December 17, 2015

Dec 17, 2015 | Fukushima Accident Updates

  • Takahama units #3 & #4 clear more restart hurdles. The evacuation plan for the 30km radius was approved on Wednesday, covering not one, but three Prefectures; Fukui (home prefecture), Kyoto and Shiga. Officials from all prefectures “confirmed the plan is reasonable”. It is the first evacuation plan covering multiple prefectures and covers 180,000 people living within the 30km radius. It is expected that PM Shinzo Abe will formally approve the evacuation plan on Friday. On a second note, the Fukui Prefecture Assembly has approved the restarts. A draft resolution supporting of the move was submitted on today to the plenary session of the assembly, and passed by majority. Industry Minister Motoo Hayashi will meet Fukui Governor Issei Nishikawa on Sunday to urge a formal approval for the resumption of operations. After that, the restarts will have one remaining roadblock to overcome; a Fukui district court injunction barring it happening. An appeal decision is expected next week. http://www.japantimes.co.jp/news/2015/12/16/national/evacuation-plan-compiled-residents-around-takahama-nuclear-plant/#.VnFp1ZDUgdV
  • Confusing reports in the Japanese Press about unit #2 valve failures on 3/14/11. It seems that the valves that were supposed to automatically depressurize the reactor vessel (RPV) failed to operate as designed. The earliest report was with NHK World, saying the inability to depressurize the RPV kept operators from using a low pressure fire pump to inject cooling water over the overheating fuel. http://www3.nhk.or.jp/nhkworld/english/news/20151217_05.html  Operator records show that the SRVs worked as they were supposed to until the afternoon of March 14th. The operator records show that just after noon on March 14, no-one could enter the Suppression Chamber, which housed the 600,000 gallon “torus”, because the temperature in the room was nearly 150oC! The only way this could have happened was if safety relief valves had opened earlier. Further, with the torus that hot, all of the water within had probably boiled away. The operator record says that pressure build-up inside the PCV might possibly prevent proper SRV function since the pressure inside the PCV was climbing and would work against SRV operation. As it turns out, the operators did open two SRVs that evening by operating manual actuation valves that were energized by car batteries. Thus, there is something confused in the NHK report. It also seems the parallel Asahi Shimbun’s report has at least two technical errors. First, the Asahi (as with nearly all Japanese Press) routinely confuses matters by referring to the entire contents of the reactor building as “the reactor”. They seem to have done it again. Next, the Asahi says that the SRVs did not function because they were “designed to open under the pressure of nitrogen gas piped in from tanks and other sources.” However, BWR SRVs do not use nitrogen “pressure” to open! It is the steam pressure inside the RPV that forces them open by overcoming the large springs that hold them shut.  http://ajw.asahi.com/article/0311disaster/fukushima/AJ201512170031  In both cases, the reports fail to mention the situation as reported in the operator records. The operator records show that just after noon on March 14, no-one could enter the Suppression Chamber, which housed the 600,000 gallon “torus”, because the temperature in the room was nearly 150oC! The only way this could have happened was if safety relief valves had often opened earlier in the crisis. Further, with the torus that hot, all of the water within had probably boiled away. The pressure inside the PCV necessarily increased, which would have inhibited SRV operation. Regardless, it may take many days to sort this all out because Tepco has yet to post what they actually told the reporters. At this point, we only have the confused news reports.
  • Tepco says the release of radioactive material that began March 14, 2011, was from unit #3. This was the day that the wind direction shifted inland. Unit #3 had vented its containment repeatedly beginning March 11th, with the plume going out to sea. However, at 9pm on March 13th, a venting showed only a moderate pressure drop inside the PCV, indicating problems with the operation. Tepco feels that the monitored increase in airborne radioactivity on March 14th was because the PCV’s integrity had been compromised due to over-pressurization, beginning the previous evening. Tepco also feels that the heat generated by the unit #3 meltdown exacerbated the loss of PCV integrity. http://www3.nhk.or.jp/nhkworld/english/news/20151217_27.html (Comment – Until now, Tepco attributed the aforementioned March 14th inland releases to unit #2 having its large fifth floor blow-out panel open. We have challenged this since Tepco first speculated the releases came from unit #2. It’s about time that Tepco gave at least some credit to unit #3 for the releases! A major fraction, if not most of the releases had to have come from the unit #3 hydrogen explosion. To date, the unit #3 hydrogen explosion has not been included in Tepco’s “official position” as to the cause of the inland atmospheric releases.)
  • New, more versatile decontamination robots should facilitate F. Daiichi in-plant cleanup. The device was demonstrated to the Press on Wednesday. The new robots can reach upper floors inside the buildings where other clean-up robots could not. The several robotic sections are connected by hoses and cables that can extend upwards as much as 65 meters, including an arm that can blast high-pressure water, one robot that uses dry ice, and another that employs abrasives with a suction function. The interconnected robots are being deployed on the second and third floors of reactor buildings. The robots were developed in conjunction with International Research Institute for Nuclear Decommissioning, Mitsubishi, Hitachi-GE, and Toshiba, in addition to Tepco’s robotic engineers. http://www3.nhk.or.jp/nhkworld/english/news/nuclear.html — http://www.tepco.co.jp/en/press/corp-com/release/2015/1264416_6844.html  A video has been posted by Tepco to demonstrate the several functions of the new device… https://www.facebook.com/video.php?v=1009017499157549&set=vb.415607698498535&type=2&theater
  • The budget for rural Fukushima decontamination is boosted in order to meet the March, 2017, deadline. Last summer, the Environment Ministry requested a fiscal 2016 budget of just under $4 billion. However, that might not be enough to complete decontamination in the targeted municipalities that are supposed to be repopulated in April of 2017. The new budget should be about $4.5 billion. The increase is due to higher-than-expected costs of decontamination work, equipment maintenance costs, and rural waste disposal. http://www.japantimes.co.jp/news/2015/12/16/national/japans-radiation-decontamination-budget-to-hit-record-%c2%a5522-3-billion/#.VnFqQZDUgdV
  • Japan plans for more nuclear and renewable energy production. The Industry Ministry wants increased reliance on both in order to reduce greenhouse gas emissions caused by the burning of fossil fuels. The plan will be to have nukes and renewables account for at least 44% of Japan’s electricity by 2030, and will allow cooperative efforts between utilities in order to meet the prospective goal. In addition, energy conservation standards will be tightened to promote a shift to energy-saving light-emitting diode (LED) bulbs. The plan is intended to help make Japan’s goal of reducing greenhouse gas emissions 26% by 2030. http://jen.jiji.com/jc/eng?g=eco&k=2015121500275