- Continued monitoring near the unit #1 high radiation hot spots discovered earlier this week have confirmed a radiation field more extensive than previously thought. TEPCO has found the high levels of at least 10 sieverts/hr all along the venting pipe leading out of unit #1. The utility company believes the source is water inside the pipe that accumulated after the venting operations of March 12 ended. TEPCO thinks the water has an extremely high concentration of radioactive Cesium generating the radiation field. TEPCO adds that two grams of Cs-134 and Cs-137 would produce a 10 sievert/hr field. The field’s intensity could be lethal if someone stayed in it for an hour or more. TEPCO says they plan to have employees avoid the area.TEPCO also believes that small amounts of airborne Cesium is being released from the contaminated water as it slowly evaporates. It is possible that the humidity-borne material is getting into the outside atmosphere, but TEPCO points out that the plastic enclosure being built around the unit #1 reactor building will stop further airborne releases after construction is complete.
- Japan Times says TEPCO is making “little headway” in the waste water decontamination effort. They point out what has become the usual; the system has not worked as efficiently as the utility had predicted. They add that of the ~122,000 tons of contaminated water facing the effort at the start of the system’s operation, ~120,000 tons remain to be processed. 28,000 tons have been cleansed to date and is now the sole source of RPV injections. At the very end of the article was find the “good news”. (1) The new system designed by Toshiba should be operating at some point next week. The explanation of the acronym SARRY is included…Simplified Active water Retrieval and Recovery system. (2) The carbon steel piping which has occasionally clogged and forced shutdowns for cleaning, is being replaced with heavy-duty PVC because it’s properties are less susceptible to materials adhering to it. (3) New bypass piping is being installed around the problem area so that it can be worked on without having to shut down the whole system. (4) This week, system improvements and upgrades have raised over-all efficiency to 74% and the week’s volume of water cleansed was close to 8,500 tons. (5) Torrential rains over the past month have added to the volume of water to be decontaminated, but the total amount remaining is still ~2,000 tons less than when this all started.
- Mainichi Shimbun reports the Nuclear Safety Commission (NSC) has approved NISA’s current estimate of additional nuclear accidents with units 1, 2 & 3. Mainichi says the report claims the possibility of another meltdown and hydrogen explosion at any of the three units is “slim”. Further, the report concludes that radiation levels are unlikely to increase outside the 20 km no-go zone from spent fuel pools, even if their cooling waters were lost for a long time. Of course, Mainichi negatively challenges all these conclusions, which is to be expected. We challenge two of them ourselves, but with a different approach.First, we want to know how fuel cells that are considered to be fully melted down could possibly melt down again? The decay heat production is now probably less than a MW-thermal with unit #1 (which has the greatest inventory of fission products in the corium) and in the hundreds of kilowatts range for units 2 & 3. Temperatures for re-liquification would be in excess of 2,500 oC. A complete loss of water injections would have to occur for 24 hours or more to reach that point in unit #1 and much longer for #2 & 3. Even if that happened, it would not be another meltdown. A more correct term is re-liquification.
In addition, the idea of another hydrogen explosion at any of the three units is an even greater stretch. Fully melted fuel cells have already produced just about all the hydrogen possible. How could they generate enough hydrogen for another explosion? Where would the hydrogen come from? We can’t find any credible source that can can answer any of these questions.
- Another nuke will be shut down this weekend for routine refueling and inspection. It is the No.1 unit at the Kashiwazaki-Kariwa nuclear power station. Another unit is also scheduled for routine shutdown near the end of August. The power shortage in Japan continues to literally spiral out of control.
- The Tokyo government says it will succumb to radiation fears and lower their upper limit of children’s exposure. The present limit (which no child has actually received) is 20 msv/yr. What the new limit will be has yet to be announced. The Education Ministry says it will be setting the new limit after a tour of the zones around Fukushima Daiichi and a complete study of the radiation levels they find. They hope to be ready to set the new standard before the start of the next semester, after the current late-summer recess is over. Their target date is late August.
- The Tokyo government also says they are planning to allow residents to return home in the zones outside the 20km “no-go” radius, at some point later in August. They say they will wait no longer than early September. Tokyo believes TEPCO has done a good job of controlling the situation at Fukushima Daiichi, radioactive releases are relatively innocuous, and once the plastic enclosure around unit #1 is completed, its assumed releases should stop.
- Ministry of the Economy (METI) Minister Banri Kaieda has “sacked” three NISA officials to “end cozy ties over nuclear power policy”. Revelations of NISA officials having attempted to “stage questions in symposiums” since 2007 has caused a national scandal. METI has been taking harsh, albeit justified criticism for its nuclear regulatory policies (per their sub-group NISA) since March. The latest scandal has reduced METI’s reputation and they are trying to recover some credibility.Prime Minister Kan has exploited the opportunity to add his view on the dismissal of the three officials. He implies the “sackings” don’t fix anything, adding that METI is trying to cover up data disadvantageous to itself concerning “in-house and underground” power generation. Kan further said he literally doesn’t trust anything METI is doing. If he doesn’t trust a wing of he cabinet Ministry he should clean house administratively. But, such an overhaul might make him look bad so he probably won’t do it.
- Meanwhile, more information has been released on the future re-organization of nuclear regulatory responsibilities within the government. The new nuclear regulatory body will report to the Ministry of the Environment, but it seems that will be on paper more than in reality. The new Nuclear Safety Agency (NSA) will be an “extra-ministerial” group with independence concerning its operation. The NSA will be advised by the recently-created Nuclear Safety Council, which includes many academic and technical members from outside the Japanese nuclear community. The goal is to completely separate nuclear regulation from nuclear promotion within the government. In addition, nuclear responsibilities presently in the Ministry of Education will be transferred to the NSA. Nuclear Disaster Minister Hosono says the bill to create the new agency will be presented to the Diet for approval this autumn, for full implementation in April, 2012. It sounds good, but let’s see what actually happens.Some members of the ruling Democratic Party of Japan are critical the government’s attempt at nuclear reorganization under Prime Minister Kan, who says he will soon be resigning. “Creation of the nuclear safety agency involves the reorganization of government ministries,” said Azuma Koshiishi, chairman of the DPJ caucus in the upper House of Councillors, “It is not what the government should be doing now. Instead, it should pass pending bills and move into a new administration.” It seems Koshiishi wants to keep Kan’s penchant for political posturing out of the new system, to which we wholly agree.