The Potential Catastrophe of Reactor 2 at Fukushima Daiichi: What Effect for the Pacific and the Entire Northern Hemisphere?
Expert: “Potential Global Catastrophe” from Fukushima Unit 2 highly radioactive fuel… Reactor could be destroyed, “making Tokyo area uninhabitable”… This is “most dreaded” scenario — Already “partially liquefying” below reactors
It is clear to us now that the radiation level in the containment vessel of the crippled Reactor 2 is much higher than experts had believed… The danger of Reactor 2 begs us to ask many new questions…
Dr. Shuzo Takemoto, professor of the Department of Geophysics, Graduate School of Science, Kyoto University — responded to Mr. Matsumura concerns: Potential Global Catastrophe of the Reactor No.2 at Fukushima Daiichi, by Professor Shuzo Takemoto — On July 28, 2016, the [Tepco] published the images of the F1 Unit 2 reactor screened by muon particles… They showed the shadow of materials equivalent to 180 – 210 tons at the lower part of the pressure vessel… It can hardly be said that the Fukushima accident is heading toward a solution. The problem of Unit 2, where a large volume of nuclear fuels remain, is particularly crucial. Reactor Unit 2 started its commercial operation in July 1974. It held out severe circumstances of high temperature and high pressure emanating [after 3/11]… years long use of the pressure vessel must have brought about its weakening due to irradiation. If it should encounter a big earth tremor, it will be destroyed and scatter the remaining nuclear fuel and its debris, making the Tokyo metropolitan area uninhabitable. The Tokyo Olympics in 2020 will then be utterly out of the question… [Fukushima is] situated in the aftershock area of the 2011 earthquake off the Pacific coast of Tōhoku. In this area, we must foresee a number of magnitude 7 class earthquakes. Consequently, we cannot exclude the possibility of intensity 6 and intensity 7 earthquakes befalling the Fukushima Daiichi. What is most dreaded is what could happen to the Unit 2 whose pressure vessel contain a large volume of nuclear fuel debris. This pressure vessel has endured the sudden change of temperature and pressure in the accident of March 2011, but in light of its possible weakening due to irradiation, it could be seriously damaged if a new big earth tremor occurs nearby.
Dr. Helen Caldicott, Feb 13, 2017: What the photos taken by the robot did reveal was that some of the structural supports of unit 2 have been damaged… all four buildings were structurally damaged by the original earthquake… and by the subsequent hydrogen explosions, so, should there be an earthquake greater than seven on the Richter scale, it is very possible that one or more of these structures could collapse leading to a massive release of radiation as the building fell on the molten core beneath… The reactor complex was built adjacent to a mountain range and millions of gallons of water emanate from the mountains daily beneath the reactor complex, causing some of the earth below the reactor buildings to partially liquefy…
Here is bonus coverage FYI (from Feb 3, 2017):
Collapse imminent at Fukushima — TV: Officials find large section under reactor is “unstable… about to collapse” — “Bad, bad news… Time to reconsider that trip to the east coast of Japan”
NHK World, Feb 3, 2017 (emphasis added): The operator of the crippled Fukushima Daiichi nuclear power plant is examining if it can go ahead with a plan to deploy a robot into one of the damaged reactors at the facility… An analysis of the images found that the radiation level inside the vessel was up to 530 sieverts per hour. Officials speculate that fuel debris–a mixture of nuclear fuel and melted parts of the reactor’s facility–may be emitting strong radiation inside the vessel… Last week’s probe found that part of a metal grating just beneath the reactor was missing. The robot was supposed to move around on the grating. The image analysis also found that an around one square-meter section near the missing segment is about to collapse.
NHK World transcript, Feb 3, 2017: “[Tepco] is facing more setbacks. Tepco has found unstable grating near a rector that will make it difficult to conduct further surveillance to help it decommission the plant… They found a section the size of a square meter is about to collapse. They had already found holes in other sections… A nuclear power expert suggests that will make it difficult for workers to locate the fuel.”
NHK World transcript, Feb 3, 2017 (at 1:30 in): “Engineers were able to get a glimpse inside Reactor No. 2… They found that a section one meter square is about to collapse. They had already found holes in other sections.”
Asahi, Feb 3, 2017: TEPCO said it will consider a different route for the robot… Fumiya Tanabe, an expert on nuclear safety… said the findings show that both the preparation for and the actual decommissioning process at the plant will likely prove much more difficult than expected. “We have few clues on the exact locations, the sizes and the shapes of the nuclear fuel debris,” he said. “The planned investigation by the robot needs a rethink. Work to decommission the plant will require even more time.”
CNET, Feb 3, 2017: High radiation levels at Fukushima reactor is bad, bad news — Time to reconsider that trip to the east coast of Japan. A containment vessel at the destroyed Fukushima No. 1 power plant has reached off-the-chart radiation levels, reported the Japan Times… Experts believe that escaped melted fuel can account for the spiked reading.