Contract for a nuclear powered mining robot to dig a large, horizontal shaft in a Lunar crater
Nuclear powered, like a nuclear powered submarine (reactor) or a nuclear powered space probe? (nuclear thermionic generation)
transported on a long, conveyor belt “tail”, out the tunnel entrance to a waste pile
So now we have a nuclear powered robot, and a long industrial conveyor belt. how much to you think this would weigh (or more accurately mass)?
even a cistern for Lunar ice,
How much lunar ice (if any) do you think there is?
you then say
The entire process would take a year or two,
but you previously stated
at an inch or two a day
This leads to a tunnel from 365 inches (30 feet long) to a max of 120 feet in two years. DO you seriously think that this is adequate?
The sensible plan to create a Moon base.
At what cost? How much do you think this will cost? A "sensible" plan to create a moon base is the very definition of an oxymoron.
And for what? NASA Has shown that the composition of the moon is nothing remarkable - rocks and dirt. If you want cold rocks and dirt with some ice nearby, then there is Antartica. Two enormous advantages over the moon. It has air, and the cost to get a kilogram of equipment there is conservatively about 5 orders of magnitude LESS than to get to the moon
To answer your questions.
1) nuclear thermionic generation, with the added advantage that shielding can be significantly reduced.
2) The total mass of each Manned Lunar landers was about 32,400 lbs, or 16.2 short tons. I truly doubt that weight would be a huge issue.
3) The conveyor belt would only have to transport rubble that weighed 1/6th of its weight on Earth.
4) In March 2010 NASA reported Mini-SAR radar aboard the Chandrayaan-1 detected what appear to be ice deposits at the lunar north pole, at least 600 million tonnes in sheets of relatively pure ice at least 2 meters thick.
5) 120 feet is one third the length of a football field. This is quite roomy compared to the Spacelab sized area in a prefab habitation. Ever run a 40 yard dash? That is a big tunnel.
6) The dust on the surface of the Moon has a large amount of Helium-3 (sometimes called tralphium), which is exceedingly rare on Earth, and has powerful potential for use in fusion reactors and other purposes. If you take Lunar dust and heat it somewhat, the Helium-3 vaporizes and can be collected. Estimated value, $40,000 per ounce.
7) Another important idea is that much of the technology created by developing a Lunar base can later be applied to a Mars base.
I should add that the economic consideration of “opportunity cost” applies, that if the money is not spent on exploration and discovery, it will be spent as largess to individuals who have voted themselves the treasury.