Posted on 02/07/2012 5:36:50 AM PST by TigerLikesRooster
Temperature remains high at damaged reactor
An unknown rise in temperature at one of the reactors at the damaged Fukushima nuclear plant is troubling its operator. Tokyo Electric says the temperature hasn't gone down even after it increased the volume of cooling water on Tuesday.
One of the thermometers at the bottom of reactor No. 2 at the Fukushima Daiichi plant gradually rose to about 70 degrees Celsius since January 27th. It had stayed around 45 degrees before.
In an effort to lower the temperature, the operator increased the amount of water sprayed on the nuclear fuel by 3 tons to 13.5 tons per hour Tuesday morning.
But Tokyo Electric said readings were down only about 3 degrees after some 5 hours of operation, hardly showing signs of improvement.
The utility said the flow of water in the reactor may have changed after plumbing work in late January, causing difficulties in cooling part of the melted nuclear fuel.
It added that no temperature rise has been observed at 2 other thermometers in the same reactor and that it will continue to carefully monitor the reactor.
TEPCO has been unable to visually confirm conditions inside the reactors since the nuclear disaster last March because of high radiation.
Tuesday, February 07, 2012 13:05 +0900 (JST)
While individual nuclear reactions can release significant energy at the atomic scale, you need a lot of them occurring in the same place over a short time period to get significant energy production at the macroscopic level. This was the basis of chain reaction theory developed by Meitner, Fermi and others in the 1930s. As discussed above, there is no credible evidence that uncontrolled criticality has occurred in the damaged cores.
If you're alluding to quantum effects, things like tunneling and so forth, you really need to do a calculation that relates to the probability of those things happening with the particles that are interacting. That quantity, called the expectation value, is vanishingly small for classical particles interacting at energies in the tens or hundreds of MeV range.
Aside from that, I must admit I don't know what you mean by "windows of opportunity".
Certainly some of the red-hot radioactive waste with short half-lives has to be doing something.
It was. It was decaying, releasing energy, some of which showed up eventually as thermal energy which produced other effects, fuel damage, hydrogen evolution, etc. All of this is well-known and understood from decades (going back to the 1950s) of studying the likely evolution of LWR core accidents. The thermal energy released in decay heat, while producing chemical effects and changes in the state of materials, was insufficient to approach the unification energy for the electroweak force, certainly insufficient to initiate even random fusion events. If you don't have the energy, those things simply don't happen.
Can't we assume some criticality based on temperatures going up under circumstances of massive water infusion?
You can assume it, but it is likely an incorrect assumption. Criticality would manifest itself in ways other than just heat production, and those manifestations would be more immediately detectable than the thermal effects. IOW, you're going to get radiation effects a lot sooner than you are thermal effects. And there has been no evidence of these characteristic radiation effects.
Thanks for sharing - interesting discussion...
Thank you. Good questions asked by all.
Some recnt info:
http://physicsforums.com/showthread.php?t=480200&page=768
“http://www3.nhk.or.jp/news/genpatsu-...207/index.html The core spray system flow rate was increased by 3 tons/hour at around 4 AM on 7 February. Total flow rate: 13.5 tons/hour. Tepco is surveying with deep care the effects of the flow rate increase over the next 24 hours or so.
http://www.nikkei.com/news/headline/...E0E2E2E2E2E2E2 :
7 February 08:00 : 71.4°C
7 February 10:00 : 69°C
http://www.nikkei.com/news/headline/...E09180EAE2E2E2 :
7 February 13:00 : 71.5°C
No xenon was detected on 7 February.
http://sankei.jp.msn.com/science/new...4230004-n1.htm
7 February 17:00 : 68.5°C (and the other two thermometers have dropped to around 41°C)
http://www.tokyo-np.co.jp/article/na...702000039.html The core spray system had been interrupted for 6 hours on 26 January in order to change a pump. Tepco says the way the water is flowing might have changed at that time, no longer reaching the areas close to the fuel as well as before. Institute of Applied Energy department head Masanori Naito said some fuel might have fallen into the RPV bottom and formed a small heap.”
Sounds like the one thermocouple may have been damaged. I mounted an experiment in the ATR and one of the thermocouples showed significant drift compared to the others. I think it was a radiation effect on the thermocouple junction, although we never did any PIE to precisely determine that.
Well!
As a former factory tech that info makes me think it was shifting debris.
Typically, when we did something-like remove that pump- whatever changes was caused by what we did... somehow!
Thermocouples I’m familiar with are easily changed out .
Though there could be concern that the well is punctured- or some other issue- could prevent it here of course (seems a simple task for a robot if radiation is the problem).
.
Then, finally, the rogue waves were found, and they weren't as rogue as once thought ~ in fact, they are quite predictable ~ today we have computers analyzing satellite images to see if they are out and about.
What a change.
Now, keep that mind as we revisit your statement about ".... That quantity, called the expectation value, is vanishingly small for classical particles ....." ~ no doubt you've had to think about this in the past so what is the explanation for classical wave forms? (understanding that all those particles are themselves waves of some kind, and in various manners linked together).
Can we change the functions that create the columbe barrier in virtually any wave form? Or are we simply stuck with condensed states of matter as suggested by Widom and Larsen?
Seems to me that if we can sink a large ship with simple wave functions we should be able to stuff a proton or two inside a hydrogen nucleus, right?
As far as "stuffing protons inside a hydrogen nucleus", remember that a hydrogen nucleus in its most common form is simply a proton, so the "stuffing into a nucleus" becomes more a problem of simply joining another particle. This is difficult with a charged particle like another proton, but it can be done if you have enough energy. Fusion reactions that are done in things like tokamaks and the older-style stellators used D-D or D-T reactions. I used to run D-D reactions all the time in a simple linear accelerator when I was a physics student. It was a source of relatively energetic neutrons. We also ran D-T reactions with a tritiated target and a deuteron beam. That produces 14 MeV neutrons. The simplest nucleus beyond hydrogen is the deuteron, wherein a neutron is "joined" to a proton. It is just barely stable. A little bit of added energy (relatively speaking) will separate them.
As far as I know the source range and intermediate range neutron monitors at all of the reactors are functional at least with enough redundancy to be able to check for low-level neutron emissions. That is how some of the initial hysterical reports of uncontrolled criticality (i.e., "blue lights", neutron "beams") were debunked. There was absolutely no indication of neutron events near the reactor pressure vessels or the spent fuel pools.
Rogue waves were found to be both identifiable and predictable through the simple expedient of watching for them from satellites orbiting the Earth.
Distance effectively reduces the scale so the quantum effects become visible ~ to wit, the towering rogue wave standing out among its brethren.
A similar approach resolved the orbit problem associated with Mercury.
The math should apply to matter manifest as waves!
Ocean waves are explainable in terms of classical fluid mechanics. Even the appearance of "rogue waves" is simply a manifestation of the superposition principle for classic wave theory. No appeal to quantum mechanics or general relativity is necessary. It's a problem a first-year physics student can solve using vector calculus.
The wave-particle duality of matter is well known, but the effects are only noticeable on the quantum scale. Application of the de Broglie wavelength, for example, to macroscopic particles, like pieces of matter, baseballs, boulders rolling downhill, planets in orbits, gives ridiculous results. Try it sometime. Calculate, for example, the de Broglie wavelength of a bowling ball thrown down an alley. Assume a normal bowling ball of 4 kg, and a velocity of 1.5 meters/second. You'll never be able to detect that wavelength. You're better off using Newtonian mechanics.
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