NASA Wants Nuke Reactor on Moon - But WHY ?

[166p1]

https://phys.org/news/2021-11-nasa-ideas-nuclear-reactor-moon.html

If anyone has a good idea on how to put a nuclear fission power
plant on the moon, the U.S. government wants to hear about it.

NASA and the nation's top federal nuclear research lab on Friday
put out a request for proposals for a fission surface power system.

NASA is collaborating with the U.S. Department of Energy's Idaho
National Laboratory to establish a sun-independent power source
for missions to the moon by the end of the decade.

"Providing a reliable, high-power system on the moon is a vital
next step in human space exploration, and achieving it is within
our grasp," Sebastian Corbisiero, the Fission Surface Power Project
lead at the lab, said in a statement.

. . .

One TINY question ... do you NEED a nuke plant on the moon ???

That is an environment where photovoltaic could really shine,
so to speak. PV grids built strong enough for lunar gravity
would be vastly LIGHTER than the stuff needed for a fission
reactor too - a major issue.

I'm not all that concerned about launching loads of uranium
pellets, but the WEIGHT of them, framework, shielding,
plumbing and all those bits, are going to be insane. And
yes, even on the moon, you need a good safe structure since
it will still be fairly close to humans and humans may have
to do service work.

Frankly, this sounds like a big govt hand-out to the
contractors that would be involved. There's just no
real justification ... for half the money you could
assemble a PV farm with twice the output or more.
Don't have to worry about clouds or rain. Don't have
to build with high winds in mind.

[M I Wakefield]

The moon is tidally locked with earth — that's why the full moon
always looks the same — so sunrise to sunrise is 29.53 days.

A reactor sounds like a surer bet than batteries to suppy power for
over two weeks.

[J. Clarke]

On Sat, 20 Nov 2021 11:41:12 -0500, 166p1 <z24ba6.net> wrote:

Nuclear reactors on other planets:
Apollo 12, 14, 15, 16, and 17 Lunar Surface Experiments Package on the
Moon (the one from Apollo 13 is in the Tonga Trench)
Viking 1 and 2 on Mars
Curiosity Rover on Mars
Lunokhod 1 & 2 on the Moon
Chang'e 3 and Yutu on the Moon

There are numorous others in orbit or in escape trajectories.

This isn't new.

As to why, you might want to research the length of the lunar night.
Photovoltaic without massive storage is a nonstarter for any kind of
extended lunar activity.

You would know this if you actually did a little bit of homework.

[166p1]

Batteries are big and heavy too.

Perhaps a more unique form of energy storage might
be devised, something that would not require a large
excess of heavy expensive parts ?

What if during the daylight weeks, a lot of the power
was diverted downwards to heat rock ? Then you can
recover it rather like any geothermal power plant.
There may be some phase-changing chemicals that could
be largely made from local minerals, even more
efficient. We do have to keep the laws of thermodynamics
happy ... want max temperature differential between
source and sink.

There may be ways to use the large heat differential
between lighted and shadow areas to good effect as
well for energy generation. Likely the sink area
would have to be substantially larger than the
insolated panels.

In any case, the sheer mass of a colony-sized nuclear
reactor seems to be the doom of the idea without even
getting into the finer details. The "small" ones, like
used in submarines, would be the best bet though they
do need a squad of mother-hens hovering over them
at all times.

Oh, and depending on where you PUT your colony, there
might not be a problem lighting PV panels. One of the
prime sites oft mentioned are those craters at the
south pole. Icy dirt in the bottoms, constant sun
to be had above the rim. Similar conditions at the
north pole, dig your own pit if need be.

[J. Clarke]

Why don't you get right on inventing that?

> What if during the daylight weeks, a lot of the power
> was diverted downwards to heat rock ?

So how do you go about heating it? How much do you have to heat? How
do you recover the heat?

> Then you can
> recover it rather like any geothermal power plant.
> There may be some phase-changing chemicals that could
> be largely made from local minerals, even more
> efficient.

So how much equipment and power do you need to make these phase
changing chemicals?

> We do have to keep the laws of thermodynamics
> happy ... want max temperature differential between
> source and sink.
>
> There may be ways to use the large heat differential
> between lighted and shadow areas to good effect as
> well for energy generation. Likely the sink area
> would have to be substantially larger than the
> insolated panels.

So why don't you invent that?

> In any case, the sheer mass of a colony-sized nuclear
> reactor seems to be the doom of the idea without even
> getting into the finer details. The "small" ones, like
> used in submarines, would be the best bet though they
> do need a squad of mother-hens hovering over them
> at all times.

Where was "colony-sized" mentioned? They were looking for 40KW. The
dimensions and weight were also specified. The "small" ones used in
submarines are several times more powerful than was specified.

>
> Oh, and depending on where you PUT your colony, there
> might not be a problem lighting PV panels. One of the
> prime sites oft mentioned are those craters at the
> south pole. Icy dirt in the bottoms, constant sun
> to be had above the rim. Similar conditions at the
> north pole, dig your own pit if need be.

Again with the "colony". Objection counsel, assumes facts not in
evidence.

[166p1]

THOSE are thermoelectric units ... a hot isotope
plus essentially thermocouples. Good for 50+ years,
yes, but the power output is quite small. Good
for probes and certain instrumentation.

A colony needs much more power. NASA was talking
about a "real" reactor - uranium and turbines.

The ones meant for submarines are perhaps the most
compact and light. Rumor is that they take a LOT
of work to ensure continued safe operation. There
is also a serious problem in COOLING the things
on the moon. No oceans of water to pump through
them, not even any air to cool off radiators.
All you can do is put thin radiator panels into
some permanent shadow area. According to WikiPedia,
"The surface of a perfect black body (with an emissivity
of 1) emits thermal radiation at the rate of approximately
448 watts per square metre at room temperature (25 °C,
298.15 K); all real objects have emissivities less than
1.0, and emit radiation at correspondingly lower rates"
I do not know if there's a straight-line relation to
temperature or some sort of curve.

An accompanying table does suggest that anodized aluminum
is going to be the best all-around material.

Someone better at math than I could scale that up to
the number of square meters needed to keep a liquid
sodium reactor of, say 0.5 MW, at a safe temperature.

> As to why, you might want to research the length of the lunar night.
> Photovoltaic without massive storage is a nonstarter for any kind of
> extended lunar activity.
>
> You would know this if you actually did a little bit of homework.

No, that did not elude me at all.

And neither did the mass of the components for a uranium,
or thorium, fission reactor.

There MAY be convenient ways to STORE the PV energy - heating
rocks for example. Batteries would be as massive as the reactor
parts (and tend to be short-lived) so you wouldn't have many
of those.

However there IS a fix - put your colonies AT THE POLES.
There are permanently shadowed craters there - H2O in the
southern ones for sure - but the big trick is that you
can put your PVs up on the crater rim and they'll
get sunlight from one direction or another most of
the time. Any 'gaps', put another farm 150km away in the
best spot and run a power line. Rather short power-poles
could be used, maybe just insulators affixed to rocks in
some areas. Wire is heavy, but you can send it up one spool
at a time amongst the other cargo. Microwave link ... um ...

Anyway, from the poles, you could have relatively short
links to somewhere the sun WAS shining.

[J. Clarke]

The article does not mention "turbines". In point of fact multiple
copies of the reactor on Voyager come close to meeting the
specification.

> The ones meant for submarines are perhaps the most
> compact and light. Rumor is that they take a LOT
> of work to ensure continued safe operation.

You seem to operate a lot on rumors.

> There
> is also a serious problem in COOLING the things
> on the moon.

Voyager manages it.

> No oceans of water to pump through
> them, not even any air to cool off radiators.

This is engineering. Size as needed.

> All you can do is put thin radiator panels into
> some permanent shadow area. According to WikiPedia,
> "The surface of a perfect black body (with an emissivity
> of 1) emits thermal radiation at the rate of approximately
> 448 watts per square metre at room temperature (25 °C,
> 298.15 K); all real objects have emissivities less than
> 1.0, and emit radiation at correspondingly lower rates"
> I do not know if there's a straight-line relation to
> temperature or some sort of curve.

You really should take a heat transfer course before spouting off
about things you don't understand.

> An accompanying table does suggest that anodized aluminum
> is going to be the best all-around material.
>
> Someone better at math than I could scale that up to
> the number of square meters needed to keep a liquid
> sodium reactor of, say 0.5 MW, at a safe temperature.

The specification is for a reactor less than 1/10 that capacity, so
why are you on about ".5 MW"? And who said anything about a sodium
reactor? You seem to have your head stuck solidly in the box of
commercial power plants.

>> As to why, you might want to research the length of the lunar night.
>> Photovoltaic without massive storage is a nonstarter for any kind of
>> extended lunar activity.
>>
>> You would know this if you actually did a little bit of homework.
>
> No, that did not elude me at all.
>
> And neither did the mass of the components for a uranium,
> or thorium, fission reactor.

What do you believe this mass to be and why? What is the mass and
output of the reactor on Voyager? How close does it come to meeting
the stated requirements?

> There MAY be convenient ways to STORE the PV energy - heating
> rocks for example.

Yes, you've gone on about that before. If you took that heat transfer
course (you'll want to pass three semesters of college calculus and a
first course in differential equations before you tackle it) you'd be
able to figure out what's wrong with this idea. But let's make is
simple. 40,000 watts for 14 days works out to 13,440,000 watt-hours
or 48,384,000,000 kJ. Now, assume 30% efficiency. That's reasonable
for a thermal plant based on using heated rocks to boil water, where
you can't use any of the fancy techniques that are used in natural gas
power plants. So now we're up to 161,280,000,000 kJ that we have to
store.

Now let's say that we want to store our energy at not less than 300C
(typical of a steam plant on a warship) and not more than 1000C (don't
want to melt the rock).

Basalt stores .84 kJ/kg-K. So we're using a 700C range. That means
that we need 287,286 kg of basalt. So how much is the drilling
equipment, piping, and heat transfer medium to utilize that source
going to mass?

Don't try to teach engineers how to do engineering until you've become
one yourself.

> Batteries would be as massive as the reactor
> parts (and tend to be short-lived) so you wouldn't have many
> of those.

Gee, ya _think_?

> However there IS a fix - put your colonies AT THE POLES.

When you start creating colonies you can put them anywhere you want
to. Perhaps you should start an electric car company and raise a few
hundred billion in pocket money . . .

Meanwhile, this is NASA's program, they have said nothing whatsoever
about "colonies", and they are going to put them wherever they need
them to be, which may not be in a location that you would find
convenient.

> There are permanently shadowed craters there - H2O in the
> southern ones for sure - but the big trick is that you
> can put your PVs up on the crater rim and they'll
> get sunlight from one direction or another most of
> the time.

Yes, you've said that before. Repeating it doesn't make it any more
meaningful.

> Any 'gaps', put another farm 150km away in the
> best spot and run a power line.

So now you're got multiple "farms" and microwave transmission
equipment capable of carrying the same wattage as your power plant,
and all of that to save using a nuclear reactor.

> Rather short power-poles
> could be used, maybe just insulators affixed to rocks in
> some areas. Wire is heavy, but you can send it up one spool
> at a time amongst the other cargo. Microwave link ... um ...
>
> Anyway, from the poles, you could have relatively short
> links to somewhere the sun WAS shining.

Run the numbers on all this stuff. If you don't know how then instead
of blathering endlessly here, go over to MIT Open Courseware and start
studying.
>

[Anders Eklöf]

Please read the previous reply again:
The devices on the probes listed above are *NOT* nuclear
reactors.
They are basically packets of hot, refined nuclear waste heating
thermocouples, generating electric power in the order of 1 kW.

--
I recommend Macs to my friends, and Windows machines
to those whom I don't mind billing by the hour

[166p1]

Most people do not understand the difference.

You might get, initially, a KW out of a big thermoelectric
unit but any bona-fide moon base will need a LOT more than
that. A low-end "whole house" generator unit is 25kw and
that's barely enough to not wreck the AC unit when it starts.
The extremes at a moon base - figure 250kw minimum.

Air-reconditioning units, fluid pumps, waste recycling,
airlocks, lighting and electronics - everything there
would be electric. Can't just crack a window for some
fresh air ...

I have nothing against nuclear power - though I tend to
promote pebble-bed reactors over the new gee-whiz
liquid-sodium screamers. My question is whether - given
the mass and size of ALL the needed components - whether
a nuclear power plant is the BEST solution on the moon.
Eventually too, you've got the waste - which without
being kept underwater can get hot enough to vaporize
itself. It'd make a rather large, forever, 'hot spot'.

He DOES have a point about lunar night and power storage.
It's a problem. I offered a few suggestions, but someone
would have to crunch the numbers. Batteries are as heavy
as nuke-plant parts, so "something else" is indicated.

I will try to find some sim that shows the extent of
long-term light and darkness at the poles. The moon is
a lot smaller than earth - so I proposed somewhere to
put PV farms a hundred miles or so from the poles, with
little power poles or something connecting them to a
base AT the pole. The theory is that two of three or
four should always be exposed to the sun. No atmospherics
to weaken the sunlight even if it's right at the horizon.

PVs can be very light and don't require a heat sink like
nuclear units (including thermoelectrics). On the moon
all you've got is blackbody emission to serve as the
heat sink - no flowing river, no blowing breeze. PV
farms are also easy to EXPAND, so as your base grows ...

Ah, the wires, at 50,000 or 100,000 volts they don't
have to be all that big to deliver 250kw. I think #12
copper would about do it (add a bit for resistance)
at 10kv. Aluminum wire would be better though, lighter
and stronger. At 50kv or 100kv ... the wiring equation
looks very good mass-wise.

[J. Clarke]

157 watts from 37.7 kg. The spec is for 40,000 watts from 6,000 kg.

So let's see how close those devices are. 40,000/157=255.
255*37.7=9613. So you're at 1.5 times the target mass just taking a
pile of the Voyager reactors.

Now let's try the reactor used in Cassini.

300 watts at 57kg.

So, 40000/300=133. 133*57=7581.

That's for actual, operational, in use reactors. So tell us again why
you think it's such a stretch to hit 40,000 watts with 6000 kg, using
"pockets of hot, refined nuclear waste".

[J. Clarke]

Yes, NASA says 40 times that.

> A low-end "whole house" generator unit is 25kw and
> that's barely enough to not wreck the AC unit when it starts.
> The extremes at a moon base - figure 250kw minimum.

NASA has specified 40,000 watts. Whatever you are envisioning that
requires "250kw minimum" has no relation to the article which you
initially linked and apparently either did not read or did not
understand.

> Air-reconditioning units, fluid pumps, waste recycling,
> airlocks, lighting and electronics - everything there
> would be electric. Can't just crack a window for some
> fresh air ...

So?

> I have nothing against nuclear power - though I tend to
> promote pebble-bed reactors over the new gee-whiz
> liquid-sodium screamers.

Earth to "166p1", it's the 21st century. You seem to be stuck in the
'50s.

> My question is whether - given
> the mass and size of ALL the needed components - whether
> a nuclear power plant is the BEST solution on the moon.

So tell us your alternatives. With numbers, not just ignorant
opinions.

> Eventually too, you've got the waste - which without
> being kept underwater can get hot enough to vaporize
> itself. It'd make a rather large, forever, 'hot spot'.

So let it vaporize itself. It's the Moon, there's no ecology to
damage. However so far Voyager doesn't seem to have vaporized itself.

> He DOES have a point about lunar night and power storage.
> It's a problem. I offered a few suggestions, but someone
> would have to crunch the numbers.

Why don't _you_ crunch the numbers instead of just whining
incessantly?

> Batteries are as heavy
> as nuke-plant parts, so "something else" is indicated.

Considerably heavier, which is why Voyager uses nuclear instead of
batteries.

> I will try to find some sim that shows the extent of
> long-term light and darkness at the poles.

How about instead you find evidence that NASA is planning to use this
reactor at the poles? You can't set the rules for NASA's mission.

> The moon is
> a lot smaller than earth - so I proposed somewhere to
> put PV farms a hundred miles or so from the poles, with
> little power poles or something connecting them to a
> base AT the pole. The theory is that two of three or
> four should always be exposed to the sun. No atmospherics
> to weaken the sunlight even if it's right at the horizon.

OK, work out the mass of four 40KW solar power stations with cables
and poles.

> PVs can be very light and don't require a heat sink like
> nuclear units (including thermoelectrics). On the moon
> all you've got is blackbody emission to serve as the
> heat sink - no flowing river, no blowing breeze. PV
> farms are also easy to EXPAND, so as your base grows ...

Seems to work fine for Voyager, which has consierably less heat sink
than the Moon.

> Ah, the wires, at 50,000 or 100,000 volts they don't
> have to be all that big to deliver 250kw.

So how much does the machinery weigh to step the voltage up from the
0.58 volts that a solar cell puts out to the 50,000 that you need for
your scheme?

> I think #12
> copper would about do it (add a bit for resistance)
> at 10kv.

You're proposing four solar power plants a hundred miles from the
poles. So that's at least 800 miles of #12 copper. #12 copper weighs
19.8 pounds per 1000 feet. Your plan requires 4,224,000 feet of wire,
so that's 83,635 pounds or 37,936 kilograms. NASA is targeting 6000
kilograms for the entire system. So you do not even come close to
meeting the spec.

> Aluminum wire would be better though, lighter
> and stronger. At 50kv or 100kv ... the wiring equation
> looks very good mass-wise.

Show us the numbers by which you arrived at that value.

[166p1]

40kw ? Are the limits of their ambitions one little
tin can on the moon ? I can't support that. A decent
base - 50 to 100 - or DON'T BOTHER.

Well, in FULL unfiltered sunlight, a conventional 2'x4'
PV panel can produce about 400 watts - so they'd only
need TEN of the things - 20 if they also wanted to
charge a battery bank.

NASA likes to use the more expensive dual-layer PVs,
ten to twenty percent more efficient. So, cut 40
to the low 30s. EASY. NO need for a nuke plant.
PV and batteries would be VASTLY cheaper.

>> A low-end "whole house" generator unit is 25kw and
>> that's barely enough to not wreck the AC unit when it starts.
>> The extremes at a moon base - figure 250kw minimum.
>
> NASA has specified 40,000 watts. Whatever you are envisioning that
> requires "250kw minimum" has no relation to the article which you
> initially linked and apparently either did not read or did not
> understand.
>
>> Air-reconditioning units, fluid pumps, waste recycling,
>> airlocks, lighting and electronics - everything there
>> would be electric. Can't just crack a window for some
>> fresh air ...
>
> So?

"So" ??? Are you KIDDING ???

Maybe you work for a nuke-plant maker ?

>> I have nothing against nuclear power - though I tend to
>> promote pebble-bed reactors over the new gee-whiz
>> liquid-sodium screamers.
>
> Earth to "166p1", it's the 21st century. You seem to be stuck in the
> '50s.

Pebble-bed is very 21st - and they CAN'T melt down.

No, you DON'T know anything about nukes.

>> My question is whether - given
>> the mass and size of ALL the needed components - whether
>> a nuclear power plant is the BEST solution on the moon.
>
> So tell us your alternatives. With numbers, not just ignorant
> opinions.

I've spent several posts now doing just that.

>> Eventually too, you've got the waste - which without
>> being kept underwater can get hot enough to vaporize
>> itself. It'd make a rather large, forever, 'hot spot'.
>
> So let it vaporize itself. It's the Moon, there's no ecology to
> damage. However so far Voyager doesn't seem to have vaporized itself.
>
>> He DOES have a point about lunar night and power storage.
>> It's a problem. I offered a few suggestions, but someone
>> would have to crunch the numbers.
>
> Why don't _you_ crunch the numbers instead of just whining
> incessantly?

Because good engineers are MUCH better at those numbers.

But, they ARE going to agree with me.

>> Batteries are as heavy
>> as nuke-plant parts, so "something else" is indicated.
>
> Considerably heavier, which is why Voyager uses nuclear instead of
> batteries.

No, not "considerably" ... probably about a third
the weight of a properly-shielded reactor/generator
setup. Lithium-Iron-Phosphate are ideal, and don't
burst into flames.

And will you get off the crappy thermoelectric units ???
Those are for LOW, very low, consumption devices.

>> I will try to find some sim that shows the extent of
>> long-term light and darkness at the poles.
>
> How about instead you find evidence that NASA is planning to use this
> reactor at the poles? You can't set the rules for NASA's mission.

Depends on who I lobby ... :-)

>> The moon is
>> a lot smaller than earth - so I proposed somewhere to
>> put PV farms a hundred miles or so from the poles, with
>> little power poles or something connecting them to a
>> base AT the pole. The theory is that two of three or
>> four should always be exposed to the sun. No atmospherics
>> to weaken the sunlight even if it's right at the horizon.
>
> OK, work out the mass of four 40KW solar power stations with cables
> and poles.

May not even need "poles" - lunar soil, sun-baked, is a
good insulator. Just lie the wire on the surface.

>> PVs can be very light and don't require a heat sink like
>> nuclear units (including thermoelectrics). On the moon
>> all you've got is blackbody emission to serve as the
>> heat sink - no flowing river, no blowing breeze. PV
>> farms are also easy to EXPAND, so as your base grows ...
>
> Seems to work fine for Voyager, which has consierably less heat sink
> than the Moon.

Voyager doesn't use shit for power.

>> Ah, the wires, at 50,000 or 100,000 volts they don't
>> have to be all that big to deliver 250kw.
>
> So how much does the machinery weigh to step the voltage up from the
> 0.58 volts that a solar cell puts out to the 50,000 that you need for
> your scheme?
>
>> I think #12
>> copper would about do it (add a bit for resistance)
>> at 10kv.
>
> You're proposing four solar power plants a hundred miles from the
> poles. So that's at least 800 miles of #12 copper. #12 copper weighs
> 19.8 pounds per 1000 feet. Your plan requires 4,224,000 feet of wire,
> so that's 83,635 pounds or 37,936 kilograms. NASA is targeting 6000
> kilograms for the entire system. So you do not even come close to
> meeting the spec.
>
>> Aluminum wire would be better though, lighter
>> and stronger. At 50kv or 100kv ... the wiring equation
>> looks very good mass-wise.
>
> Show us the numbers by which you arrived at that value.

Crunch a number or two yourself. #12 copper is good for
20 amps. It's the most common used for household circuits.
Those are 120v (usa). Now ramp up the voltage and see
the figures. AMPERAGE is the limitation, not voltage.
You'll see that you can get to 250kw at voltages not
even considered extreme for earthly transmission lines.

For a 100-200 mile line though, resistance becomes an
issue. You might have to go up to #6 or #4. Use
hollow-core ... at high AC voltages almost all of
the current rides the outer layer of the wire.

And why do you think power companies use aluminum wire
even though it's not as good a conductor as copper ?
It's CHEAPER - and - it's STRONGER ... meaning longer
spans of larger wire between poles.

40kw ... you could use guitar strings ...

I am not the worlds ultimate expert, but YOU seem to
know DICK about electric power.

[J. Clarke]

Well then don't support it and see if they care.

> Well, in FULL unfiltered sunlight, a conventional 2'x4'
> PV panel can produce about 400 watts - so they'd only
> need TEN of the things - 20 if they also wanted to
> charge a battery bank.

Uh, how big a battery bank do you need to story 40KW*14 days * 24
hours?

> NASA likes to use the more expensive dual-layer PVs,
> ten to twenty percent more efficient. So, cut 40
> to the low 30s. EASY. NO need for a nuke plant.
> PV and batteries would be VASTLY cheaper.

Uh huh. So tell us what the batteries weigh.

>>> A low-end "whole house" generator unit is 25kw and
>>> that's barely enough to not wreck the AC unit when it starts.
>>> The extremes at a moon base - figure 250kw minimum.
>>
>> NASA has specified 40,000 watts. Whatever you are envisioning that
>> requires "250kw minimum" has no relation to the article which you
>> initially linked and apparently either did not read or did not
>> understand.
>>
>>> Air-reconditioning units, fluid pumps, waste recycling,
>>> airlocks, lighting and electronics - everything there
>>> would be electric. Can't just crack a window for some
>>> fresh air ...
>>
>> So?
>
>
> "So" ??? Are you KIDDING ???
>
> Maybe you work for a nuke-plant maker ?

No, I'm an engineer or was one in a former life. Unlike you I know
how to read a specification. The requirement is for 40kW. NASA,
which collectively forgot more about space travel between breakfast
and lunch than you are ever going to know, seems to think that that's
adequate for "air conditioning units, fluid pumps, waste recycling,
airlocks, lighting and electronics".

>>> I have nothing against nuclear power - though I tend to
>>> promote pebble-bed reactors over the new gee-whiz
>>> liquid-sodium screamers.
>>
>> Earth to "166p1", it's the 21st century. You seem to be stuck in the
>> '50s.
>
> Pebble-bed is very 21st - and they CAN'T melt down.
>
> No, you DON'T know anything about nukes.

It's a '60s design.

>>> My question is whether - given
>>> the mass and size of ALL the needed components - whether
>>> a nuclear power plant is the BEST solution on the moon.
>>
>> So tell us your alternatives. With numbers, not just ignorant
>> opinions.
>
>
> I've spent several posts now doing just that.

No, you haven't. You've spouted opinions but never actually given any
numbers. Numbers look like this: -12345689.0. I don't see any in
your posts.

>>> Eventually too, you've got the waste - which without
>>> being kept underwater can get hot enough to vaporize
>>> itself. It'd make a rather large, forever, 'hot spot'.
>>
>> So let it vaporize itself. It's the Moon, there's no ecology to
>> damage. However so far Voyager doesn't seem to have vaporized itself.
>>
>>> He DOES have a point about lunar night and power storage.
>>> It's a problem. I offered a few suggestions, but someone
>>> would have to crunch the numbers.
>>
>> Why don't _you_ crunch the numbers instead of just whining
>> incessantly?
>
> Because good engineers are MUCH better at those numbers.

And they seem to disagree with you.

> But, they ARE going to agree with me.

And yet NASA wants a reactor, not hundreds of miles of copper wire. I
wonder why that is?

>>> Batteries are as heavy
>>> as nuke-plant parts, so "something else" is indicated.
>>
>> Considerably heavier, which is why Voyager uses nuclear instead of
>> batteries.
>
> No, not "considerably" ... probably about a third
> the weight of a properly-shielded reactor/generator
> setup. Lithium-Iron-Phosphate are ideal, and don't
> burst into flames.

OK, genius, what kind of battery can produce 150 watts continuously
for over 40 years and weigh less than 40kg?

> And will you get off the crappy thermoelectric units ???
> Those are for LOW, very low, consumption devices.

OK, show us exactly why they can't meed the specification. Include
numbers.

>>> I will try to find some sim that shows the extent of
>>> long-term light and darkness at the poles.
>>
>> How about instead you find evidence that NASA is planning to use this
>> reactor at the poles? You can't set the rules for NASA's mission.
>
>
> Depends on who I lobby ... :-)

You can lobby anybody you want to.

>>> The moon is
>>> a lot smaller than earth - so I proposed somewhere to
>>> put PV farms a hundred miles or so from the poles, with
>>> little power poles or something connecting them to a
>>> base AT the pole. The theory is that two of three or
>>> four should always be exposed to the sun. No atmospherics
>>> to weaken the sunlight even if it's right at the horizon.
>>
>> OK, work out the mass of four 40KW solar power stations with cables
>> and poles.
>
>
> May not even need "poles" - lunar soil, sun-baked, is a
> good insulator. Just lie the wire on the surface.

I don't see you working out the mass, just blowing more hot air.

>>> PVs can be very light and don't require a heat sink like
>>> nuclear units (including thermoelectrics). On the moon
>>> all you've got is blackbody emission to serve as the
>>> heat sink - no flowing river, no blowing breeze. PV
>>> farms are also easy to EXPAND, so as your base grows ...
>>
>> Seems to work fine for Voyager, which has consierably less heat sink
>> than the Moon.
>
> Voyager doesn't use shit for power.

No, it doesn't, it uses plutonium.

>>> Ah, the wires, at 50,000 or 100,000 volts they don't
>>> have to be all that big to deliver 250kw.
>>
>> So how much does the machinery weigh to step the voltage up from the
>> 0.58 volts that a solar cell puts out to the 50,000 that you need for
>> your scheme?
>>
>>> I think #12
>>> copper would about do it (add a bit for resistance)
>>> at 10kv.
>>
>> You're proposing four solar power plants a hundred miles from the
>> poles. So that's at least 800 miles of #12 copper. #12 copper weighs
>> 19.8 pounds per 1000 feet. Your plan requires 4,224,000 feet of wire,
>> so that's 83,635 pounds or 37,936 kilograms. NASA is targeting 6000
>> kilograms for the entire system. So you do not even come close to
>> meeting the spec.
>>
>>> Aluminum wire would be better though, lighter
>>> and stronger. At 50kv or 100kv ... the wiring equation
>>> looks very good mass-wise.
>>
>> Show us the numbers by which you arrived at that value.
>
> Crunch a number or two yourself.

Look up a couple of paragraphs and you'll see numbers.

> #12 copper is good for
> 20 amps.

What leads you to believe that 20 amps is sufficient? And that is on
earth where it has air around it. How much do you need to derated it
in vacuum?

> It's the most common used for household circuits.
> Those are 120v (usa). Now ramp up the voltage and see
> the figures. AMPERAGE is the limitation, not voltage.
> You'll see that you can get to 250kw at voltages not
> even considered extreme for earthly transmission lines.

What leads you to believe that 250kw is sufficient, since you seem to
be determined to ignore the actual specification.

> For a 100-200 mile line though, resistance becomes an
> issue. You might have to go up to #6 or #4. Use
> hollow-core ... at high AC voltages almost all of
> the current rides the outer layer of the wire.

Where are you getting the AC?

> And why do you think power companies use aluminum wire
> even though it's not as good a conductor as copper ?
> It's CHEAPER - and - it's STRONGER ... meaning longer
> spans of larger wire between poles.

What of it? You need to show that your entire power plant weighs less
than 6000 kilos.

> 40kw ... you could use guitar strings ...
>
> I am not the worlds ultimate expert, but YOU seem to
> know DICK about electric power.

OK, brainiac, what is the mass of 800 miles of guitar strings?

You have yet to show how your proposed system will meet the
specifications. You leave that to "engineers" who, I being one of
them, I can assure you are either rolling on the floor laughing at
your arguments or looking at them through a facepalm.

[166p1]

Your "20 amps" comment means you REALLY don't know
anything about electric power.

Clue, the POWER, ability to DO stuff, is "watts" -
amps TIMES voltage.

20 amps at 120 volts = 20x120=2400 watts, 2.4 kw

20 amps at 1200 volts = 20x1200=24000 watts, 24kw

20 amps at 12000 volts = 20x12000=240000 watts, 240kw

See how a little wire can become a serious workhorse ?

Or maybe you don't.

I think you don't. Your skill seems to be in being
a contrarian.

While I'm more a computer guy, I had to repair and
'tune' a 40kw phase converter just a week ago because
I was the only one who understood the things - the
local electricians look at it and say "What ???".
So I'm hands-on with this sort of shit. Would you
like a lecture about how you can produce a fair
3rd phase using a transformer and capacitor bank ?

No, I'm not going to bother. Learn it yourself.

And screw NASAs plans for a hyper-expensive little
tin can 'moon base' - Musk will do MUCH better,
MUCH sooner - or the Chinese will ....

Bye.

[J. Clarke]

On Tue, 23 Nov 2021 00:50:53 -0500, 166p1 <z24ba6.net> wrote:

>Your "20 amps" comment means you REALLY don't know
>anything about electric power.

I note that you snipped all the context and then went off on a
tangent.

You are the one who claimed that 12 gage wire, capable of carrying 20
amps was sufficient. You have not demonstrated that. You have just
blathered incessantly.

>Clue, the POWER, ability to DO stuff, is "watts" -
>amps TIMES voltage.
>
>20 amps at 120 volts = 20x120=2400 watts, 2.4 kw
>
>20 amps at 1200 volts = 20x1200=24000 watts, 24kw
>
>20 amps at 12000 volts = 20x12000=240000 watts, 240kw
>
>See how a little wire can become a serious workhorse ?
>
>Or maybe you don't.

How about you show us the rest of the numbers. First, show that 240KW
is sufficient. Second show us how you will generate 240KW. Include
all details. Third calculate the masses.

Oh, I know, that's for stupid engineers like me who don't appreciate
your genius to do.

>I think you don't. Your skill seems to be in being
>a contrarian.

ROF,L.

>While I'm more a computer guy, I had to repair and
>'tune' a 40kw phase converter just a week ago because
>I was the only one who understood the things - the
>local electricians look at it and say "What ???".
>So I'm hands-on with this sort of shit. Would you
>like a lecture about how you can produce a fair
>3rd phase using a transformer and capacitor bank ?

No, I would like you to show your calculations that demonstrate that
your proposed design meets the stated specifications.

>No, I'm not going to bother. Learn it yourself.

Learn what myself, electrical engineering?

>And screw NASAs plans for a hyper-expensive little
>tin can 'moon base' - Musk will do MUCH better,
>MUCH sooner - or the Chinese will ....

In other words you're having a hissy-fit because nobody will pat you
on the head and tell you what a clever little boy you are.

<pat-pat> What a clever little boy you are.

<plonk>

[166p1]

What do you pay ? :-)

And the "stated specifications" - WHOSE ? NASAs ?
As I said, screw their tin-can 'moon base'. Let
Musk do it right.