What would happen if an energy storage device failed?

KitemanSA · Post by **KitemanSA** » Wed Nov 16, 2011 2:23 pm

I wrote:
bk78 wrote:I think we are discussing 2 different things here.
For a dedicated energy storage device, quenches are a serious issue. In the 70s, they planned devices with several 100m diameter, for storage of some 10 TWh, so a quench could release the energy of a small atomic bomb.
For superconductors that are not meant for energy storage but to produce a magnetic field, i have to agree Josef, this is not an unsolvable problem (although i disagree that the energy is evenly heating the whole magnet. Instead of 17 degrees increase for the whole structure, it could be 1700 degrees for 1% of it). They can be built to release the energy safely. The quench-videos on youtube actually demonstrate this, they are doing as they were designed to. The magnets for a fusion reactor could be pumped separately, evaporation of helium and a overpressure ventile might already be sufficient. There will be repairs, it may cost a bit to have the reactor offline for a few days, but there will certainly not be a real hazard for people.
But if you have one of these 10TWhr units and a terrorist comes along and shoots a shaped charge missile at it, and the shaped charge penetrates across the worst case number of strands of the SC magnet, what will happen to all that energy? KaBOOM, no?

Does anyone have anything to say?

ladajo · Post by **ladajo** » Wed Nov 16, 2011 2:31 pm

Boom?

KitemanSA · Post by **KitemanSA** » Wed Nov 16, 2011 3:42 pm

ladajo wrote:Boom?

So you are on the kaboom side. Anyone else?

mdeminico · Post by **mdeminico** » Wed Nov 16, 2011 3:46 pm

KitemanSA wrote:
ladajo wrote:Boom?
So you are on the kaboom side. Anyone else?

That's what my point was.

Worst case, if someone blows the whole gig simultaneously, and all the rings become shattered instantly... boom?

Now the likelihood of that happening is probably low, but still. If it happens over a matter of microseconds, big boom. If it happens over the course of 5 seconds, big heat in one area.

Skipjack · Post by **Skipjack** » Wed Nov 16, 2011 6:14 pm

I say it make a kaboom, but only a small one. Orders of magnitude smaller than some here claim.

Joseph Chikva · Post by **Joseph Chikva** » Wed Nov 16, 2011 7:34 pm

mdeminico wrote:
KitemanSA wrote:
ladajo wrote:Boom?
So you are on the kaboom side. Anyone else?
That's what my point was.

Worst case, if someone blows the whole gig simultaneously, and all the rings become shattered instantly... boom?

Now the likelihood of that happening is probably low, but still. If it happens over a matter of microseconds, big boom. If it happens over the course of 5 seconds, big heat in one area.

Transient processes in so high inductance have milliseconds order. And pole will not help. As processes are not dependent on myths in which Kiteman or any other believe. Nobody here speaks about nature (form) in which that energy can be released. There will be self-inductive current heating conductor in which that flows. On 17 deg by my estimation in ITER's toroidal coils case.

Alchemist · Post by **Alchemist** » Wed Nov 16, 2011 10:35 pm

Correct me if I am wrong, but if you have a a superconducting ring storing say 100 TWh of energy and some catastrophic even comes along and in the matter of a few milliseconds shatters that ring I would think that the magnetic flux would immediately begin expanding out since there is no longer any material to contain it, plus the individual particles of superconducting dust in the air are going to become semiconducting at the very least. You'll also likely have a rapidly expanding plasma ring of ionized air or some noble gas coolant.

What I'm basically saying is that yes there, will be some sort of explosion very similar to what happens in a lightning strike, plus secondary explosions from the cryo systems rupturing. Then on top of all that you'll have a MASSIVE EMP to deal with. The EMP will likely be the most financially destructive component of the whole failure even if it was the least physically destructive portion.

KitemanSA · Post by **KitemanSA** » Thu Nov 17, 2011 2:56 am

Skipjack wrote:I say it make a kaboom, but only a small one. Orders of magnitude smaller than some here claim.

My statement included the assumption of 10TWhr that bk78 made. This equals 36E15 Joules if my mental math is up to snuff. Given that high explosive is about 5MJ/kg IIRC, this would be ~7.2E9 kg of HE. This is 7.2 megatonnes. This is not a small amount of explosive, unless a vast majority of the energy disappears. Still say "small one"?

I suspect we are talking different machines.

KitemanSA · Post by **KitemanSA** » Thu Nov 17, 2011 2:58 am

mdeminico wrote:
KitemanSA wrote:
ladajo wrote:Boom?
So you are on the kaboom side. Anyone else?
That's what my point was.

Worst case, if someone blows the whole gig simultaneously, and all the rings become shattered instantly... boom?

Now the likelihood of that happening is probably low, but still. If it happens over a matter of microseconds, big boom. If it happens over the course of 5 seconds, big heat in one area.

Given my response above, even if the 7.2megatonnes equivalent of high explosive takes 5 second to go off, STILL no boom?

Joseph Chikva · Post by **Joseph Chikva** » Thu Nov 17, 2011 3:45 am

KitemanSA wrote:Given my response above, even if the 7.2megatonnes equivalent of high explosive takes 5 second to go off, STILL no boom?

"High explosive in 5 second" is nonsense phrase as high explosive unlike others is a compound generating shock wave. Order of magnitude of propagation velocity of that wave 7000 m/s. So, 35 km linear dimension. If you say "7.22megatonnes TNT equivalent" by energy, this corresponds to ~3.5E15J of stored energy. In ITER's site energy stored in toroidal field estimated as 41GJ=4.1E10J or in 85.3 thousand times lower.
This energy converts in transient oscilation of current with dissipation mechanism of ohmic heating, increasing the temperature of copper matrix weighing 365 tons on 17 deg K. This is not boom or kaboom.

DeltaV · Post by **DeltaV** » Thu Nov 17, 2011 5:29 am

I think this question is resolved by looking at the historical data:
Local Inventor Laments Loss of Backyard Fusion Reactor

KitemanSA · Post by **KitemanSA** » Thu Nov 17, 2011 1:52 pm

DeltaV wrote:I think this question is resolved by looking at the historical data:
Local Inventor Laments Loss of Backyard Fusion Reactor

Wish we had a REAL picture, might be more spectacular than this!

KitemanSA · Post by **KitemanSA** » Thu Nov 17, 2011 1:54 pm

Joseph Chikva wrote:
KitemanSA wrote:Given my response above, even if the 7.2megatonnes equivalent of high explosive takes 5 second to go off, STILL no boom?
"High explosive in 5 second" is nonsense phrase as high explosive unlike others is a compound generating shock wave. Order of magnitude of propagation velocity of that wave 7000 m/s. So, 35 km linear dimension. If you say "7.22megatonnes TNT equivalent" by energy, this corresponds to ~3.5E15J of stored energy. In ITER's site energy stored in toroidal field estimated as 41GJ=4.1E10J or in 85.3 thousand times lower.
This energy converts in transient oscilation of current with dissipation mechanism of ohmic heating, increasing the temperature of copper matrix weighing 365 tons on 17 deg K. This is not boom or kaboom.

Joe, keep up. you are falling behind and looking like an idiot.

Skipjack · Post by **Skipjack** » Thu Nov 17, 2011 3:31 pm

This is 7.2 megatonnes. This is not a small amount of explosive, unless a vast majority of the energy disappears. Still say "small one"?

It is utter nonsense.
For explosives we are talking the release of the energy at once in microseconds, or at least milliseconds. That is orders of magnitude less than 5 seconds.
Then do the math from there...
I am totally siding with Joseph here. He is the only one who gets it.

ladajo · Post by **ladajo** » Thu Nov 17, 2011 4:00 pm

http://en.wikipedia.org/wiki/Table_of_e ... velocities

and

http://en.wikipedia.org/wiki/Brisance

The other factor impacting effectiveness is whether the charge is contained or uncontained. This affects the time to peak as well as the the effects range of peak.

The point of discussion regarding mag field collapses to destructive capacity is truly a function of mode of collapse, means of collapse, and obviously stored potential.
I think it is silly to argue in absolute, it will go boom, or it will not go boom. It is very circumstantial, and you could fail a device to not go boom, just like you could fail one to go boom.
Well engineered devices seek to have graceful failures, and failure containment. this could be a rapid fail but using a means that can control and contain. Or, it oculd be engineered to have a slow fail, via a less robust means. It is always about the clock and the dollars.
Good, Fast, Cheap. Pick two.

The basic point that I see, no matter how you concentrate a high amount of energy, once concentrated it becomes something to worry about. It will seek "ground" via the fastest and most convienent method it can find. I does not just "dissapate" into nothing via nothing. Energy can neither be created nor destroyed...

I have personally witnessed many large magnetic fields (stored energy) collapse in an uncontrolled manner, create spectacular plasma balls using any convenient material at hand, and generate explosive shockwaves doing so. Arguing that this can not happen is just plain silly.
Arguing that it can be managed, is not silly, and in fact the core point to high energy electrical systems design. For example, High Voltage Heavy Duty Breakers without Arc Chutes would be useless and dangerous.