen.
1435: Following earlier reports, it appears there has been more than one strong aftershock in Japan - AP reports two tremors measuring over 6.0 within three minutes of each other.
Twitter-
-US Geological Survey counts 451 aftershocks since the initial earthquake struck Japan Friday. 238 of them registered magnitude 5.0 or more.
-Despite situations in Japan & Libya, spksmn Jay Carney says Pres Obama's 5-day trip to Brazil, Chile & El Salvador starting Fri night is on.
-FLASH: More U.S. military personnel in Japan testing positive for low-levels of radiation, relief missions to continue - Navy 18 minutes ago via web
People have banded together making graphs keeping track of radiation levels for many cities. Scroll down.
After thinking about it, the answer is simple. When refueling, the overhead crane can pull the fuel rod assembly right out of the reactor and then set it down in the pool. No need to take the fuel rods outside. Easy transfer.
First off, it's a first gen reactor. In later models the pool is at or below grade in insanely think concrete and steel. Add to that that the pond is only meant to be a termporary storage area while the fuel cools completely down when it then can be more easily moved for disposal or recycling. Now since recycling fuel is now banned and there is no place to dump it...
Ooooh, “Fleepers”. :-)
Is it banned in Japan? I know that France recycles, but the US has banned it since Jimmy Carter's executive order mandated it.
I wouldn't expect much more water on target from one truck, but if they use a number of trucks, it could be effective. One problem with this delivery method, it seems to me, is the water becomes contaminated and contaminates everything it fall down on.
What would be much more effective would be taking a length of 2 - 4 inch aluminum pipe with a 120 degree bend in the middle and attached to 2-1/2 in fire-hose on the other end.
The helicopter could be used to drop it into position onto of the roof. Water could be pump directly into the tanks then with no waste to speak of.
If they were close enough to make an accurate drop then they would be risking their lives.
Just be careful where you order your sushi for the next 200 years.
Remember that Unit 3 was in a maintenance outage when this happened. For some reason they had to do a complete core offload. When the outage was over there was the intent to reload that same fuel back into the core. So it made very practical sense to have that fuel where it was, right at the discharge point from the reactor vessel head. That is why those pools are where they are, so make the transfer from pressure vessel to storage as simple as possible to avoid mistakes.
It was the worst misfortune that the seismic event happen in this particular outage configuration. If the material were in the core it would have been better, because even if it was damaged it would be contained by the pressure vessel and the containment. But it was in the storage pool. Very, very unfortunate that the timing was as it was. But how can you tell when you're going to have a 300-year earthquake, one that exceeds all historical records for the region and thus exceeds the design basis earthquake for the plant design?
Japanese FReepers? :)
Cooper/CNN said it would take 100 drops direct hits to fill the pool to cover the rods - ? Not sure where he got that from.
NHK waiting on a press conference about the helicopters
Maybe Cooper’s theme song could be the one from REO Speedwagon (?), that starts, “heard it from a friend, that, heard it from a friend, that, heard it from a friend that....” CNN’s credibility is pretty much shot with me.
Anderson is about as one top of things as Shep is. But just looking at it, it seems these drops would be just that - mere drops in a bucket. Add in that minimal amounts of water will evaporate at a fast rate so more would have to be dropped to make up the difference.
UPDATE AS OF 9:00 P.M. EDT, WEDNESDAY, MARCH 16:
Crews began aerial water spraying operations from helicopters to cool reactor 3 at Fukushima Daiichi shortly before 9 p.m. EDT on Wednesday, March 16. The operation was planned for the previous day, but was postponed because of high radiation levels at the plant. News sources said temperatures at reactor 3 were rising. Each helicopter is capable of releasing 7.5 tons of water.
Spokesmen for TEPCO and Japan’s regulatory agency, Nuclear and Industry Safety Agency, on March 17 Japan time refuted reports that there was a complete loss of cooling water in the used fuel pool at Fukushima Daiichi reactor 4.
The spokesmen said the situation at reactor 4 has changed little during the day today and water remained in the fuel pool. However, both officials said that the reactor had not been inspected in recent hours.
"We can’t get inside to check, but we’ve been carefully watching the building’s environs, and there has not been any particular problem," said TEPCO spokesman Hajime Motojuku.
At about 7 p.m. EDT, NISA spokesman Takumi Koyamada said the temperature reading from the used fuel pool on Wednesday was 84 degrees Celsius and that no change had been reported since then. Typically, used uranium fuel rods are stored in deep water pools at temperatures of about 30 degrees Celsius.
Recent radiation levels measured at the boundary of the Fukushima Daiichi plant have been dropping steadily over the past 12 hours, Japan's Nuclear and Industrial Safety Agency said on Wednesday night (U.S. time).
At 4 a.m. EDT on Wednesday, a radiation level of 75 millirem per hour was recorded at the plant's main gate. At 4 p.m. EDT, the reading at one plant site gate was 34 millirem per hour. By comparison, the Nuclear Regulatory Commission’s annual radiation dose limit for the public is 100 millirem. Radiation readings are being taken every 30 minutes.
Japan’s Chief Cabinet Secretary, Yukio Edano, said earlier today a radiation level of 33 millirem per hour was measured about 20 kilometers from the Fukushima Daiichi plant earlier this morning. He said that level does not pose an immediate health risk.
Edano said that TEPCO has resumed efforts to spray water into the used fuel pool at the damaged reactor 4.
TEPCO also continues efforts to restore offsite power to the plant, with up to 40 workers seeking to restore electricity to essential plant systems by Thursday morning, March 17.
I’m sure you’re right. There was probably no risk to them at all. There was no reason for them to apply radiation shielding to those choppers, or to restrict their crews to 45 minutes of exposure. They really shouldn’t have evacuated all those people within a 30 mile radius either. There wasn’t any risk for them.
Sorry my bad. But, Japan only recycles fuel for the LWR (Light Water Reactor). The units in question are BWR (Boiling water reactor)
I used “beam” simply to express the nature of the radiation - direct straight line and very intense. If a human looked directly into it it would only take 20 seconds to get a lethal dose. BTW from space it will look like a very “hot” spot on radiation detectors. It will be like a beam or beacon to anyone that points a neutron detector in this general detection.
It was said "100 errr 200 drops would be needed"
Each load carried by the helicopters 7.5 tons of water or 1,875 gallons of water.
He did not elaborate if that was for one or more reactors.
this should be repeated:
“Japan’s Chief Cabinet Secretary, Yukio Edano, said earlier today a radiation level of 33 millirem per hour was measured about 20 kilometers from the Fukushima Daiichi plant earlier this morning. He said that level does not pose an immediate health risk.”
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