UPDATE 2:50 P.M. EST -- NRC Chairman Gregory Jaczko had been quoted as saying that the spent fuel storage at Fukushima Daiici unit 4 is dry, and that high radiation levels around the unit could effect crews' ability to take "corrective measures."
Jaczko, in congressional testimony, also said he's received reports that the unit 3 spent fuel tank may have a crack in it that could lead to a loss of water inside.
Workers at the Fukushima Daiichi nuclear plant were
evacuated briefly late Tuesday night after radiation levels at the gate of the
power plant peaked at 6.4 millisieverts per hour.
They returned after radiation levels fell again. Tuesday also
saw the Japanese government increase the legal radiation exposure for nuclear
workers to 250 millisieverts.
Tepco had cut the number of workers at the plant to just 50
following a fire Monday in unit 4 and subsequent increased radiation readings.
Crews continue to try vent steam and pump seawater into
units 1, 2 and 3 to prevent containment damage from excess pressure and heat.
Explosions have ripped through the outer buildings of all three reactors in the
last few days, indicating a buildup of hydrogen that could be caused by water
contacting damaged fuel cladding.
The New York Times reported Tuesday that the U.S. military has
helped put out fires at the plant, and other news agencies indicated U.S.
forces may be asked to increase their assistance at the plant.
For more information on units at Fukushima Daiichi, please see the updated reactor status list in our most recent post.
Please check your facts before publishing. According to the IAEA website Unit 4 has not gone dry, as you say above. Please see: www.iaea.org/.../tsunamiupdate01.html
Like almost all data emerging from "Official Sources" during this disaster, It's challenging to attach deep credibility to ANY source. US NRC Chairman Jaczko says no water in #4 pool. Where did he get that data? IAEA says water in #4 pool. Where did they get that data?
One Status Report I have found is as official as I can find. It's published by JAIF and updated at least twice daily. Here's the link. www.jaif.or.jp/.../ENGNEWS01_1300322727P.pdf
I'm not sure a truly credible source exists, other than the 50 brave samurai standing watch at the site, and very probably sacrificing their lives as they attempt to navigate their way to as safe an outcome as can be made. I sincerely hope the world appreciates their efforts.
Has anyone ever thought of using ice pellets/cubes to cool? It can be fired safely from further away with less dispersion and ice starts working at a lower temperature point and has a longer cooling period before it vaporizes.
Thanks for your post. Conflicting information on the status of the unit 4 spent fuel pool emerged almost as soon as Jaczko made his statement at the committee hearing, with Tepco denying it was dry.
When confronted with the conflicting report awhile later, Jaczko stood by his statement, saying the information came from NRC staff working in Japan with authorities there. As radiation levels have made observations at the plant extremely difficult, I held off on updating the post until I could receive confirmation one way or the other. The fact that the head of the NRC made such a statement was newsworthy.
At a press conference a few minutes ago, Tepco officials said that observations from a helicopter made yesterday indicated water remained in unit 4's tank, although they could not say how much. As the helicopter observations were made a day ago, it is unclear if information Jaczko received was more current than that.
I'm preparing an update for tomorrow morning that will include more of this information. In any event, I certainly appreciate your desire for accuracy, and I also appreciate your pointing this out.
Nuclear Street News Team