RADIATION DECONTAMINATION: Locals borrow equipment to do own decontamination work
FUKUSHIMA – At around 11 a.m. on Oct. 18, members of the media and local residents crowded around in front of a house in the Onami district in the city of Fukushima.
The gathering was partly because Prime Minister Yoshihiko Noda was about to attend the kickoff of the city’s radiation decontamination work on all residences in the area in a program that is slated to run two years.
Locals were curious to see what the cleanup – washing the houses’ walls and roofs with a high-pressure water hose – would be like after their lengthy efforts to get city officials to take action.
“Finally, (the cleanup of the houses) is starting. I have to say this is a little too late,” said a 63-year-old woman who lives in Onami, a neighborhood whose claim to fame is its high radiation readings due to nuclear fallout from the Fukushima No. 1 power plant.
While the government is aiming to clean up areas that have recorded high radiation levels, the municipalities and residents are actually carrying out decontamination in areas where annual radiation levels are less than 20 millisieverts.
Since home radiation cleanup chores were the last thing locals thought about before the catastrophe struck, municipalities are still trying to work out ways to carry it out effectively and involve residents in the process.
Many people living in Fukushima, especially those with small children and babies, are worried about radiation and want to know how to lessen the danger.
“We have removed vegetation from our yard every day,” and the radiation level decreased from 1.2 microsieverts per hour to about 0.8 microsievert, said the woman in Onami.
If someone is exposed to 0.8 microsievert 24 hours a day, 365 days a year, that would amount to about 7 millisieverts over the course of a year. While Japan’s legal limit is 1 millisievert per year, Fukushima residents are being allowed to live in areas recording less than 20 millisieverts per year since March 11.
The woman has three grandchildren, so she wants to do as much as she can to prevent them from being exposed.
For residents, however, cleaning their roofs is difficult so the kickoff of the city’s decontamination work was something many had been waiting for, although the city’s move was not as quick as residents had wished.
“I understand the residents’ claim that it was slow. I myself think that there should have been a system that enabled us to act more quickly,” said Fukushima Mayor Takanori Seto.
“Japan does not have any legal guidelines about what to do in the event of a radiation disaster, but municipalities have been somehow trying to deal with the situation,” Seto said in frustration.
It took more than five months for the central government to come up with a basic policy for decontamination work.
Based on that policy, municipalities have drafted their own boots-on-the-ground cleanup plans, with many placing priority on lowering radiation readings at schools and along school routes.
The city of Fukushima, for instance, aims to decrease radiation levels in areas where people carry out their daily lives, such as houses, schools, stores and public facilities, to less than 1 microsievert per hour in two years.
As for areas where readings are currently below 1 microsievert per hour, the city plans to cut radiation levels by 60 percent in two years.
While municipalities are trying to proceed with cleanup efforts, it is difficult for them to do everything alone.
Thus the participation of residents is essential, and some cities are organizing ways to better involve their residents in these programs.
Fukushima has created a manual explaining decontamination work for residents and it has also organized several training sessions for people working in decontamination-related fields.
In Date, which is located next to the city of Fukushima, the municipal government opened a decontamination support center for residents on Oct. 11.
In a building next to City Hall, decontamination experts are advising residents.
Tools for cleaning, such as brushes, high-pressure sprayers and bags to store waste, are either given away or are allowed to be used free of charge.
Kimihiro Sugeno, a Date official, said since people are concerned about radiation around their homes, “we wanted to have a one-stop service facility for decontamination” in which people can get advice and tools.
The center also provides a service to check radiation levels in food products.
Since the opening, decontamination experts at the center said they are fielding about 10 consultations a day on average. The most common inquiry from affected residents is how to decontaminate their houses.
By KAZUAKI NAGATA, Japan Times Staff writer, November 9, 2011
http://www.japantimes.co.jp/text/nn20111109f2.html
RADIATION DECONTAMINATION: Radiation cleanup plan falls short—Experts liken current strategy to letting nature run its course
Radioactive fallout from the crippled Fukushima No. 1 nuclear plant has caused widespread fear, prompting the government in August to adopt basic targets for decontamination efforts in and around Fukushima Prefecture.
But the government’s plan falls short and efforts should focus in particular on residential areas with more aggressive decontamination measures and goals, including reducing current radiation levels by 90 percent, two radiation experts said when interviewed by The Japan Times.
“I really doubt their seriousness (about decontamination),” said radiation expert Tomoya Yamauchi, a professor at the Graduate School of Maritime Sciences at Kobe University.
Areas with radiation exposure readings representing more than 20 millisieverts per year have been declared no-go zones, and the government has shifted the focus of its decontamination plan to areas with radiation readings, based on an annual accumulative amount, of between 20 millisieverts and more than 1 millisievert, with the goal of reducing the contamination by 50 to 60 percent over two years.
Decontamination efforts by humans, however, are expected to only yield a reduction of 10 to 20 percent.
Nature, including the impact of rain, wind and the normal degradation of the radioactivity of cesium-134, whose half-life is roughly two years, is assumed to do the rest, thus reaching the best-case scenario of cutting the contamination by 60 percent.
The experts said the government’s goal of human effort achieving a 10 to 20 percent reduction is not ambitious enough.
“A 10 percent reduction doesn’t really mean anything. I mean, 40 percent of the radiation would be reduced just by natural causes, so I think the government is almost saying it is just going to wait for the radioactive materials to decrease naturally,” said Shunichi Tanaka, former chairman of the Atomic Energy Society of Japan.
The main radioactive materials that spewed from the Fukushima No. 1 plant are cesium-134 and -137, the second of which has a half-life of 30 years. Given the relatively short half-life of cesium-134, the total radiation will naturally be halved in four years and fall to one-third in six years, although the threat from the latter will remain for a longer time.
The government is now trying to reduce contamination mainly by using high-power water hoses, known as pressure washers, on structures and removing surface soil and vegetation in limited areas.
But radioactive cesium can find its way into minute cracks and crevices. It is hard to remove, for example, from roofs made of certain materials, or surfaces that are rusted or whose paint is peeling, Yamauchi said.
He has monitored radiation in areas in the city of Fukushima and found that the levels were still quite high after the city performed cleanup operations.
To lower the contamination to pre-March 11 levels, Yamauchi said drastic, and highly costly, efforts by the government are needed, including replacing roofs and removing the surface asphalt of roads.
Tanaka meanwhile pointed out that the government has not even floated a plan for decontaminating the no-go zones where the radiation exceeds 20 millisieverts per year Å\ areas where there isn’t even a timetable for when evacuees will be able to return.
If the government doesn’t speed up the decontamination work, it will be years before the evacuees may be able to return home, he said, adding that the government can’t set a target date because it isn’t sure how the cleanup effort will fare.
The government’s stance regarding the no-go zone is largely based on recommendations by the International Commission on Radiological Protection and other scientists that call for the maximum radiation exposure of between 20 and 100 millisieverts per year under an emergency situation.
The ICRP theorizes that cumulative exposure of 100 millisieverts could increase the cancer mortality risk by about 0.5 percent, meaning about 50 out of 10,000 people exposed to that level could die of cancer caused by radiation.
Scientists are split over whether exposure to less than 100 millisieverts is harmful. Yamauchi maintains that low-level exposure could pose risks to residents in Fukushima, and he heard from many that they don’t want to continue living there due to the fear. The government should thus widen the evacuation zone, he said.
Because the decontamination process is closely connected with the people living in the affected areas, Tanaka said their participation in the process is crucial.
He has been conducting cleanup work in Fukushima while serving as a decontamination adviser for the municipal government of Date, Fukushima Prefecture. He noted decontamination also entails cleaning up private spaces.
Another issue is the need for communities to reach consensus on where to temporarily store contaminated waste.
“Municipalities need to communicate closely with residents (to solicit their involvement) . . . without the participation of the residents, they can’t find space for the storage,” Tanaka said.
By KAZUAKI NAGATA, Japan Times Staff writer, November 9, 2011
http://www.japantimes.co.jp/text/nn20111109f1.html
Study starts on ’long-term no-return zones’ in Fukushima
The government started discussions on establishing “long-term no-return zones” in areas with high radiation levels near the crippled Fukushima No. 1 nuclear power plant.
The administration of Prime Minister Yoshihiko Noda is also considering extending assistance for a “two-stage return,” whereby new towns are created in areas of low radiation levels to prepare for a future return of evacuees.
Radiation levels will soon be measured in the no-entry zone within a 20-kilometer radius of the nuclear plant. Areas that are designated long-term no-return zones will be announced when a state of cold shutdown is achieved at the plant, which the government plans by the end of the year.
The government has not decided on the length of the ban on entry to these zones, but expects it will continue for a long time.
The central and local governments may lease out or buy up land from residents of the zones and provide them with public-run “reconstruction housing.”
A science ministry survey in mid-October found that annual human exposure to radiation exceeded the evacuation threshold of 20 millisieverts at 37 of 50 measurement locations in the no-entry zone. Annual exposure exceeded 100 millisieverts at 15 locations, where more than 10 years will be needed for the figure to fall below 20 millisieverts.
The government plans to start model projects in the no-entry zone to verify how far decontamination measures can lower radiation levels. The results will be used to calculate how many years it will take before residents can return and to designate areas where a return will remain difficult in the longer term.
The designation will also include areas where everyday life is expected to remain difficult, even if the radiation levels are low, because of scant prospects for a recovery in infrastructure.
The town of Okuma in Fukushima Prefecture, in which part of the Fukushima No. 1 plant lies, has already incorporated a “two-stage return” in its draft reconstruction design.
According to the plan, a “new town” with a concentration of public facilities will be created in an area of low radiation levels to prepare for the eventual return of all evacuees. The central government plans to extend assistance to similar initiatives.
By SHINICHI SEKINE, Asahi Shimbun Staff Writer, November 09, 2011
http://ajw.asahi.com/article/0311disaster/life_and_death/AJ2011110916955
Incineration of cesium-tainted vegetation resumes in Chiba Pref. city
KASHIWA, Chiba — An incineration plant here resumed burning radioactive cesium-contaminated vegetation on Nov. 9 after about a three-month suspension.
The Kashiwa Municipal Government had stopped incinerating the vegetation tainted in the disaster at the Fukushima No. 1 nuclear plant after contamination exceeding the government limit of 8,000 becquerels per kilogram was detected in the resulting ash in August. However, a lack of storage space has forced the city to resume burning the vegetation. The new round of burning will apparently last about a month.
The incinerators at one of the city’s waste processing centers began burning the vegetation at about 9:30 a.m., though to prevent high concentrations of radioactive substances in the ash, the vegetation is being mixed in with other garbage at a 10 to 20 percent ratio. As ash exceeding the government’s contamination limit cannot be buried in a landfill, it will be stored at the waste processing center.
Mainichi Shimbu n, November 9, 2011
http://mdn.mainichi.jp/mdnnews/national/archive/news/2011/11/09/20111109p2a00m0na018000c.html
Japan to Decontaminate Areas with Radiation of One Millisievert or More
Tokyo, Nov. 11 (Jiji Press)—The Japanese government decided Friday to decontaminate areas where annual radiation doses stand at one millisievert or more following the nuclear crisis at Tokyo Electric Power Co.’s <9501> Fukushima No. 1 plant.
Under the basic policy decided at the day’s cabinet meeting, the government will fully start the decontamination work, including the disposal of contaminated waste, in January next year, when a special law on radiation cleanup comes into force.
The work will cover wide areas, including Fukushima Prefecture, home to the crippled nuclear plant, and other parts of the Tohoku northeastern Japan region and the Kanto eastern region in and around Tokyo.
In areas where annual radiation levels are below 20 millisieverts, the government will aim to halve ordinary citizens’ exposure by the end of August 2013 from levels two years before. For children, it intends to reduce exposure by 60 pct.
As for areas where annual radiation doses are at or above 20 millisieverts, the government will reduce citizens’ exposure in stages.
Jiji Press, Nov. 11, 2011
http://jen.jiji.com/jc/eng?g=eco&k=2011111100265
Gov’t releases map of radioactive tellurium-129m contamination around nuke plant
The government has released a map showing the diffusion of radioactive tellurium-129m within a 100-kilometer radius of the crippled Fukushima No. 1 nuclear plant.
The map, released on Oct. 31 by the Ministry of Education, Culture, Sports, Science and Technology, displays concentrations of the element — a byproduct of uranium fission — in the soil as of June 14 this year. The map shows relatively high amounts of tellurium-129m were discovered both to the plant’s northwest and as far as 28 kilometers south along the coast, in the cities of Iwaki, Fukushima Prefecture, and Kitaibaraki, Ibaraki Prefecture. Major concentrations of radioactive iodine-131 were also found in these areas, and officials believe the tellurium was probably deposited by clouds at the same time as the iodine.
The highest tellurium concentration detected was about 2.66 million becquerels per square meter, about two kilometers from the Fukushima No. 1 plant in the town of Okuma. The element, however, has a short half-life, and present levels are already a fraction of what they would have been just after the beginning of the nuclear disaster.
Okuma, part of the exclusion zone around the plant, is currently empty.
Mainichi Shimbun , November 1, 2011
http://mdn.mainichi.jp/mdnnews/national/archive/news/2011/11/01/20111101p2a00m0na011000c.html