February 22, 2013

Feb 22, 2013 | Fukushima Accident Updates

  • Fukushima Prefecture say their radiation monitors recorded releases from Fukushima Daiichi unit #1 several hours before the plant’s venting operations began. Before 3/11/11, the prefecture had 25 operating monitors surrounding the power station. Five along the shore were washed away by the tsunami. The other twenty were constantly recording data, powered by their batteries and solar panels, but the region’s complete power failure kept the data from being transmitted to Fukushima City and Tokyo. After the chaos of the week following the tsunami, the prefecture collected the data. Subsequent analysis was published on the prefectural website and shared with government bodies. However, it seems no-one noticed that some of the monitors recorded increased radiation levels in four Futaba town districts hours before the unit #1 venting began. Futaba is adjacent to the F. Daiichi property line. Because of the varying wind directions in the pre-dawn hours of March 12, radiation levels fluctuated. Typical background levels recorded before the accident were between 0.04 and 0.05 microsieverts per hour. At 5am on March 12, radiation levels began to jump. The highest peak in the Koriyama district, located about 2.5 kilometers from the nuke station, was 7.8 micro-Sv/hr (9am). The highest in the Yamada district, 5.5 kilometers away, was 32.47 micro-Sv/hr (10am). By the time most of these readings were registered, nearly all the 3km radius around F. Daiichi was evacuated. (F. Daiichi staff records) However, the 10km evacuation began at 5:44am affecting some 50,000 persons, thus those in the “plume pathway” were subject to the elevated exposures. It should be noted that after the final venting operation in the early afternoon, the monitor in Kamihatori district registered a peak of 1,591 micro-Sv/hr. The Diet’s investigative team (NAIIC) was unaware of the existence of the information when they posted their report last summer. Mitsuhiko Tanaka, the outspoken loose-cannon of the NAIIC team, was shocked by the announcement. He said this opens up a whole new set of issues concerning the condition of F. Daiichi unit #1 before the hydrogen explosion at 3:36pm on March 12. He says it could further delay restarts of idled nukes. Tanaka stated, “There’s a mountain of issues that should be examined before we start talking about restarting nuclear reactors.” Reiko Hachisuka, who represented Fukushima Prefecture at the NAIIC, said, “If the prefectural government was thinking firstly about the health of its residents, then it would have considered the data vital information that needed to be analyzed quickly. As a prefectural resident, I find the Fukushima Prefectural Government’s response shameful.” (Mainichi Shimbun)
  • Two mayors in Fukui Prefecture are asking for nuke restarts. The mayors of Takahama Town and Tsuruga City made the request to industry minister Toshimitsu Motegi. Fukui Prefecture has Japan’s largest number of nuclear units. The caveat is that the units must be confirmed safe by the Nuclear Regulatory Authority before they resume operation. The mayors demand the government’s final decision must be made public with details as to the reasons behind it. The mayors say the sudden decision to shutter all nukes has pushed local businesses to the brink of financial collapse. Takahama’s mayor said the former Tokyo regime’s no-nuke policy was a severe blow to his community. He also suggested government subsidies should be made to local communities to defray economic shortfalls during the current nuclear moratorium. Motegi said the government will support the NRA’s safety judgments and address restarts accordingly. (NHK World)
  • Sources from inside the Japanese nuclear community believe the Ikata station, Ehime prefecture, will be the first to be restarted once the nuke moratorium is over. The two Oi station units currently in operation will be shuttered later this year for maintenance and refueling. It is believed they will not be allowed to restart until they meet the new regulations the NRA plans to have in place by July. The Ikata units are said to have some of the most advanced safety systems in Japan’s nuclear fleet. (Japan Daily Press) [Comment – All three Ikata units are Pressurized Water Reactor (PWR) systems. More than half of Japan’s nukes are Boiling Water Reactor (BWR) systems. Since F. Daiichi is a BWR station, it is felt that most new regulations will more severely impact BWRs than PWRs.]
  • The NRA has conditionally approved the final wastewater decontamination system for F. Daiichi. The advanced liquid processing system (ALPS) will begin field trials in March. Full operation is conditional on the integrity of the containers that will hold the concentrated radioactive material removed from the water. ALPS will remove the residual radioactive isotopes from the massive quantity of water that has been run through the existing water clean-up system. Tepco has found some 62 radioactive isotopes in the water now being stored. All but one will be removed by ALPS. The one that cannot be removed is Tritium, an isotope of hydrogen. Although the Tritium levels are tiny, they are detectible. Whether or not the Tritium must also be removed before the waters can be pumped out to sea, is anyone’s guess. (Japan Times)
  • About 65% of the tsunami debris in the Tohoku region has yet to be disposed of. The total already disposed is about 9.5 million tons, leaving some 17.5 million tons that are yet to be handled. 3.5 million tons of the tsunami remains in Fukushima have been untouched due to radiation fears, but ~ 600,000 tons have been disposed of. In Iwate and Miyagi prefectures, 8.9 million tons have been handled, but another 14.5 million remains. The Environment Ministry hopes the job will be finished by March, 2014, but disposal assistance from other prefectures has not met expectations. The Ministry is looking into building new disposal facilities in the three prefectures in the hope that their timetable will be met. (jiji Press)