November 2, 2011

Nov 2, 2011 | Fukushima Accident Updates

  • The source of the high radiation level near a Tokyo, Setagaya Ward supermarket has found it to have nothing to do with Fukushima. After tearing up the asphalt overlying the location of the source, technicians dug down nearly a foot into the soil and found a bottle containing material suspected to be Radium. Soil analysis revealed isotopes of Lead and Bismuth, two radioactive decay daughters of Radium. Contact reading on the bottle was 40 millisieverts (4 REM) per hour. The bottle was placed in a lead-lined box and sent to the Science Ministry for further investigation. With the removal of the bottle, radiation levels in the area dropped back to those found elsewhere in the ward. (Mainichi Shimbun)
  • TEPCO has announced there may have recently been a short period of increased fissioning inside the fuel cell of reactor #2. When analyzing gas from inside the Primary Containment surrounding the RPV, two isotopes of the inert gas Xenon were detected; Xe-133 and Xe-135. Each has a short half life, with Xe-133’s being five days and Xe-135 being nine hours. These isotopes cannot be residuals of the March 11 emergency shutdown, thus they must have come from a recent refissioning. The concentrations are miniscule, so it is likely the rate of fission was very, very low. Whether or not the fuel cell experienced brief re-criticality is speculative. Even if it did, the fission rate at temperatures below 100 oC would be tiny. Not even enough to measurably raise the water temperature. TEPCO is sending their data to Japan’s Atomic Energy Agency for review and confirmation. TEPCO has increased the level of boric acid in the RPV water injections to prevent this from recurring. They are also checking units 1 and 3 to see if something similar has happened. (NHK World; Mainichi Shimbun) What none of today’s reports mention is a fully melted and relocated fuel cell makes something like this highly unlikely. However, a partially melted cell could possibly give us something like this. Is it possible that unit #2’s fuel cell did not experience a full meltdown?
  • In a related story, Professor Koji Okamoto of the University of Tokyo Graduate School says the possibility of recriticality in a melted fuel cell being cooled by water full of boric acid is unlikely. He says, however, that pieces of melted fuel “scattered around” that are in the natural neutron field surrounding nuclear fuels might produce some low level fissioning. He concedes the presence of xenon in the No.2 reactor leaves open the possibility that localized and temporary fission could occur. Okamoto stresses that a self-sustaining chain reaction that creates criticality is unlikely in a boric acid environment. (JAIF)
  • The Mayor of Genkai, Saga Prefecture, has given approval for the re-start of Genkai unit #4, which was shut down due to an operator mistake about a month ago. “I am persuaded to some degree,” Hideo Kishimoto told reporters after talks with Kyushu Electric Executive Vice President Haruyoshi Yamamoto. The Nuclear and Industrial Safety Agency rated the utility’s report on the cause of the shutdown and error-prevention measures they have taken as “basically appropriate,” which seem to have satisfied the Genkai Mayor. Because the shutdown was due to human error, the stress test required for other idled nukes is not needed. (Mainichi Shimbun)
  • Following the Genkai Mayor’s positive response, Kyushu Electric has begun restart of Genkai #4. Operating preliminary functions prior to the resumption of electricity production will be later today. Kyushu Electric plans on full 1,200 Mwe output to the national grid by Friday. (JAIF)
  • After months of gloomy stories about Asian nations turning away from Japanese foods due to fear of Fukushima radiation, we find that the food scare may have ended months ago. At least in Hong Kong, Japan’s largest consumer of Japanese foods. Hong  Kong’s Japanese restaurants took a terrible downturn in April. “People simply lost confidence in eating Japanese food, especially fresh food like sushi,” said Simon Wong, chairman of the Hong Kong Food Council. Diners slowly began to return around the end of May, and by late August business for most Japanese restaurants and supermarkets specializing in Japanese food had recovered. Wong said, “Actually, some restaurant owners told me that they are getting even better business than before March 11.” Yata Ltd., a popular Japanese-style store, also saw its fresh produce business recover after overall sales plunged at least 70 percent in April and May. Yata Managing Director Daniel Chong said, “In August, when we started selling Japanese peaches, they were immediately sold out. We are already above last year’s sales record (for peaches).” (Japan Times) If the recovery has been happening in Hong Kong since August, why has it taken until November for a Japanese news source to report the good news?
  • Japan Nuclear Energy Safety Organization (JNES) under the jurisdiction of the government’s Nuclear and Industrial Safety Agency (NISA), is being charged with “sloppy inspection procedures”. Yoshihiro Nishiwaki, a visiting professor at the graduate school of the University of Tokyo, has revealed, “Inspections are carried out by the government itself, and therefore they should make painstaking efforts to determine the content of inspections on their own.” It seems that JNES, the principle nuclear regulatory inspection body, did not write their own inspection procedures, but rather cut-and-pasted instructions from nuclear plant manuals. Also, instead of performing their own inspections, they would have the utility operating the plants run them and then get the data generated by the plant staff to be analyzed. From 1991 through 1993, Nishiwaki was sent to America to observe Nuclear Regulatory  Commission (NRC) inspection processes while working in the Ministry of International Trade and Industry (now defunct). He found NRC inspectors decided on when and what they planned to inspect on their own and often conducted inspections without advance notice. Connecting their own computers with the local area network, they even check e-mails exchanged between facility workers and subcontractors. If necessary, they bring in their own inspection equipment to see if devices at the nuclear plant have deteriorated. All this to prevent nuclear plant operators from doctoring inspection documents. “I was impressed with the attitudes taken by inspectors to check master inspection procedures on their own and try to uncover problems and illegal practices at nuclear facilities,” Nishiwaki said. However, there are no such fail-safes in the JNES system. He says Japan’s plant operators carry out inspections first and then JNES inspectors check to see if the examinations are sound by using almost the same techniques as the plant operators. JNES defends their shoddy practices by saying, “There is no problem even if we prepare inspection procedures in accordance with the draft steps prepared by the plant operator.” Also, the timing of inspections is notified to plant operators in advance. While working for MITI through 2002, Nishiwaki observed trouble in which some devices were not operating properly during inspections of a nuclear power plant. “When we asked them to show us maintenance records, a worker said to us, ‘We will have them operational for sure. Please have sushi or something with our executives until then.’” Nishawaki added he was troubled by such practices, but could find no governmental support to correct the obvious problem. (Mainichi Shimbun) Once again, we find the American regulatory system is many times better than the one which seems to have been the case in Japan for at least two decades.