- TEPCO has found a higher-than-expected concentration of hydrogen in some of the pipes passing through unit #1’s containment walls. The levels are above the maximum detectable reading on TEPCO’s monitoring equipment, which is 1%. TEPCO believes the hydrogen is likely a residual from the unit #1 meltdown on March 12. This is the first time they have tested the contents of these specific pipes since the emergency developed. While it is possible that a tiny amount of hydrogen continues to be generated by radiolysis (separation of hydrogen and oxygen in a neutron field), it is unlikely that this nuclear process is the cause of the hydrogen discovered. TEPCO will look into the contents of pipes which pass through the containment walls of units 2 & 3, as well.All Japanese news media, with the exception of NHK World, have presented TEPCO’s announcement in the most frightening context possible, using incorrect data to support their spins. Perhaps the most alarming error is reporting 4% hydrogen can explode, and further implying that radiolysis could drive levels up to that point. The first problem with the reports is the very weak rate of radiolysis that might exist…if it exists at all. It’s just as possible that radiolysis stopped when the corium resolidified after melting. The greatest problem, however, is that 4% hydrogen in dry air is the minimum level for ignition, not explosion. Hydrogen at 4% will burn if there is an ignition source, like an electrical spark. The minimum level for an ignition-initiated explosion, in an oxygen-rich atmosphere, is ~8%. But, an ignition-initiated explosive level is 13% hydrogen when mixed with oxygen at its atmospheric level of 20%. The mixture becomes auto-explosive at about 15% hydrogen, in an atmospheric level of oxygen. With low oxygen of ~5%, hydrogen becomes auto-explosive at a 59% concentration. Below 5% oxygen, the possibility of explosion is nil, although a burn is still possible down to 1% oxygen. (Data from NASA’s hydrogen safety manual, and several college chemistry websites)
It seems most of the the Japanese news media is bending over backwards to keep the specter of the three hydrogen explosions of mid-March fresh in the public mind. And TEPCO is adding to the public’s nuclear angst by saying there is no threat of another hydrogen explosion “in the immediate future” (Mainichi Shimbun), leaving the door open for negative media spins.
- Slowly but surely, new P.M. Yoshihiko Noda is moving the Japanese government away from the “shut-all-nukes-down” politics of Naoto Kan. Yomiuri Shimbun says Kan told the United Nations he not only wants the idled nukes in Japan to be restarted as soon as it is politically possible, but he also supports the possibility of completing all nuclear construction projects that were suspended by the Kan regime. The Yomiuri reports a government source said this was because Noda wanted “to clearly show other countries that his policies were different from those of the Kan administration.” Noda believes the best way to revitalize Japan’s economy is to use a mix of all electrical sources, including existing and near-future nuclear capacity.
- Kyodo News reports that the heads of the five municipalities which will soon have their evacuation advisories lifted, are balking at the government’s decision. In general, the town heads want to know what Tokyo is going to do about decontamination efforts and radioactive waste disposal. In addition, three of the towns have some residential areas inside the 20km no-go zone, so their heads want the government to clarify what should happen there. Plus, all five say residents who have left are wary about returning home until all concerns are resolved by the government.However, not all communities are twiddling their thumbs. Mainichi Shimbun reports the resident’s who remain in the city of Minamisoma (less than half have left) are actively decontaminating buildings and streets, in the hope of bringing their evacuated neighbors home. In August, the people created the “Ota Area Reconstruction Council” to investigate getting the job done themselves, rather than wait for Tokyo to do it for them. “We can’t keep on relying only on the government,” Kisao Watanabe, chairman of the Council, said. “We decided to do what we could by ourselves, hoping we can return to normal life as soon as possible.” Watanabe also said it seems Tokyo has no plans for helping the towns recover their lost populations, so his group has taken matters into their own hands. The group has been trained in the use of detection technologies and has produced a detailed map of contamination levels in their district (Ota). They have found most of the district is actually below the 1 microsievert per hour national standard. The locations with higher readings, up to 4.62 msv/hr, are in forests and parks.
- Burial of cesium-laced incinerator wastes continues to be a problem, not only in Fukusima Prefecture, but also in Tokyo. NHK World says more than 400 waste incineration plants in Japan have found their burned remains have detectable cesium levels below the national standard of 8,000 becquerels per kilogram of ash. The main areas of local citizen opposition to burial of the below-standard ashes concerns many of the incineration plants in and around Tokyo. It appears a vocal minority of radiation-phobes have kept these Tokyo companies from safe burial because of the bad Press they have generated in the metropolitan area. The same is true for a few Fukushima-area companies. In total, 22 of the 410 incineration companies have not been burying below-standard ash due to vocal locals. NHK points out that ash above the 8,000 becquerel standard has not been buried by anyone. The 42 Fukushima-region companies that have produced the above-standard ash are storing it all at their facilities until the Tokyo government issues guidelines for safe disposal. It is mentioned by NHK that the higher-level ash could be solidified in concrete and buried in the same fashion as toxic chemical and heavy metal wastes.
Yomiuri Shimbun reports that as much as 28 million cubic meters of cesium-laced material could be generated in a decontamination of the Fukushima locations showing exposure levels above 5 millisieverts per year (msv/yr). The estimates include 1.02 million cubic meters of soil removed from houses and gardens, 560,000 cubic meters from schools and child care centers and 17.42 million cubic meters from farmland. The remainder would come from Fukushima’s forests. If the standard for decontamination were raised to 20 msv/yr, the volume would drop to 7.4 million cubic meters.
- We advocate using the 50 msv/yr exposure level safely experienced by millions of people in the world due to natural background sources. Establishing a standard at that level would be politically and socially difficult given the “unsafe-at-any-dose” myth which dictates the current radiation issue. But, it would not hurt anyone. If the 50 msv/yr level were adopted, the volume of material to be removed would drop another several million cubic feet, at least. Wishful thinking? Yes…reality is taking a back seat to political expediency in Japan.