Here’s the latest of our news bulletins from the ongoing crisis at Japan’s Fukushima Daiichi nuclear power plant.
A magnitude 7.4 earthquake struck off the northeastern coast of Japan at 5:18 pm JST on Friday, triggering three small tsunamis and highlighting the fact that the crippled Fukushima Daiichi plant remains vulnerable to the country’s frequent quakes. The first tsunami, which was approximately one meter in height, struck Ishinomaki City in Miyagi Prefecture at 6:02 pm; the second measured 20 cm at the Ofunato Port in Iwate and occurred at 6:10 pm. The third, which hit Karakuwaosaki Port in Miyagi, measured 80 cm. Workers at the Fukushima plant were evacuated to higher ground. TEPCO reported no immediately apparent damage to its reactors, although many areas remain off limits to humans because contamination levels are still astronomically high. In addition, the utility said that radiation monitors in the area showed no unusual increases. There have been almost 40 aftershocks greater than magnitude 4.5 affecting the East Honshu region since then, the largest of which measured magnitude 6.2. Seismologists believe that the temblor was an aftershock of last year’s magnitude 9.0 earthquake, which triggered a massive tsunami and led to three nuclear meltdowns at the Fukushima plant. (Source: NHK)
Other Nuclear Politics in Japan
A 15-member panel has been formed to follow up on three investigatory reports published last year in the wake of the Fukushima nuclear disaster. The panel hopes to determine whether the government is following recommendations compiled in the reports, which were published by the Diet, the central government, and an independent group called the Rebuild Japan Initiative Foundation. Koichi Kitazowa, who chaired the Rebuild Japan report, is leading the panel, which also hopes to ensure the independence of the newly-created Nuclear Regulation Authority (NRA). Members expect to publish an interim report in March, around the time of the two-year anniversary of the nuclear disaster. (Source: NHK)
The NRA will reportedly begin safety checks on idled nuclear reactors next spring, although it is not expected to publish revised safety guidelines until July. Currently, 48 of the nation’s 50 nuclear reactors are offline. Earlier this year, the Diet passed a law requiring reactors to meet safety standards based on the most current information, starting in July. If they don’t meet NRA standards, utilities will be required to make modifications, even if that means building new equipment or facilities. However, reactors might be allowed to restart even before those safety upgrades are made.
The NRA plans to update the definition of an “active fault,” from that which has experienced movement within the last 120,000 to 130,000 years to changes to land forms and geological conditions within the last 400,000 years. The decision could have a major impact on a number of idled reactors across Japan, a country that is riddled with faults and is highly seismically active. The new standard is in line with guidelines followed by Japan’s Headquarters for Earthquake Research Promotion.
State of the Fukushima Reactors
Hitachi announced it has created a new robot, dubbed Astaca-Sora, which it hopes will assist in decontamination and decommissioning efforts at Fukushima Daiichi plant. Reactor buildings remain so highly radioactive that humans cannot enter. The radio-operated robot, which sports two arms with pincers and a remote camera, is small but can reportedly lift objects up to 300 kg.
Meanwhile, Mitsubishi Heavy Industries (MHI) unveiled a robot of its own, called MHI-MEISTeR, whose arms have multiple joints. The MEISTeR can reportedly operate a circular saw, drill, and pliers.
Radiation Contamination, Including Human Exposure
More than a year and a half after the Fukushima nuclear disaster, Japan has declared 96% of Okuma, home to the Daiichi plant, uninhabitable for the foreseeable future because of extremely high radiation levels. The town was originally home to 11,000 people, all of whom were evacuated and up until now, have remained in limbo about whether or not they would be able to return to their homes.
Worker Safety Issues
Newly-released data from TEPCO, which was submitted to the World Health Organization in March of this year, showed that dozens of workers at the badly damaged plant were exposed to high levels of radiation between March 11, 2011 and January 31, 2012. One hundred sixty-five received doses of 100 millisieverts or greater during that period, a level which researchers believe increases one’s lifetime risk of developing cancer, including thyroid cancer. Of those who were exposed to that dose, 25 were in their twenties, an age during which people are more susceptible to the effects of radiation exposure. A total of six workers received more than 250 millisieverts, including three in their twenties. The data did identify individual workers who were exposed. (Source: NHK)
Japan’s Ministry of Health, Labour, and Welfare announced this week that it will order eight subcontractors of TEPCO to stop engaging in illegal multi-layered contracting arrangements in which the company that hires nuclear workers is not the same one which provides work assignments. Such arrangements are against the law because the party responsible for workers’ safety is ambiguous. And often, workers don’t feel confident about the security of their employment status. One worker confided, “More people work without seeing a doctor because they fear they might be told not to come anymore the next day. It is a distortion caused by the layers of subcontractors involved. I want the government to protect us.” But, the convoluted employment arrangements have been an ongoing problem in the nuclear industry. An executive from one of the affected companies admitted with no trace of irony, “We knew it was illegal, but we had no other choice to secure profits.”
The issue came to light when the President of one of the subcontracting companies, Access Aomori, ordered four of his workers to cover their dosimeters with lead shields in December 2011, in order to prevent them from accurately recording the full amount of radiation they were receiving. Access Aomori is a subcontractor of Tokyo Energy & Systems, Inc., a subdivision of TEPCO. The move violated Japan’s Industrial Safety and Health Act. The annual radiation limit for workers in Japan is 50 millisieverts. As the disaster drags on, workers are becoming harder to find, a situation expected to worse over the next 40 years, the length of time TEPCO estimates it will take to decommission the Fukushima Daiichi plant.
In response to the employment scandal, authorities from the Tomioka Labor Inspection Office have filed a complaint with the Fukushima District Public Prosecutor’s Office against Access Aomori, alleging intentional underreporting of workers’ radiation exposure and violation of Japanese labor law.
Reactor Safety at Other Nuclear Plants in Japan
An NRA-appointed panel of five seismic experts, led by NRA Commissioner Kunihiko Shimazaki, announced yesterday that a fault line running directly beneath one of the reactors at Japan Atomic Power Company’s Tsuruga power plant in Fukui Prefecture is active, and could move in conjunction with another active fault just 250 meters away, if an earthquake occurs. The plant has two reactors, both of which have been offline since last year’s massive earthquake and nuclear disaster at the Fukushima plant. The team made the assessment after performing trench surveys during a two-day trip to the Tsuruga plant earlier this month. The panel’s decision is significant and could prompt the permanent shut down and decommissioning of reactor #2. Japanese law prohibits nuclear reactors from being built over active faults. “There is no way we can implement safety assessments for the resumption of the plant under the current conditions,” said NRA Chairman Shunichi Tanaka.
New data shows that experts warned about dangerous faults beneath Hokuriku Electric’s Shika nuclear plant in Ishikawa Prefecture as early as 1987, but those warnings were ignored. In July of this year, the government suggested that the fault might be active, which would be a violation of Japanese law and could lead to decommissioning of the plant.