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The plot thickens...
Reports out of Japan since Monday have revealed a number of disturbing items. Remarkably, the most recent reports concerning the events at Fukushima Daiichi, March 11 through March 16, suggest that several of this writer's previous conjectures were correct (in italics).
TEPCO information, through the Japanese Atomic Industrial Forum (JAIF), indicates that meltdowns occurred in all three fuel cores of Units #1, 2 & 3, with the worst degree of damage in RPV #3's core.
Asahi Shimbun says the hydrogen explosion on #4 refueling deck came from Unit #3 core, which had the worst of the three meltdowns and produced the highest volume of hydrogen.
Kyodo News reports Unit #2's delay in venting was because two initial attempts to vent failed. The operators did not vent earlier because they couldnot. Further, the delayed water injection to #2 RPV was due to the inability to reduce pressure enough for pumping to work. This unavoidable delay, plus damage to the Unit #2 refueling deck due to flying chunks of concrete from the Unit #3 explosion which allowed some of the hydrogen buildup to escape, avoiding a Unit #2 hydrogen explosion.
*This writer is not omniscient, of course. Asahi Shimbun reports that all three reactor cores experienced severe, if not full meltdowns during the first few days of the accident. I have surmised damage to Unit #2 to be much less than the other two fuel cores, and that now appears to have been correct. Unit #3 is the worst, without a doubt, with Units 1 being second-worst, and unit #2 the least-worst.)
The reasons behind the nearly two month delay in reporting the above items is disturbing. It now seems that Monday's Asahi Shimbun article alleging TEPCO concealing early-on radiation data, may be the virtual tip of the concealment iceberg. Important items of information were known to TEPCO and the government during the first days of the emergency, but have been withheld until now. Both should be held accountable for what now seems to have been an intentional act.
JAIF reports operators of Unit #1 manually shut off the automatically-initiated flow of cooling water to the core 10 minutes after the earthquake, because of an unexpected pressure drop inside the RPV. Cooling water flow remained shut off for three hours. No wonder Unit #1 melted first. Decay heat production is massive for the first hour after reactor fissioning ceases (SCRAM), and remains high for several hours after that. This is a gross example of operator error. Never, ever should emergency cooling water flow be stopped...not for any reason! (Operator records show that this report was totally incorrect)
Asahi Shimbun reports that all three RPVs experienced sharp pressure drops, many hours before venting began from each system. It appears that instrumentation penetrations through the RPVs failed first. Instrument penetrations are acknowledged as the weakest points on the RPV. However, they are quite small in size. Such failures of instrumentation penetrations would cause a rapid initial drop in pressure, but not a complete loss of pressure, as was the case in all 3 RPVs. A complete loss of pressure would be an indication of a larger pipe or control rod drive mechanism (CRDM) shearing off, literally draining the RPV in rapid fashion. This did not happen. Yet, the failure of an instrument penetration would be sufficient to lower water levels, albeit slowly, if there were no cooling water flow to replenish the level. This seems to have been the case with Unit #1.
Some news media outlets have reported that Unit #1 meltdown began during the 3 hours of no cooling water flow to RPV #1, because water level was lost through a leak. Highly unlikely. The leak definitely lowered water level slowly, but would not have uncovered the core long enough to initiate meltdown before the water flow was restarted by operators. Fuel meltage begins at more than 2,800 oC (~5,100 oF). Yes, the fuel was overheated severely during the three hours of cooling flow shut off and generated hydrogen, but it is unlikely the fuel reached the melting temperature. This writer continues to believe that the onset of severe melting occurred after venting began on March 12.
Asahi also reports Haruki Madarame, chairman of Japan's Nuclear Safety Commission, said that the meltdowns should not come as a surprise. "When highly contaminated water was found at the No. 2 reactor building in late March, we recognized that a meltdown had taken place. So I informed the government," he said. "As for No. 1 and No. 3 reactors, we recognized that, given the processes that led to the accidents there, the same thing had occurred."
So, why didn't Prime Minister Kan's government tell us about this in March? It seems the concealment issue extends to the government as well.
JAIF reports power generation trucks were brought to the Fukushima power complex within 24 hours of the complete loss of power. The first attempted hook up was to Unit #2 switchboard, and some power was sent into the system for a short time until the Unit #1 hydrogen explosion, which “fried” the connection. Two days later, a second hookup with Unit #2 was about to be completed when concrete chunks from #3 hydrogen explosion destroyed the truck. (At least they tried! They should have told us.)
JAIF also reports that the back-up batteries for Units #2 & 3 were “engulfed” by the tsunami and shorted out. They were completely useless thereafter.
Asahi Shimbun contends that during the first week of the emergency many “experts” in Japan said one or more meltdowns occurred , but niether TEPCO nor the government would confirm. Instead, they downplayed the possible extent of damage to the cores and proceeded on that false assumption.
It now seems that the physical integrity of RPV penetrations larger than instrumentation lines were compromised for a time on each Unit, and TEPCO had more than enough evidence to tell us upon discovery of the turbine basement waters. For Unit #3, this may have included one or more of the CRDMs through the bottom of the RPV. Speculation now exists that some of the fully melted core (corium) from Unit #3 fuel cell may have broken through the CRDM housing (or housings) and fell to the concrete floor beneath. The base mat below the RPV is ~ 10 feet thick, made of high-density steel-reinforced concrete. Even a full corium breach to the floor wouldn't get more than a few inches into the base mat before cooling and solidifying. Regardless, the leaked corium would have cooled and solidified almost immediately upon contact with the floor.
This morning, NISA ordered a full disclosure of all information concerning the first week of the emergency, specific to the reasons for all accident-related events at the facility, both inside (leading to fuel damage) and outside (loss of all electrical supplies). What else will we find out?
Now for some good news....
All three cores are thousands of degrees below fuel melting temperature, so the large volumes of corium that dropped into the RPV bottom heads have cooled and solidified. This means any bottom head breaches sealed early-on, and have been closed for two months! Thus, any continuing leaks from the RPVs must be higher up, through wall penetrations.
RPV #1 temperatures at the bottom head and feedwater nozzle high above the head, are both below the 95 oC criteria for “cold shutdown” conditions. The unsteady nature of plant conditions, however, make a cold shutdown declaration imprudent, to say the least.
Core temperatures for Units #2 & 3 continue to decrease. It makes no sense to continue reporting RPV pressures since the new revelations make it unlikely the pressure detectors survived the intense heat.
Two on-going questions have remained in the background concerning the Fukushima emergency. First, how did hydrogen find its way into the upper refueling deck of Unit #4 to cause an explosion? There is no evidence of a massive hydrogen release from the pool's stored fuel bundles, so where did the hydrogen come from? Second, why was there no hydrogen explosion on the refueling deck of Unit #2? The progression of events, including considerable fuel damage inside #2 reactor pressure vessel (RPV), parallels the sequence of circumstances in Units #1 and #3, so why didn't a hydrogen explosion occur as with the other three buildings? It seems we can now answer the first question, but the second remains open to possibilities.
Japan's Atomic Industrial Forum (JAIF) and NHK News have reported that the source of the hydrogen which exploded in the #4 refueling deck came from Unit #3. This web site, as well as French government and American University sources, have previously rejected speculations that the hydrogen explosion in Unit #4 was due to the spent fuel in pool (SPF) #4 having been completely or partially uncovered at some point prior to the onset of spraying operations on March 17. Remote portable camera inspection of the SPF show little or no damage to the fuel bundles, and any damage that may be the case came from hydrogen explosion debris. It now seems the hydrogen came from pathways that interconnect Units #3 and #4, especially the ducting common to both units for the venting of pressure from the containment suppression pool (torus). Unit's 3&4 were built together, providing common auxiliary systems and interconnections for use by both power plants. These interconnections allowed the hydrogen generated from #3 RPV to cause the unit #4 explosion. The indirect hydrogen pathway between Unit's 3 & 4 probably delayed the build-up on Unit #4 deck, resulting in the explosion occurring a day after Unit #3 detonated. Plus, it is probable that the Unit #3 explosion occurred nearly 2 days after Unit #1 because the hydrogen from Unit #3 RPV had to fill two refueling decks before detonating, rather than the single deck of Unit #1.
This revelation also adds evidence to this web site's contention that the worst fuel damage is in RPV #3. We can now safely assume that #3's volume of hydrogen produced from the fuel core was probably the greatest of the three RPVs, sufficient to generate two violent hydrogen explosions. This, combined with the ongoing inversion of temperature gradients above and below the Unit #3 fuel cell, strongly suggests the fuel damage in Unit #3 is worse than that now assumed for Unit #1. If Unit #1 experienced a meltdown, it seems Unit #3 has had a worse one.
Nuclear and Industrial Safety Agency (NISA) records show some interesting differences between the event sequence at Unit #2 and the other two units. For example, operator's began injecting seawater into RPV#2 on March 14, but similar seawater injections began with #1 RPV on March 12 (after the #1 explosion) and RPV #3 on March 13 (10 hours before its explosion). In addition, Unit #2 began its venting several hours after Unit#3 venting began, and nearly two days after Unit #1 venting. Both of the above sequential differences indicate that, for some reason not yet possible to ascertain, the operators of Unit #2 must have had indication(s) telling them that the rate at which conditions were deteriorating was much less than Unit #1, and somewhat less than Unit #3. It is unlikely that parametric instruments (e.g. temperatures, pressures, water levels) were functioning reasonably well until after any venting started, when RPV temperatures increased enough to overheat them. It will be most interesting to find out what caused the operators to delay #2 water injection and venting for so long.
It will also be interesting to find out where the #2 unit was vented to. Reviewing the last two months of information out of Japan, it seems Units #1&3 were vented internal to the secondary containment, releasing the hydrogen from the RPVs and suppression chambers, resulting in the three hydrogen explosions. Assuming Unit #2 RPV core damage is somewhat similar to the other two, there ought to have been roughly the same amount of hydrogen generated as with RPVs #1 and #3. Thus, venting ought to have resulted in a fourth refueling deck explosion. But, that did not happen. Four possibilities emerge...
1. The degree of fuel damage in Unit #2 core is considerably less than anyone (including this writer) have assumed.
2. Flying debris from the explosions in refueling decks #1 and #3 penetrated the walls of unit #2 refueling deck, allowing the hydrogen to escape sufficiently to prevent an 8% concentration to build up, thus avoiding an explosive reaction with atmospheric oxygen.
3. The reported explosion in the area of #2 suppression pool torus on March 15, soon after venting began, may have been due to hydrogen buildup around the torus, but inside the primary containment (PC). The PC is many times stronger in its construction than the outer containment, so it may well have survived the detonation. If this is the case, much of the core-generated hydrogen may have been removed by the PC explosion, keeping the buildup in the outer containment refueling deck below explosive concentration.
4. Or, the operators for Unit #2 realized that a venting like Unit #1 might cause another hydrogen explosion. Instead, they may have vented through the tall external exhaust stack, directly to the atmosphere. If this is the case, we must ask why the operators of Unit #3 did not do the same.
All we know for sure is that Unit #2 experienced no refueling deck hydrogen explosion, and finding out why could be extremely important.
Now, a few other update items...
TEPCO has told JAIF they are making plans to have workers enter Units #2 and #3 reactor buildings to recalibrate the RPV water level instruments, similar to what was done last week in Unit #1. They will follow the same sequence of preparatory events (e.g. cleaning the air of contaminants, etc.) before sending the workers in.
TEPCO also informed JAIF and NHK News that the attempt to raise the water levels in RPV #1 and PC #1 to above what they feel is now the top of the remaining fuel cell, has failed. A reactor building basement area was filling up with water almost as fast as the rate of water injections into the RPV and PC, indicating there is yet another leak from the system into the building. It is unlikely that the thick RPV walls are leaking, so it is likely coming either from piping attached to the RPV or leaking instrumentation penetrations. TEPCO says their goal is still to make a temporary “water entombment” surrounding RPV #1.
Prime Minister Kan reports that the “road map” for complete safe shutdown of the four stricken Fukushima Daiichi power plants is still valid. However, NISA also reports TEPCO is re-thinking the road map based on the new information generated out of the Unit #1 reactor building entries last week. This dichotomy might be due to Kan's order for all TEPCO press releases to be approved by his office, made two days after the earthquake/tsunami hit. In other words, the road map was approved by Kan, and his controlling nature wants that map followed to the letter. TEPCO doesn't seem to agree.
Temperatures in the three stricken RPV's continue to slowly decrease. The problem, last week, of getting cooling water into RPV #3 seems to have been solved since the temperature readings have decreased this weekend. However, as temperatures decrease, the pressure instrument readings remain unchanged. TEPCO ought to recalibrate them, while they're at it!
NHK News reports some of the companies in east-central Japan want TEPCO to scrap all Fukushima Daiichi power plants as soon as possible, even entombing the four stricken units similar to Chernobyl. Why? Because the reports of radiation leaks, broadcast around the world, have hurt their international business. Has their business been hurt because of Fukushima, or is it because of the world-wide infection of the Hiroshima Syndrome? You know what this web site would say.
Saturday, Asahi Shimbun headlined “TEPCO concealed radiation data before explosion at #3 reactor”. Asahi says TEPCO had radiation readings inside reactor building #3 in the 300 millisievert range (30 REM) on March 13, which was not relayed to workers trying to bring the deteriorating condition of Unit #3 under control. Further, Asahi implies that seven workers injured in the March 14 hydrogen explosion chould have been avoided (which may well be the case). However, two “experts” in Japan, Keiji Miyazaki of Osaka University and “another nuclear expert” Kiyoshi Sakuri, believe that public protective actions would have happened sooner if the information was made immediately available, which makes little or no sense. Public announcements of the emergency at Daiichi came but a few hours after the quake/tsunami, and evacuations out to 3 kilometers began at 10:20 at night on March 11. The government declared a state of emergency an hour later. The announcement for a 10 kilometer “stay indoors” precaution came a few hours after that, early in the morning of March 12. By following the public protection factor sequence of events there-after, we find that all reasonable actions were taken well-before the above “concealment” began on March 13. On the other hand, TEPCO maintains that “severe radiation levels inside the plant” were reported as quickly as possible to the Press, but releasing the actual data before it had been internally scrutinized and verified was not possible. Could TEPCO mean this happened after Kan's “all information goes through my office” dictum was issued? Is there a connection?
As a result of the recalibration and other maintenance work performed by plant staff on water level instruments for reactor pressure vessel (RPV) #1, it appears that water level has been much, much lower than anyone had previously speculated. In fact, TEPCO and NISA now believe that the fuel cell was completely uncovered for at least a half day between the loss of power on March 11, and seawater injections on March 12...perhaps even longer. We can now re-examine RPV #1 events the first few days of the emergency. The following has been deduced by this writer resulting from more than two months of constant study on the Fukushima situation, and greatly influenced by the current understanding of water-levels in the core March 11-12...
About 2 hours after the earthquake, cooling water flow into the reactor was no longer possible due to the complete loss of power. Decay heat, at this point, was in the 4 megawatt range, which heated up the water in the RPV.
The morning of March 12, RPV pressure indication was increasing rapidly, which prompted planning for the operators to vent steam pressure out of the RPV. Early that morning, Prime Minister Kan arrived at the Emergency Facility 5 km from the power plant complex, and demanded venting begin as soon as possible. Venting occurred a few hours after Kan left. The hydrogen gas which built up in the upper refueling deck and exploded had to have come from the core, so it seems the operators were ordered to vent internally, and not through the tall stack external to the reactor building. The external release would have been into the atmosphere, which Kan was probably trying to avoid. A stack vent may have avoided the hydrogen explosion, in hindsight.
Five hours after venting began, at ~3:30 pm, the top of the reactor building for unit #1 was decimated by a hydrogen explosion.
When venting began at just after 10 am, it is probable that the decreasing water level inside RPV #1 accelerated. By the time of the refueling deck explosion, it is quite possible the entire fuel core of reactor #1 was no longer covered with water. However, the environment within the vessel was not completely dry. Water was still in the bottom of the vessel, producing steam. Steam is about 20 times less effective than hot water as a cooling medium, so while some decay heat was being carried away by steam, most of it stayed within the fuel bundles. Eventually, the bundles over-heated, with the first fuel damage being embrittlement of the zirconium cladding around the fuel pins. Copious amounts of hydrogen were rapidly generated as the hot zirconium stripped the oxygen from the water molecules in the steam. The hydrogen production probably started after the venting began. As venting continued, the hydrogen got out. The core continued to heat up faster than the residual steam could cool it. Fuel melting eventually began.
Using the TMI studies of the melted fuel taken from it's core, we might assume similar processes occurred in RPV#1. The uranium fuel, zirconium, boron-carbide control rods, and steel supports that held the fuel bundles in place were liquified into a composite metallic substance called “corium”. As the degree of meltage progressed in, through, and/or around the core, the liquid corium ran down and/or through the unmelted fuel bundles, with much of it going into the bottom RPV head. It's possible the super-hot corium may have boiled off the residual water in the RPV bottom. As with all liquids, the corium spread out along the bottom head's inner surface as it accumulated. Some of the corium probably worked it's way into the instrumentation penetrations that go through the lower RPV and compromised their physical integrity. Plus the extreme heat, over 2000 oC, probably cracked some of the other instrumentation penetrations in the sides of the vessel. But one thing is sure...the corium did not burn its way through the thick, cast-steel bottom head. This is because the temperature instrument on the very bottom of the head is still working, which would not be the case if corium had burned its way through.
Corium production continued as time passed. At ~10:20 pm, plant operators began injecting seawater into the RPV. While it is somewhat unclear as to how they did it, it seems likely they used a steam-powered emergency cooling (RHR) pump. The water flow was very low at the start, but the cooler water immediately began knocking down the high pressure inside then RPV. As the pressure dropped, the pump was injecting water at a faster rate because it was working against decreasing resistance. Soon, the corium inside the bottom head was covered with water, cooled and solidified. The water level inside the RPV rose as pressure dropped and water injection increased. When steam pressure inside the RPV dropped too low to keep the pump operating, the pump was shut down. When decay heat raised the steam pressure sufficiently, flow was resumed. With water injection occurring in an “on and off”fashion, it's probable that the fuel core's temperature and water level fluctuated up and down with it. Regardless, somewhere after midnight of March 12, the meltdown was essentially over. The damage had been done. Where the Three Mile Island core was uncovered for maybe an hour or two, it now seems the Fukushima #1 core was uncovered for many hours. How RPV #1 meltage compares to TMI will not be known until the vessel head is removed sometime in the future.
It would be more than 4 days before fire trucks and their pumps would assist in the water injections, and fresh water would be used instead of seawater. Until fresh water was used, the seawater in the core was subject to neutron irradiation. All nuclear fuel, once it has been in an operating core for a brief period, naturally releases neutrons out of its fission products. The longer the fuel is in the core, the more intense the emitted neutron field becomes. Most of the fuel in RPV #1 was in the core more than 2 years before March 11, thus the neutron field in and around the fuel was considerable...and this included after the reactor SCRAMed (auto shutdown acronym), and after the fuel melted. The neutron field continues until this very moment, and will continue until the neutron-emitting fission products have radioactively burned out. The neutron field unquestionably caused most (if not all) of the Chlorine-38 production, which many “experts” and prophets of nuclear energy doom said was an indication of “re-fissioning” in mid-March. There was never even the remotest possibility of re-fissioning! The control rods, melted into the corium and uniformly mixed with the fuel itself, made re-fissioning impossible. The Cl-38 was produced by the neutron field generated by the “waste” atoms in the fuel.
TEPCO and NISA have both maintained the core was partially uncovered for the past two months. This writer found the concept of certified reactor operators allowing this to be something unthinkable...unless they had no other choice. As it turns out, this may have been the case all along, and the reasons also answers the question of why a constant injection of water over the past two months hasn't raised indicated water levels in the RPV. First, we now know that the extreme heat generated by the un-cooled core caused the water level instruments to malfunction. Until yesterday, nobody knew what the level of water in the core was. Also, it now seems that much of the upper fuel cell has melted and slumped/dripped into the lower core area and the bottom head, thus lowering the actual top of the fuel several feet. TEPCO and NISA indicate that the actual water level in the fuel core area, after yesterdays recalibration, is about half-way up the damaged cell. In other words, the remaining fuel inside the cell after the meltdown has probably been adequately covered and cooled for more than a month....maybe since March 13.
Why did the operators not fill the RPV any higher? First, they didn't know the actual water level. Second, they were limited in how fast they could inject water into the core (reasons are currently not available). Finally, there were slow leaks out of the reactor vessel through the heat-damaged instrument penetrations on the RPV itself, as well as weeping, seeping leaks through cracks in the overheated piping attached to the RPV. Even if the operators knew the core was actually uncovered, they were severely limited as to what they could do about it. TEPCO reports that 10,000 tonnes of water have been injected into RPV #1, and more than 8,000 tons have leaked out, into the surrounding primary containment. It's still there, it seems. Primary Containment #1 shows no evidence of physical compromise.
Now for today's abbreviated updates...
TEPCO and NISA report that the increased water flow into RPV #3 has begun to drop temperatures inside. In fact NISA has posted a rather comprehensive chart of all operating temperature instruments on RPV #3, though they now note that these may be reading incorrectly due to heat damage.
NISA speculates that since the water injections seem to have curtailed further RPV #1 fuel damage since March 13, and current injection rates seem to be keeping the remains inside the reactor adequately covered and cooled, there may be no need to completely fill the vessel in order to achieve cold shutdown. Further, filling the primary containment to a level equivalent to the top of the fuel in the reactor may also be all that is needed.
While pumping water out of Turbine #3 basement, a leak developed in one of the tunnel accesses outside the building. The leak was stopped by plugging it with “cloths and concrete.” Regardless, some radioactive water did find its way into the enclosed sea port area next to the plant, inside both the silt dams and break-wall. None of the contaminated water seems to have reached the open sea.
NISA also reports that two-thirds of Japan's nuclear power stations are currently shut down, some due to automatic earthquake functions (and required follow-up safety inspections), others due to regularly scheduled outages, and (of course) the three good units at Hamaoka. By the end of May, another five units will be going into scheduled refueling outages, resulting in 75% of Japan's nuclear plants shut down. NISA is concerned that the utilities will be too intimidated by government actions at Hamaoka to restart the units when they are ready to go. This will probably lead to summer power shortages.
JAIF reports all but one of schools in Fukushima prefecture have soil contamination below the health standards. The one that is above the standard will have the topsoil skimmed off and buried elsewhere, at ~2 feet below ground. At that depth, there will be no addition to background levels and no chance of the contamination becoming airborne again. Further, once “fixed” in the soil, the radioactive isotopes will not migrate anywhere. (see the “Nuclear Waste : Is It?” page, and its section on Oklo) This indicates that Fukushima's airborne levels deposited very little activity on surrounding surfaces. This may seem to contradict the recently published "map" of contamination compiled in April. The "map" was calculated from gamma readings takea from a helicopter and airplane, and mathematically deduced for specific isotopes. Specific isotpic analysis is only possible using field samples, and the new information comes out of analysed samples taken from the school's soils. The "map" is literally old news, and can be now understood to be grossly in error.
In addition, there have been no reports, as yet, of finding above-standard surface contamination levels on the debris from the tsunami in Fukushima Prefecture. If this trend continues, the Japanese government will have a difficult time trying to justify the evacuation and no-entry orders, in hindsight. Personally, I'm a bit surprised. I did not expect numerous high contamination locations to be commonplace in the 20 km zone, but this is an early indication that even my worst concerns were unfounded. Unfortunately, this is another “good news” story the news media inside and outside Japan have failed to broadcast.
Reactor pressure vessel (RPV) temperatures on Units #1 & 2 slowly continue to decrease, with the bottom heads now reading below 100oC (the Japanese criteria for cold shutdown condition). The temperatures on RPV #3 continue to rise, which TEPCO believes is due to water flow somehow bypassing the RPV or not getting into it at all. They are making preparations for sending water to #3 RPV through an alternative flow path, beginning Thursday. The significant discrepancy between RPV #3 temperature and pressure continues. There also seems to be a possible pressure/temperature discrepancy with RPV #1, but not the same as #3. On #1, the pressures have shown 65 and 145 psi (2 instruments) for weeks, while temperature has fluctuated considerably. If all instruments are reading correctly, this indicates the reactor is full of water, but TEPCO seems to maintain that the fuel cell remains partially uncovered. Either the RPV instruments are faulty or the reactor is full...it cannot be both.
It seems the attempt to fill the primary containment of unit #1, which surrounds the RPV, was stopped several days ago because the monitoring instruments were either malfunctioning or in need of re-calibration. Workers have been going inside reactor building #1 to fix the problem before re-starting water flow into the containment. At the time of this update, TEPCO announced all instruments, including reactor (containment?) water level, have been re-calibrated. The airborne activity levels for the workers is low enough that they can safely work with face masks. Whole body exposure varies between 0.7 and 1.2 mrem/hr. These whole body levels restrict how long a person can stay in the area and work. It seems the effort is literally a tag-team process.
JAIF reports video footage taken inside spent fuel pool (SPF) #3 by a remote camera, attached to a robot arm, reveals significant debris on top of the fuel cells. The debris is definitely due to the hydrogen explosion inside the fifth floor fuel handing area, atop the containment. It appears that any fuel damage must have been caused by the debris. A water sample was taken and analyzed, as well. The isotopic matrix is too-rich in Iodine to have been released from the stored fuel bundles. It is now believed the water's activity is due to unit #3 reactor-based fission products “carried into the water with the debris”. The concentrations match those found in SPF #2, more than a week ago. To date, the early-on speculations of one or more of the SPFs going dry, or partially uncovering fuel clusters, has been effectively disproved for units #2, 3 & 4.
The spraying of dust inhibitor around the plant property seems to be having a considerable mitigating effect on airborne activity levels on-site. All property perimeter monitors show airborne concentrations to be 100 and 1000 times below atmospheric standards. Yet another example of good news not being “newsworthy” enough for the press to broadcast. <sigh>
It seems the Japanese government is in the process of a “takeover” of TEPCO. This is not like your traditional corporate takeover, common to the rest of the business world. Rather, in order for the government to insure the evacuees from Fukushima are fully compensated by Japanese law, the government will have to supply some of the money. TEPCO is in the process of selling off their stock. It appears that the stock sell-off will not cover the legally-mandated compensations. Before any of this happens, the government demands TEPCO streamline its operations and cut costs, except for insuring a stable supply of electricity. It also told the utility to allow an independent panel to study its economic structure for better asset and expense management. (JAIF and Kyodo News)
We can now understand why Prime Minister Kan's regime refused to help TEPCO cover the compensatory costs...control! We have the potential for irreversible harm to everyone in Japan. I fear this may be the first step in a nationalization of all Japanese utilities, where the only winners will be the politicians.
On a more promising note, Asahi Shimbun reports of a major effort to unify the disparate Japanese regulatory agencies charged with nuclear oversight, into one unified body. NISA, NSC, and the nuclear wing of the Health Ministry will be blended into a new, government-sponsored agency. They will use the organizational structure of the American NRC as a model, but unlike the NRC the new agency will work independent of the government itself. This writer agrees with this move, for several reasons. Perhaps the most important is nuclear information flow ought to be through one expert source, vice the events at Fukushima Daiichi where contradictory information was being broadcast by at least four sources at the same time (including the nuclear-inept government). Too many cooks spoiled the stew! Also important is this writer's view that a self-regulating body is far superior to political control.
Hiroshima Syndrome update...
Yesterday's Kyodo News had a one-sentence blurb about “American anti-nuclear activists” claiming nuclear energy cannot ever be safely controlled by humans; one of the paradigms of the prophets of nuclear energy doom. I checked for recent articles, and did considerable Google cross-referencing, before I found two possibilities...Jonathan Schell of the Nation Institute (New York City), and/or Truthdig.com's editor-in-chief Robert Scheer. Both argue that we cannot ever hope to safely control nuclear weapons, therefore we cannot hope to safely control nuclear power plants. The bomb/reactor misconception is clearly at work here. But digging deeper, we find neither did their homework on the development of the bomb. They state nuclear power is a process which was created out of of nuclear weapons, and imply it is also an explosive technology. (which it isn't, of course) They got it backwards. The first reactor, Fermi's Chicago Pile, was started in Dec., 1942. The Manhattan Project came after and, if anything, was the spawn of the reactor...naaah...even that is a stretch. They were developed independent of each other, with the only possible connection being the use of primitive breeders to make Plutonium for the “Fat Man” bomb dropped on Nagasaki.
The airborne activity levels inside Reactor Building #1 have decreased considerably since the six air filtration units have been operating. Workers reopened the building on Sunday and began analyzing the atmosphere with portable air samplers to check on airborne levels, make detailed radiation area scans, and examine the condition of containment water level instruments. This morning, the initial results of area (whole body) radiation levels revealed a general exposure level of 1 REM/hr., with localized “hot spots” of up to 70 REM/hr. TEPCO will use these readings as a planning base-line, and then re-scan after the containment is flooded. While it seems everyone expected a puff of airborne activity to be released when the doors were opened, monitoring devices covering all of the plant property showed no increases at all. It seems the air cleaners have done a good job.
The temperatures and pressures inside the RPVs (reactor pressure vessels) for Units 1 & 2 continue their steady decreasing trend, so TEPCO will continue water “injections” of 8 tons/hr. and 7 tons/hr. respectively. Reactor #1 feedwater nozzle temperature has dropped to 120 oC, where it was before the “injection” flow was fluctuated last week. Temperature indications on the #3 RPV continue to climb, with the feedwater nozzle now at over 200 oC, and the bottom head at >150 oC. However, the #3 RPV pressure indication remains essentially unchanged at below atmospheric. One or both sets of detectors must be malfunctioning. Vapor pressure for ~200 oC is ~235 psi. The obvious disparity ought to be explained.
All Japanese news media report that Strontium isotopes (Sr-89&90) were detected at three on-site sampling points on April 18. The levels warrant workers wearing full face masks when toiling in the areas from where the samples were taken. However, the wearing of full face masks was mandated for the entire power complex at the time, and it still is for many locations. Regardless, this is old news that ought to have been reported weeks ago.
Today, NHK Japan reports NISA and the “Ministry of the Environment” are starting to analyze for surface contamination levels in the 20 km. evacuation zone. This needs to be done before tsunami debris can be removed and recovery can proceed. It seems the debris removal companies have serious concerns about getting their people contaminated. Today ~120 locations will be scanned and sampled.
How bad was the March 11 earthquake? One very telling item has been portions of the Japanese coastline closest to the off-shore epicenter dropping more than a foot. Kyodo News reports one city, Ishinomaki, experiences knee-high waters in their near-shore streets two times a day at high tide. Also, geographic monitors indicate that Tokyo has moved nearly 4 inches west of it's former location. Imagine the incredible forces that can move a huge land mass like Japan with such significant geological after-effects. Further, consider that the earthquake/tsunami had little or no damaging effect on the nuclear power stations on the coast. (It was the loss of power that doomed Fukushima.) The nuclear community has broadcast long and loudly, for decades, that the only buildings built to survive the worst that nature can throw at us, are nuclear power plants! This continues to be correct. Technically, all Japanese nuclear power stations need to have sufficient portable/mobile electric supplies available in order to reasonably avert another Fukushima. This either has been done, or is in the process of being done at all Japanese nuclear facilities. Plus, tsunami-mitigating sea break-walls have been constructed as an added safety factor for many of the Japanese nukes, and are planned for all of the remaining ones. Regardless, political attempts to quell public fear of radiation, and accommodate Hiroshima Syndrome-inspired “concerns”, proceeds undaunted...
On Saturday, May 7, Asahi Shimbun reported Prime Minister Kan was only “suggesting” the shutdown of Hamaoka NPS because he does not have the legal authority to actually order it's closing. His suggestion was due to the hypothetical 87% chance of a severe earthquake occurring sometime over the next 30 years. Kyodo News reports that the Board of Directors at Chubu Electric, Hamaoka's operating company, has taken the Prime Minister's suggestion as an order and decided to comply with Kan's wishes. The Board points out that Hamaoka provides 10% of the region's electricity, and a shutdown might make energy conservation measures (rolling blackouts) necessary this summer. Chubu Electric is also seeking new, additional sources of “thermal fuels” (mostly oil) as a replacement for the nukes. The utility has plans to replace the existing 10-15 meter Hamaoka tsunami sand dune break-wall (more than a mile long) with a concrete one. Steel-reinforced concrete buildings survived the tsunami, so the wall should, too. The utility is in the process of implementing all NISA emergency electricity requirements. Kan wants Hamaoka shut down until all of these jobs are completed. He argues that public concerns and safety must not be “compromised in the slightest”. (What about the reduced level of safety during power shortages?)
NHK Japan reports Kan's move has spawned considerable criticism from some of the major party leaders in the Japanese government. For example, the Secretary General of the Liberal Democratic Party, Nobuteru Ishihara, said he wants to confront the prime minister in the Diet itself, and ask him if he ever considered Japan's overall energy needs before making his statement. NHK also reports nuclear opponents are expected to grill Kan on his decision to close down only Hamaoka, rather than all nukes. However, everyone wants the Prime Minister to explain his vision for how Japan will meet its mid-to-long-term energy needs with such a large power supply removed from the grid for more than a year (to build the new break-wall). Many Diet politicians feel the Prime Minister's move was made “prematurely”.
What nearly no-one seems to consider; some researchers say the Greenland ice sheet has a chance of being gone in as little as 30 years, raising the seawater levels of the world ~23 feet. Shutting down nukes that produce no greenhouse gasses and replacing them with fossil fuels (the only rational alternative) will only speed up the demise of Greenland.
On Sunday, NHK Japan reported on a nuclear protest concerning the Hamaoka NPS. About 1000 attended the protest to demand the utility comply with Kan's shut-down order immediately, dismantle the three operational power plants, and replace them with conservation and renewables. It's “shut them down at all costs”. NHK identified one student attending the rally, who said, “Demonstrators must take responsibility for the consequences of their protests if they're successful.” Amen!
All TEPCO seawater sampling points, at 30 meters, 3 kilometers, 5 km. and 10 km. from the Nuclear Power Station, reveal I-131 and Cs-134/137 concentrations below health standards. All of them. The seas around Fukushima are now “clean”. I have not seen this wonderful news reported by any western or Japanese news media...at least not yet.
NISA reports reactor (RPV) temperatures and pressures for Units 1 & 2 continue to slowly decrease. However, Unit #3 temperatures have shown a significant rise over the past 4 days, with the feedwater nozzle now at 157oC and the bottom vessel head at 144oC. Previously, the vessel head was reported as being hotter than the feed nozzle, but that had now reversed. Also, the indicated pressure in the RPV has dropped to a rather significant vacuum. This makes no sense. The reason(s) for these changes ought to be revealed.
TEPCO has increased the water “injection” flow to RPV #1 from 6 to 8 tons per hour.
Kyodo News and NHK Japan report that workers entered the #1 reactor building at Daiichi for the first time since the initial refueling deck explosion. They each stayed inside ~10 minutes to “install” a “ventilating device” located in the Turbine Building. It sounds like the portable air filtering system reported earlier this week. Air will be “pulled” through the device, “purified”, then returned to the reactor building. This is the first step in reducing worker radiological risk before the work of inspecting and eventually recovering the reactor's designed cooling system piping. It is hoped the building's air will be cleansed sufficiently by Sunday. This morning, TEPCO reports they have six “exhausters” operating.
NHK Japan reports the water cooling system planned for Unit #1 reactor will use a new heat exchanger to be installed outside one of the Reactor Building entrances. The reactor's heated water will flow through internal “tubes” which will be cooled by water outside the tubes from a cooling tower. The cooled reactor water will then return to the reactor vessel (NHK says it's the “containment vessel”, but they seem confused). It is currently estimated that the reactor fuel is producing 1.5 megawatts of decay heat, which seems to be a reasonable number. Regardless, it sounds like a lot of construction and installation must be performed, especially the “cooling tower”, which does not currently exist. TEPCO told NHK they hope this will bring the reactor to less than 100oC in no more than a few days after the system begins operating.
KYODO News reports TEPCO has begun a slow process of filling the primary containment around RPV #1 with water. They will continue until the water level is above the top of the fuel inside the RPV. Once again, it seems they are doing this to provide additional shielding from the radiation field generated from the fuel cell, in the effort to make the work environment safe.
Massachusetts Inst. of Technology (MIT) has put together a world-wide map of nuclear power stations versus earthquakes that have exceeded 7 on the Richter scale (1973-2010). MIT points out that most nuclear plants are far away from any of the earthquake epicenters, except for Japan, eastern Asia, and southwest USA. Other than those three locations, nuclear plants are an average of 785 miles from the epicenters. MIT has posted the map because many people have gotten the idea that all nuclear plants have been cavalierly built on top of severe earthquake faults. Hopefully MIT's effort will be the beginning of the end for that myth. (http://web.mit.edu/nse/)
Prime Minister Nan has ordered the two operating power plants at Hamaoka Nuclear Power Station shut down. One other operational plant was already shut down prior to the earthquake of March 11. Nan says he has ordered this out of concerns of an 8.0 Richter scale quake deemed “likely” for the region (87% probability??). It seems to make no difference that 2 of the BWRs are more than a decade newer than Fukushima Daiichi, with unit number 5 an advanced system rated to be the safest design on the market. It also doesn't seem Kan cares that he's keeping 3,400 Mwe of recovery-needed electricity off the grid. All he cares about is votes (he has a 20% popularity rating) by catering to Hiroshima Syndrome-inspired public fears.
Asahi Shimbun reports that TEPCO is having difficulty in finding nuclear-experienced workers for Fukushima Daiichi. The newspaper makes it sound alarming, but the number of workers has gone up from ~1,000 to more than 1,300 in the past week. It seems a few people have denied jobs at Daiichi, and Asahi is taking the western news media tactic of making a relatively minor situation sound significant.
Birds of a feather...
Now, the prophets of nuclear doom have found a way to “validate” each other. The European Committee on Radiation Risk (ECRR), has rejected their previously reported estimate of a few hundred thousand Chernobyl cancer deaths. It seems that number isn't frightening enough. They have adopted two relatively new, unproven “tools” of assessment...the “Tondel” method and their own, internally-generated concept called the “ECRR Absolute” method. The Tondel method alleges that cancer incidence rises 11% for every kilo-becquerel of Chernobyl fallout per square mile of land surface in Sweden. On the other hand, ECRR Absolute supposedly corrects for ICRP (International Council on Radiation Protection) methods which have “absorbed dose inadequacies”, by assigning arbitrary biological pathway and internal deposition considerations for each radionuclide released into the atmosphere. The two methods each predict ~500,000 Chernobyl cancer deaths happened in the first 10 years after the accident, and ~1 million will occur by 2016. They conclude that after 50 years (2036) there will be 1,400,000 Chernobyl cancer deaths. (http://www.llrc.org/) This number “agrees” with the previously reported cancer death threat by Alexey Yoblokav.
Paradoxically, there is a recent report that cancer death rates have dropped considerably across Europe since 2000. Between 2000 and 2004, the rate dropped ~9% compared to the 5 year period of 1900-04. Further, since 2007, the cancer death rate has dropped another ~7%. What's more, the country with the most significant drop has been Germany! http://www.sciencedaily.com/releases/2011/02/110208202356.htm
Just to place the percentages in perspective, the estimate for 2011 is 1.3 million. One would think, if the above Chernobyl cancer death threats were correct, decreases of this magnitude would not have happened. Further, the country which claims the worst Chernobyl soil contamination (outside Belarus and the Ukraine), Germany, ought to have the worst statistics rather than the best.
Besides being irresponsibly misleading, aren't death threats supposed to be something criminal?