Thursday, June 23, 2011

Saga of the Fukushima Spent Fuel Pools #3 and #4

Here is the narrative I've pieced together of these spent fuel pools. Notice the pattern of report and denial.

On the morning of Tue March 15, the International Atomic Energy Agency (IAEA) released a statement warning that the Japanese authorities had reported a fire in spent fuel pool #4

"Japanese authorities also today informed the IAEA at 03:50 UTC that the spent fuel storage pond at the Unit 4 reactor of the Fukushima Daiichi nuclear power plant is on fire and radioactivity is being released directly into the atmosphere." http://www.iaea.org/press/?p=1248

Dose rates of up to 400 millisievert per hour were reported at the site. Japanese authorities claimed that there was a possibility that the fire was caused by a hydrogen explosion. (http://www.iaea.org/press/?p=1248). The fire was reportedly extinguished later on March 15 (IAEA http://www.iaea.org/press/?p=1252).

However, Jim Riccio, a nuclear expert for Greenpeace, reported on March 16 to The Guardian that the spent fuel pool at unit 4 was still boiling: "The spent fuel pool in unit 4 is boiling, and once that starts you can't stop it… The threat is that if you boil off the water, the metal cladding on the fuel rods that is exposed to the air, and is volatile, will catch fire. That will propel the radiation even further" (cited in Goldenberg, 2011 3/16 http://www.guardian.co.uk/environment/2011/mar/16/japan-nuclear-fire-fuel-pools-radiation?INTCMP=ILCNETTXT3487).

On March 19, The Los Angeles Times reported that spent fuel pool #4, which contained the reactor core for unit 4, was cracked and leaking, and in danger of overheating (Maugh  http://www.latimes.com/news/science/la-sci-japan-reactor-damage-20110319,0,6212176.story).

The report that a fire occurred at spent fuel pool #4 was later confirmed in an IAEA report (IAEA “Japanese Earthquake,” 2011), although the U.S. Nuclear Regulatory Committee subsequently tried to deny it in June (Daly, 2011 http://www.huffingtonpost.com/huff-wires/20110615/us-us-japan-nuclear/).

On June 20th Tepco reported that the water in spent fuel pool #4 was down by two-thirds as of June 11th and that radiation levels were so high workers could not approach the pool (“Tepco Injects” http://www3.nhk.or.jp/daily/english/20_03.html).

The pool at Unit #4 was not the only one to have problems. The Guardian reported on March 16 that a fire had broken out in the #3 spent fuel pool (Goldenberg http://www.guardian.co.uk/environment/2011/mar/16/japan-nuclear-fire-fuel-pools-radiation?INTCMP=ILCNETTXT3487).

Nuclear engineer Arnie Gunderson of Fairewinds subsequently reported in one of his video-updates of the disaster that he believed the explosion at the number 3 reactor in March was caused by “prompt criticality” in number 3’s fuel pool, rather than in the reactor itself (Gunderson, http://fairewinds.com/content/gundersen-postulates-unit-3-explosion-may-have-been-prompt-criticality-fuel-pool?).

A media blackout on the exact condition and status of unit #4’s and unit#3’s spent fuel pools subsequent ensued for the next few months although large amounts of steam could be seen released from the general vicinities of the spent fuel pools for units 3 and 4 on Tepco’s live video cam trained on the Fukushima plants (http://www.tepco.co.jp/nu/f1-np/camera/index-j.html).

1 comment:

  1. I think the 80,000 lbs gorilla in the room is "reactors" 5 and 6. If the radiation level gets so bad even those will have to be abandoned, and they will react into 40 to 80 Chernobyls all by themselves.

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