Japanese Regulator Confirms No Criticality at Fukushima Daiichi
November 9, 2011
- Sustained nuclear fission did not occur at the Fukushima Daiichi nuclear energy facility last week, Japan’s Nuclear and Industrial Safety Agency said, confirming earlier reports from Tokyo Electric Power Co. Plant employees detected a trace amount of radioactive xenon-135 gas in the reactor 2 containment vessel last week, which led to initial concerns there might have been an ongoing nuclear reaction in the vessel. After investigation, TEPCO said the xenon was produced through spontaneous fission, a form of radioactive decay. NISA said the density of the xenon did not change when a boric acid solution was injected into the reactor, demonstrating that criticality was not occurring.
- Japan’s environment ministry has begun a study of radiation levels within 12 miles of Fukushima Daiichi to pinpoint areas that should be decontaminated first. An interim report is expected in December, with full-scale cleanup beginning in January.
- One-quarter of the evacuees from areas around Fukushima Daiichi have no intention of returning, a Fukushima University survey has found. More than half of the respondents in their mid-30s or younger said they won’t return to their hometowns. The Fukushima University group sent questionnaires to all households in eight municipalities near the nuclear energy facility, receiving responses from about half of them.
- Energy costs will rise over the next two decades if governments don’t promote renewables and nuclear power, Bloomberg News reports. The online article says the International Energy Agency predicts global demand for energy will increase by 40 percent by 2035.
- Following computer-simulated stress tests of its systems, Kansai Electric Power Co. reported that its Ohi 3 nuclear energy facility has sufficient safety margins to withstand beyond-design-basis events, Nuclear Engineering International reports.
- The Dalai Lama said after a tour of tsunami-damaged northeastern Japan that he supports using nuclear energy as a peaceful way to bridge the economic gaps in developing countries, the Wall Street Journal Japan Realtime blog reports.
- A French radiological organization has proposed hardening the country’s nuclear reactors so a limited number of “hard core” safety-related systems, structures and components can withstand extreme external events like floods and earthquakes that are outside the plant’s safety parameters. The organization said analysis of the country’s reactors showed that external events had not been considered as thoroughly in plant design as internal events, Platts reports.
- NEI’s Safety First website continues its ongoing focus on practices that enhance nuclear safety. This week the site features an interview with Bonnie Bryant at Seabrook nuclear energy facility, where she and her husband have both worked since the early 1990s. Each holds a senior reactor operator’s license. Bryant discusses safety procedures at the facility.
Note: There will be no Friday Update due to the Veterans Day holiday. Updates will return Monday.