From the ‘Rains it Pours’ department:
Information trickling out of Fukushima Daiichi makes this the data- dump that keeps on giving. Since the weekend news has not been good. The four reactors are a cauldron of ‘broken’ with hellish radiation and extreme temperatures. Evidence suggests that reactions taking place within the reactors are escaping operators’ control:
Figure 1: this video shows significant steam emissions from reactor unit 3 along with what appears to be a fire, either in the adjoining turbine building or reactor 4.
Here are some screenshots of the reactors, from a Japanese news feed:
Figure 2: The immediate environs of the reactors is truly the devil’s playground. The emissions from these plants are intensely radioactive. The containments contains tens of thousands of cubic meters of water which is a witches’ brew of radionuclides, dissolved gases and suspended particles. This so- called ‘water’ releases material onto everything within the containment, much of this material winds up in the atmosphere.
Figure 3: The spike in the emissions of cesium 137 accompanied the smoke/steam in Figures 1 and 2. The dotted line in the chart is the highest level of Cesium 137 emitted from the Chernobyl 2 reactor.
Figure 4: Isotope Iodine 131 has a short half- life of 8.0197 days. The increase in this isotope indicates fission reactions are taking place somewhere inside the reactor buildings.
Keep in mind, TEPCO is pumping 7 or 8 tons of water into each reactor every hour, (Please click on chart for a larger image):
Figure 5: The upper band highlights the water flooding of the reactor containments. A cubic meter of water weights 1,000 kg. or approximately 2,200 lbs. This water has to go somewhere. Some is flooding the basements under the reactor auxiliary buildings and the turbine hall. The rest is leaking into the ground, contaminating groundwater and flowing into the Pacific Ocean.
Notice the bottom highlight indicates a negative pressure within the reactors 2 and 3. This means atmospheric oxygen can enter the containments and combine with any hydrogen being produced as a result of thermolysis or nuclear dissociation.
TEPCO during the first month of the emergency pumped several thousand tons of seawater into the reactors. As the water component boiled away the salt (NaCl) was left behind within the pressure vessels. Adding fresh water has not removed the salt as this has to ‘flow’ in solution to somewhere else. There is no indication that water leaking from the reactors is carrying any salt. This means it is still within the reactors, possibly insulating the reactive fuel from the cooling water.
Ominously, the temperature @ reactor 3 has been rising rapidly for the past week. It is now higher than the design temperature of the reactor and still rising. Unit 3 is the reactor containing the MOX fuel along with more MOX fuel in the building’s spent fuel ‘area’.
Reactor 3 is the source of much of the steam/smoke in the videos.
Here are some temperature and radiation readings from within the three reactor pressure vessels (NISA/Japanese government website. Please click on chart for a larger view:)
Figure 6: Note the high temperature highlighted in reactor 3. The feedwater nozzle is at the bottom of the dry- well, see Figure 7. Presumably, the sensor is several dozen meters higher than the heat source which would be the molten core @ the bottom of the suppression pool.
Here is an Wikipedia image of the identical Browns Ferry Reactor Number 1 under construction. Please click on image for a larger view:
Figure 7: The feedwater nozzle would be the bottom arrow of the core location (a), within the neck of the pressure vessel. The dry- well is the outside of the pressure vessel which is inside the containment. All of this is now presumably under water with the core molten at the very bottom of the reactor containment.
Make note of the intense radiation within the pressure vessels, particularly within the suppression pool (S/C) of reactor 1 and the dry- well (D/W) of reactor 3. The suppression pool is the donut- shaped item in the photo. The radiation monitor indicates a level of over 1 Sv/hr in reactor 1. The radiation level within the upper level of unit 3 pressure vessel is almost 10 Sv/hr. The range of 3-4 Sieverts per- hour is a lethal dose of radiation for half the humans exposed to it.
Here is another temperature chart for the different reactors. There are different monitoring devices in different locations within the reactor buildings. Readings differ depending upon where the sensors are located:
Figure 9: You can see that the temperatures measured by TEPCO are increasing in different parts of the unit 3 reactor. All of the reactors are being flooded by tons of water per hour. What is likely taking place is the core materials are liquid. They are reconfiguring into critical masses. Enough moderating material exists within the corium to increase neutron flux. This flux splits more fuel atoms and a chain reaction takes place.
The reactions are the source of both the short- lived Iodine 131 and the increase in reactor temperatures.
At issue is when will the self- sustaining reactions begin to amplify themselves. The temperatures in the reactors are increasing exponentially. The reactivity coefficient of the core material is now positive. Reactivity depends on fuel density, temperature, flux and core configuration. As temperatures increase, the power emitted by the core materials also increases. Temperatures increase causing reactivity to increase in a positive feedback loop. The fuel becomes hotter, more dense and more reactive.
The outcome of self- amplification will be a prompt criticality event. This could take place next week or five minutes from now. This will take place alongside — or in place of — powerful steam explosions. The water pumped into the reactors currently does not cool the core material. This likely the result of pumping seawater into the containments: salt ‘crust’ is insulating the hot fuel from the water. At the same time, molten material from the core construction may be acting as a neutron moderator, increasing reactivity.
The hoped- for outcome would be for the reaction coefficient to spontaneously return to negative. There is little else reactor operators can do to reduce temperatures within the pressure vessels. They are currently injecting eight or nine tons of water into the buildings right now. Adding more water will not work.
The spent fuel pools that exist intact on top of the reactor buildings are hostage to the conditions that exist in the buildings’ basements. Pressures within the reactor pressure vessels are atmospheric or less, there is no effective containment for any of the nuclear material on the site.
An outcome is that molten core material can explosively reconfigure itself. The hot dense fuel would blow itself apart blasting the pressure vessels out of the containments while spewing core remnants into the atmosphere. The water within the containments would be the ‘fuel’ for steam explosions.
Nuclear expert Arnold Gunderson suggested last month that a prompt criticality in the spent fuel pool was responsible for the explosion in unit 3 in March. While current information about the the unit 3 spent fuel pool questions a prompt criticality analysis, the explosive power of such an incident is considerable. The explosion and fire at Chernobyl nuclear plant was also a prompt criticality amplified by a steam explosion.
There are multiple cores within spent fuel pools at the top of the reactor. The the core material in reactor 3 contains both Uranium and Plutonium. If the core reconfigures explosively the complex will be unapproachable due to massive, intense radiation contamination in the area of the reactor.
There is possible criticality taking place within the fuel pools as well. Large amounts of Iodine 131 have been sampled in the pool of unit 3. The presence of radioisotopes during tests last month suggest damage to fuel and criticality in the pools of units 2 and 4 as well.
Considering the radiation loads and the exponential increase in temperatures within the buildings, TEPCO’s ‘scheme’ to jury- rig replacement primary cooling systems out of items bought on Ebay within the three reactors and the multiple spent- fuel pools is an absolute farce.
Here is information that the building that contains unit 4 is leaning suggesting that it might collapse:
Figure 10: Unit 4 contains several cores in its damaged spent fuel pools. A building collapse would “scatter” radioactive material across the site. The containment is contaminated as well: should the building fail, the containment material would also spread far and wide. The Zircalloy fuel cladding on the fuel rods would burn. It is possible that some of this fuel rod cladding is already catching fire as water leaks out of the spent fuel pool.
Water leaking out of the pool has to go somewhere: the basements of unit 4 and associated buildings are being filled with contaminated water.
Any one or a combination of events taking place would require evacuation of the entire complex along with the surrounding countryside.
If reactor 3 is destroyed, there will be nothing to prevent core material within reactors 1 and 2 from also reconfiguring themselves explosively.
It is possible that the train of events leading to explosive prompt criticality is already underway @ the three reactors. The activity taking place within all of the reactors must be taken seriously by TEPCO operators as well as nuclear agencies worldwide. If steps are not taken the outcome is three or more Chernobyl- type eruptions of radioactive materials taking place at the same time!
Instead of water, sand and boron needs to be pumped into the containments. Whatever it costs to perform this step, it must be paid. Japan needs to realize there is no time to lose. At any exponential rate, the doubling time decreases: the temperature rise will not continue to increase to infinity, one or more reactors will blow up first.
Meanwhile, TEPCO’s attempt to filter the air within unit 1 unsurprisingly failed. A few blowers and fans are not going to effect the overall radiation level of a containment building containing over a thousand tons of radioactive materials.
Opening the containment to install the ventilators and ‘check’ the radiation levels within the containment allowed more radiation to escape into the environment, for absolutely no gain.
Japan detects radiation up to 700 milliserverts at Fukushima nuke plant(Xinhua)
TOKYO, May 9 (Xinhua) — Tokyo Electric Power Co. (TEPCO) on Monday detected radiation levels in the building housing the faltering No. 1 reactor that far exceeded expected levels reaching as high as 700 millisieverts per hour, the utility firm said.
The latest readings for the troubled reactor has lead Japan’s Nuclear and Industrial Safety Agency to embark on new radiation shielding measures so that work to bring the crisis under control can go ahead with risks of massive doses of deadly radiation poisoning hopefully being lessened for the TEPCO workers and their affiliates as they attempt to embark on a massive project to install a nuclear fuel cooling system.
TEPCO is currently mulling ideas to protect its workers — some who have only had a single medical check since the March 11 triple disasters and many who have been exposed to levels of radiation far exceeded legal levels — such as constructing a metal tunnel for people to walk through, or using lead sheeting to provide increased protection against radioactive substances and increase safer mobility for the workers moving around in high-radiation areas.
An area with a double-digit millisievert level, let alone three-digit figures, is quite tough as a working environment. So we have to do the work by using some shielding,” Hidehiko Nishiyama, a spokesman for the Nuclear and Industrial Safety Agency, told a press conference.
TEPCO and the Japanese government have been behind the curve since this accident took place. Both the company’s- and government’s approach have been nothing short of criminal. The establishment has embraced the concept that nuclear disasters can ‘heal’ themselves. Instead of an all- out assault on the reactors, there are media blackouts and public relations stunts. Instead of dropping everything else in the country except tsunami search and recovery and marshaling all resources the contain the radioactivity within the Fukushima complex there is hand wringing. The establishment has been toying with the reactors.
The reactors are making ready to punch Japan in the face as hard as physics makes possible.
The situation at the complex is spiraling out of control.A very large increase in the amounts of radiation released into the environment is going to take place. TEPCO’s only tactic from the beginning of this disaster has been to inject water along with ‘hopium’ into the reactors. The time for a ‘Plan B’ has slipped away as a consequence.
The amount of radioactive material @ Fukushima Daiichi is several times the amount in Chernobyl unit 2 when it was destroyed. You can come to your own conclusions about the consequences.
It is time to start mentally preparing for the worst.
UPDATE:
Japanese physicist acknowledges criticality in reactor unit 1 post- tsunami.
TEPCO successfully ‘recalibrated’ its temperature gauge in reactor unit 3 as the temperature indicated has dropped sharply. Meanwhile, the temps in other gauges in reactor unit 3 are still climbing.
Temperatures in reactor unit 1 can be found here, unit 2 can be found here. I don’t want to give the impression that all three reactors are overheating, only reactor unit 3. Temperatures are slowly falling in reactor units 1 and 2 … as they should as decay heat diminishes. This does not mean that re- criticality is not or cannot take place within these reactor units. Criticality may also take place within the spent fuel pools.