Japan's Atomic Industrial Forum weekend reports...
The seawater pump supplying the heat exchangers for cooling Fukushima unit #5 spent fuel pool (SPF) and reactor stopped working. They could not restart it, so workers set to task for installation of a replacement pump. It took about 15 hours, but the new pump was installed and the heat exchangers were again being supplied. Reactor internal temperature rose to ~92oC and the SPF rose from 41 to 46oC before the cooling water was restored. Unit #5 remains in cold shutdown and no radioactive material was released. This morning, Japan Times (Japan's biggest “spinners” of info) headlines “Pump failure nearly brings No. 5 to a boil”, alleging in the article that at 100oC the water would boil and expose the fuel cell.
TEPCO has successfully “restored” the SPF cooling systems for units 1-4. New SPF cooling systems are being built for all four pools and expected to be operational some time in July.
The Japanese Ministry of Science has sampled twelve locations of the seafloor off the coast of Fukushima Prefecture and has detected measurable amounts of deposited Cesium contamination in each. Residual Cesium from Cold War Pacific bomb tests have been detected all along Japan's coast for decades, so the new levels above the norm are assumed to be from Fukushima. Two locations were considered significant, off the coasts of Mito (50 Bq/Kg) and Sendai (100 Bq/kg). Both are below sea-soil contamination limits, but are considered noteworthy because they are 50-100 times greater than the “normal”.
The Japanese government has found that 26 Fukushima schoolyards have soil contamination causing a potential whole body exposure of 3 millisieverts per year (for 24 hour/day and 365 day/year exposure). In order to bring the radiation areas below the 1 msv/year benchmark, top soils as deep as 5 centimeters (2 inches) will be scraped off and disposed elsewhere. It is believed this will bring all 26 locations down to 0.6 msv/yr or lower.
Detailed radioactive contamination examinations have begun for 190,000 residents of Fukushima Prefecture, both evacuees and many of those outside the evac. zone. The examinations will be external (clothing and skin) and internal using sensitive whole body counters. The relatively few examinations so far show no contamination, either internal or external.
More than 150 of the milk-producing cows from inside the 20km no-entry-zone have been found completely devoid of any Fukushima contamination. They have been released to their owners, and their milk will not have restrictions imposed because there are no Fukushima isotopes in it. One farmer, Masatsugu Shiga was reconnected with his seven milk cows this morning, saying he was pleased to get them back, but angry that the accident happened. The remaining “clean” cows will be returned to their owners today.
One catch...the cows cannot be returned to the no-entry-zone. If they are clean, then the farms where they grazed are clean. Why not just send them and their owners home?
Professor Shunichi Yamashita of Nagasaki University reports there should be no fear of radioactive rain from Fukushima. He stresses that the “hard rain” phenomena associated with the bombings of Hiroshima and Nagasaki came from bomb fallout, which is very different from the airborne releases at Fukushima.
Meanwhile, from the Japanese News Media...
In what may well be a landmark decision, Asahi Shimbun reports the government will compensate farmers and other food-related businesses that have lost money because of “harmful rumors” concerning Fukushima “radioactive fallout”. Compensation will be extended to Fukushima Prefecture and the four surrounding prefectures. “The amount of compensation will be determined by taking into account decreases in sales due to consumers' reluctance to buy the products, suspended business transactions and decreases in workers' incomes,” Asahi Shimbun reports. The government considers the public aversion toward food produced from prefectures near Fukushima “rational” because the public believed the rumors were “serious and real.” However, the rumors themselves are defined as “groundless hearsay.”
This writer has not confronted anything like this before. The Japanese may well be the first government in the world to address the “groundless rumor” issue, rather than “just let it go.” This should be a nuclear community “lesson learned”.
Asahi Shimbun also reports the person who correctly disregarded TEPCO (Prime Minister?) orders to stop sea water flow to #1 reactor was/is the Plant Manager, Masao Yoshida. He decided to come forward with the truth May 25, when he discovered he was to be interviewed by a team of International Atomic Energy Agency (IAEA) officials investigating the Fukushima emergency. He did not wish to continue keeping what he did a secret in front of the most prestigious nuclear organization in the world. Yoshido said he, “...wanted to file a report based on the facts so that this can be used as an international lesson." Here is Yoshido's scenario as to what happened...
1. On March 11, 7:04pm, he ordered the seawater flow to begin.
2. At 7:25pm, a Tokyo TEPCO official from Tokyo told him to stop and said, "We do not have the approval of the prime minister. They are discussing what to do." Yoshida told the operators to disregard the TEPCO order.
3. At 8:20pm, Yoshida was told by TEPCO to resume sea water pumping because Kan has given them permission. Yoshida told them he would do so, but declined to tell them what he had already done.
TEPCO did not begin looking at actual control room records until ordered by NISA last week. On May 25, TEPCO discovered Yoshida's decision. However, it was Yoshida who decided to go public, saying, "I continued with the pumping of seawater based on the judgment that the most important thing was to continue with pumping water into the reactor core in order to prevent the spread of the accident." In response to Yoshida's disclosure, TEPCO says that the Plant Manager has total control of routine operations and “normal accidents”, but decision-making during extreme accidents resides with the home office. TEPCO president Masataka Shimizu had approved the 7:04pm seawater flow start-up, but other TEPCO executives wanted it stopped because of their feelings concerning Prime Minister Kan's anxieties. TEPCO vice president Sakae Muto said, in hindsight Yoshida's decision to protect the reactor and disregard TEPCO orders, was correct. TEPCO is considering disciplinary action against Yoshida.
I'd give him a medal!
In a related editorial this morning, Asahi Shimbun addresses a disturbing possibility, “It is outrageous if officials at the government and TEPCO are putting greater importance on protecting their political interests, saving their faces and avoiding displeasing their bosses than on the safety of the public and workers directly dealing with the situation.” Amen...
Japan Times reports some of Japan's independent radiation experts warn against members of the public using “cheap and easy to handle” radiation monitoring devices for self-monitoring of radiation levels. These devices, apparently common in Japanese stores, often read more than 25% too high. Also, the public is untrained in how to correctly use monitoring devices in order to get representative measurements. Genichiro Wakabayashi professor of radiology at Kinki University says he speaks for a group of radiation experts who have monitored the country's radiation levels since late March. The group has a website in Japan and wants to, "prevent false rumors from being spread by non-experts who have monitored radiation levels on their own. Alarming the public (by challenging the credibility of) the government's announcements is not our purpose, as some media apparently are attempting." They add that magazines, bloggers, sensationalist news articles, and random internet postings by non-experts are routinely used to “slam” the Science Ministry for “publishing results deemed meaningless.” Wakabayashi and his group add that the 20 millisievert per year emergency public exposure standard invoked by the government is completely safe. https://fukushimanewsresearch.wordpress.com/2011/05/28/japan-experts-leave-radiation-checks-to-us/
I don't recall any such reputable public denouncements of irresponsible and exaggerated claims of radiation exposures, during or after TMI and Chernobyl. Is this the beginning of a drive for radiation responsibility?
On a more negative note, an Asahi Shimbun Saturday editorial says a government panel is being created to investigate Fukushima, which ought to include competent and influential people recruited from “outside the nuclear power village.” The op-ed piece says Japan should seek opinions from overseas experts and get critics of nuclear power involved in the probe.
First, what is the “nuclear power village”? This sounds like nuclear conspiracy paranoia routinely proffered by nuclear nay-sayers. Second, the critics of nuclear power never say anything positive about nuclear energy. Does this make them any better than the so-called “nuclear power village”? Asahi Shimbun alleges many nuclear companies conceal negative information, but they fail to consider that nuclear critics have a proven track record of obsessive confabulation and exaggeration.
Before addressing recent Fukushima updates, we want everyone to be aware of the preliminary findings on Fukushima's long and short-term health effects from one of the oldest and most prestigious scientific organizations in the world; United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR). Japan Times reports on a press conference in Vienna, held by UNSCEAR on May 23. Wolfgang Weiss, chairman of UNSCEAR, said, "So far, what we have seen in the population, what we have seen in children, what we have seen in workers . . . we would not expect to see (short term) health effects,. We cannot identify and attribute health effects to these doses." He added that this short term assessment can be applied to the next two year period. If no further releases of radioactive materials come from Fukushima, the same can be said of long term health effects. However, the emergency has not ended, and the possibility of future, significant releases is not zero, so UNSCEAR will delay it's long term health effects estimate for two years. Work on the final report will probably begin this summer, with a preliminary assessment coming next May. UNSCEAR estimates are primarily based on the historically understood 1000 millisievert threshold of curable radiation sickness, which is many times higher than any actual dose to Fukushima plant workers or any member of the public. The threshold for Acute Radiation Sickness (to less than 1% of those exposed) of 1500 millisievert is even more inapplicable.
Now, back to Fukushima...
Japan Times also reports that one of the pipes for the Emergency Core Cooling System (ECCS) for Unit #3, may have been critically damaged by the earthquake, and not the tsunami, and may be the reason for the unit #3 meltdown. The Times says an anonymous TEPCO official “admitted” that if there was damage to the piping, it would have been due to the earthquake and not the tsunami, adding “We can not deny the possibility.” Later in the article, the Times alleges TEPCO is trying to downplay the possibility, plus the possibility of RPV “holes” reported earlier in the week. TEPCO points out the above possibilities are based on instrument read-outs that were probably damaged during the peak of the accident, thus no one should take the possibilities as indisputable fact. Asahi Shimbun quotes TEPCO's Junichi Matsumoto (May 24), “We suspect a malfunctioning of pressure instruments.” For “balance”, Asahi Shimbun refers to Kyoto University professor Keigi Myazaki who speculates that if the piping were indeed compromised, it could not have been due to the tsunami, so it had to be the earthquake.
Later in the article, we find the reason behind this speculative uproar is due to a slow, unexpected pressure decrease hours after the core was uncovered and ECCS injections started. The pressure drop occurred over a 6 hour period. When the cold sea water suddenly contacted the extremely hot ECCS piping, considerable thermal shock must have happened. We at this site feel cracking (not complete failure) of attached piping due to thermal shock is a more realistic explanation for the slow decrease in pressure. Also, the progression of the situation does not indicate the pipe breaking off or having some other kind of severe compromise. A catastrophic break on pipes as big as ECCS would cause something like a rapid depressurization, not a partial loss of pressure over a six hour period, regardless of the accuracy of the indicated pressures. Lastly, suggesting this ECCS piping issue is a significant cause of the unit #1 meltdown is literally making a mountain out of a mole hill.
That is, if the pressure indications from the heat damaged, albeit unreliable pressure instruments is in fact the case...which it probably isn't. It's starting to seem like a dark, confuddled (confused and befuddled) comedy of wild speculations based on bad information!
The TEPCO operating personnel at Unit #1 say they never shut off the sea water flow to the reactor on March 12, even though they reported compliance with Prime Minister Kan's “suggestion” to shut it down. Kyodo News reports TEPCO's ranking officers told the plant's operators to follow Kan's wishes. The control room “head” said they would do so, but then he ordered the operators to ignore the order and continue the water injection.
The control room supervisor gets a “shout out” and “well done” from this writer for doing the right thing! Never let a politician compromise the safety of the core. Never!
Japan's Nuclear and Industrial Safety Agency (NISA) has formally “admonished” (reprimanded) TEPCO for allowing worker over-exposures and skin contamination incidents which have occured since March 11. The admonishment also extends to TEPCO's not implementing any and/or all possible measures to keep worker exposures as low as reasonably achievable and eliminate potential contaminations, until April 3.
TEPCO deserves to be reprimanded, but this writer wonders what has taken NISA so long to actually do it?
There is a possible loss of 57 tons of water from one of the waste facility storage tanks at Fukushima Daiichi. If the loss is confirmed to be a leak, water will no longer be transferred there from unit #3, which could delay start of recovery work in the turbine building.
Decontamination (purification) of the stored contaminated waste waters could start in about two weeks, “on an experimental basis”.
Prime Minister Kan has announced Japan will reduce it's reliance on both nuclear and fossil fueled electricity, and replace them with renewable sources. He says Japan will be producing 20% of its electricity from renewables by 2020. One key aspect of the plan is installing solar panels on the roofs of 10 million homes. In addition, Kan says the cost of solar will drop by one third of the present level by 2020. How? Government cost controls.
Because of a large public anti-nuclear rally estimated at 20,000 people last Sunday, the government of Switzerland will consider shutting down its five nuclear power stations. The proposed shutdowns will be in 2034, at the end of their current operating licenses. They will instead turn to renewables to replace the 40% of the country's electricity currently coming from the nuclear plants. The Swiss Parliament will begin debate on the issue next month. The reason given for this sudden move is, of course, Fukushima.
The Japanese government recently announced it would “cull” all cattle remaining in the 20-kilometer, no-entry zone. That is, have them euthanized. This is because many of the cattle have already died of malnutrition, and the survivors are malnourished as well. Plus, milk and meat from the cattle would be virtually worthless because of radiation fears. Now, the Democratic Party of Japan (DPJ) wants some of the surviving cattle spared, if they are owned by people who protest the government's “culling” plans. DPJ says numerous veterinary groups want the animals saved and studied because there is no Japanese record of the effects of increased low level radiation exposure on lactating (milk producing) animals.
The veterinary notion makes sense because there can never be enough reputable data on biological radiation-effects in the natural world outside the laboratory. But, if the animals are already past the biological point of no return, then maybe they should be put out of their misery.
The Japanese Ministry of Education says the 20 millisievert/year limit on radiation exposure to school children has been an emergency regulation since its inception. It is not something that is customary. They have also adopted a 1 millisievert “benchmark” which, when approached, will result in exposure mitigating actions like removal of top-soils. Both exposure levels fall in line with the standards recommended by the International Commission for Radiation Protection (ICRP).
Finally, there has been some media pop about Greenpeace claiming to be finding more fish contamination above “safe limits” than the Japanese government has reported. They also claim the government's monitoring of fish has been superficial. The local prefectural government of Fukushima countered by saying the fish sampled by Greenpeace came from waters where all fishing has been banned. We should also keep in mind that Greenpeace's definition of “safe limits” for radioactive contamination are based on unverified modeling which is not internationally recognized. Greenpeace also claims to have found contamination on floating seaweed 50km out to sea, but neglects to mention that radiation detection equipment is ultra sensitive and can measure vanishingly tiny levels. Just because something is measurable with sensitive equipment does not mean it is hazardous. Clearly, Greenpeace is once again misrepresenting data for the purpose of amplifying public phobic fears, and trying to discredit everyone but themselves.
Each day that passes reveals more details with the sequence of events leading to the meltdowns at Fukushima units #1, 2 & 3. Further, world-wide meltdown reports vary from source to source, which indicates considerable confusion over the revealed data. It is not merely a translation problem. Nearly all Japanese news sources also seem confused. Of the bunch, NHK News seems to get it right more often than the rest. In addition, TEPCO seems to have a penchant for leaving itself open to extreme speculation, which nearly all news media voraciously feed off of. Who should we believe? From our perspective, one information source has best stood the test of time through-out the emergency; Japan's Atomic Industrial Forum (JAIF).
Tuesday morning, JAIF and several Japanese news sources reported TEPCO revealed meltdowns occurred in the fuel cells of units #2 & 3. NHK News reports Unit #3's steam powered cooling system pump (RCIC) was lost at 2am on March 13, and fuel began to be uncovered several hours later. TEPCO believes fuel started melting in localized spots inside the core at about 9am. JAIF reports that by 3am on March 14, some 60 hours after the March 11 quake, most of the core had melted causing molten fuel to drop out of the cell and find its way into the bottom RPV head. The molten corium cracked and fractured as it dropped through the residual water in the bottom of the reactor vessel. It is not known if all residual water was eventually boiled off. TEPCO says it's possible the core was never completely uncovered, and a full meltdown like that assumed for core #1 may not have happened. World Nuclear Assn. surmises that some water was being sporadically injected into the RPV during this most critical period, which may have averted full meltdown. But, it is safe to assume a slow process of additional fuel melting continued for the better part of three days until fire truck pumps boosted sea water “injections” to the RPV on or before March 17, stopping further melting.
JAIF and NHK report unit #2's RPV cooling function was lost at 1 am on March 14. It is possible all fuel cell bundles were exposed by 8am, March 15. Fire trucks were on the scene, but attempts to use their pumps to boost the flow of cooling sea water to the RPV were unsuccessful, probably because of the great a pressure. By 8pm on March 15, enough of the fuel core had melted to begin dropping into the bottom head of RPV #2. This was about 101 hours after the earthquake. A relatively slow progression of continual melting probably continued until fire truck pumps could begin boosting water flows on March 17.
Both unit's core decay heat levels had dropped considerably before fuel uncoverage began. Although the initial decay heat of both units might have been ~50% greater than unit #1 at shutdown, their longer time periods between tsunami and core uncovery made heat production in units #2 & 3 much less than was the case when unit #1 fuel cell was uncovered. Because of the lower heat production, the time periods between loss of cooling functions and the onset of melting for units #2 & 3 were considerably longer than with unit #1. From the reports, it now seems more probable that unit #3's core experienced considerably more melting than unit #2's core because fuel liquification began about 40 hours sooner. Even though the decay heat rate dropped slowly in unit #2, the 40 hour difference in the onset of fuel melt could have caused unit #3 to have as much as twice the level of meltdown as in unit #2.
TEPCO says it has taken more than two months to draw these preliminary conclusions because they were more concerned about controlling the accident situation than compiling and analyzing data. It's a weak excuse. Masanori Naito of Japan's Institute of Applied Energy told NHK News says confident analysis of the data available since mid-March should have taken no more than a day. He added it would have been relatively “easy” for TEPCO to have come to this conclusion much, much sooner.
This morning, all Japanese news media, reputable international nuclear information sites (e.g. WNA) and JAIF report holes were burned through the RPVs of units #1 & 2. The number of holes and cracks from the burn-through episodes total the equivalent of a 10 cm (4 inch) hole. This speculation comes from a computer simulation run by TEPCO. The primary, if not sole origin of these computer-based speculations comes from pressure instrument readings inside each RPV from March 11 through March 15.
These speculations are rife with problems. First, the corium would have to have been molten long enough to burn through 8 inches of solid, cast, high-carbon steel. For this to happen, the corium in the bottom head would have to have been dry for many hours. However, even at the very low level of sporadic injection flows into the RPVs between march 11-15, it is highly unlikely that the corium was completely molten long enough for such a severe burn-through.
Second, if a burn-through of this magnitude did happen, the cores would have rapidly depressurized...rapidly. And any level of re-pressurization would have been highly unlikely. That's a very big hole. However, pressure indications show that while pressures dropped dramatically from time to time, there was never a complete depressurization of either of the vessels. TEPCO assumes the pressure drops indicated several moments of core burn-through for each of the RPVs. However, each of the suspect pressure drops come just after water injections began. Any physics teacher knows that introducing room-temperature water into a closed, super-hot container will cause a rapid, significant internal pressure drop due to quenching.
Third, TEPCO's RPV-failure speculation entirely depends on the pressure instruments for the two reactors providing reliable read-outs during the peak period of high RPV temperatures. We now know unit #1 water level instruments suffered greatly due to the extreme heat, thus it's safe to assume the same for units #2 & 3 water level instruments. Pressure instrumentation is just as susceptible to extreme heat-related malfunction as water level instruments. So why assume the pressure instruments worked OK, when the water level instruments failed? This website has maintained for weeks that there has been a constant mismatch between indicated temperatures and internal pressures for all 3 RPVs, making the accuracy and efficacy of the pressure instruments questionable, at best. Basing a computer simulation on highly uncertain data makes no sense!
The question may be asked...would not the temperature instruments also be too damaged to be relied upon? Possible...yes. But, temperature instruments have a much higher reliability factor in extreme heat conditions than pressure and water level devices, which TMI data and extreme accident laboratory experiments show us to be the case. The most reliable parametric indications during the March 11-15 period at Fukushima Daiichi, units #1, 2 & 3, are most likely the temperature devices. Pressure and water level read-out data is simply too unreliable to counted on...especially when it leaves the door open for the news media to give it a negative speculative spin.
On the other hand, JAIF and NHK's report of cracked piping on unit #3 RPV makes sense. (more on this Friday?)
It had to happen...much of the Japanese news media is beginning to use western news media “spin tactics” to try and keep their readers/viewers on edge. It doesn't matter if a suggested possibility is highly unlikely. If it's not absolutely impossible, it's implicitly reported as a distinct possibility.
For example...Kyodo News reports that some of the piping attached to the #3 RPV might have been damaged by the earthquake itself, implying TEPCO's statement of no earthquake damage is false. JAIF reports TEPCO as saying earthquake damage to any part of an RPV is highly unlikely. Thus, Kyodo News spins “highly unlikely” into “distinct possibility”.
In perhaps the most disappointing example, Asahi Shimbun headlines “More radioactive water may leak from Fukushima plant”. The article attached says the storage tanks for the removal of the waters from the basements of the Fukushima power plant buildings are getting full. Does this mean more leaks to the sea is a distinct possibility? JAIF says 90% of the water in the unit #3 basement has been relocated, plus14,000 tons remain to be removed from each of the other basements. Unit #3 storage tanks are full, but not the storage locations for the other three. Further, once a water clean-up and filtration system is completed, the stored waters will be run through and used as reactor cooling replenishment supplies. Every gallon cleaned will be another gallon of additional storage space. At least Asahi adds it will be three or four days before the storage tanks for units #2 & 3will be filled. Regardless, the end is in sight. Does nearing the end of water removal mean more leaks? Highly unlikely, but...
The Social Democratic Party of Japan (DPJ) has published a proposal to scrap all Japanese nuclear power plants by 2020. DPJ says the power loss can be recovered by 2050 using solar and wind generation. In the interim, government-enforced conservation plus increased production from hydro-electric, geothermal and “thermal” plants can keep Japan's energy infrastructure from collapsing. By “thermal” they mean burning fossil fuels; mostly oil.
There seems to be several problems with the plan, beyond the increased use of fossil fuels. First, DPJ's estimate of hydro and geothermal generation is based on them operating nearly 100% of the time, which is horribly naïve. Hydro availabilities run in the 80% range, since the units have to be shut down periodically for maintenance and repair. Second, their outputs are seldom 100% of their design ratings due to several variables. A typical hydro plant averages about 50% capacity over the course of the year because the amount of water above the dam is less during dry seasons and much lower with winter's icing and snowfall not melting. Geothermal capacity factors when operating are higher than hydro, at 90%. However, the corrosive nature of the steam generated in the deep, hot rock formations (lots of SO2 and CO2) cause material failures, making availabilities of about 65%.
Finally, it seems DPJ falls prey to the traditional, overly-optimistic notion of solar and wind being a sure-fire, magical remedy. Using the latest, best estimates of future solar efficiencies, a solar farm of 1000 megawatts electrical (Mwe) would cover more than 10 square miles. (vice a 1000 MW nuke at a few hundred acres). A 1000 Mwe wind farm would be of similar size. To replace Japans nuclear capacity with solar and/or wind would doom more than 500 square miles of Japan's precious, non-mountainous terrain. And, this doesn't include that ideal solar and wind capacity factors necessarily run below 40%, meaning an additional 750 square miles of Japan's land would be sacrificed to produce enough energy for non-productive period storage. The exacerbating solar problem is sunshine for only half of each day (on the average), and the wind farm problem of needing a steady 8mph velocity for the turbines to work (cut-in speed).
This website advocates a realistic mix of voluntary conservation, solar, wind and nuclear to wean the word off its fossil fuel addictions. Without nuclear in the mix, DPJ's proposal is clearly unrealistic.
Japan's Atomic Industrial Forum (JAIF) has been told the emergency operation manual for Fukushima #1 was not followed. NHK allegedly has a copy of the emergency manual, and it reveals several key violations of emergency procedures. By procedure, the primary containment's suppression chamber is to be manually vented to the outside air at ~2 times it's operating limit (120 psi) if automatic venting fails (which it did?). As it turns out, Prime Minister Kan's order to vent unit #1 as soon as possible on March 12 was to try and accelerate the execution of manual pressure relief. The pressure inside the #1 torus was at the manual relief trigger point for 6.5 hours before venting began. Pressures at the point of venting was at least four times the torus' design limits. Radioactive steam must have streamed out of the torus through weak points (such as instrument penetrations) and into the secondary containment. This may well be the source of the hydrogen which exploded in the #1 upper refueling deck on March 12. Former Japanese nuclear engineer, Masashi Goto, says that if the venting would have started at the prescribed pressure, the hydrogen explosion could have been avoided in Unit #1. This writer totally agrees.
Regardless, the explosion occurred more than six hours after the venting began, which in most interesting. Did it take that long for the hydrogen released to the secondary containment to migrate to the upper level and concentrate? One must also wonder if similar emergency procedure violations occurred with units #2 & 3? Could the “abnormal noise” reported for unit#2 suppression chamber on March 15 have been a result of steam being released by a severe over-pressure condition?
Sunday's Japan Times reports Prime Minister Kan wanted the cooling sea water flow to reactor pressure vessel (RPV) #1 stopped on the morning of March 12, causing TEPCO operators to stop sea water injection. After an hour, the operators re-started sea water cooling flow. Kan's staff maintains the Chairman of Nuclear Safety Commission (NSC) told him the use of sea water for cooling could cause “recriticality”...the restart of a fission chain reaction. Haruki Madarame, Chairman of the Commission, denied he made any such claim to Kan. Madarame told Kyodo News, ''It is unlikely for me, as an expert, to say such a thing. I feel quite upset about that.'' This morning, Asahi Shimbun reports Kan himself denies giving TEPCO an order to stop the seawater injection. He says he was concerned about recriticality, but merely asked NSC to investigate into the possibility. Kyodo News quotes Kan saying he never received a response from NSC, ''I cannot have said 'stop' with regard to something that had not been reported to me.” Even if Kan issued no “instruction” for seawater flow to stop, TEPCO certainly understood him to be making just such a suggestion, at the very least.
On Sunday, Japan Times reported growing criticism toward Kan's decision and that, “a delay in the seawater injection may have caused a meltdown in the reactor.” This morning, Asahi Shimbun reports that the President of Japan's Upper House, Takao Nishioka, has asked for Kan to resign. In Japan, it is literally unheard-of for the head of one branch of government to ask for the resignation of the head of another branch. Nishioka calls Kan's responses to the quake/tsunami disaster and the nuclear emergency at Fukushima “inept”. He cites slow public safety responses to the tsunami, and a failure to disclose timely information concerning the status of reactor #1 on March 11 & 12. Nishioka also calls for the Lower House to pass a “no confidence” vote if Kan refuses to step down. This would legally compel Kan to resign. Asahi Shimbun says Nishioka's move is “making the House look like an arena of political conflict”, and admonishes him for doing something that violates past political practices. Asahi Shimbun calls for unity in the government, not conflict, at this critical point in Japanese history.
NHK News reports TEPCO denies the earthquake caused any “safety abnormalities” at Fukushima Daiichi on March 11. TEPCO's operating staff had fully functional instrumentation and emergency operational control for the ~1 hour time period between the quake and tsunami. After the tsunami struck and stopped all emergency electricity flow, data became sporadic and unreliable, aggravated by minimal communication capabilities between the four unit's operating staffs. TEPCO says it has taken them more than two months to get all the information together to make this determination. The question now emerges... why has it taken them so long?
NHK also reports that work has begun to reinforce the bottom of the spent fuel pool (SPF) in unit #4. TEPCO says this reinforcement is two-fold. First, it ought to be done before installing a new SPF cooling system. Second, it will insure the SPF will not lose integrity should another massive quake/tsunami hit.
TEPCO reports they have reduced cooling water flow to unit #1 reactor pressure vessel (RPV) through the “fire extinction system” down to 3 tons per hour, but increased water flow via feedwater piping to 12 tons per hour. As a result, water temperatures at the feedwater nozzle and RPV bottom head have dropped below 110oC for the first time in two months. The other two RPV's temperatures seem to have stabilized, which means the feedwater injection rates have finally been adjusted such that temperatures remain constant.
JAIF now reports the water level in RPV #1 is below what used to be the fuel cell in the reactor. They are assuming a full meltdown with all of the core materials in the fuel cell mixed together and located in the bottom head of the RPV. Bottom head temperature readings indicate the corium (melted mixture) is being adequately cooled by water injections. They also report that the fuel cells in units #2 and 3 are either partially or fully uncovered with water. They continue to maintain that there is 35% meltage in RPV #2, and 30% meltage in RPV #3. This writer continues to suggest that #3 RPV has the worst damage of the two, and is quite possibly a full meltdown of Unit #1 proportions.
NHK News reports that the removal of debris from the exteriors of the four tandem reactor buildings at Fukushima is hampering TEPCO's ability to provide new cooling systems for the reactors. This should come as no surprise to anyone, but does show that the events at Fukushima Daiichi have wound down to the point that the news media is literally scraping the bottom of the barrel to keep Fukushima “in the news”.
TEPCO reports that the seawater sampling point 30 meters north of their enclosed port/quay now shows a cesium 134/137 isotopic concentration slightly above health standards. All other sampling points are below standards, with most not showing detectable cesium levels. All sampling points, however, show no detectable iodine-131.
All Japanese news media outlets have reported the discovery of five broken sea water tubes inside the condenser of the recently shut down Hamaoka #5 NPS. Most reports make it sound like radiation has been leaking through the pipes and into the atmosphere. However, this is impossible. The condensation of steam exhausted from the turbines creates an internal vacuum similar to outer space. Thus, any leakage was into, not out of the condenser. After shutdown, the source of radioactive steam is gone.
Thursday afternoon, RPV temperatures for Unit #1 had dropped to 93oC on the upper feedwater nozzle, and 88oC on the vessel bottom head. This morning, TEPCO decided to lower feedwater injection flow from 10 tons per hour to 6 tons per hour. Why? They don't say. As a result, temperatures have risen to 102oC (feed nozzle) and 89oC (bottom head). Thus, the temperatures are no longer in the cold shutdown range. Temperatures inside RPVs 2&3 continue to decrease.
Japan's NHK News reports the radiation levels inside reactor building #2 are considerably lower than those in unit #1. Whole body exposure levels surveyed in unit #2 on Wednesday ranged from 10 msv/hr to 50 msv/hr. While these levels are relatively high, they are not nearly as limiting for individual worker “stay time” (length of time before an exposure limit is reached) when compared with unit #1. The survey suggests the core damage in #2 RPV may be less severe than unit #1. Earlier this week, TEPCO speculated that unit #2 core damage is equal to units #1 and #3, where complete fuel cell meltage is believed to be the case. While unit #2's core has melted, it may be a severe (TMI level) rather than complete meltdown.
One of the issues confronting work in Unit #2 reactor building is the extremely high humidity, which has many of the ceilings dripping water. It is assumed the humidity comes from evaporation of the large volume of ~65 oC water in the 5th floor spent fuel pool (SPF), combined with a lack of an operating ventilation system to remove the moisture from the air. A new SPF cooling system is now being planned to improve the situation.
Regarding the Unit #2 accident sequence, TEPCO points out that reports of a hydrogen explosion in the pressure-suppressing torus area of the primary containment on March 15 are misleading. They have maintained all along that an “abnormal noise” came from the area followed by a sudden drop with the pressure inside the torus on March 15. TEPCO says they believe the event connected to the “abnormal noise” caused a leak from the torus.
NHK News reports that two HP (Health Physics) workers entered unit #3 reactor building early Thursday. The surveyed radiation fields are at least as extreme as unit #1, if not higher. The general area exposure levels range between 160 msv/hr and 170 msv/hr, with some locations having localized “hot spots” of much higher exposure levels. The two HPs could stay in the building for only 10 minutes before they approached the planned exposure limits of their survey (stay time, again). These radiation levels add more evidence to the belief that unit #3 fuel core has melted at least as severely as unit #1, if not worse.
Japan's Atomic Industrial Forum reports TEPCO is making plans to start nitrogen injections into the primary containments of Units 2&3, similar to Unit #1. TEPCO says it is being done to avoid future hydrogen explosions. However, this new move poses the question as to where TEPCO thinks the feared hydrogen will come from, at this point? The cores are as melted as they can get, and further hydrogen production is highly unlikely. Is this something necessary, or merely window dressing to make it appear as if they are improving safety?
Kyodo News reports that a report on potential radioactive dispersal patterns for a worst case release from Fukushima Daiichi was created by Japanese nuclear officials and sent to Prime Minister Kan's staff on March 12. Kan's people received it before he was helicoptered to the Fukushima Emergency Center, but the report never got to the Prime Minister. It seems “someone” in Kan's staff kept the report and didn't pass it on.
This another instance of malfeasance within the Japanese government during the critical early days of the emergency.
Although the soils of all schoolyards in Fukushima Prefecture outside the 20 km no-entry zone were tested last week and found to be below health standards for radioactive contamination, 90% of the schools are not allowing outdoor activities for the students. NHK News reports parents have demanded the schools to not allow outdoor activities because there is still a trace of “dangerous” contamination detectable, and they feel the health standards are not safe enough.
Fear of radiation, no matter how trivial the level, is the root of the parent's concerns. These fears are needless, but not irrational. Their fear is totally rational because the parents truly believe all radiation is terribly risky, no matter how tiny the level. They fear for their children. It makes all the sense in the world. They have no idea these fears are empty...vacuous...without substance. What is the root of this wide-spread phobia? Is it the Hiroshima Syndrome? Perhaps, but there are more recent culprits who have magnified the parent's fears.
The world's news media, including the Japanese, have routinely presented prophets of nuclear energy doom as credible “experts” with respect to the biological effects of radiation. Many such “experts” are holdovers from the days of Three Mile Island and Chernobyl who lost their moments in the sun because the news media lost interest in their fear-mongering for more than 20 years. Nuclear bigots are having a popularity renaissance because of Fukushima, and are now wrecking the lives of innocent parents and their children in Japan.
The two greatest culprits are Greenpeace and Physicians for Social Responsibility (PSR). Last week, most Japanese news outlets reported Greenpeace and PSR condemnations of the Japanese government for setting schoolyard exposure limits at the “unconscionable” level of 20 millisieverts per year. Both groups of notorious nuclear nay-sayers pointed out that this is also the annual limit for nuclear workers, and proclaimed that children are more susceptible to radiation-induced cancer than adults. Further, PSR said the chances of a Fukushima child getting cancer from 20 msv/yr is 1 in 200! They added that two year's exposure doubles the risk, at 1 in 100. Their numbers are based on unproven, unverifiable hypotheses, but the Press seems uninterested in “balancing” such irresponsible doomsday claims. The evidence against these claims is considerable.
For example, 1.5 million people who live in the Kerala region of India receive natural exposures of 20-35 msv/yr, yet have one of the lowest cancer rates on the sub-continent. In a most astonishing case, the village of Ramsar, Iran, has radiation exposures due to natural background between 132 and 260 millisieverts per year! By PSR modeling, all Ramsar residents have about a 1 in 4 chance of cancer per year. The village should be inundated with cancer suffering. But, it isn't. Reputable research shows that Ramsar cancer rates are actually less than Iranians receiving 200 times less exposure. The lead researcher on this astounding phenomena, Biologist S.M. Javad Mortazavi, reports, “Based on results obtained in studies on high background radiation areas of Ramsar, high levels of natural radiation may have some bio-positive effects such as enhancing radiation-resistance. There are many other areas with high levels of background radiation around the world, and epidemiological studies have indicated that natural radiation in these areas is not harmful for the inhabitants. The risk from exposure to low-dose radiation has been highly politicized for a variety of reasons. This has led to a frequently exaggerated perception of the potential health effects, and to lasting public controversies.” In other words, actual radiation exposures considerably greater than the 20 millirem exposure limit for Fukushima school children show lower cancer rates...not greater! Yet, horrible exaggerations abound, frightening the parents of Fukushima over literally nothing-at-all.
Ethically-negligent fear-mongers like Greenpeace and PSR have but one goal in their incessant anti-nuclear crusade...amplify the public's Hiroshima Syndrome-conditioned fear of radiation to a phobic level of paranoia. They are nothing more than street-corner prophets given tacit credibility by a willing Press.
Mortazavi, S.M. Javad; High Background Radiation Areas of Ramsar, Iran; Biology Division of Kyoto University; http://www.angelfire.com/mo/radioadaptive/ramsar.html