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Russia Plans Martian Nuclear Station
An anonymous reader writes "The BBC reports that Russian scientists have announced plans to build a nuclear power station on Mars.
They say that all the necessary technical drawings have now been completed, and all will be ready for the construction work to begin. The power plant should be up and running by 2030."
That would be the "pellet" type reactors that most people think will replace the current rod type. You take hundreds of those spheres that, individually, are sub-critical...and put them together in a big pile. They go critical and produce heat. If you want hotter, you add more to the pile...if you want cooler, you take them away. I'm not certain how much safer they are in the case of a coolant loss (core exposure,) but the pile itself is more resistant to melting into a mass; if anything, individual pellets would melt through their containment and thus reduce the reaction. But still, those pellets are not light, and the accompanying machinery and generators will be very, very heavy. I think RTG's would be a better short-term solution...of course at the expense of irradiating their surroundings.
From article
From nasa:
Consider that radiation on Mars is very intense this should be a simple problem to solve. NOT!
I shouldn't say that. Human engineering has overcome much worse. I'm torn, though... a country that can produce very reliable Soyuz but at the same time consider shooting up one of the back street boys up there for the money.
Maybe they can do it. I am not holding my breath. This is a press release, not a reviewed plan.
... isn't even worthy of the title "junk science." It's been debunked thoroughly.
Dahlmann tightly grips the knife, which he may have no idea how to use, and steps out into the plain.
Maybe it's Chernobyl, but somehow I still don't trust Russian nuclear reactor designs.
If you're gonna put a nuclear reactor on Mars, ferchrissake, make it a CANDU. Not only was the CANDU designed in Canada (w00t!), but it's also really, really safe.
I don't know about what happened in Soviet Russia, but these days no one sticks a gun to an astronauts head and tells him he's flying or else. I don't mean to belittle the commitment of the people who fly to space, but they are not unaware of the risk they are taking.
The only way to make space flight safer for men in space is to send men in space. Even in our enlightened computing era, automated probes are good only for reporting back on things we anticipate ahead of time and build sensors for. They cannot report on the unexpected, nor can they cope with it. Also the speed of light is a factor, our best control systems are far from instantaneous over the distances in question.
I don't advocate sending live humans into totally unknown and unpredictable situations. And smaller unmanned probes are certainly a cheap way of doing just that. At some point however you need a real brain out there on the spot, and the day is coming.
I'm not certain how much safer they are in the case of a coolant loss (core exposure,) but the pile itself is more resistant to melting into a mass; if anything, individual pellets would melt through their containment and thus reduce the reaction. But still, those pellets are not light, and the accompanying machinery and generators will be very, very heavy. I think RTG's would be a better short-term solution...of course at the expense of irradiating their surroundings.
Actually, part of the point of a pebble-bed reactor is that it can't run away. Pellets expand as temperature increases, moving them outside of the envelope for criticality. The result is a core that automatically balances itself right at the critical threshold, resisting changes in either direction. The number of fuel spheres present (and the shape of the collection) determines the temperature at which the whole thing stabilizes (more material, and it needs to be farther apart - and so hotter - to stabilize). When designed with safety in mind (e.g. with the best possible core arrangement and little enough fuel to stay below problematic temperatures) there's no way for it to have a runaway reaction.
Tapping heat off drops the temperature, cooling the pile, and increasing the reaction rate until temperature stabilizes. Losing coolant causes it to heat and expand, dropping the reaction rate, and letting it stabilize. The only way you'd get an accident happening is by adding more fuel, or breaking up the fuel pebbles and carefully arranging fuel and graphite moderator for a higher reaction rate. Not going to happen by accident.
Re. RTGs, a radiothermal source generally doesn't cause activation of its surroundings. It's neutron radiation that does that; RTGs generally just emit alpha or beta radiation (depending on material used, of course). They're easy to shield, too (against primary radiation; you'll still get gama shining through, and x-rays as secondary radiation produced in the shielding).
A fission reactor, by contrast, produces neutron radiation and makes everything near the unshielded core radioactive.