The question of whether or not the geologic “seam” running under the Oi nuclear station remains an issue. A Nuclear Regulatory Authority (NRA) team of experts looked at the excavated geology last Friday. However, the panel is split over whether or not a displaced stratum above the bedrock is a seismic indicator. Some say it is seismic while others say it’s just as possible it is not. Disagreements among principles in such proceedings are not uncommon. However, this may be the first time an expert debate on a controversial issue has been laid bare for the Japanese press to witness. The news media is not accustomed to the policy of full transparency and the NRA isn’t experienced in the media interest the policy has generated.

  • Earlier this week, Toyo University Professor Mitsuhisa Watanabe said he feels the evidence shows the geological seam has moved in the past 125,000 years, he says it is seismic. His conviction is so strong that his formal presentation contained Oi survey maps overlaid with the words “active fault” in bright red. Shinshu University professor Daisuke Hirouchi gave tacit support to Watanabe saying there is no evidence to show that the stratum in question is not seismic. On the other hand, Ritsumeikan Univ. professor Atsumasa Okada said the displaced stratum may well be the result of a landslide and judging it seismic would be a hasty decision. He called for additional study using experts more familiar with the geologic evidence of ancient landslides. To further muddy the waters, Norio Shigematsu, senior seismic researcher at the Institute of Advanced Industrial Science and Technology, said the indicated direction of movement within the stratum does not match the likely movement of the underlying bedrock’s fault, if the fissure is indeed seismic. It is likely that additional excavations will be needed and more experts added to the investigation before the current deadlock can be broken. Making the debate public has brought criticism with it. Fukui Prefecture official Hiroshi Sakuramoto said, “It’s critical to carry out the investigation and render a decision that everyone can understand, one based on objective data and scientific proof, but that’s not what we have. The members shouldn’t have these kinds of vague discussions.” (Yomiuri Shimbun; Japan Times; Wall Street Journal – Japan Realtime)
  • The NRA’s investigative team met again on Wednesday in the hope of resolving the deadlock. Instead, the rift among the team members remained. One problem is the discovery made by Kansai Electric that the fissure is considerably shorter than had been expected. Several months ago Prof. Watanabe and his colleagues estimated the seam to be 900 meters long, but Kansai now believes it to be about 600 meters. In response, some of the team members say Kansai’s survey “lacked three-dimensional data” which could show the fissure to be the prior estimated length. Thus, NRA commissioner and team leader Kunihiko Shimazaki concluded that failure to reach an agreeable conclusion is due to a lack of sufficient data. He said, “It is desirable for the five members to reach a conclusion by consensus.” He told Kansai to expand their survey to accommodate all panel concerns. Once the Kansai excavations have been expanded, the NRA will inspect it themselves. Professor Watanabe urged the NRA decision be made quickly because two of the Oi nukes are operating at full power. (Kyodo News Service; NHK World)

Here are some additional Fukushima updates…

  • More errors have been found in the contamination projections released by the NRA last week. The new mistakes were found in prognoses for Kyushu Electric’s Genkai and Sendai nuclear stations. The NRA says the errors were due to Kyushu Electric supplying incorrect weather pattern data. Last week, NRA Chairman Shunichi Tanaka instructed the responsible staff to insure they do everything possible to prevent incorrect projections. As a result, the NRA staff uncovered the faulty data. NRA spokesman Hikeda Morimoto said the blame should not be directed at Kyushu Electric, but rather that the NRA staff as the culpable party. They relied on utility meteorological projections without cross-referencing them with independent meteorologists. Regardless, Kyushu Vice President Masanao Chinzei said, “We sincerely apologize for causing trouble.” Because the projections did not include the effects of topography on the hypothetical release pathways, Morimoto said the NRA has told their staff to produce an “advanced” version. (Kyodo News Service; Japan Times)
  • The NRA will create expert panel to discuss the criteria for the administration of Potassium Iodide (KI) tablets. Many municipalities say they cannot draw up emergency plans until they receive expert guidance on the (KI) issue. KI is a thyroid-blocking medication that saturates the gland and prevents the deposition of radioactive Iodine-131. NRA commissioner Kayoko Nakamura said she wants domestic criteria established on KI administration. She said the panel will be selected from private-sector experts familiar in KI administration, such as radiologists. KI is designated as a “powerful medicine” in Japan and this label seems to be at the root of the issue. “If we deliberate on the details of administering [the pills] without an airtight plan, it could cause a panic like the one that occurred in Fukushima Prefecture. We will work out specifics, including which people will be asked to take the pills,” Nakamura said. (Yomiuri Shimbun)
  • Recent medical examinations show no radioactive Cesium in the breast milk of Fukushima mothers. While the number of mothers who volunteered for the medical survey was a bit fewer than had been hoped, there were enough volunteers to produce results with a reasonable degree of confidence. One reason suggested for the low number of participants was the survey posted in July showing no Cesium content in the participant’s milk. (Asahi Shimbun)
  • Tokyo Electric Company (Tepco) is said to have “over-reported” the number of people working at Fukushima Daiichi. Tepco has maintained 24,000 people have been working at F. Daiichi, but NHK World has discovered the number is more like 8,000 per month. The Tepco number is for everyone who has worked there since 3/11/11. Many have left due to layoffs while others quit because the work was too strenuous. Tepco maintains they need an average of just under 12,000 workers per month to stay on their published recovery time-table. The company told NHK that the number of people working at Fukushima fluctuates from week to week and the survey was run during a low point in staffing. Many of those currently laid-off are temporary contractor employees who will be re-hired when they are needed. Tepco says that on any given day, about 3,000 people work at F. Daiichi; some full-time and some part-time.