• An interim report on Tepco’s muon scan of unit #2. Muons are elementary sub-atomic particles, similar to electrons, but with a different mass. They are generated by cosmic rays interacting with atmospheric particles. They literally inundate the surface of the Earth. Muons pass through most materials without interaction, but are sometimes deflected by thick, dense materials. Thus, detectors can map the location of the dense objects inside structures, which proved successful with imaging the interior of unit #1 reactor pressure vessel (RPV). The unit #1 scan more than six months to record a reasonably confident image. The scanning equipment for unit #2 was started on March 22nd. The picture generated since then is incomplete, although the outer light-bulb-shaped walls of the primary containment are visible. One of the more important discoveries, at this point, is that the bottom head of the RPV will be included in the final image. The geometry of the scan with unit #1 did not allow the bottom head to be visible. It is hoped that the unit #2 scan will provide clues as to whether or not some of the corium melted through and dripped onto the concrete base-mat below it, before solidifying. http://www.tepco.co.jp/en/nu/fukushima-np/handouts/2016/images/handouts_160526_01-e.pdf
  • JAIF posted an interview with Okuma Town Mayor Toshitsuna Watanabe. He says recovery has been slow, but steadily progressing. His town has drawn up a new reconstruction plan and general strategy, which is encouraging. Watanabe added that it has been difficult to maintain a sense of community due to the prolonged Tokyo-mandated evacuation, but his administration has funded many citizen events to keep residents in touch with each other. He laments that Tokyo has yet to establish policy on Okuma’s decontamination and other needs for repopulation, and he is not optimistic that the government will do anything soon. On another issue, Watanabe understands the difficulty Tokyo must be having in trying to get ownership of the property for the temporary low level waste storage repository in Okuma, given that there are 2500 owners that need to be satisfied. On a positive note, the mayor feels that the new construction of 750 housing units for F. Daiichi workers, which could bring as many as 3,000 people to the Ogawara district, will encourage former residents to eventually return, once Tokyo allows it. Okuma has received support from all over Japan, but Watanabe says, “…we should not let ourselves become conditioned to receiving such support and help. Ultimately, we must be independent. Some citizens have achieved that, but others, so far, not at all.” http://www.jaif.or.jp/en/vol-5-special-interview-with-toshitsuna-watanabe/
  • Tepco is given permission to expand the F. Daiichi ice wall. Tepco will also be allowed to pour cement into the gravel-impregnated ground where soil around a few of the refrigerant pipes has not fully solidified. The Nuclear Regulation Authority allowed 55% of the in-ground barrier to groundwater flow to begin operation in March. The about half of the system had been held in abeyance due to NRA fears of groundwater level inside the barrier getting too low and contaminated water in the four turbine basements flowing out. To date, Tepco has shown that it can maintain the groundwater level such that the NRA fears should not happen. http://mainichi.jp/english/articles/20160602/p2a/00m/0na/011000c
  • Another suit against a nuke restart is filed. Residents of Shikoku Island are seeking an injunction against resumption of operations with Ikata unit #3, which is presently undergoing a final safety inspection for a possible July restart. The suit demands that Shikoku Electric Company suspend all plans to reactivate Ikata-3 because of last month’s severe earthquake on nearby Kyushu Island. The residents claim there is a geologic connection between a tectonic line five kilometers from Ikata station, and the fault that caused the Kyushu quake. They claim the safety of an Ikata station nuke cannot be assured because the power company has not presumed the possibility of a significant quake in the near future. This is the second such suit filed by Ehime Prefecture residents since the restart of Ikata #3 was announced.  http://english.kyodonews.jp/news/2016/05/414251.htmlhttp://www3.nhk.or.jp/nhkworld/en/news/20160531_33/  (Comment – The suit completely ignores the fact that the operating nukes on Kyushu Island experienced no impacts whatsoever from the severe quake that seriously damaged more than 1,000 buildings in Kumamoto City and killed nearly 50 people. Further, the March 2011 Great East Japan Earthquake was about 50 times more powerful than the Kyushu quake, and did nothing to any of the nukes along the Tohoku coastline.)