petrv
Space Pioneer
Posts: 93
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Post by petrv on Jun 24, 2017 22:39:52 GMT
there are two main types coming into consideration: Radioisotope thermoelectric generators (RTGs) and fission reactors. The first ones are safer, but giving less power (the MMRTG on mars rovers generates 110W at launch with lifetime of minimum of 14 years), the fission reactors could make about 40kW.
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Mike
Space Pioneer
Posts: 82
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Post by Mike on Jun 25, 2017 16:59:58 GMT
The main question is: Can isotopes for those Reactors can be harvested on site? (Mars, or Moon surface)
Although Nuclear Reactors seems good on paper they have few disadvantages: 1. Shielding is needed to ensure safety of Colonists, and it weights A LOT. Plus it doesn't have any other useful function. Even after disassembling such Reactors, Shielding will be already radiated, and can't be used for anything else. 2. They don't work that long. Fuel will be enough for few dozens years, and then you have to get rid of used rods. On Earth it is made by burying inside meters of concrete, but it would be quite hard in environment of Mars, or Moon.
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petrv
Space Pioneer
Posts: 93
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Post by petrv on Jun 26, 2017 22:01:45 GMT
There are small reactors used for decades on submarines, icebreakers etc. so the security shouldn´t be so big issue, the used pellets/rods could be sent directly to the sun in special container by EMG..
There many companies working on SMRs, especially those with molten salts could be usable. Their lifetime vary from 5-40 years so there are some alternatives to be available within 10 years...
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Post by phicksur on Jun 27, 2017 12:52:10 GMT
Nuclear power might work as a backup, but given the ability to refine and produce fuel in space will be highly limited I suggest not using it for everyday operations.
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petrv
Space Pioneer
Posts: 93
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Post by petrv on Jun 27, 2017 22:20:13 GMT
I meant to use it on surface, not in space. Separated location (in some crater/excavated hole/behind the "hill") for the reactor and just the power line to base.
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Post by zachisajerk on Jun 28, 2017 22:10:46 GMT
Fusion is a great idea in concept, at any rate. With the recent breakthrough in the UK, it may well be possible that in the time it would take us to collect the funds, resources, and necessary manpower to build a colony (whether in LEO, the moon, or Mars), the technology rendering nuclear fusion a viable source of power could well be in place.
Aside from fusion and that fission has already been touched on, solar wouldn't be inconvenient -- not for a satellite base of sorts. It wouldn't be quite as efficient, or even more just a hindrance, on other planets and the like.
We could always have human-sized hamster wheels and the like, I guess.
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petrv
Space Pioneer
Posts: 93
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Post by petrv on Jun 29, 2017 0:29:48 GMT
There are many interesting activities in this area, but the issue here is they all need at least 10-25 years to "mature" and be available commercially. I spoke with guy who´s n charge of reactor core development at TerraPower and he told me they will not have commercial prototype until 2028-2030...
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Post by phicksur on Jun 29, 2017 1:01:16 GMT
Fusion has been 10-25 years away for most of my lifetime (45 years).
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petrv
Space Pioneer
Posts: 93
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Post by petrv on Jun 29, 2017 23:35:30 GMT
Terrapower is not making fusion, but small, molten salt reactors with "travelling wave"...
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Post by phicksur on Jun 30, 2017 16:32:13 GMT
Oh, a breeder reactor. I have read about them but not actually studied how they work.
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petrv
Space Pioneer
Posts: 93
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Post by petrv on Jun 30, 2017 23:26:24 GMT
I´m in touch with czech guy who is responsible for development of core of their reactor ) They plan to use used fuel bars from other reactors with only small anoumt of enriched fuel for "first ignition", then the reactor enrich the rest of fuel itself, going as wave down through the core - so travelling wave... They won the grant of about 45Mio USD and the company is partially funded by Bill Gates (they are based in Seattle).
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petrv
Space Pioneer
Posts: 93
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Post by petrv on Jun 30, 2017 23:50:32 GMT
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Mike
Space Pioneer
Posts: 82
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Post by Mike on Jul 1, 2017 16:05:52 GMT
15 millions? In USA you can not even design new pistol for that sum. Obvious misinformation.
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petrv
Space Pioneer
Posts: 93
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Post by petrv on Jul 23, 2017 21:58:45 GMT
I realized one more reason for usage of nuclear energy on Moon´s surface - as there are 2 weeks day/night cycles, the solar power is "usable" just half of month only, but nuclear power is available 365 days/year... so I expect to use nuclear power at least until there will not be placed some "power generating solar arrays/sats" on Moon´s orbit, which will "beam" power down to the surface via laser beams or so...
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Post by phicksur on Jul 24, 2017 1:54:07 GMT
I realized one more reason for usage of nuclear energy on Moon´s surface - as there are 2 weeks day/night cycles, the solar power is "usable" just half of month only, but nuclear power is available 365 days/year... so I expect to use nuclear power at least until there will not be placed some "power generating solar arrays/sats" on Moon´s orbit, which will "beam" power down to the surface via laser beams or so... If solar stations are spread around the moon such that there is a cluster in the sun at all times that doesn't really become an issue, especially near the poles where there is reported to be ice.
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petrv
Space Pioneer
Posts: 93
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Post by petrv on Jul 26, 2017 19:19:41 GMT
Right, but those will not be in place immediately - you have to build habitat/plant first, then the "receiving point" and after that you can deploy the solar arrays on the orbit. And in the meantime lot of energy is needed exactly for construction works - so there is the place for one-fuel-cycle-reactor to be utilised.
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petrv
Space Pioneer
Posts: 93
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Post by petrv on Jul 26, 2017 23:11:00 GMT
NASA wants to have some concepts for compact nuclear reactors till end of 2017 (Project Kilopower) and plans to use 4-5 reactors (abt 10kW each) on Mars - they will be "sent cold" and activated on Mars surface...
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Mike
Space Pioneer
Posts: 82
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Post by Mike on Jul 31, 2017 20:08:54 GMT
I realized one more reason for usage of nuclear energy on Moon´s surface - as there are 2 weeks day/night cycles, the solar power is "usable" just half of month only, but nuclear power is available 365 days/year... so I expect to use nuclear power at least until there will not be placed some "power generating solar arrays/sats" on Moon´s orbit, which will "beam" power down to the surface via laser beams or so... If solar stations are spread around the moon such that there is a cluster in the sun at all times that doesn't really become an issue, especially near the poles where there is reported to be ice. Nope, there is no water source at our Moon. Some water molecules accumulated in forever dark parts of craters, but there is no glacier there. Some Indian craft have tested it, by crashing. And Earth is so big, that Solar Eclipses on Moon are quite frequent. So no continuous source of solar energy is possible. The main problem with current Nuclear Reactors is that they use lots of water. Not only for cooling, but also for producing energy with steam. They have to be completely redone to work in vacuum, and without water.
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petrv
Space Pioneer
Posts: 93
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Post by petrv on Aug 2, 2017 22:22:03 GMT
If solar stations are spread around the moon such that there is a cluster in the sun at all times that doesn't really become an issue, especially near the poles where there is reported to be ice. Nope, there is no water source at our Moon. Some water molecules accumulated in forever dark parts of craters, but there is no glacier there. Some Indian craft have tested it, by crashing. And Earth is so big, that Solar Eclipses on Moon are quite frequent. So no continuous source of solar energy is possible. The main problem with current Nuclear Reactors is that they use lots of water. Not only for cooling, but also for producing energy with steam. They have to be completely redone to work in vacuum, and without water. Actually there could be some water on the Moon ( www.space.com/37596-moon-interior-could-have-water.html ) but using molten salt breeder reactor (MSBR), which operates at around 700°C and generating electricity directly from heat using Brayton, Stirling or Rankine cycle (like SNAP-10A in 60´s) can drastically reduce the need of water for power generation.
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petrv
Space Pioneer
Posts: 93
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Post by petrv on Aug 2, 2017 22:43:55 GMT
Just found good article on this theme .
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petrv
Space Pioneer
Posts: 93
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Post by petrv on Nov 19, 2017 18:36:27 GMT
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