Sunday, August 2, 2015

In the News


TEPCO has recently announced success in removing a large piece of debris from unit 3 spent fuel pool.  (here): TEPCO removes canopy panel from Fukushima reactor building

The photo of the plant accompanying the story on unit 3 shows the ubiquitous "fog/mist" that has recently entombed the plant at night. Here is a screenshot from today:



TEPCO also announced it removed a roof panel from unit 1. You can see the missing panel in the screenshot above, in the front of the building, roughly center, marked by yellow light.

I went through my old records trying to find news coverage addressing the radiation releases from the last time TEPCO removed a roof section from unit 1.  I couldn't find the story in my files but I do recall that TEPCO expected significant radiation releases to occur with the roof panel removal.

I wonder whether the increased "fog" is from unit 1?  Or perhaps it is from unit 3?  Perhaps both are involved. How long can TEPCO feed and bleed the hot fuel?

When reviewing my files, I did find this interesting news story from 2011 covering a document about plant dangers that I think worthy of re-posting:
James Glanz and William Broad, "U.S. Sees Array of New Threats at Japan’s Nuclear Plant," The New York Times. (April 5, 2011) http://www.nytimes.com/interactive/2011/04/05/world/asia/20110405-japan-leak.html?nl=todaysheadlines&emc=tha22

…The document, which was obtained by The New York Times, provides a more detailed technical assessment than Japanese officials have provided of the conundrum facing the Japanese as they struggle to prevent more fuel from melting at the Fukushima Daiichi plant. But it appears to rely largely on data shared with American experts by the Japanese.

Among other problems, the document raises new questions about whether pouring water on nuclear fuel in the absence of functioning cooling systems can be sustained indefinitely. Experts have said the Japanese need to continue to keep the fuel cool for many months until the plant can be stabilized, but there is growing awareness that the risks of pumping water on the fuel present a whole new category of challenges that the nuclear industry is only beginning to comprehend.

The document also suggests that fragments or particles of nuclear fuel from spent fuel pools above the reactors were blown “up to one mile from the units,” and that pieces of highly radioactive material fell between two units and had to be “bulldozed over,” presumably to protect workers at the site. The ejection of nuclear material, which may have occurred during one of the earlier hydrogen explosions, may indicate more extensive damage to the extremely radioactive pools than previously disclosed... 
…The N.R.C. report suggests that the fuel pool of the No. 4 reactor suffered a hydrogen explosion early in the Japanese crisis and could have shed much radioactive material into the environment, what it calls “a major source term release.”

1 comment:

  1. Yoichi Shimatsu Nov 24 2013 Why TEPCO is Risking the Removal of Fukushima Fuel Rods. The Dangers of Uncontrolled Global Nuclear Radiation www.globalresearch.ca/why-tepco-is-risking-the-removal-of-fukushima-fuel-rods-the-dangers-of-uncontrolled-global-nuclear-radiation/5359188

    TEPCO: July 17 2014 Dismantling the Reactor Building cover of Unit 1 ofFukushima Daiichi NPS www.tepco.co.jp/en/nu/fukushima-np/handouts/2014/images/handouts_140717_04-e.pdf

    NEI Magazine July 17 2014 Dismantling the Reactor Building cover of Unit 1 of Fukushima Daiichi NPS October 18 2011 www.tepco.co.jp/en/nu/fukushima-np/handouts/2014/images/handouts_140717_04-e.pdf https://www.youtube.com/watch?v=0KYkjUeICkg

    TEPCO: Main works to help remove spent fuel Unit 1: Two roof panels of the Unit 1 Reactor Building (R/B) were removed to facilitate investigation of the rubble status on the R/B top floor. https://fdada.info/currentstatus/decommissioning-4

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