High levels of soil contamination caused by radioactive cesium have been detected in Tokyo and neighboring Kanagawa Prefecture, but only sporadically, according to the science ministry.On Oct. 6, it released its latest version of a map showing soil contamination by cesium 134 and 137 due to the accident at the Fukushima No. 1 nuclear power plant, adding Tokyo and Kanagawa Prefecture to the previous version.Contamination in the Tokyo metropolitan area is limited. Relatively high levels of cesium accumulation were detected only in some areas, such as Tokyo’s Katsushika Ward, Okutama, western Tokyo, and the town of Yamakita, Kanagawa Prefecture.The ministry, through aerial surveys, measured amounts of cesium 134 and 137 accumulated in soil between Sept. 14 and 18. It also measured actual concentrations in soil at some locations.Accumulations of cesium 137 in parts of Katsushika Ward and the town of Okutama were between 30,000 and 60,000 becquerels per square meter. No place in Kanagawa Prefecture recorded those levels.
Cesium 137 will have a long-term impact on the environment because its half-life period is 30 years, compared with two years for cesium 134.
Accumulations were 10,000 becquerels per square meter or higher in parts of Edogawa and Adachi wards, near Katsushika Ward, and the village of Hinohara, near Okutama.
Measurements were mostly less than 10,000 becquerels elsewhere in Tokyo.
In Kanagawa Prefecture, accumulations were 10,000 becquerels per square meter or higher in parts of Yamakita, Sagamihara’s Midori Ward and the village of Kiyokawa.
Other places in the prefecture recorded less than 10,000 becquerels.
After the 1986 Chernobyl nuclear power plant accident in the former Soviet Union, areas with 37,000 becquerels of cesium 137 per square meter or more were designated as the contaminated zone.
Radiation levels were higher than 0.2 microsievert per hour in parts of Katsushika Ward and Okutama. Annualized figures exceed 1 millisievert in additional radiation.
The government has said it will provide financial support in removing radioactive materials if annual additional radiation levels are 1 millisievert or more.
Okutama cesium level seen spiking (Japan Times, Saturday, Oct. 8, 2011)
The science ministry’s aerial monitoring of Tokyo and Kanagawa Prefecture finds highly contaminated areas in the capital’s northwest area, but most of the areas surveyed are within normal levels.
[MORE below] ->
Gov’t releases new radiation map for Tohoku, Kanto districts (Mainichi Japan) October 7, 2011
The Japanese Ministry of Education, Culture, Sports, Science and Technology (MEXT) has released a new map showing the spread of radiation from the crippled Fukushima No. 1 Nuclear Power Plant across 10 prefectures, including Tokyo and Kanagawa.
The map released on Oct. 6 shows levels of radioactive cesium (cesium-137 and cesium-134) that have accumulated in soil in the prefectures of Yamagata, Miyagi, Fukushima, Tochigi, Gunma, Ibaraki, Saitama, Chiba, Kanagawa and Tokyo.
The map shows 30,000 to 60,000 becquerels of radioactive cesium per square meter of soil in the areas of Higashikanamachi, Mizumotokoen and Shibamata in Tokyo’s Katsushika Ward, as well as some parts of Kitakoiwa in Tokyo’s Edogawa Ward.
Radioactive amounts ranging between 30,000 and 100,000 becquerels per square meter were detected in the mountain areas in northwestern Okutama, in western Tokyo.
Meanwhile, there was almost no radiation detected in Kanagawa Prefecture besides the 30,000 to 60,000 becquerels of cesium per square meter measured in only few locations in the northern parts of the western town of Yamakita.
According to MEXT’s radiation measurements, which were taken from helicopters in the nine prefectures, outside Fukushima, the highest levels of radiation leaking from the crippled Fukushima power plant were registered in Tochigi and Gunma prefectures, with some areas in Ibaraki and Chiba prefectures also highly affected.
Experts believe that radioactive materials were carried to the prefectures from the Fukushima plant by rain and wind.
MEXT is planning to expand its radiation map by the end of 2011 to cover a total of 22 prefectures located between northeastern and central Japan.
Kashiwa locals to check food radiation levels (The Yomiuri Shimbun, Oct. 8, 2011)
CHIBA–A do-it-yourself radiation measuring station will open in Kashiwa, Chiba Prefecture, where relatively high levels of radiation have been detected due to the crisis at the Fukushima No. 1 nuclear power plant.
The privately run station opens Tuesday and will enable consumers to measure the amount of radioactive substances that may be in food and other products they have bought or grown.
The facility, which is equipped with eight radiation measuring instruments, is about a five-minute walk from JR Kashiwa Station. Consumers pay to use the self-service devices for 20 minutes to check for radioactive material as low as 10 becquerels per kilogram for 3,980 yen, while testing for levels at 20 becquerels costs 980 yen.
Checking food takes between 15 minutes and 20 minutes. If a product does not contain radioactive material, the test will be done in about one minute.
Motohiro Takamatsu, 47, who manages a software firm in the city, started the company to manage the facility in July.
After the Fukushima crisis started, the father of 9-year-old and 4-year-old daughters was talking with his neighbors with children about food safety, wondering if it was safe to eat processed foods or if vegetables from home gardens had been contaminated by radiation.
Such concern among parents drove Takamatsu to start the business to “reduce people’s anxiety as much as possible.”
“It’s not about looking for hazardous foods. The facility is a place for consumers to get a feeling of safety,” he said.
For more information, call the Becquerel Center at (04) 7189-7416.
True radiation decontamination still a long way away (Mainichi Japan) October 7, 2011
Though the government last month lifted the “emergency evacuation preparation zone” designation of some areas greatly affected by the ongoing crisis at the Fukushima No. 1 Nuclear Power Plant, radiation decontamination efforts are still taking place in areas with high levels of radiation.
The three main decontamination methods that have been highly publicized through media reports are: the stripping away of surface soil from school playgrounds and athletic fields, the removal of mud accumulated in gutters, and the washing of roofs using high-pressure water cleaners. While the first method is considered effective, the remaining two have been found to be effective only to a certain point, and some especially warn against overestimating the effects of high-pressure water cleaners.
“It might make you feel like you’re decontaminating, but there’s a limit to the amount of radioactive cesium that’s caked onto roofs that can be eliminated with high-pressure water cleaners,” says Kunihiro Yamada, a professor of environmental science at Kyoto Seika University. “The water cleaners wash surface dirt off, but then that tainted water goes into sewers and can contaminate rivers, thereby affecting farm goods and seafood. If people in highly populated areas were to begin using water cleaners, we may end up finding people forcing tainted water onto each other.”
Since his launch of the “Radiation Contamination and Recovery Project” with colleagues from Fukushima University and Osaka University in May, Yamada has been running trials in the city of Fukushima on methods of decontamination that residents can undertake themselves. He has compiled a manual, which is available on the website of the Society for Studies on Entropy, an organization of which he is a representative.
What exactly is meant by the “limitations” of high-pressure water cleaning, a method that is featured in manuals available from both the central government and the Fukushima Prefectural Government?
According to Yamada, radioactive cesium is believed to exist in three states: dissolved in water, loosely bonded to organic materials such as moss and leaves, or tightly bonded to rock such as silicate salt. In other words, if soil is removed and washed away with high-pressure water cleaners, radioactive cesium found in surface soil and gutters can be eliminated. The cesium that has become affixed to roofs remains, however.
At the request of Fukushima residents and civic groups, on Sept. 14, Kobe University Professor Tomoya Yamauchi, a radiation metrology specialist, measured radiation levels in Watari, which was believed to have some of the highest radiation levels in the city of Fukushima. At a building used for afterschool activities for elementary school children, Yamauchi found 0.33 microsieverts of radiation close to the floor, while radiation levels near the beams and the ceiling were 0.52 microsieverts and 0.72 microsieverts, respectively. Near the concrete roof tiles, radiation levels were at 1.74 microsieverts.
“Apparently the roof had been cleaned using high-pressure water cleaners, but that was as low as the radiation levels got,” says Yamauchi. “To bring the roof’s radiation levels down, there’s probably no other way but to replace the roof. First and foremost, we must aim to bring indoor radiation levels to 0.05 microsieverts, which they were before the disaster unfolded, and thereby creating safety zones.”
According to Yamauchi, just like what has happened with roofs, radioactive cesium has become stuck to asphalt on the road, concrete utters and cobblestones, and high-pressure water cleaners can only do so much.
At a July 27 meeting of the House of Representatives Committee on Health, Labor and Welfare, Tatsuhiko Kodama, professor and director of the University of Tokyo’s Radioisotope Center, denounced the government’s handling of the nuclear crisis: “What is the Diet doing at a time when 70,000 people have had to leave their homes and are wandering around?”
He illustrated the gravity of the situation and the dire need for decontamination efforts, saying: “The amount of radioactive materials that have been released in the latest nuclear disaster, if converted to uranium, is the equivalent of 20 of the atomic bomb that was dropped on Hiroshima.”
At a lecture held at the Japan National Press Club in Tokyo on Sept. 30, Kodama explained that radiation decontamination referred to isolation of radioactive materials in the environment to await its radioactive decay, and that the “radiation decontamination” that he had thus far conducted at kindergartens and other facilities in the Fukushima Prefecture city of Minamisoma were not enough. “The decontamination I’ve done is a type of emergency measure to protect children and pregnant women, and not true decontamination.” He continued: “Permanent decontamination requires the knowledge and technology of experts and corporations, and a massive amount of funds. It must not become an interest-driven public project.”
Kodama says that before his decontamination activities, a certain kindergarten in Minamisoma was found to have small hot spots, recording 33 microsieverts of radiation on the roof and 5 to 10 microsieverts under a slide. While radiation levels can be lowered by around 50 percent after a single decontamination session, Kodama says that it’s difficult to bring roof radiation levels down to 0.5 microsieverts or lower.
“To take the next step, we need the cooperation of house builders to determine whether a roof’s surface should be scraped off or the roof in its entirety should be replaced, depending on the materials used,” says Kodama.
Meanwhile, because replacing roofs will inevitably result in more radioactive waste, Kyoto Seika professor Yamada and his project team are collaborating with a house manufacturer to create cloth-like adhesive stickers that would be affixed to roofs and peeled off to remove just the radiation-contaminated surface.
According to the Basic Policy for Emergency Response on Decontamination Work released by the government’s Nuclear Response Emergency Headquarters on Aug. 26, the government has set a provisional goal for the next two years to reduce yearly radiation exposure by 50 percent (60 percent for children). In setting this goal, the government presupposes that natural phenomena such as physical attenuation and weathering will decrease radiation exposure by 40 percent in two years, and that the remaining 10 percent (20 percent for children) will come from decontamination activities.
“What residents want is not half the exposure to radiation,” says Yamada. “What they want is for a return to levels that allow them to live with peace of mind. Massive amounts of radioactive materials have been spread across wide areas in the ongoing disaster, so we can’t count on the weathering effect. There’s also the possibility that radiation will not only spread, but will start to accumulate in large concentrations in certain places. The half life of cesium 137 is approximately 30 years, but that of cesium 134 is 2 years. What the government has said is the equivalent of saying that they won’t engage in full-fledged decontamination activities.”
Both Yamada and Yamauchi agree that children and pregnant women living in areas that have not been subject to evacuation orders but have nonetheless been found to have high levels of radiation — like the cities of Fukushima and Koriyama — should be evacuated temporarily, and that those areas be thoroughly decontaminated while those populations are away. Kodama also says that residents living in areas with yearly radiation exposure of 1 millisievert or higher who want to evacuate should be fully supported by the government and Tokyo Electric Power Co., the operator of the stricken power plant.
Kodama finishes his book, “Naibu hibaku no shinjitu” (The Truth about Internal Exposure), with the following: “We have contaminated our country’s earth, this irreplaceable inheritance from our ancestors that we had been charged with and must pass on to our children. However, if humans are the ones who contaminated it, then we humans should be able to clean it up again.”
With challenges such as the designation of temporary radioactive waste dumps and interim storage facilities yet unsolved, the road to true decontamination remains a long one.
SENDAI — Fish catches at eight major ports in the tsunami-hit Tohoku region have plunged since April in part because of the severe damage the fleet suffered in the March 11 disaster but mainly due to radiation fears amid the Fukushima nuclear crisis that are making hauls hard to sell.
Fishing boats have gone out less frequently this year on the assumption that consumers will shun fish caught near Fukushima Prefecture. Staying in port at least saves commercial fisherman the price of fuel, preventing their financial losses from growing even worse.
Compared with a year ago, catches are down by as much as 85 to 99 percent in volume in five Tohoku areas, as consumers continue to shun fish from the region, local officials and fishery cooperatives said Friday.
Fish hauls are down sharply at major ports in Aomori, Fukushima, Iwate and Miyagi prefectures, and fishermen and fish market officials lay the blame on the accident at the Fukushima No. 1 nuclear plant.
“Fish from Chiba and Ibaraki are all caught from the same areas of the sea, yet only ours aren’t selling well because they are labeled ‘Fukushima.’ It’s absurd,” said a fish market official at Fukushima’s Onahama fishing port.
Others in the fishing industry said the sales total, including those for exports to China and South Korea, have also dropped as buyers beat down prices because of the nuclear crisis.
Of the eight major fishing ports, only Shiogama, Miyagi Prefecture, saw an increase in catch and sales, thanks to relatively little damage to its port facilities from the tsunami and an increase in fishing boats diverted from nearby ports because they could not land their catches at them.
According to a Tokyo-based national association of fisheries wholesalers, the decrease in the catch in the northeast is unlikely to trigger an immediate supply shortage or price hikes as hauls from other parts of the country are making up for it.
But industry officials are concerned that consumers may stay away from eating fish due to the nuclear crisis.
The fishing industry has been a major economic pillar of many coastal communities in the northeast.
OCT. 02, 2011
Seagulls flock around passengers on the deck of a cruise boat, hoping for scraps; hotels and inns show no-vacancy signs and fresh oysters are served in seaside restaurants.
But despite an appearance of normality, business is far from booming in Matsushima, where serene pine-covered islands have attracted generations of tourists to an area classed as one of Japan’s three most beautiful spots.
The guesthouses and hotels—in a district the Michelin Blue guide gives its maximum three stars—owe most of their business to workers helping to rebuild coastal communities shattered by the March 11 tsunami.
Matsushima, in Miyagi Prefecture, escaped the worst of the disaster, its island-dotted bay breaking up the ferocity of the giant waves that devastated hundreds of kilometers of picturesque Pacific coast.
But the tourists on whom Matsushima’s economy depends are few and far between.
Fears about the effect of leaking radiation from the crippled Fukushima nuclear plant 110 kilometers south have all but stopped the influx of visitors from China, Hong Kong, South Korea and Taiwan.
“The real problem is fear,” Oxford University professor emeritus Wade Allison said at the Foreign Correspondents’ Club of Japan in Chiyoda Ward, Tokyo.
Citing the doses of radiation received in medical procedures, such as CT and PET scans, Allison said Japan’s standard — which bans the sale of food containing more than 500 becquerels per kilogram of radiation and requires the evacuation of areas receiving 20 millisieverts a year — is far too conservative.
While setting standards is difficult for the government, which must balance radiation risks against the hardships of evacuation, Allison argues its conservatism does more harm than good.
The 500-becquerel limit on food sales imposed by the Japanese government is identical to the EU’s limit but lower than the 1,200-becquerel limit set by the United States, which, Allison asserts, is also overly cautious.
PET scans, which emit gamma rays to map internal organs, usually the brain, give patients a dose of 15 millisieverts of radiation in a couple of hours, which is the equivalent of eating 2,000 kg of meat tainted with 500 becquerels per kilogram of cesium, he said.
Therefore, the government regulation is “unreasonable,” he said. He also cited an article in Swedish newspaper Dagens Nyheter from April 24, 2002, that states, “the Swedish Radiation Protection Authority admits: ‘We condemned tons of meat unnecessarily.’ ”
As for the evacuation criteria used in Fukushima, the government adheres to the standard set by the International Commission on Radiological Protection, which advocates a yearly limit of 20 millisieverts of radiation exposure.
Allison said that cancer patients receiving radiotherapy can tolerate in excess of 20,000 millisieverts per month, far beyond the “unreasonable” evacuation criterion of 20 millisieverts, he said, adding that 100 millisieverts a month would be appropriate.
“Evacuation is at least as traumatic as radiotherapy treatment,” he said. “The criterion has taken no account of damage to personal and socioeconomic health.”
Seiichi Nakamura, a researcher at the Health Research Foundation, in Kyoto, said he agrees that Japan can raise the limits, but stresses his position is not as extreme as Allison’s.
“My feeling is that 20 millisieverts a year is already quite high, but it may be OK to raise it a bit more,” said Nakamura, who helped research cancer risk in people in Kerala, India, an area of unusually high naturally occurring radiation. “The food standard can be raised closer to the more internationally recognized level of 1,000 becquerels per kilogram.”
Allison insists that he has no ties to the nuclear industry.
The science ministry was tardy when it reported last week for the first time that traces of plutonium fallout were found outside the Fukushima No. 1 power plant’s compound through tests conducted in June, a nuclear expert said Monday.
The plutonium traces, which are too low to present a hazard to human health, were found at six spots far away from the plant’s premises.
A soil contamination map released Friday by the science ministry shows that plutonium drifted as far as 45 km northwest from the crippled plant to the village of Iitate, Fukushima Prefecture.
In late March, plutonium and strontium isotopes were reportedly found in soil at Fukushima No. 1 based on tests by Tokyo Electric Power Co.
It is not clear what caused the plutonium, a massively heavy element, to drift so far.
“The results came too late. The government should have conducted the tests much earlier,” said Michiaki Furukawa of the nonprofit Citizens’ Nuclear Information Center, a noted antinuclear group based in Tokyo.
The largest amount of plutonium-238 detected was 4 becquerels per square meter in the town of Namie, 24 km northwest of the plant. As for plutonium-239 and -240, the largest combined amount found was 15 becquerels per square meter, the ministry’s report said.
If someone lives for 50 years in an area contaminated with 4 becquerels of plutonium-238, his total dose would be 0.027 millisieverts, the report said. The area with 15 becquerels would provide a cumulative dose of 0.12 millisievert, it said.
A cumulative dose of 100 millisieverts increases one’s cancer risk by 0.5 percent, scientists say.
“Plutonium won’t do harm unless it gets into people’s bodies. And from the amount detected, (that) possibility is very low. People shouldn’t be concerned about it,” said Furukawa.
Plutonium-239 has a half-life of 24,000 years and plutonium-238 about 88 years. Plutonium-240 has a half-life of about 6,600 years.
Unlike cesium, which emits powerful gamma rays, plutonium emits alpha rays, which can be stopped by skin or clothing but pose a greater risk to cellular material within the body.
Furukawa said when plutonium is inhaled it may stay in the lungs for a very long time. But because the amount found was very low, the chance of inhaling it is very small, he said.
As for strontium, the amount detected was, on average, less than 1 percent of the radioactive cesium, the ministry report said.
The largest strontium amount was 5,700 becquerels per sq. meter in the town of Futaba, about 3 km north of the power plant, Friday’s report said. Someone living in the area for 50 years would get a cumulative dose of 0.12 millisieverts, it said.
Strontium-90, which has a half-life of 29 years, is known to accumulate in the bones when ingested or inhaled. But the small amount of strontium-90 that was detected is also not worth worrying about, Furukawa said, emphasizing that the biggest risk is being posed by cesium isotopes.
The ministry said it has no plans to expand its checks beyond the survey’s current 100-km radius, which means that Tokyo — whose massive population could magnify the consequences of any results — will be excluded.
Although it would be better if the government conducted more soil tests outside that range, it would be very difficult because conducting an analysis of strontium and plutonium takes much longer than it does for cesium, Furukawa said.
Ensuring the financial stability of Tokyo Electric Power will require the restart of halted nuclear reactors, said a panel advising the Japanese government on restructuring the utility.
New rice 10%-20% more expensive (Yomiuri, Oct. 3, 2011)
This year’s new rice is 10 percent to 20 percent more expensive on average than last year’s crop, it has been learned. A major reason for the increase is believed to be the efforts of wholesalers to purchase rice free …The Yomiuri Shimbun
This year’s new rice is 10 percent to 20 percent more expensive on average than last year’s crop, it has been learned.
A major reason for the increase is believed to be the efforts of wholesalers to purchase rice free of radioactive substances.
According to a list of new-rice dealings between the Japan Agricultural Cooperatives (JA) and wholesalers for the Sept. 26-Oct. 2 period, the largest price increases were for the Haenuki brand in Yamagata Prefecture and the Kinuhikari brand in Shiga Prefecture.
Both brands jumped 21 percent in price with the former brand selling for 14,500 yen per 60 kilograms and the latter for 14,800 yen.
The well-known Uonuma Koshihikari brand of rice grown in Niigata Prefecture costs 22,000 yen per 60 kilograms, an increase of 5 percent. Many other brands are 10 percent to 20 percent more expensive.
JA is involved in 60 percent of rice transactions.
The rise in prices is reflected in stores, with one large Tokyo supermarket saying the retail price of new rice is about 200 yen more per five kilograms than last year’s rice.
Preliminary tests carried out by the central government for radioactive substances have detected 500 becquerels of radioactive cesium per kilogram in rice grown in Nihonmatsu, Fukushima Prefecture, the prefecture that hosts the crippled Fukushima No. 1 nuclear power plant.
As 500 becquerels is the provisional upper limit in the government’s guidelines for radiation in rice, prices may rise further depending on future test results.
A rice production index released by the Agriculture, Forestry and Fisheries Ministry on Sept. 15 indicated that the amount of rice produced this year is about the same as in normal years.
According to the Food Marketing Research and Information Center, a number of districts begin shipping their rice in early October, and supplies will be sufficient.
Based on this prediction, rice prices among dealers may stabilize, industry sources said.
Hitachi, Ltd. is considering ways to transport electricity generated at its factory in Hitachi, Ibaraki Prefecture, to evacuation centers by buses equipped with storage batteries in the event of a disaster.
Plans to construct mega solar power plants are also under way. Mitsui & Co., Ltd. is considering building a mega solar power plant on quake-hit vacant land, and SoftBank Corp. has established an organization to promote cooperation with local governments across the country.
Local governments in quake-hit areas are eager to restore their infrastructure by introducing smart city and mega solar power projects.
Rikuzen-Takata in Iwate Prefecture is considering a mega solar and large-scale power storage system in collaboration with Ofunato and Sumitacho in the prefecture. The plan aims to build a smart city and create jobs, according to an official at the Rikuzen-Takata municipal government.
Sendai is also considering a plan to build a solar power plant on devastated farmland in the city and run food processing facilities with electricity from the plant.
However, the plans being considered by companies and local governments are based on the precondition that the use of farmland will be deregulated and tax breaks will be available.
The central government’s support and encouragement of companies and local governments are indispensable for the restoration of devastated areas.
An independent panel advising Japan’s Ministry of Economy, Trade and Industry confirmed the ministry’s nuclear watchdog was involved in attempts by utilities to manipulate public opinion in favor of nuclear power.
No explosion at No. 2 reactor / TEPCO: Only 3 hydrogen blasts occurred at Fukushima N-plant (Mainichi Japan) October 3, 2011
The Yomiuri Shimbun
The Tokyo Electric Power Co. panel investigating the nuclear crisis at the Fukushima No. 1 power plant has concluded that a hydrogen explosion did not occur at the plant’s No. 2 reactor, overturning its previous conclusion that an explosion took place on March 15, according to a draft of the panel’s interim report.
The panel, chaired by TEPCO Vice President Masao Yamazaki, devoted pages of the draft to defending the utility’s handling of the crisis, such as saying that TEPCO could not reasonably have anticipated the size of tsunami before the disaster. The panel also said the company’s slow initial response to the nuclear disaster could not be avoided.
TEPCO said it would publicly release the interim report after submitting the draft to a third-party verification committee of experts.
According to TEPCO, the first hydrogen explosion took place in the No. 1 reactor building on the afternoon of March 12, followed by an explosion at the No. 3 reactor on the morning of March 14.
Early on the morning of March 15, TEPCO confirmed the sound of an explosion, and then found damage in the No. 4 reactor building.
The power company also confirmed that pressure in the No. 2 reactor’s pressure suppression pool, which is the lower portion of the reactor’s containment vessel, dropped significantly immediately after the sound was heard. So the company concluded that explosions must have occurred almost simultaneously at the Nos. 2 and 4 reactors, and the government reported the same conclusion to the International Atomic Energy Agency in June.
However, the panel studied a seismometer at the plant and found only one explosion tremor recorded at 6:12 a.m. that day. Based on analysis of the tremor, the panel concluded that the explosion occurred at the No. 4 reactor.
However, due to the fact that the pressure at the No. 2 reactor’s pressure suppression pool dropped around that time, the panel said the reactor’s containment vessel may have sustained other damage. The interim report did not further explain the damage or its cause.
Indeed, the core of the No. 2 reactor is believed to have sustained the most serious damage among the power plant’s six reactors, and the pace of cooling at the No. 2 reactor has been slow.
On Wednesday, the temperature at the base of the No. 2 reactor fell below 100 C for the first time since the March 11 disaster, meeting one of the two conditions for the reactor to be declared in a stable cooling state known as cold shutdown. The temperatures of Nos. 1 and 3 reactors have already fallen bellow 100 C.
According to the draft of the interim report, a blowout panel installed at the upper part of the No. 2 reactor building opened accidentally after the No. 1 reactor’s hydrogen explosion on March 12. The draft says a hydrogen explosion was avoided at the No. 2 reactor because a certain amount of hydrogen escaped through the blowout panel.
The interim report also referred to a possible reason why hydrogen explosions occurred at the Nos. 1 and 3 reactors. The report said silicon rubber used to seal the spaces between doors and wall, and between the containment vessels and their lids, may have not functioned properly due to the high temperatures, opening gaps that allowed the release of hydrogen into the reactor building.
The panel defended the company’s slow initial response to the nuclear disaster, such as preparations to vent steam from reactor, by saying, “It can’t be helped that that [the initial response] took time, as workers had to prepare in the darkness.”
The interim report said the nuclear reactor’s major equipment sustained no damage due to the earthquake itself, but instruments ensuring the safety of the nuclear reactors lost their functions simultaneously due to tsunami, worsening the situation exponentially.
TEPCO established the panel on June 11. The panel comprises eight senior TEPCO officials, including company executives and those equivalent to department chiefs. The power company plans to release the interim report in November at the earliest, after submitting the draft to the verification committee chaired by Genki Yagawa, a professor emeritus at the University of Tokyo who specializes in nuclear structural engineering. Other than Yagawa, the committee has six members.
Panel defends TEPCO
In the spring of 2008, TEPCO estimated that a 15.7-meter tsunami could hit the Fukushima No. 1 nuclear power plant in the future, which was about the size of the March 11 tsunami.
The utility came up with another estimate in December that year, modeled on the Jogan tsunami that hit northern Japan in 869. This estimate was 9.2 meters.
However, the draft of the interim report said TEPCO was justified in not utilizing the estimates to take measures against catastrophic tsunami. It said the estimates were “conceptual ones and were unsuitable to be used as bases for tsunami measurements.”
The draft defended a 2002 estimate made by the Japan Society of Civil Engineers, which envisaged a 5.7-meter tsunami hitting the power plant. TEPCO adopted this estimate in taking measures against tsunami at the power plant.
The draft said this estimate was “based on the latest scientific findings, which have been recognized academically.”
“It was impossible for TEPCO to estimate the size of the [March 11] tsunami,” the draft concluded.
Former Prime Minister Naoto Kan visited the Fukushima No. 1 power plant for about an hour in the early morning of March 12 before TEPCO began venting steam from the reactors. Some opposition party members have criticized Kan for causing a delay in TEPCO’s handling of the nuclear crisis.
The draft said, “There is no evidence that [Kan’s] visit delayed the start of venting.”
However, it did state: “Plant Manager [Masao] Yoshida briefed [Kan] on the emergency situation. A senior official stationed at the off-site [emergency response] center entered the nuclear plant to guide Kan around from the time of his arrival.”
At the request of NHK, the government on Monday released a simulation report by Tokyo Electric Power Company.
TEPCO had predicted that waves between 8.4 and 10.2 meters high could hit all 6 reactors at the plant in the event of an earthquake similar to one that devastated the area in 1896.
But the prediction was not conveyed to the government’s nuclear safety agency until March 7th, just 4 days before the plant was crippled by tsunami.
In the report, TEPCO also said it would begin examining the plant’s tsunami-resistance measures in April of this year. It said it planned to deal appropriately with the matter by around October of 2012, when academics were expected to review their tsunami evaluations.
TEPCO official Junichi Matsumoto says the company did not feel the need to take prompt action on the estimates, which were still tentative calculations in the research stage.
But a Nuclear and Industrial Safety Agency official says it is regrettable that TEPCO did not start work on its tsunami measures right after it made the estimate 3 years ago. He said TEPCO should have called on experts to discuss its calculations in public.
Earlier news from Mainichi: Rubble from quake- and tsunami-hit areas to be disposed in Tokyo | Japanese robot set to contribute toward Fukushima plant’s cold shutdown | TEPCO finds own nuclear accident manual useless | Fake questions on N-energy / Report finds 7 cases of events staged to promote nuclear power (Yomiuri, Oct.2) | Decontamination slowed by uncertainty over storage (Yomiuri, Oct 2)
Japan’s minister in charge of the nuclear disaster says the government will provide financial assistance for clean-up efforts in municipalities where radiation levels are below 5 millisieverts per year.
The Environment Ministry was criticized for its decision late last month not to offer financial help to such municipalities, except when cleaning ditches and other highly contaminated spots.
Cabinet minister Goshi Hosono met Fukushima Prefecture Governor Yuhei Sato on Sunday.
Sato said many people in his prefecture are wondering why they have to clean up the contaminated areas by themselves.
He said he wants the government to understand that either the government or the operator of the nuclear plant should do the work.
Sato asked the government to provide financial assistance when municipalities decide to clean up areas where radiation levels are between one and 5 millisieverts per year.
Hosono said the government is responsible for cleaning up the contaminated areas, and those with radiation levels of one to 5 millisieverts per year qualify for the support.
He promised that the government will provide financial and technical assistance if municipalities compile plans that show how they intend to clean up the contaminated areas.
Citizen fund investments Oct 3 More and more people are investing their money in citizens’ funds. People can invest a small amount of money to help organizations that are tackling issues close to people, such as community building, nursing care support for the elderly and care of children after school classes are over. Especially since the March 11 earthquake and tsunami, citizens’ funds have helped to prop up enterprises and to promote green energy development in the disaster-hit areas. In the public sector, even when budgets are passed by the Diet or local assemblies, it is difficult for the central and local governments to act quickly. They have to clear legal provisions, and a lot of administrative documents must be prepared. (Japan Times)