Fukushima 112


July 27, 2017

  • Possible formerly molten fuel debris (corium) has been discovered inside unit #3. The finding was made during Friday’s second visual examination of the underside of F. Daiichi’s unit #3 Reactor vessel (RPV). It shows what appear to be dark masses, some shaped like icicles, hanging from a few of the control rod drive mechanisms (CRDM). There are also orange-colored globs on the CRDMs and the walls of the PCV atop what might be corium. As a result of the discoveries, another excursion inside the RPV’s supporting pedestal was scheduled. On Saturday, images of locations on and below the maintenance platform (carousel) were obtained. One shows that most of the platform is indeed gone, and has dropped to the floor of the PCV, several meters below. Two of the Saturday images (#1 & #3) show debris that has collected in the bottom of the PCV, atop the base-mat. Tepco says most of the nuclear fuel is believed to have melted and fallen through the pressurized vessel, although none of the images have a gaping hole on the bottom head of the RPV. Industry Minister Hirosage Seko said, "Valuable information has been obtained from a survey inside the reactor [pedestal] using a submersible robot. At the current stage, we will proceed with the decommissioning in line with the road map." On related note, the usually-reliable NHK World seems confused. It posted that “…structural components and other material is piling up at its [the PCV’s] bottom.” This makes it sound as if the material continues to fall from the underside of the RPV, however the accumulation has clearly stopped. http://www.jaif.or.jp/en/fuel-debris-at-fukushima-daiichi-unit-3-apparently-located-under-pressure-vessel-and-at-bottom-of-pcv/ -- https://www4.tepco.co.jp/en/nu/fukushima-np/handouts/2017/images/handouts_170721_01-e.pdf (Friday’s handout) -- https://www4.tepco.co.jp/en/nu/fukushima-np/handouts/2017/images/handouts_170722_01-e.pdf (Saturday’s handout) -- https://english.kyodonews.net/news/2017/07/adadf7591673-govt-to-decide-in-sept-debris-extraction-method-at-fukushima-unit.html --  https://www3.nhk.or.jp/nhkworld/en/news/20170723_01/  
  • Muon imaging of unit #3 reveals little corium remains in the Reactor Vessel. The image produced with unit #3 has been compared to the one made with unit #2. The unit #2 image posted last July 28th strongly indicated that some of the corium (9-23%) remains at the bottom of the bottom of the core barrel, and possibly all of the rest collected in the hemispherical bottom head of the RPV. On the other hand, Tepco’s unit #3 image indicates that only a small fraction of the corium remains “in the core and at the lower area of the RPV…” The Tepco handout says, “The evaluation at present shows the possibility that some fuel debris remain(s) inside the RPV, but massive and high density material has not been found.” The company feels the greatest amount of corium that exited an RPV was unit #1, with unit #3 the second-most, and unit #2 the least (if any at all). Tepco stresses that detailed evaluation of the unit #3 imaging continues. http://www.tepco.co.jp/en/nu/fukushima-np/handouts/2016/images/handouts_160728_01-e.pdf (unit #2 muon imaging results) -- https://www4.tepco.co.jp/en/nu/fukushima-np/handouts/2017/images/handouts_170727_01-e.pdf (unit #3 preliminary muon imaging results)
  • Unit #2 radiation levels are actually 2-3 times lower than initial estimates. When unit #2 estimated radiation levels were first reported in late January, the numbers seemed incredible. It was reported that “light flickers” on the imaging from a robotic probe indicated a localized radiation field of 530 grays per hour, and a subsequent localized field estimate of 650 Gy/hr on a second robotic probe.  However, reassessment of the situation reveals the actual levels were 170 Gy/hr and 180 Gy/hr, respectively. The initial high estimates did not take into account the amount of “noise” caused by the radiation on the visual monitors. The February 16th robotic probe carried an actual radiation monitor, and registered a localized hotspot of 210 Gy/hr, but it was not calibrated for the primary source isotope, Cesium 137. After compensating for the calibration factor, that reading was actually 70 Gy/hr. [A gray is of radiation is equivalent to a Sievert of exposure.) https://www4.tepco.co.jp/en/nu/fukushima-np/handouts/2017/images/handouts_170727_03-e.pdf
  • Robotic images for unit #1 are “sharpened”, and show no fuel debris external to the RPV pedestal. Because of the clearer images from the four main vantage points on the grating in the PCV, external to the RPV pedestal, “it is considered that there is no fuel debris or very little even if it exists.” Like unit #2, the dose estimates have been considered using Cs-137 as the calibration isotope, but it seems to have had little or no effect on the originally-reported values. https://www4.tepco.co.jp/en/nu/fukushima-np/handouts/2017/images/handouts_170727_02-e.pdf
  • Fukushima’s main train system to reopen October 21st. The East Japan Railway Company made the announcement on July 19th, but none of Japan’s popular Press saw fit to report it. Regardless, only one section of the system, between Okuma and Futaba, will remain closed. The reopened section runs between Tomioka and Naraha Towns. The Tomioka station was heavily damaged by the tsunami of 2011, and the rail line between the towns was distorted by the earthquake. Restoration work was delayed until June, 2016, after decontamination work was completed. The company plans to have eleven round trips per day from Namie to Sendai City. This is a major infrastructural improvement for the entire region. http://www.jaif.or.jp/en/entire-joban-train-line-in-fukushima-prefecture-to-be-reopened-by-march-2020/
  • Another request by antinuclear activists to shut down a nuke is denied. Matsuyama resident’s had filed a legal demand with the Hiroshima District Court to have Ikata unit #3 shuttered. The residents who filed the case alleged that Shikoku Electric Company had underestimated the worst-possible earthquake for the plant, and also that evacuation plans for the area are inadequate. To the contrary, the court found the company’s seismic protection adequate and the emergency plans in accord with national standards. As usual, the plaintiffs plan to file an appeal with a higher court. A lawyer for the plaintiffs said, "It was a disappointing decision. We will continue to fight to stop the reactor at any court." Three other injunction requests against the nuke are pending in Hiroshima, Oita, and Yamaguchi Prefectures.  Ikata #3 has been in full, uneventful operation since August of 2016. https://mainichi.jp/english/articles/20170721/p2g/00m/0dm/060000c 
  • Kashiwazaki mayor says two K-K units may be restarted if all others are permanently shuttered. Mayor Masahiro Sakurai said he will agree to restarts of units #6&#7 at Kashiwazaki-Kariwa station, if and only if Tepco “presents a plan to decommission the remaining five in two years.” Tepco President Tomoaki Kobayakawa responded, “We should exchange opinions further.” All five units began operation between 1985 and 1994, so none of them will be subject to the essentially arbitrary 40 year licensing limit. Regardless, Mayor Sakurai explained his bold demand, “The No. 1 to No. 5 reactors are old, and some of them have remained offline since the Niigata Chuetsu-oki Earthquake (of July, 2007).” The mayor was elected to office on a campaign promising to support restarts “with conditions”. http://www.asahi.com/ajw/articles/AJ201707260037.html

July 20, 2017

  • Tepco posted a Press handout concerning their submersible robot's (ROV) initial probe inside the Fukushima Daiichi unit #3 RPV pedestal. The device literally swims under the surface of the 6.4 meters deep water in the bottom of the Primary Containment (PCV). The robot entered the pedestal through the opening for replacement of Control Rod Drive Mechanisms, staying near the opening. The handout says, “The ROV took photographs of the conditions inside the PCV around the pedestal opening and enabled us to achieve the objective of the exploration, which was to examine conditions inside the pedestal.” The robot's twin propulsion propellers stirred up sediment, limiting visibility on and around the personnel grating below the reactor's CRDMs. Regardless, some intact CRDM supporting clamps below the Reactor Pressure Vessel are clearly visible, and the bottom of a CRDM is also quite clear. Tepco reports, “Today’s exploration revealed damage to multiple structures inside the pedestal and also that some of the support fittings for the CRD housing have fallen.” Last week, Tepco said it will keep the robot docked in the outer PCV until Friday’s investigation. One thing they have to ponder is how to get the ROV back through the pedestal opening without stirring up more sediment. NHK World reports a Tepco official saying that the maintenance platform (a.k.a. carousel) under the RPV appears to be gone, which seems to be confirmed by one of the handout images (i.e. “Platform condition”). The Asahi Shimbun speculates, “It is highly likely that melted nuclear fuel fell through the pressure vessel and weakened the scaffolding, leading to its collapse.” The Associated press says "the images contained no obvious sign of the melted nuclear fuel that researchers hope to locate..." and that unit #3 has more damage than unit #2. https://www3.nhk.or.jp/nhkworld/en/news/20170720_01/ -- http://www.tepco.co.jp/en/nu/fukushima-np/handouts/2017/images/handouts_170719_01-e.pdf  -- http://www.asahi.com/ajw/articles/AJ201707200046.html -- http://abcnews.go.com/Technology/wireStory/swim-robot-probes-fukushima-reactor-find-melted-fuel-48719330
  • Tepco’s chairman says F. Daiichi’s purified waste water will be released when the NRA allows it. All radioactive isotopes have been removed from the waters, except for biologically-innocuous Tritium. Widespread unfounded fear about radiation (radiophobia) has kept the harmless water from being released to the sea. Company Chairman Takashi Kawamura said, “The decision has already been made,” and stressed that the company cannot do it until the Nuclear Regulation Authority gives them the go-ahead. The NRA has had a panel studying the situation for many months, examining several possibilities. But, only a controlled release to the sea makes any real sense. NRA Chairman Shunichi Tanaka has previously expressed support for an ocean release, which Kawamura acknowledged, "Technically, we fully support the chairman's proposal. [But] I think we should have acted sooner. ... We should start moving faster." Not unexpected, Japanese antinuclear activists condemn it. Green Action Japan antinuclear campaigner Aileen Mioko-Smith said, “The accident happened more than six years ago and the authorities should have been able to devise a way to remove the tritium instead of simply announcing that they are going to dump it in the ocean.” She then exaggerated to the extreme, “They say that it will be safe because the ocean is large so it will be diluted, but that sets a precedent that can be copied, essentially permitting anyone to dump nuclear waste into our seas." http://www.japantimes.co.jp/news/2017/07/14/national/science-health/tepco-says-decision-already-made-release-radioactive-low-toxic-tritium-sea-fishermen-irate/#.WWi6GKMUkdU -- http://www.foxbusiness.com/markets/2017/07/13/tepco-chair-nuclear-plant-must-release-contaminated-water.html -- http://www.telegraph.co.uk/news/2017/07/14/fishermen-express-fury-fukushima-plant-set-release-radioactive/
  • Japan’s reconstruction minister Masayoshi Yoshino says he opposes the alleged release. Why? Because groundless rumors that will hurt the Fukushima fishermen. He said there would “certainly be [perception] damage due to unfounded rumors.” He urged Tepco “not to create fresh concerns for fishermen and those running fishing operations in Fukushima Prefecture." Yoshino added that releasing the essentially harmless water to the ocean could drive the fishermen “further towards the edge”. In response, Tepco said its chairman meant to say there is "no problem [with the release] according to state guidelines based on scientific and technological standpoints."   https://mainichi.jp/english/articles/20170715/p2g/00m/0dm/064000c -- http://www.japantimes.co.jp/news/2017/07/15/national/tepco-backpedals-disaster-reconstruction-chief-knocks-plan-dump-tritiated-water-sea/#.WWoL5KMUkdU 
  • Fukushima fishermen protest the Tepco president’s misinterpreted remark. Tepco Chair Takashi Kawamura was accused by the Press of saying the company had decided to release the Tritium-laced waste waters into the sea. On Wednesday, Kawamura met with the head of Japan’s fisheries federation, Hiroshi Kishi, to deny the media-sourced claim. Kawamura said the news media misunderstood him and apologized for the worry it caused the fishermen. Regardless, Kishi urged Tepco to refrain from a release without the consent of fishermen and the public. https://www3.nhk.or.jp/nhkworld/en/news/20170720_02/
  • Fukushima’s most popular beach reopens after a seven year hiatus. Usuiso beach, Iwaki City, closed at the end of the summer season of 2010. The Great East Japan Earthquake and tsunami pounded the Iwaki shoreline, killing more than 100 people and making the beaches uninhabitable. The closure of Usuiso beach was prolonged due to detectible levels of radiation and fears of contamination. On Saturday July 15th, some 1,800 people came to the reopening. Prefectural officials say the radation levels have dropped to pre-2011 levels. https://japantoday.com/category/national/fukushima%E2%80%99s-most-popular-beach-reopens-for-first-time-since-march-2011-disaster
  • Wild boar hide is used to make leather in Fukushima Prefecture. A leather workshop in Date is making baby shoes and key fobs out of it. The products have become so popular that production cannot keep up with demand. The boars are captured by hunters, but the meat cannot be sold due to a 2011 Tokyo mandate. The hides have proven to be free of contamination, so they have been used to make the leather products since 2015. The boar population in Date continues to grow and causes considerable damage to crops, thus hunters are used to cull the population. Roughly 1,800 have been captured in the city since March, 2011.  http://www.fukushimaminponews.com/news.html?id=845 
  • Fukui politicians ask Defense Minister Inada to beef up nuclear station protection against missile attacks. There are three stations on the north shore of the prefecture, containing a total of 15 units. Governor Issei Nishikawa and six mayors presented a formal request to the minister, saying (in part), “Ignoring international criticism, North Korea repeatedly launches missiles and conducts nuclear tests. On July 4, it launched a new type of missile, one that fell inside Japan’s exclusive economic zone. The danger of an armed attack on Fukui’s 15 reactors in the south of the prefecture, the largest number in Japan, is rising. In order to deter a missile attack, and in order to secure peace of mind of local residents, we ask that Self-Defense Forces be dispatched to the southern part of the prefecture.” http://www.japantimes.co.jp/news/2017/07/20/national/politics-diplomacy/fukui-governor-mayors-ask-inada-added-protection-reactors-north-korea-attacks/#.WXCVUKMUkdU (Comment – The news report failed to mention that the three nuke stations are Tsuruga, Mihama, and Ohi, plus that none of the fifteen units are currently operating. Further, only two of the units at Ohi have operated in the last six years.)

July 13, 2017

  • Tepco posts plans for next week’s unit #3 underwater investigation. The investigation will occur over a three day period, March 19-21, 2017. The underwater ROV (Remote Operated Vehicle) will pass through the Primary Containment Vessel wall via existing piping that was modified to accommodate the robot on July 11th. It will then move underwater on a path parallel to the Control Rod Drive Mechanism replacement rail, then swim into the inside of the Reactor Pressure Vessel pedestal. Unlike units #1&2, the water level in the bottom of the unit #3 PCV is high enough to allow the ROV to make its search entirely submerged. The first day will provide images of the physical conditions inside the pedestal, in and around the CRDMs. On the second day, the Tepco staff will review the images of the first day and map out a plan of attack for the third day’s excursion. The three-day strategy has been dictated by the possibility “of damage inside the pedestal including dropped grating and cut TIP guide pipe”, based on what was seen inside the unit #2 pedestal. The ROV will be “moored” just inside the PCV penetration pipe during the second day, awaiting the review of the day #1 images and modification of “the priority order of investigation.” By swimming into the pedestal, the ROV should not encounter the debris problems that hampered the robot excursion into unit #2. Being submerged, the ROV should not experience the high radiation exposures that limited the operation of the prior robotic investigations, because water itself is an effective radiation shield. It remains to be seen if the unit #2 water is murky, as with unit #2, or clear, as with unit #1. https://www4.tepco.co.jp/en/nu/fukushima-np/handouts/2017/images/handouts_170713_02-e.pdf
  • A Harvard University instructor says fear is more dangerous than radiation. David Ropiek writes that fear of radiation is “deeply ingrained in the public psyche”, so much so that it is believed any exposure, no matter how tiny, is unacceptably dangerous. He continues, “The truth, however, is that the health risk posed by ionizing radiation is nowhere near as great as commonly assumed. Instead, our excessive fear of radiation – our radiophobia – does more harm to public health than ionizing radiation itself.” He concludes, “Our fear of radiation is deep, but we should really be afraid of fear instead.” https://aeon.co/ideas/fear-of-radiation-is-more-dangerous-than-radiation-itself
  • The main road through Namie will open in the fall. It is the most direct highway between Namie and Fukushima City. It will shorten the time to go from the capital to nuclear host community Futaba by at least 30 minutes. Local residents and “designated parties” are currently allowed to use the thoroughfare during the day, but not at night. When the restrictions are lifted, the highway will improve traffic flow to the coast and accelerate reconstruction. Most of the highway runs through Namie’s remaining “difficult to return” zone. It will happen only if the prefectural and local governments agree to unrestricted use of the road. Namie Mayor Tamotsu Baba said, “We'd like to realize open transit along Route 114 and thus hasten reconstruction.” http://www.fukushimaminponews.com/news.html?id=843
  • NRA chairman Shunichi Tanaka makes a verbal blunder, and is castigated by the Press. The head of the Nuclear Regulation Authority was speaking to a group of about 30 anxious Takahama residents concerning the restarts of two nuclear units. He was asked what would happen if a North Korean nuclear-tipped missile hit the power station. They feared it would cause a nuclear catastrophe worse than the missile alone. He responded, “I do not know if North Korea's technology has the level of precision that can land a missile at a small reactor. If I were in charge, I would believe that targeting the middle of Tokyo would be a lot better idea.” When the attending Press took umbrage with what Tanaka said, he apologized for the offhand comment and said he used an inappropriate example. https://japantoday.com/category/national/nuclear-authority-chief-draws-flak-over-n.-korea-missile-gaffe
  • The NRA chides Tepco for a lack of initiative with Fukushima Daiichi decommissioning. NRA Chair Tanaka says, “I feel a sense of danger” because it seems Tepco does “not have a will to take initiative. An operator lacking will to take initiative does not have the right to resume operation of nuclear reactors." The admonishment was specific to treatment of the increasing volume of contaminated water and removal of melted fuel at the plant. This reproach was made at a meeting with the company concerning the possibility of restarting two Kashiwazaki-Kariwa units. Tepco chair Takashi Kawamura replied, "There are citizens who believe nuclear power is necessary. Operating reactors is our responsibility." He added that there is only enough space at the nuke station for two more years of additional decontaminated water storage, implying that the NRA needs to do something pro-active to resolve the problem. Tanaka responded that the NRA feels it has not received sufficient information on F. Daiichi decommissioning, and “[Tepco] which caused the [Fukushima] accident, is not [treated as] an ordinary operator.” https://www3.nhk.or.jp/nhkworld/en/news/20170710_21/ -- https://mainichi.jp/english/articles/20170711/p2g/00m/0dm/028000c  (Comment – Every time Tepco takes initiative, the NRA puts up roadblocks to impede progress. So, who is to blame for the so-called lack of initiative? The NRA needs to look at itself!)

July 6, 2017

  • Takahama station restarts result in 3.15% rate reduction for Kansai Electric Co. customers. The utility submitted its plan to cut its household consumer electricity costs to the Industry Ministry, effective August 1st. The reduction reflects the recent restart of two units at the Takahama nuclear station in Fukui Prefecture. The reason is that nuclear fuel costs less than fossil fuels for the production of electricity. http://jen.jiji.com/jc/eng?g=ind&k=2017070600656
  • The Japanese Press’ obsession with mixed oxide nuclear fuel continues. A shipment of recycled (MOX) fuel left Cherbourg, France, on Wednesday, destined for Takahama unit #4. MOX is fabricated from the Uranium and Plutonium isotopes that exist in abundance in used nuclear fuel bundles. Kansai Electric Co. says the sea-going route of the shipment is being withheld for at least two weeks due to security concerns. https://www3.nhk.or.jp/nhkworld/en/news/20170706_17/
  • The much ballyhooed criminal retrial of three Tepco executives starts as a news media circus. The three are former Tokyo Electric Power Company Chairman Tsunehisa Katsumata and former Vice Presidents Ichiro Takekuro and Sakae Muto, all of whom were in office on March 11, 2011. In 2013, Tokyo prosecutors rejected the allegations that the three were criminally negligent with respect to the Fukushima accident. However, the plaintiffs who were rebuffed in 2013 persisted in their efforts to get a citizen’s tribunal to reverse the court’s decision. They were finally successful last February when court appointed lawyers, acting as prosecutors, moved to indict the executives. All three plead not guilty when the trial opened on Friday. Former Chair Katsumata said it was impossible to predict the massive tsunami that spawned the nuke accident. The plaintiffs argued that an internal Tepco investigation in 2008 found that a tsunami capable of swamping the nuke station was possible. Plaintiffs insist that the 44 hospital patients who died in the chaotic evacuation and ten Tepco employees injured during the effort to stop the three-unit meltdown, were entirely avoidable, "They [Tepco] should have suspended the operations of the reactors until they have taken measures [to protect the plant] such as by building seawalls, making reactor buildings watertight, or moving reactors to higher ground." The prosecutors said the “astounding” tsunami predicted in 2008 resulted in a blueprint for upgrading the emergency electrical systems being drawn up and presented to Mr. Muto and Mr. Takekuro. The prosecutors alleged that the Tepco Chairman attended the decision-making meeting, but Mr. Katsumata said he had no recollection of it. The head of the plaintiff group said, “I hope we will get to know the truth [through the trial].” https://www3.nhk.or.jp/nhkworld/en/news/20170630_16/ - http://the-japan-news.com/news/article/0003794390 - http://www.asahi.com/ajw/articles/AJ201706300043.html - https://english.kyodonews.net/news/2017/06/7502f1b1b6c3-update1-ex-tepco-execs-go-on-trial-over-fukushima-nuclear-disaster.html and etc.
  • Ikata unit #1 is the latest to be approved for decommissioning. This is the sixth unit to have its dismantling permitted by the Nuclear Regulation Authority; the other five are Tsuruga #1, Genkai #1, Mihama #1 & #2, and Shimane #1. All are relatively small units with outputs less than 600 MWe, where the cost of meeting Japan’s new safety standards would cost more than the operation of the units could generate over a 20 year period. http://www.jaif.or.jp/en/japans-nra-approves-ikata-1-decommissioning-plan/

 

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