Fusion reactor overload?

[Trent]

I was wondering if it would be possible to deliberately overload a fusion reactor in traveller to produce an explosion. I know, from T4 if it was canon, that most civilian stuff uses "fusion+", a cold fusion process that' safe, but I've heard some applications use a "hot fusion" process that is more dangerous but more powerful.

I was thinking of a process designed to blow up a military ship rather than let it fall into enemy hands. It would involve running more fuel into the reactor to create a more powerful fusion reaction in the containment, and channeling all power into the containment field to keep the fusing core intact until it reached a level sufficient to vape the whole ship.

I was wondering if this was possible/canon in traveller.

 

[jfetters]

Well, the thing that jumps out at me is the whole "black globe overload" scenario. It's not quite what you are looking for, but close.

It should be one of those things you can get away with using some technobabble - "the coolant system has malfunctioned and the fusion reactor is overheating! We have five minutes until it reaches critical mass! Blah blah blah..."

I guess it is kind of how I envisioned the "vaporized" damage category in ship combat - you get a lucky shot that hits the power plant which overloads and destroys the entire ship.

 

[Trent]

Well, the thing that jumps out at me is the whole "black globe overload" scenario. It's not quite what you are looking for, but close.

It should be one of those things you can get away with using some technobabble - "the coolant system has malfunctioned and the fusion reactor is overheating! We have five minutes until it reaches critical mass! Blah blah blah..."

I guess it is kind of how I envisioned the "vaporized" damage category in ship combat - you get a lucky shot that hits the power plant which overloads and destroys the entire ship.

Well, I was kind of going with something more technically plausible here. I think a lot of this "the reactor's gonna blow!" is pure bullshit from a technical viewpoint. I mean, the fusion reactor gets a stream of fusionable matter, like hydrogen, deuterium, He3, whatever. As long as the stream remains constant then the power output must remain constant as the reactor can't pull power out of nothing.

So to get an "overload" you're going to have to funnel more fuel into it, to get it to produce more than normal energy levels.

Then the containment field usually is meant to contain a certain amount of force, if it increases then the increase would likely melt/vape the interior of the reactor, which should stop the reaction as the containment, initiators, etc, are melted.

As to a reactor exploding, maybe if it was containing a truly huge amount of force, like a on e megaton fusion bomb detonating power level, and the containment failed or was breached, it could release it in an explosive burst but that wouldn't be an "overload", and as to "containment failing in 5 minutes!" well if you had a backup power supply to run the containment if main power fialed that might have a limited life, but in the first place if the reactor's running can't it's power be used to run the containment, and if not and the backup containment powersource has only 5 minutes of juice, maybe you could simply stop feeding fuel into the reactor, even if it meant manually disconnecting the lines?

All in all the classic "exploding reactor" is BS, but I was wondering about a deliberate effort to make one explode thru steps like feeding in more fuel, using the extra energy to strengthen the containment until the levels of force in the reactor matched a nuclear warhead detonation, then releasing the containment. BOOM! But again, this would be a deliberate act carried out
with thought, not an accident.

 

[Doyle Hunt]

Liquid hydrogen converted to a gaseous state, even without being heated to plasma temperatures, has a coefficient of expansion of about 700 to 1 (one cubic meter of liquid hydrogen is roughtly equal to 700 cubic meters of gaseous hydrogen at 1 atmosphere.

So, if you lose containment, and the hydrogen feed doen't immediately shut off, here's what I expect would happen, not necessarily in chronological order:
1) The fusion reaction stops immediately as soon as the containment bottle is gone. There's not enough hydrogen inside the reactor to allow fusion to be self-sustaining without the containment.
2) The liquid hydrogen being fed to the reactor expands fast enough due to exposure to the superheated plasma to mimic an explosion. There would be tremendous overpressure almost instantaneously throughout the engineering spaces and any contiguous volume not isolated by bulkheads and iris valves. Everyone inside the engineering spaces is killed instantly, unless wearing hostile environment suits. Note that there's not enough oxygen in the ship's atmosphere to actually burn that much hydrogen. There's no actual fire, just tremendous heat.
3) The ship does not explode, but it may develop pressure leaks in the engineering spaces as welded seams in the hull are stressed beyond their ultimate strength. This is a good thing, because those with enough patience might eventually be able to enter the engineering spaces after it vents to vacuum, to begin assessing the damage.
4) Everyone else aboard ship would be deafened by the incredibly loud BANG as the sudden overpressure of expanding hydrogen causes the engineering spaces to ring like a bell.

Just my opinion. Your opinion may vary.

 

[whartung]

Well, in a simple word "No."

I can't explain the tech, maybe the containment field "leaks" before enough force for this to happen occurs, or something else.

Simply put, it should be very remote, if not impossible to even do this on purpose with a stock, everyday, fusion plant.

Fusion is cheap and "safe", or we wouldn't have it in everything from jeeps to starships.

Consider something as extreme as a grav tank. When things can go wrong, they will go wrong in military equipment, particularly in combat. If every tank in the troop is a potential megaton blast due to a lucky shot frying the crew and some select portion of electronics, I don't think anyone would feel comfortable deploying them. The fratricide issue of it taking out the entire troop, plus perhaps the escorting infantry is secondary to what might happen in a populated area with civilians.

If every fusion plant were a potential fusion bomb, hoo boy -- look at the terrorism potential we give to bottles of water and a pair of shoes right now. It's bad enough suggesting some "disgruntled party" can fly ships in to solid targets, but add in the ability to convert a stolen air/raft in to a nuclear truck bomb to set off in the market place??

umm..no. Hell No...uh uh.

No, fusion power is as safe as "Mr. Fusion" and immune from critical "and in traffic today, downtown went up again in a bright flash leaving the city center glazed glass and only 150,000 estimated casualties. Authorities suspect a fender bender between a taxi and a delivery sled according to video feeds before the blast." fault issues, or it's not going to be deployed ubiquitously like it seems to be within the Traveller universe(s).

Pebble Fusion Reactors maybe, who knows. Intrinsic hair trigger dampers without which the fusion reactor can't start, and with which will shut down the reactor as soon as levels break tolerance. But, no, they can't be "wired to blow", I don't care how much engineering skill Scotty has.

 

[veltyen]

Well, I was kind of going with something more technically plausible here. I think a lot of this "the reactor's gonna blow!" is pure bullshit from a technical viewpoint. I mean, the fusion reactor gets a stream of fusionable matter, like hydrogen, deuterium, He3, whatever. As long as the stream remains constant then the power output must remain constant as the reactor can't pull power out of nothing.

Since we don't have reliable energy positive fusion reactors at the present time this is all conjecture.

Assuming you have a stream fed fusion reactor. This would involve a small fusionable area (suspended away from everything else with magnetic of gravitational fields) where D and T are closely brought together and fused. On one side there will need to be an intake of new fusionable material. On the other side there will need to be some way to extract the fused material.

Assuming that for a safe flow there are regulators to only allow a limited quantity of material into the fusion chamber.

On failure -

Input fails, the fusion reaction will conk out without significant errors after running dry. Reactor needs to be restarted. This would be similar to a normal shutdown sequence.

Chamber containment fails. Fusionable material leaks out contacts the walls of the chamber and starts eating things away. Result similar to being shot with a fusion gun. Extensive damage, fusion chamber probably slagged. May be jury rigged depending on how extensive the damage is.

Output fails. Material is stuck in chamber. Isotopes and elements start to climb up the periodic table (generating less energy each time). If input fails to be regulated eventually you would end up with excess matter in the reaction chamber. Eventual overload of chamber would be the likely result - with much more material being in a hot state this would be more catastrophic then the chamber containment failure.

Start up would involve placing a small amount of material in the reaction chamber, running the containment field off alternative power (batteries or another reactor) and then igniting the chamber. It may be possible to load the reactor "to the brim" and then ignite.

So two options for catastrophic failure.

1. Disable extraction mechanism, override input regulators
2. On start up deliberately overload the reaction chamber (flood the engine so to speak) and then spark the lot.

Neither strike me as likely from a weapon hit. More likely containment going off line and slagging the reactor would be an outcome, and this may be just as bad as being vaporised.

 

[Drakon]

Fusion takes very high pressure, inside the reaction chamber. It should be real easy to establish a series of interlocks, relief valves, and such to prevent an overpressure problem. Or, in the event of any other irregularities, remove that pressure, thereby killing the reaction. Physical limitation in injector size can serve to prevent overfill situations to begin with.

In fission reactors, it is the physical design, the density and geometry of the fissile material that make nuclear explosions physically impossible. You may get a melt down, and steam explosion, which can be very devastating, and all that would spread contaminiation. But not as bad as a bomb going off. And with proper design, addition of blowout plugs in the compartment, can go a long way from minimizing damage.

And fission reactors are only capable of melting down because they have all their reactant, or fuel, self contained. Fusion reactors, especially those along Bussard's polywell fusion project, require the fuel to be fed to it. That makes explosions impossible.

Fusion is a tough process to get going. Killing either the pressure or fuel flow, shuts down the process, safely. Its very easy to build reliable instruments and physical devices, ones that do not rely on electrical power, that make accidentaly explosions impossible. You would really have to work at screwing up the design.

 

[far-trader]

...I was thinking of a process designed to blow up a military ship rather than let it fall into enemy hands.

Simple, just place a nuclear charge in a critical area and install command lockouts for the trigger. To scuttle the ship activate the self destruct system and you have an automatic critical ship destroyed damage result.

It's a military ship so having the nuke bomb isn't an issue. It's your ship so placing it for maximum effect is simple. And it won't result in any scenario where a civilian ship becomes a jump capable weapon of mass destruction.

 

[veltyen]

Fusion is a tough process to get going. Killing either the pressure or fuel flow, shuts down the process, safely. Its very easy to build reliable instruments and physical devices, ones that do not rely on electrical power, that make accidentaly explosions impossible. You would really have to work at screwing up the design.

Explosions as in uncontrolled spontaneous extensive fusion, yeah. But catastrophic failure could be hard to tell the difference.

For example, you have a spinning magnetic containment setup. The fusile material is contained inside the ring (toroid) containment vessel and spun very quickly. Heavier material exits by dint of being heavier and spills out of the ring in a circular plane to be collected and removed from the chamber. Ionised D and T are dropped into the chamber where the magnetic field collects the material into the torus.

You make this torus as big as possible to maximise the energy output (you can put the power collectors over a larger surface this way). If you deliberately reverse the magnetic field suddenly you have an expanding ring of superheated material moving at high speed. If the energy contained is extensive enough this could cut your vehicle in two, above and below the plane, this may be somewhat detrimental to your survival. On the other hand it will primarily impact where the exit groove just outside the containment vessel is. This should be hardened.

On the other hand if you just cut off some of the magnetic containment (say leaving 3/4 of the ring available) then you would end up with a line of fusile material coming out of the reactor in one specific direction, enough potentially to punch a long hole.

Most of these failure modes aren't spontaneous, but more come down to very unusual failure or deliberate well informed arcane sabotage. Most of the time it is hard to tell the difference.

On "everyday" reactors - those without a maintenance and engineering crew, most of these options should be very hard to disable. Blackbox mechanisms. Tamper detection emergency shutdown and so on. For larger ones (city power, starship power) where you may need to do esoteric things due to need then it may be possible to selectively arrange for interesting failures.

 

[Drakon]

On failure -

Input fails, the fusion reaction will conk out without significant errors after running dry. Reactor needs to be restarted. This would be similar to a normal shutdown sequence.

Chamber containment fails. Fusionable material leaks out contacts the walls of the chamber and starts eating things away. Result similar to being shot with a fusion gun. Extensive damage, fusion chamber probably slagged. May be jury rigged depending on how extensive the damage is.

Depends on distance and cooling time of the plasma. Once containment drops, fusion stops, power drops, plasma is going to cool pretty fast.

Possibly design a capacitor bank such that if main power is loss, instead of containment completely disappearing, it decays off slowly. This would give the plasma more time to cool before contact with the walls of the containment vessle.

Output fails. Material is stuck in chamber. Isotopes and elements start to climb up the periodic table (generating less energy each time). If input fails to be regulated eventually you would end up with excess matter in the reaction chamber. Eventual overload of chamber would be the likely result - with much more material being in a hot state this would be more catastrophic then the chamber containment failure.

To get this isotope climb, it would require more and more pressure, stronger and stronger containment. You don't increase containment, you can't get isotope climb. Containment gets overwhelmed, it is real easy to build trip circuits which drops containment altogether and therefore shuts down the whole fusion process. Plasma cools and vented.

Start up would involve placing a small amount of material in the reaction chamber, running the containment field off alternative power (batteries or another reactor) and then igniting the chamber. It may be possible to load the reactor "to the brim" and then ignite.

So two options for catastrophic failure.

1. Disable extraction mechanism, override input regulators

And override pressure relief valves, and containment trips. The more things you have to do, the harder it is to sabotage. Or damage in battle, or accidentily.

2. On start up deliberately overload the reaction chamber (flood the engine so to speak) and then spark the lot.

And using the capacitive containment decay circuit I mentioned above, you could rig it to dump its power into the containment field, thereby boosting its strength, at least temporarily. Which might produce a nuclear effect. I think this would have to be a specially designed thing, overriding containment trips, pressure relief and other safety features.

Neither strike me as likely from a weapon hit. More likely containment going off line and slagging the reactor would be an outcome, and this may be just as bad as being vaporised.

Agreed.

 

[Gadrin]

I was wondering if it would be possible to deliberately overload a fusion reactor in traveller to produce an explosion. I know, from T4 if it was canon, that most civilian stuff uses "fusion+", a cold fusion process that' safe, but I've heard some applications use a "hot fusion" process that is more dangerous but more powerful.

I was thinking of a process designed to blow up a military ship rather than let it fall into enemy hands. It would involve running more fuel into the reactor to create a more powerful fusion reaction in the containment, and channeling all power into the containment field to keep the fusing core intact until it reached a level sufficient to vape the whole ship.

I was wondering if this was possible/canon in traveller.

I don't think so.

The best way to vaporize a large military ship would be to either detonate
one of the ship's nuclear missiles (assuming it has any) from a distance or inside, or for the ship to carry a satchel nuke which is expressley for that
same purpose.


>

 

[boomslang]

The best way to vaporize a large military ship would be to either detonate one of the ship's nuclear missiles (assuming it has any) from a distance or inside, or for the ship to carry a satchel nuke which is expressley for that same purpose.

If it's a starship, I always figured the recommended scuttling procedure was simply to plot a deliberate catastrophic misjump.

N.B: works great as a suicide attack, as well...

(Plan B: simply overcharge the capacitors as per the "black globe overload" scenario above.)

 

[far-trader]

If it's a starship, I always figured the recommended scuttling procedure was simply to plot a deliberate catastrophic misjump.

Seems iffy and highly situational dependent (something to cause a catastrophic misjump) as it would require a functional bridge, computer, jump drive, power plant and fuel. If you've got all that why not just jump somewhere safe? Even a micro jump buys you a week to make repairs. I don't see how it works as a suicide attack either.

(Plan B: simply overcharge the capacitors as per the "black globe overload" scenario above.)

Again, you need a working powerplant and jump drive and fuel, and time. It's also very iffy in that you don't (in real life at least) know precisely when capacitors will blow, only a general failure threshold.

I think you're back to the simple nuke charge to scuttle the ship.

 

[boomslang]

I think you're back to the simple nuke charge to scuttle the ship.

Well, maybe not a "simple" one; the tacnukes typically deployed in missiles are going to be too low-yield to make a properly-thorough job of it, but stratnuke-sized demolition packages bring al sorts of handling and security risks with them.

It is worth noting that (the Battle of Two Suns notwithstanding), the one canonical example of a deliberately-abandoned starship is the INS Bard Endeavor, which was in more-or-less flyable shape when she was set into a decaying orbit around a GG and ditched.

 

[Gadrin]

If it's a starship, I always figured the recommended scuttling procedure was simply to plot a deliberate catastrophic misjump.

that's works too. Have the engineer pump whatever you have on hand either into the fuel or some sort of equivalent. then head for the nearest
gravity well. Go to vacc suits and open the doors...

basically anything that = Big Boom


>

 

[Icosahedron]

Well, maybe not a "simple" one; the tacnukes typically deployed in missiles are going to be too low-yield to make a properly-thorough job of it, but stratnuke-sized demolition packages bring al sorts of handling and security risks with them.

Going from the damage ratings in the rules for a missile hit, I might be tempted to agree, but explosions are less effective in space than onboard.

Realistically, I can't see the Engineering department being repairable after a well-placed charge the equivalent of a couple of thousand tons of TNT has turned the reactor core to molten slag and created a pressure wave that has over-stressed every joint and seal, and ripped the ship's tail off...

A satchel nuke is more powerful than a car bomb, and over here in the UK I've seen what damage the latter can do to a city block - and how long it takes to repair the damage. And when you figure most of the blast is dissipated outdoors...

I reckon a well-placed tactical nuke should be near enough 'catastrophic' to make no difference.

 

[veltyen]

Getting back to the original scuttling concept.

After going through options for a magnetic containment fusion device the general response has been towards deliberate overload probably damaging the fusion reactor beyond reasonable repair, and maybe causing enough damage to the engineering sector to write off several other systems. Gravitic fusion containment systems are likely to be similar - but the context has nothing concrete in the real world to compare too so would be complete conjecture.

Blowing the powerplants for a ship isn't a bad start. It would make it difficult to just press such a hulk back into service. Blowing the powerplant while in a rapidly decaying orbit around a gas giant strikes me as a pretty good option. Smaller celestial objects not so much, small planets and planetoids may leave enough for some mechanical and information salvage but at the bottom of a gas giant any ship is unlikely to return.

Nukes on board is certainly viable for a military ship. Distributed nukes, a small (10kT) "satchel nuke" placed on the bridge, the backup bridge, the primary computing environment, each of the backup computing environments, in engineering, in each bay and spinal weapon, basically installed into every major system on the ship would allow spontaneous scuttling to the point of allowing no information or mechanical salvage.

On the other hand it would allow spontaneous scuttling. Any saboteur would have a field day if they could find out enough about them. In that case only critical systems (ones that give a likely advantage to an opponent that could salvage them) should have a system of that type set up in them. Cutting edge technological items and information repositories in other words. In that case conventional explosives may do the trick. A (conventional) satchel charge in each computer environment and one on the bridge would probably do it.

 

[Andrew Boulton]

Even a sub-kt nuke will pretty much vapourise anything smaller than 1000dt, and rip apart anything bigger. (A .1kt warhead leaves a crater 25m across).

 

[boomslang]

Even a sub-kt nuke will pretty much vapourise anything smaller than 1000dt, and rip apart anything bigger. (A .1kt warhead leaves a crater 25m across).

But "ripping apart" isn't necessarily thorough enough; you want to obliterate all three drives, the spinal mount focussing mechanism, the radiation-hardened computer, every sensor, and as many of the secondary (bay) and tertiary (turret/barbette) weapons as well, to preclude salvage.

Which brings up the need for the genuinely huge atomizing blast, and I'm still looking at capacitor overload and/or forced misjump as the only destruction-guaranteed alternatives to carrying a problematic demolition charge.

Self-targeted spinal mount fire might also do it, especially from an m-gun, but again, that presumes enough ship's systems are still functioning that scuttling seems unnecessary in such a scenario.

As for craters, a good old "controlled flight into terrain" has the virtue of simplicity, and at high-enough velocity, should provide the desired level of obliteration...

 

[veltyen]

Even a sub-kt nuke will pretty much vapourise anything smaller than 1000dt, and rip apart anything bigger. (A .1kt warhead leaves a crater 25m across).

I was being somewhat excessive.

That was however to allow no salvage whatsoever. Nothing that could be used to convey information. No interesting charred remnants, or even chemical compositions or alloy mix information.

In a more realistic case you want the ship non-viable, and any privileged information not recoverable. Personally I would tend towards carrying nukes specifically for this purpose as being extremely rare - maybe on technology demonstrators and spyships.