Posted: Sat Nov 19, 2011 6:13 pm
Deleted, see next post.
Dan Tibbets
Dan Tibbets
a discussion forum for Polywell fusion
https://talk-polywell.org/bb/
Actually you are wrong concerning BP. Concerning the Texas refinery explosion and fire a few years ago. Aside from stupid operational decisions, they had planed costs of the plant with certain conditions. One was that they assigned a monetary value to the workers lives. The had a limit where if making the system safer cost more than ~ 1.5 to 3 million dollars per worker, then it was financially reasonable to avoid this cost. After the accident, and the ongoing lawsuits, I suspect this attitude is regretted, but I doubt their policies have changed much other than perhaps better hiding of the decision process.Joseph Chikva wrote:I think that in developed country such as USA or Japan, etc. each occurred death is very very costly for BP or any other company e.g. TEPCO....D Tibbets wrote:The real question is not if a few people will be killed (BP cared little about that aspect in their Texas refinery), but the cost of the accident.
The hypothetical safety measures that would prevent the hypothetical explosive release of said hypothetical energy if a hypothetical terrorist shoots a hypothetic shaped charge thru the hypothetical device would hypothetically be several instead of one.Please describe, hypothetically, a safety measure that would prevent the explosive release of said hypothetical energy if a hypothetical terrorist shoots a hypothetic shaped charge thru the hypothetical device.
Joseph Chikva wrote: Energy releases in milliseconds vs. nano or microseconds in high explosive case (1000-1000000 times slower), energy released in heat form by the current oscillating in resistive matrix of superconducting cable. That energy is enough only for heating of that matrix only on 17 deg K. Not enough?
Yes, energy appears at the break or at any switching off. Then we have transient process. And do you know that alternate electric current flows through the dielectric (read e.g. capacitor)? And in considering here case ITER's SC cable weighing 365 t (or real numbers) there is not any other way that energy will not transfer in the heat form.KitemanSA wrote:Absolutely not. The heat does NOT appear evenly throughout the matrix. It appears at the break. And that is enough to make the material at the break go KABOOM!
The links that ladajo provided abonve show the result of a measily 1MJ (ONE mega joule) of energy dumping across a gap. That kind of EXPLOSION (read kaboom) kills many people a year around the world. Dumping TJ (Tera Joules) across gap would be a bigger kaboom.
Actually, TJ is WAY too small. 10TWHr = 36000TJ = 36 PJ (peta Joules)
Please, show me such supplers who hates TOKAMAK. As I am sure that any supplier of custom design electric components will then include ITER with the pride into their reference-list (past projects).D Tibbets wrote: I have heard repeatedly that electrical providers hate the Tokamak for these reasons. It is just too big for practical application.
Lets estimate together.D Tibbets wrote:But, you say, the rate of the explosion is slower and this greatly mitigates the blast. True, but there are two adjustments. How much slower?
"European Atomic Energy Commission disperses EU Butter Mountain in ITER Tokamak" - that sounds not so much dangerous as downright messy to me JCJoseph Chikva wrote:....
Now please describe the same for Inductive Energy Storage or Tokamak as 41GJ of energy is also equivalently to 1.36 t of butter.
I did not say that it is not dangerous. But the following statement of Dr. Bussard does not correspond to true:rcain wrote:"European Atomic Energy Commission disperses EU Butter Mountain in ITER Tokamak" - that sounds not so much dangerous as downright messy to me JC
(though perversely not far from the truth of recent EU/ITER news).
Where he saw "Typically stored energy in large scale superconducting magnetic fusion systems; e.g. large tokamaks; is of the order of 10^12 joules" in the beginning of 90s? If ITER - the largest TOKAMAK will have only 25 times lower stored and 25 years after.However, many magnetic fusion power systems, especially those using large fields over large volumes, have been designed to use superconducting magnets in order to reduce drive power requirements and thus improve system power balances. In such systems, coil failures can cause the stored magnetic energy to be dumped precipitously as ohmic heating in “normal going” superconductor coils, potentially leading to coil material meltdown. If the coil inductance is; or becomes suciently small during failure, this can even result in quasiexplosive vaporization of coil material. The stored magnetic energy in such systems is thus a very large hazard and potential source of
system catastrophe. Typically stored energy in large scale superconducting magnetic fusion systems; e.g. large tokamaks; is of the order of 10^12 joules;10^6 MJ; 4 MJ is equivalent to energy content of 1 kg of high explosive.
He was not referring to an experimental or existing machine, he was probably referring to the operational parameters of some of the designs for commercial working Tokamaks of the 90's.Joseph Chikva wrote:Where he saw "Typically stored energy in large scale superconducting magnetic fusion systems; e.g. large tokamaks; is of the order of 10^12 joules" in the beginning of 90s? If ITER - the largest TOKAMAK will have only 25 times lower stored and 25 years after.
Because an uniform increase of temperature over all the mass of the reactor will require an uniform and instantaneous failure over all the superconducting medium, while in fact we know this type of accidents are normally localized, so there is little to no chance that a spot of material can handle all that energy without vaporizing. Just remember what happened in the LHC.Joseph Chikva wrote:Why "the stored magnetic energy to be dumped precipitously as ohmic heating in “normal going” superconductor coils, potentially leading to coil material meltdown" if that coil material will have enough heat capacity to be not molten?
Why "quasiexplosive vaporization" and not temperature increase on several tens Kelvins?
I need not to spend time for learning 90s or earlier or later projects.Giorgio wrote:If we spend some time looking we might even identify to what particular design he was referring, but I really do not see the need to do that.
We have not supeconducting medium but have thin superconducting elements (filaments or how they called in English) in resistive but well conductive medium. As I know that medium is copper matrix. Why not uniformity?Giorgio wrote:Because an uniform increase of temperature over all the mass of the reactor will require an uniform and instantaneous failure over all the superconducting medium
Real (failures) explosions of pressure vessels e.g. steam boilers taught us how to make them more safe. And now we are not bothering about pressure. On the contrary, every newer design of steam turbine uses higher parameters of steam: temperature & pressure.ladajo wrote:Whereas real failures tend to be local events,...
Seems your answer amounts to "you can't so don't build it". Well mdeminico, that is the answer afforded by skipjack.Skipjack wrote:The hypothetical safety measures that would prevent the hypothetical explosive release of said hypothetical energy if a hypothetical terrorist shoots a hypothetic shaped charge thru the hypothetical device would hypothetically be several instead of one.Please describe, hypothetically, a safety measure that would prevent the explosive release of said hypothetical energy if a hypothetical terrorist shoots a hypothetic shaped charge thru the hypothetical device.
Hypothetically, one could split up such a hypothetical energy storage device in several smaller hypothetical devices that are separated by hypothetical armor, or other means of hypothetically preventing any hypothetical bullets or other hypothetical devices from penetrating all of the hypothetical energy storage devices at once.
This should, hypothetically, keep the size of the hypothetically resulting explosion small enough that it can be contained to a small part of this hypothetical energy storage plant.
First let's consider the case when superconducting condition losses via neutron flux.ladajo wrote:Joseph, the point is that the failure starts at the point of weakness for the energy boundary.
I think that if you put the wire into the plug, result would not be pleasant.KitemanSA wrote:Seems your answer amounts to "you can't so don't build it". Well mdeminico, that is the answer afforded by skipjack.
I figured if prodded hard enough we might actually get an answer fronm one of them .