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Posted

How should we dispose of high-level nuclear wastes (HLW)? Sink them? Bury them? Burn them? Or store them?

 

If you happen to favor expanding the use of nuclear energy, as I do, then we must make a strong case for the safe disposal of HLW. I think we can do that, but I also think we are going about it in the wrong way. DOE has chosen to bury HLW in a deep, geologic repository. Yucca Mtn is the selected site. Costly indeed! So what are all the options?

 

Sink them? We could do that. Just haul them out to sea and drop them into deep oceanic trenches, and cheaply, too. Once DOE actually considered this option. Energy secretary Dixie Lee Ray believed that sinking HLW into deep oceanic trenches would put them away for good, since water in these trenches is so old it is often referred to as “fossilized water.” Even decay-heating, she argued, would not disturb the relatively heavy trench water. Needless to say, her preferred method of disposal was rejected. I found her argument credible, though, even if it flew in the face of Green attitudes.

 

Bury them? Well, that’s what DOE has chosen to do. Sure, we can make them go away by burying them deeply inside a mountain…at great cost. But what if someday, for no foreseeable reason, those HLW somehow become a valuable resource. We will be back down there digging them up like diamonds. This may seem preposterous, but not to me.

 

Burn them? Yes, that may become possible, and DOE is looking into it. There are new nuke designs on the table that use liquified heavy metals as coolants. They would be capable of burning HLW, which also involves breeding fissionable transuranics at some redeemable level. Add to that, they would produce hydrogen for fuel cells. In theory there is a quadruple benefit, since electric power is also produced along the way. I think this is a great idea, except for one thing—we might be burning away something of value to future generations.

 

Store them? Yes, indeed. I happen to favor the concept of “monitored retrievable storage” (MRS). This involves above-ground holding facilities that allow HLW to decay at the surface, but must also be monitored and maintained for a million years or more. That’s probably more trouble than technology can fix, so it must be the burden of our social infrastructure. I can easily see Hanford as such a place, giving a new focus to this valuable site. I can also see the opposition—Downwinders will scream bloody murder! But Indian Tribes might be wise enough to see the enormous value in hosting an MRS. I think it was the Mesquite Tribe that once tried to do that and got severely ridiculed for it. Personally, I think a few MRSs would be a whole lot better for them than a bunch of gambling casinos.

 

I don’t think the problem of disposing HLW should have to discourage our use of nuclear energy. France is doing well with her robust use of nuclear reactors. They are generating for France what coal is generating for us, proportionately, and I do NOT see coal as an environmentally friendly source of power.

 

So the HLW disposal problem has complexities. Any thoughts?

 

—Larv

Posted
happen to favor the concept of “monitored retrievable storage” (MRS). This involves above-ground holding facilities that allow HLW to decay at the surface, but must also be monitored and maintained for a million years or more.

 

A very complex issue, indeed. I wonder, though, how exactly do you propose monitoring them for a million years or more? We can barely monitor things for a decade...

 

I do not mean to suggest this is easy to figure out, just that this seems a blaringly strange concept to me...

Posted
A very complex issue, indeed. I wonder, though, how exactly do you propose monitoring them for a million years or more? We can barely monitor things for a decade...

Yes, this certainly is a big problem—almost laughable in its magnitude. Of course we can always solve the problem like a president does who goes into an unwinable war and expects future presidents to get us out. So there is THIS precedence, at least, for passing along the infrastructural buck. I can think of others, too.

 

But I would say in defense of MRS that a million years of monitoring is not enough to scotch the idea—not if HLW is somehow deemed a resource in the future. So the goal would be shifted to finding ways to use this unusual material. I think that will take less than a million years. As for protecting HLW from terrorists, for example, that would have to be factored too. I'm not that daunted by the problem, though, but maybe I should be.

 

—Larv

Posted
if HLW is somehow deemed a resource in the future. So the goal would be shifted to finding ways to use this unusual material.

Okay, that approach seems much more feasible. You mentioned in your introduction that you've been in the field for a while. Do you have any ideas yourself about which we could speculate, or can you share what types of uses have been proposed (and potentially even shot down) already by your peers?

Posted
Okay, that approach seems much more feasible. You mentioned in your introduction that you've been in the field for a while. Do you have any ideas yourself about which we could speculate, or can you share what types of uses have been proposed (and potentially even shot down) already by your peers?

First, I'll admit to only speculating on that possibility. At this point, so far as I know, there are no worthy ideas on the table. But I don't think those hypothetical resource futures are the only reason to select the MRS option (even though it is already used locally at reactor sites). I could see a large MRS facility at Hanford, for example, that would be reasonably safe and easily constructed at relatively low cost. Of course it would be only a few miles away from the Columbia River, and I'm sure some downstream communities would not welcome it. Ultimnately, such a facility would become an intense social issue—probably too intense for gaining acceptability right now.

 

My bottom line is that there are other HLW disposal options to consider besides Yucca Mtn. I am not very worried about our ability to safely store or dispose of HLW. What would be most helpful right now is to find ways to relieve the public's anxiety over nuclear energy; it is massively self-defeating. Electricity will be in ever higher demand when people buy more cars that can travel 40 miles on a house charge. We'll have to find a way to meet that demand. I expect that will be an important step away from oil combustion, and from wars now necessary to protect that interest.

 

I should also mention that I greatly prefer power conservation and the use of renewable energy resources. But when I take a close look at the whole picture of biodeisel and hydroelectric power I see some serious environmental problems. As for fusion, I'm not yet convinced it will work as we hope it will. (The best of all worlds would be a cold-fusion electric generator the size of a suitcase that produces enough electricity to power a household. All you need is a little seawater.)

 

—Larv

Posted

If there wasn't so much, I could see resurrecting and advancing the "Big Cannon" of Saddam Hussein fame. This concept was believed to be able to shoot a payload into orbit, at low cost Once there, we collect them into a bunch, and push the batch toward the sun, for permanent disposal.

 

Another alternative is based on the idea that the continental plates are not only rising but sinking for recycle in the mantle. We place the junk near one of these down strokes for recycle in the mantle.

 

The deep trench disposal is a good idea. Water is an excellent radiation shield. The technology only has to be connected to permanent containers. This is a good storage place until something more permanent can be thought up. What is cool about this is that the radiation will make the water glow. This allows zero energy light markers so we can find them, when the time comes.

 

I often wondered what would happen if we detonated a nuke device, underground, in a vault full of nuke waste. Maybe the stuff would be vaporized and fused into underground glass. Add the needed ingredients for the glass, before the blast, and cover the depression.

Posted
...The deep trench disposal is a good idea. Water is an excellent radiation shield. The technology only has to be connected to permanent containers. This is a good storage place until something more permanent can be thought up. What is cool about this is that the radiation will make the water glow. This allows zero energy light markers so we can find them, when the time comes.

I like your ideas about HLW disposal. It's hard to find anyone these days who looks favorably on the deep-sea alternative. What an interesting study that would be to find out what lives nearby those glowing containers. Monsters maybe? I can imagine the day when we want to bring them back up some unforseeable reason and environmental groups object on the grounds that several species have evolved to depend upon them.

 

—Larv

  • 2 weeks later...
Posted
I think we need to get away from the type of plants that generate this type of waste. Creating more of what we cannot deal with now seems to be a wrong approach. This thread talks about nuke power and waste. See post #8 for the info on the Pebble Bed Modular Reactor's. I was pretty impressed with the ideas behind the Pebble Bed.

 

http://hypography.com/forums/chemistry/6369-nuclear-energy-safe-no-way.html

Cedars, I wish I had found that early thread before I started this one. I urge others to read the WIRED article you refer to. Pebble bed reactors, thorium reactors, liguified heavy metal reactors, and other innovate designs are showing promise. I am optimistic that improved nuclear power can do a great deal of good for us. But can we become serious enough to re-educate the public about safe nukes and safe options for HLW disposal? I am worried that America's fascination with tabloid news and entertainment is a weak spot in our public mind. For this reason alone, siting new nukes will be difficult. The NIMBYs will be heard from, and it won't be very friendly to nuclear power...unless we re-educate them.

 

—Larv

Posted
if we bury them then they would evenultuly burn up in the middle of the earth, mabye.

 

I would like to use the shovel you use. In order for the heat in the center of the Earth to "burn up" any nuclear wastes, one would need to bury it approximately 6500 km (more than 4,000 miles) deep! :shrug:

 

 

 

 

That's a pretty snazzy shovel (i.e. it is not yet possible). :cup:

Posted

You cant 'burn up' nuclear wastes anyway. Radiation is a nuclear problem, and the chemical this nucleus is present in does not help with it's radioactivity.

 

The conversion-to-resource idea seems really cool though. If there is a way by which we can actually 'use' the 'harmful radiations', it would be brilliant.

 

Wait- chemically also the nuclear waste's gotta be very toxic. So maybe the burning part could help with the chemical toxicity... maybe.

Posted
You cant 'burn up' nuclear wastes anyway. Radiation is a nuclear problem, and the chemical this nucleus is present in does not help with it's radioactivity.

 

The conversion-to-resource idea seems really cool though. If there is a way by which we can actually 'use' the 'harmful radiations', it would be brilliant.

 

Wait- chemically also the nuclear waste's gotta be very toxic. So maybe the burning part could help with the chemical toxicity... maybe.

You might find the designs of heavy-metal reactors to be attentive to your concerns. The site I've linked you to provides a nice discussion of nuke history and relevant issues of risk and waste disposal, including the burning of HLW:

 

The heavy-metal reactor' date=' thus, may provide a way to utilize the energy in the world's 238U reserves, and simultaneously reduce the problem of radioactive waste to a level that appears more manageable than it has up till now. It should be stressed, however, that the heavy metal reactor is at the present time only in the research stage, and it is not known whether it, or some other new reactor design, will become a practical energy source.[/quote']

 

—Larv

Posted

The jury is back and the verdict is daunting: Global warming is real and humans have played a part in it. The ungency factor is gaining; that's clear from recent news about scientific confirmation that we are having a serious effect on our planet's oceans and atmosphere.

 

This is old news to a lot of us. And I suppose I am not alone in comparing the relevant risks of nuclear wastes to those of global warming. Nuclear energy is only part of the equation for avoiding catastrophic climate change, but we need to get going in a hurry. Nukes take >10 years to site and build. Obviously, now is the time to exploit electricity for home heating and transportation. I prefer conservation most, but non-carbon recylable energy sources, such as wind and solar, seem promising. (I am not a fan of biofuels for global-warming reasons.) Still, our infrastructure will need to deliver more electrical power than ever, and I think nukes could help. The problems with HLW disposal don't seem to me as daunting in the face of global warming.

 

—Larv

Posted
Why don't we leave them in space?:hihi:

 

 

1. Have you seen the bill for NASA just flying people up in space shuttles?

2. There is already a ring of debris, paint chips, and meteorites orbiting the earth, do you really want nuclear waste orbiting the Earth?

3. Why do you want to do this in the first place?

Posted

I would like to look at stabilizing nuclear waste with a nuke bomb. Here is my thinking, nuke waste is bad because it is very radioactive, with an extremely long half-life. Wouldn't a nuke blast speed up the half life by over dosing the waste with high energy particles and radiation. A good analogy to nuke waste is a sponge that is sopping wet. One can let it drip dry in a sealed container all day long, or one can add some extreme nuke pressure to squeeze it out in a few seconds.

 

When this waste is made, it is gentle nuke pressure that causes the materials to become radiactive. The goal is not to be so gentle.

 

The nuke blast would be done underground. Yu don't have to empty the containers in the hole. Throw in container and all, the nuke furnace will burn everything. Maybe the container can be designed with the needs of the burn in mind. Besides the nuke waste, we we also need to add other ingredients, that will fuse all the residues. The goal might be ceramics or glass containment. Someday in the future, this glass will be mined for its special properties.

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