Lose the containment even partially and the reaction stops because the plasma is no longer contained. It's all or nothing.
Hydrogen leak!
- Thread starter Carlobrand
- Start date
Lose the containment even partially and the reaction stops because the plasma is no longer contained. It's all or nothing.
mike wightman
SOC-14 10K
Where do these neutrons come from?
Traveller fusion reactors use hydrogen for fuel - the only fusion reaction that uses hydrogen is the p-p chain which doesn't produce neutrons at any point. Gamma rays and positrons (which annhilate on colision with an electron to form yet more gamma rays).
http://en.wikipedia.org/wiki/Proton-proton_chain_reaction
I'm not sure we're all meaning the same thing when we say "containment."
The fusion reaction in the power plant is contained in a small volume of space by magnetic or, for Traveller, gravitic confinement. This is necessary in part because contact with matter would draw off the heat that you need to sustain the reaction - not to mention that most matter tends to react rather unpleasantly to being exposed to that kind of heat. If that containment fails, the reaction stops dead - there's nothing "squeezing" the hydrogen hard enough to make it fuse any more.
However, there's another thing that needs to be contained. That is the radiation being given off by the reaction - positrons and gamma rays, if I have it right. I have no idea how much of that would be given off by the amount of fusion going on in a given power plant, but given that my dentist makes me wear a lead vest for a simple x-ray, I have to presume the ship's engineer is going to want a whole lot of something between him and a gamma ray source - and gravity isn't gonna meet that need. Unless Traveller has some sort of EM shield, that thing is likely to be simple mass - lead, maybe that superdense armor stuff. Maybe that's one of the reasons the power plant gets smaller with increased tech - denser shielding takes up less space.
It might help end some of the confusion if we refer to this as shielding, rather than containment, since that's really the job it does. That leaves the question: is it possible for a power plant's shielding to fail in a way that leaves the containment intact and the reactor functioning? I'm finding that one to be a stretch. My guess is that unless it were a very specific and carefully planned and executed act, breaching the shielding would be sufficiently violent and energetic that damage to the other components is a virtual certainty. And if I were a power plant designer, I would construct it so that running the thing without the shielding would be no more possible than running a V-8 without the head. If you make it impossible to begin with, you're less likely to get sued.
The fusion reaction in the power plant is contained in a small volume of space by magnetic or, for Traveller, gravitic confinement. This is necessary in part because contact with matter would draw off the heat that you need to sustain the reaction - not to mention that most matter tends to react rather unpleasantly to being exposed to that kind of heat. If that containment fails, the reaction stops dead - there's nothing "squeezing" the hydrogen hard enough to make it fuse any more.
However, there's another thing that needs to be contained. That is the radiation being given off by the reaction - positrons and gamma rays, if I have it right. I have no idea how much of that would be given off by the amount of fusion going on in a given power plant, but given that my dentist makes me wear a lead vest for a simple x-ray, I have to presume the ship's engineer is going to want a whole lot of something between him and a gamma ray source - and gravity isn't gonna meet that need. Unless Traveller has some sort of EM shield, that thing is likely to be simple mass - lead, maybe that superdense armor stuff. Maybe that's one of the reasons the power plant gets smaller with increased tech - denser shielding takes up less space.
It might help end some of the confusion if we refer to this as shielding, rather than containment, since that's really the job it does. That leaves the question: is it possible for a power plant's shielding to fail in a way that leaves the containment intact and the reactor functioning? I'm finding that one to be a stretch. My guess is that unless it were a very specific and carefully planned and executed act, breaching the shielding would be sufficiently violent and energetic that damage to the other components is a virtual certainty. And if I were a power plant designer, I would construct it so that running the thing without the shielding would be no more possible than running a V-8 without the head. If you make it impossible to begin with, you're less likely to get sued.
Positron, proton, alpha (He+) and neutron radiation is actually easily stopped. The Gamma's the only issue, really - the exceedingly high neutrino loads simply don't interact with normal matter enough to count.
And the gamma, proton, positron, and alpha all stop the instant the reaction does.
The real issue is the secondary gamma and x-ray from alpha and beta impacts...
... and isotopic changes from same. Which can be some minor residual radioactivity, but not much.
So, if you lose radiation shielding but not actual fusion bottle, you get a strong point source. Kill the fuel feed, and a few minutes later, should be good.
If you lose the bottle, but not the shielding, you've probably just totaled the plant, but nobody gets radiation hits.
Lose them both, and you just vented a LOT of hot hydrogen, some hot helium, a little hot lithium, some lithium, berylium, boron, and carbon traces.
And the gamma, proton, positron, and alpha all stop the instant the reaction does.
The real issue is the secondary gamma and x-ray from alpha and beta impacts...
... and isotopic changes from same. Which can be some minor residual radioactivity, but not much.
So, if you lose radiation shielding but not actual fusion bottle, you get a strong point source. Kill the fuel feed, and a few minutes later, should be good.
If you lose the bottle, but not the shielding, you've probably just totaled the plant, but nobody gets radiation hits.
Lose them both, and you just vented a LOT of hot hydrogen, some hot helium, a little hot lithium, some lithium, berylium, boron, and carbon traces.
Gray Pennell
SOC-12
Well there is another thread talking about navigation defectors. According to its conclusion the halls of starships have special field (hand wave) that protects them against impacts and radiation ie gama rays. This appears in the belter box set and other OTU adventures. So its pretty simple to say the shielding is made out of the same stuff as the hall.
This actually makes sense since humans had fusion drives before jump so the gama ray problem would have to been solved for both outside and inside the ship thousands of years ago. or hundreds from now what ever.
A critical hit that vaporizes the ship probably destroys this shielding and blows up tons of hydrogen for a big big radioactive boom.
This actually makes sense since humans had fusion drives before jump so the gama ray problem would have to been solved for both outside and inside the ship thousands of years ago. or hundreds from now what ever.
A critical hit that vaporizes the ship probably destroys this shielding and blows up tons of hydrogen for a big big radioactive boom.
Icosahedron
SOC-14 1K
Didn't say I agreed with it, just providing the accepted definition of Insidious as applied to Hydrogen.
Well the UK is still considering it, but then some may say we are a... CENSORED!
Enoki
SOC-14 1K
Neutrons are thrown off as part of the reaction of the deuterium and tritium present in the hydrogen. Remember, we're buring alot of hydrogen atoms here some will be deutrerium or tritium.....
Good sweet Christ... Luis Alvarez must be doing 100 RPM in his grave...
I'll "remind" you that perhaps THREE GRAMS of natural tritium existed on Earth before atmospheric nuclear testing began and then let you figure out how much natural hydrogen we'll have to "burn" in order to get the neutron flux you're bloviating about.
Deuterium? Yes.
Tritium? only as a byproduct... it's rare enough not to be significant. It's presence in the PNF experiment results was considered indicative of fusion occurring... or of contamination of the GCMS!
Gray Pennell
SOC-12
Oh now how do you describe the word vaporize?
I like to think its a big boom and with tons of gama rays wouldn't it be radioactive. Or am I missing something.The other thing that can to me while I was thinking. Suppose they do use the same shielding as the outside of the ship that means the gama rays and radiation stay in the ship building up so you have to vent. Maybe the size and or rate of the venting could be used as a sensor clue to the capabilities of the jump engines.
something like this
Your sensor just picked up a jump bumble. They are venting their gama tank. The flare shows it just came out of jump 3.
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Why will there be gamma rays? What has produced them? That's what you're missing.
A radiation storage tank? The mind boggles...
Gray Pennell
SOC-12
I am not a nuclear scientist I just play Traveller. However, first if we are talking about shielding centered on repulsive materials why cant there be a storage tank. As for the gama rays I must have misunderstood
Radiation shielding doesn't "repel" radiation. It either reflects most of it or almost none of it, and absorbs almost all the rest.
A reflective shield, like a thermos' mirroring, becomes less effective as a shield the more intense the energy inside, as both the leak and the temp rise.
Eventually, a bottle lases....
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Oh, goodness. Where to begin ...
Let's start with: it is very hard to fuse hydrogen. Nature does it by putting so freaking much of it in one place that gravity does the work. Traveller does something similar, apparently, using their knowledge of gravitics in place of sheer mass. We here on Earth have been working on it for 50-60 years and still can't manage to do it in a way that gives us more energy than it takes to make it happen. I don't think even a laser hit straight through the hydrogen tank would do it - too little pressure. So - "vaporizing" a ship is not going to cause the hydrogen fuel on board to undergo fusion, and unless the hydrogen undergoes fusion, there ain't gonna be any radioactivity in the boom.
add: I should probably mention the easiest way we here on earth make hydrogen fuse - we put it more or less in the middle of a nuclear explosion. So, unless a nuclear device happens to go off INSIDE your fuel tank ... and frankly at that point it would be rather moot from the crew's viewpoint whether the hydrogen was adding to the explosion or not.
I haven't the foggiest what goes boom other than the weapon that hits you. That can be pretty impressive by itself - being too close to a nuclear missile is always unhealthy - but it doesn't explain how 30 lasers can cause a fighter to turn into an expanding cloud of debris. I would have just expected thirty little chunks of thin-sliced fighter. Maybe there's something unusually delicate about these maneuver drives...
Gamma rays are a cousin of light. They're both electromagnetic spectrum - gamma's just way, way more energetic, incredibly high frequency. Unlike their weaker cousin, which generally bounces off your skin to show people where you are, gamma is a kind of ionizing radiation - which is a fancy way of saying they tend to penetrate into matter and have nasty, unhealthy effects on that matter, especially us biologicals but also such things as electronics, ionizing atoms in places where we really don't want ionized atoms to occur. The most effective way to shield against gamma is simple mass - put more atoms between you and the gamma source so they get hit instead of you. Superdense armor does that quite nicely, probably several times better than lead.
However, like light, gamma needs to have something generating it. Once the gamma-producing "flashlight" - the fusion reaction, in this case - is turned off, the gamma-rays stop flowing out, and any gamma already out there either keeps heading straight out at the speed of light or runs into something and transfers its energy to that. If you think of a "gamma tank" as being pretty much like trying to shine a flashlight into a "light-beam tank" to store light, you'll understand why the idea doesn't work, the more so because gamma doesn't reflect - it crashes into atoms like a speeding freight.
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shadowdragon
SOC-12
Bounce the graviton particle beam off the main deflector dish................
Ackehece
SOC-13
I'm more of a Candu 9e or ACR-1000 person... Daichi and pretty much any other conceivable nuclear failure would be avoided with them and the fuel pond problem would never have existed. Hopefully the Nuclear Renaissance will make a resurgence as it is still the most economic and green power out there.
(for those who say solar or wind, check out the exotic materials used to create the efficient panels and the variability in output....
dams are nice but they have a significant enviro footprint for the rivers they are on.... tidal power less so but they tend to dissolve (literally!))
