(This post is by Christine McCann)
Here’s the latest of our news bulletins from the ongoing crisis at Japan’s Fukushima Daiichi nuclear power plant.
A magnitude 6.8 earthquake struck the northeastern part of Japan on Wednesday, triggering a 20 cm tsunami in Hokkaido Prefecture. Nuclear operators said that no immediate damage was discovered.
State of Nuclear Politics in Japan
A new poll conducted by Asahi shows that 80% of Japanese people distrust the government’s ability to safely regulate nuclear power. In addition, 57% of respondents oppose reactivating idled nuclear reactors.
Japan’s Nuclear and Industrial Safety Agency (NISA) has admitted that it blocked Nuclear Safety Commission (NSC) efforts to adopt international nuclear safety standards in 2006, regarding evacuations in the event of nuclear emergencies, because it was worried that the move would spark concerns about nuclear power among the public. Failure to do so delayed evacuation efforts after the Fukushima nuclear crisis and exposed nearby residents to high levels of radiation. An April 2006 letter from NISA officials to the NSC stated, “ We want the discussion [on revising the guidelines] halted since it could…increase anxiety among Japanese citizens about nuclear safety.” The letter continued, “Japan’s nuclear disaster management has no particular problem and changes are not necessary.
The NSC has concluded its review of stress tests for reactors #3 and #4 at Kansai Electric’s Oi plant in Fukui Prefecture, and is expected to grant approval of the process as early as next week. However, that assessment will reportedly also include a recommendation that a second stage of stress tests be conducted. Nuclear power plants were required to submit those results in December of last year, and yet not a single one has done so. NISA has already approved the stress tests.
Once the NSC issues its report, Prime Minister Yoshihiko Noda will meet with Cabinet Secretary Osamu Fujimura; Yukio Edano, the head of the Ministry of Economy, Trade, and Industry (METI); and Goshi Hosono, Nuclear Crisis Minister in order to determine whether or not to restart the reactors. Assuming that approval is granted, they will then meet with local government officials to try to convince them that the nuclear plants are safe. That’s expected to be an uphill battle; the governor of Fukui Prefecture has already said he opposes restarting the idled reactors until the causes of the Fukushima disaster are fully studied. Public support is also very weak. Meanwhile, some members of the Diet are raising concerns that this process is moving forward before the proposed Nuclear Safety and Security Agency (NSSA) has even been established. The NSSA was supposed to begin operations on April 1, but the bill authorizing its operation has stalled in Parliament because of concerns about its independence and effectiveness.
New reports show that pressure containers of Japanese nuclear reactors built in the 1970s may be deteriorating at a faster-than-expected rate, due to a high percentage of copper. Government sources insist that the issue does “not necessarily” pose an immediate danger to humans. Reactor #1 at the Tsuruga nuclear power plant showed the highest copper percentage.
Reactor #1 at the Tsuruga nuclear plant marked its 42 nd year of operation this week, which exceeds the government’s proposed limit of 40 years of operation for nuclear reactors. The mayor of Tsuruga is pushing for the reactor to be restarted, even though it sits on a major fault line, raising the possibility of a magnitude 7.4 earthquake, and in spite of the fact that high copper content is causing faster than expected deterioration of its pressure vessel.
Meanwhile, Prime Minister Yoshihiko Noda is reportedly considering approving operations at reactor #3 at the Shimane power plant, which is under construction. Since the Fukushima disaster, the public has shown significant reluctance to build new nuclear reactors.
An NSC working group has finalized new safety guidelines for nuclear power plants, including strengthening language about preparing for tsunamis. Previous guidelines, which were last updated in 2006, included only two lines about dealing with tsunamis.
TEPCO
A former vice-president of TEPCO, Sakae Muto, admitted this week that TEPCO was negligent in preparing for the nuclear disaster that occurred last March at the Fukushima Daiichi plant. Muto, who worked for TEPCO last March, when the Fukushima disaster occurred, was testifying before a Diet committee investigating the nuclear crisis. “We caused a big accident that inflicted damage that cannot be recovered. We are sorry for giving serious, long-lasting trouble and pain to people in Fukushima Prefecture and wider society,” said Muto. “We were able to confirm that TEPCO’s preparations for possible accidents were not sufficient,” he added.
Two citizens’ groups from Fukushima Prefecture plan to file a criminal suit against TEPCO executives, charging professional negligence for failing to adequately prevent the Fukushima Daiichi nuclear disaster and as a result, exposing many residents to high levels of radiation. A representative of one of the groups said, “[It’s] nonsense that nobody has been held criminally responsible for causing a major nuclear accident.”
In an interview with The Daily Yomiuri, former Prime Minister Naoto Kan sharply criticized TEPCO for its role in last year’s nuclear disaster at the Fukushima Daiichi plant, and admitted that NISA “barely functioned right after the crisis.” Kan said, “TEPCO’s preparations for an accident at a nuclear power plant were extremely insufficient.”
Reactor Status
TEPCO workers attempted to inspect suppression chambers at Fukushima Daiichi’s reactors #2 and #3 this week in order to locate and repair damage, but were unable to complete the task. At reactor #2, radiation levels reached 160 millisieverts per hour, too high for humans to enter. The utility plans to use robots to conduct repairs. At reactor #3, they discovered that the door was damaged and would not open, probably as a result of the hydrogen explosion there last March.
TEPCO will use an underwater robot to inspect the spent fuel pond at Fukushima Daiichi’s reactor #4 next week, as workers begin preparations to remove 1,535 highly radioactive spent fuel rods from the ponds. That process is expected to take a decade.
This week, an underwater camera revealed that visibility in the pond has been reduced considerably since just last month. New video shows that visibility is now only one meter, down from approximately five meters last month. TEPCO provided no explanation for why the water has become murkier. Experts say that workers will need to have at least seven meters of visibility to successfully remove spent fuel rods from the pool.
Contamination (Includes Economic Impact and Human Exposure)
Japan’s Ministry of Health, Welfare, and Labour is finalizing new guidelines for cesium contamination of foods, which will be implemented starting on April 1. Cesium in foods for the general population, including beef, rice, and vegetables, will be limited to 100 Bq/kg, reduced from the previous limit of 500Bq/kg. If more than 50 Bq/kg is detected during initial testing within 17 prefectures where high cesium levels were discovered in food last year, samples of that food will be tested three times a week. Random samples of food from Fukushima, Miyagi, Ibaraki, Tochigi, Gunma, and Chiba Prefectures will be monitored three times a week regardless of results. Inspections of rice will begin in October, in order to give municipalities time to prepare for additional testing. In addition, cesium limits in milk products will be lowered to 50 Bq/kg, and the limit for drinking water will be lowered to 10 Bq/kg. The previous standard for both milk and drinking water was 200 Bq/kg.
Testing conducted by researchers from the Japan Atomic Energy Agency reveals that radioactive cesium may have sunk up to 30 cm into the ground after heavy rains over the past year, further complicating decontamination efforts and raising the possibility that the amount of contaminated soil that needs to be disposed of will increase multifold.
Decontamination and Radioactive Waste Disposal
Japan continues to struggle with what to do with massive amounts of radioactive debris left over from last year’s earthquake and tsunami. Currently, there are 474,000 tons of debris piled up in the evacuation zone alone, containing as much as 58,700 Bq/kg of radioactive cesium.
Other Nuclear News
A yet-unpublished draft of an International Atomic Energy Agency (IAEA) report says that 80% of the world’s 435 nuclear power reactors are more than 20 years old, and raises concerns that older reactors are not safe. “There is a concern about the ability of the aging nuclear fleet to fulfill these [updated safety] expectations,” the report said. In addition, approximately 70% of the world’s research reactors exceed 30 years, “with many of them exceeding their original design life.”
In response to a decision issued by a Swiss court earlier this week, ordering the closure of the Muehleberg nuclear plant in 2013, operator BKW FMB has filed an appeal to keep the plant open. The court cited safety and security concerns in its decision, stating, “The state of the nuclear shell, the assessment of the plant’s resistance to withstand earthquakes which is not complete, and lacking cooling possibilities independent of the Aare River allow operations of Muehleberg only up to mid-2013 at the most.” However, BKW FMB is focusing on its own financial concerns, including the high cost of decommissioning the plant, rather than safety concerns of nearby residents. The utility issued a statement that read in part, “A premature shutdown would entail significant financial and technical implications.”
South Korea’s nuclear regulator, the Nuclear Safety and Security Commission (NSSC), announced that electricity was lost for a total of 12 minutes at reactor #3 at the Kori power plant in Busan. A back up generator, designed to provide power in emergencies, also failed. Korea Hydro & Nuclear Power, the plant’s operator and a subsidiary of KEPCO, waited a full month before reporting the outage to the NSSC. The Kori plant began operating in 1978 and was scheduled to go offline in 2008, but the government has extended that limit to 2017.