Safer Nuclear Technology

[Kenbushway]

I have been reading into LFTR nuclear reactors lately and I must say I like what I see. From what I read about it, it can't be made into nuclear weapons, its waste stops being radioactive faster and there is much less of it, it can take conventional nuclear waste and use it as a fuel. It can't explode (which is a big plus) and it can shut itself off in the event of something going wrong. However whenever I mention it as a alternative to conventional nuclear power I always get that its impossible, a failure, will never work, etc. I know that it need more work still, especially for the design of the reactor and turbines but I don't know why there is so much hostility against it.

 

[Lindley]

The wikipedia page lists a large number of design challenges. One of them is that a completely new business model is required to make it profitable. That seems like a big one from a practical standpoint.

 

[YellowSubmarine]

The business model can be fixed by making publicly-built reactors.

One question: Can these be made small and light enough to power planes?

There are also other reactor designs that offer passive safety, I know of pebble bed reactors, although I understand that they have some issues of their own. Is there a good online list of reactor designs with truly passive safety?

 

[publiusr]

Conventional reactors can be made safe enough by having their reactors float--with metamaterials to cloak them:
http://www.imaginationstationtoledo.org/content/2011/03/can-you-build-an-earthquake-proof-building/
http://www.technologyreview.com/view/426877/seismic-metamaterials-could-cloak-dams-and-power/

This way, cracks don't propogate inside, allowing water to leak out.

Just having independant pumper trucks on station--and water glass to seal cracks on hand would have prevented the recent disaster:
http://cosmoquest.org/forum/showthread.php/113544-Fukushima-power-stations-nuclear-scare

 

[Kenbushway]

Conventional reactors can be made safe enough by having their reactors float--with metamaterials to cloak them:
http://www.imaginationstationtoledo.org/content/2011/03/can-you-build-an-earthquake-proof-building/
http://www.technologyreview.com/view/426877/seismic-metamaterials-could-cloak-dams-and-power/

This way, cracks don't propogate inside, allowing water to leak out.

Just having independant pumper trucks on station--and water glass to seal cracks on hand would have prevented the recent disaster:
http://cosmoquest.org/forum/showthread.php/113544-Fukushima-power-stations-nuclear-scare

What about the waste?

 

[gturner]

Kirk Sorenson is pursuing the military reactor route, which avoid a lot of the business and regulatory problems with a commercial reactor.

 

[Gary7]

It's definitely possible to have safe nuclear reactor supplied energy. The trouble is that several past catastrophes tarnish its reputation to the point of driving coalitions to seek the banning of nuclear energy. At this point in time, it is the most efficient form of energy with minimal carbon footprint. It would be senseless to abandon it. This form of energy would be a transitional one, until wind, solar and thermal generated energy technologies are perfected enough to make households largely independent of a massive energy grid.

 

[gturner]

Winds and solar are pretty well perfected, and aren't very cost effective except in specialized cases. Even if solar cells were free, the mounting structures and frames would still leave them more expensive than conventional sources. Proofing them against hurricanes, tornadoes, floods, and earthquakes isn't even on the drawing boards because the costs would skyrocket.

LFTR looks like the best low-cost, low-emissions option and is far, far safer than conventional nuclear where safety has to be grafted on at great expense. LFTR's continuously outgas their short half-life daughter products which makes seperation trivially simple while keeping the core clean of products that would produce dangerous fallout, unlike conventional nuclear reactor cores that have years worth of accumulated daughter products that get released during a meltdown.

It's a technology the commercial sector should've used since the 1950's, but as LFTR advocates point out, it wasn't useful for making bombs, and the US and the Russians wanted bombs above all else. Civilian energy production was just a way to slap a happy face on a weapons program.

 

[publiusr]

Terrapower loks to use the waste too. As it stands, we have a lot of already minded and refined fissile material. It would have to be buried at any rate--or placed on the moon. Now much of the enriched stuff isn't in Yucca Mt. It is surrounded by high explosives for the purpose of implosion--and sitting on solid rockets! So take the fissile material, place in in metal and concrete bunkers, separate with neutron moderation rods and keep it cool with water. But here--this storage media is 90% or what an atomic plant is--so you might as well add a turbine and a separate water pipe to wrap around self contained water pipes so only heat is transferred from once source of water to another.

Newe pepple beds aren't needed. Now, yes you need a lot of water--but Sterling engines could be placed to get more waste heat.

 

[MacLeod]

I suspect quite a few people would oppose transporting fissile material to the moon, (of course when you said that I thought of Space: 1999)

 

[publiusr]

But a lot of folks don't want that down here either. What I want to see is Euranium mined to the point to where we run out--than left on the Moon. A perfect no nuke situation on Earth. Then beam power back from the moon. Forget helium 3--just have nuclear installations there. If it melts down on barren rock, who cares?

 

[FordSVT]

If we could go through all of the risk and effort and expense to send nuclear waste to the moon, the extra effort to simply sling it into the sun would be minimal.

 

[publiusr]

It is actually very hard to get to the sun. We launch rockets on the earth rather near to the equator to get a boost from Earth's spin, right? The same applies to Earths orbit around the sun--that also gives you a boost. A probe to the sun would actually have to be sent to Jupiter to get a reverse version of Voyagers slingshot--then it would null enough speed to essentially free fall to the sun: http://en.wikipedia.org/wiki/Solar_Probe_Plus

As the probe passes around the Sun, it will achieve a velocity of up to 200 km/s (120 mi/s) at that time making it the fastest manmade object ever, almost three times faster than the current record holder, Helios IIhttp://en.wikipedia.org/wiki/Solar_Probe_Plus#cite_note-6

Trust me--the Moon is easier. In some ways, even easier than circularizing a perfect geostationary orbit.

 

[RobertVA]

It's a matter of aim. If a spacecraft is on a course near the sun it will whip past like a comet. It might melt or be vaporized by the sun's heat and some material blown free by the solar wind, as occurs with comets. If the trajectory crosses the sun's surface though, the molten remains would slam into the sun at high velocity, just like the early moon probes.

 

[Lindley]

Using old-fashioned propellant, it would take quite a lot to decelerate an object from the sun's orbit. Using a solar sail it might be a lot easier.

 

[sojourner]

Yep, all the speed in the world won't save you if your trajectories intersect.

 

[gturner]

Why would we even consider the expense of putting nuclear waste into low orbit, much less into the sun, when we could just dump it in New Jersey or East LA?

 

[Gary7]

Personally, I think they ought to dump nuclear waste into lava pools. The material should get very well dispersed so as to significantly lower the radioactive intensity. There's plenty of active volcanos around, too. The only thing is, if you dump in the waste and there's an eruption shortly thereafter, it probably won't be good...


All kidding aside, the technology has come a long way and is really quite safe. The melt downs that have happened are very explainable. The recent one in Japan was obvious, as the generators should have been located further up the hill. They were supposed to relocate it, but the hesitation to make the expense caused them to delay... and look what happened. In my mind, it's a suitable source of energy to get us off of burning coal and oil, at least until passive energy systems (solar, wind, thermal, hydro) make better headway.

 

[YellowSubmarine]

I think they should just feed the radioactive waste to all those Vulcan refugees that our governments have been secretly accepting after trimming their ears. And then we should send them all back home. Earth for the earthlings.

 

[publiusr]

Personally, I think they ought to dump nuclear waste into lava pools.

No--that's no good either--it just keeps being vomited up. You really want it in a subduction zone, right where one plante dives down into another. Dig a trench just in front of a subsea cliff. The next big quake and the plate moves under that cliff--that or wait some number of years for gradual subduction. Seeing how difficult Deepwater Horizon operations were at depth--putting it on the moon is actually easier.