[gary_malcolm]

Nukes are awesome! Yeah! Look ma I can spel! Yeah.

Let's bury it in Tylers yard. Yeah!

[amorando]

let's not forget in the discussion of what we are going to do when oil runs out that nuclear has not yet resolved the question of waste disposal. Recall too that no nuclear generating plants have been built for many years, due primarly to safety issues vis a vis chernobyl and 3 mile island. Also, I will have to review because I had understood that the supply of fuel available for nuclear was very limited.
Solar is a renewable or limitless resource, so long as the sun shines and our atmosphere stays clean enough to allow the sunlight to get to the earth. When the sun goes out there is no coping. Our planet is history.

[JohnDenver]

$this->bbcode_second_pass_quote('amorando', 'l')et's not forget in the discussion of what we are going to do when oil runs out that nuclear has not yet resolved the question of waste disposal.

[JohnDenver]

$this->bbcode_second_pass_quote('Dezakin', 'L')ets look at the average uranium and thorium in the crust: estimates of uranium I've seen are about 2.5 ppm for the earths crust, and for thorium its about 10 ppm.

If we are only focusing on the continental crust thats .374% of the earths mass, so .00374 * 5.9742 * 10^24, gives you about 2.79 *10^14 metric tons of nuclear fuel

Now you can run a 1 GW reactor on about 1 ton of nuclear fuel per year, and the energy necessary to give everyone on the planet an american lifestile is somewhere between 10 and 100 terawatts... lets say 100 terawatts... so you need about 10^5 tons per year of nuclear fuel.

[Dezakin]

$this->bbcode_second_pass_quote('', 'D')ezakin, how about the energy yield of this process? Suppose, for example, that we are going to mine uranium/thorium out of granite. I'm assuming that the granite will have to be cut, lifted, crushed, processed etc. So let's assume that all that work will be done by nuclear generated energy. Do you have an estimate of the EROEI in that case?

[JohnDenver]

$this->bbcode_second_pass_quote('Dezakin', 'B')ut really this is all just for the purpose of argument.

[tokyo_to_motueka]

2 weeks ago, i went to a lecture in Tokyo by David Holmgren, one of the co-originators of Permaculture.
the second half was very similar to his first lecture here a year ago, except he had added lots of example and photos gleaned during his first trip to Japan.

but the first half was very different.

it focused on one topic: PEAK ENERGY, and in large part PO, including a lot of ASPO data.

probably the most interesting part was his 4 scenarios for post-peak:

1. techno fantasy ---- see Asimov scifi etc. --- unlikey in his opinion, and hellish if it did come about.
2. green-tech stability --- switch to green technologies --- not likely
3. creative descent --- permaculture or "earth stewardship" --- you guessed it, he votes for this as his best likely outcome
4. Atlanis --- see Yeast rapid proliferation and die-off --- ouch!

so he is really in the "power down" crowd with special emphasis on permaculture design and social principles

for a graphical illustration of what i am describing, see his powerpoint (in pdf formnat):
Energy Peak: Threat or Opportunity?, slide #5

[jimmydean]

If we divvy it up we have short-term, mid-term and long term solutions I think. Assuming personel vehicle transportion as the key area of consumption that can be controlled as well as provide the most long term positive impacts on oil slack and future environment I focussed on that. I also think short to mid term we need to start focussing on energy efficient dwellings to the point that they are almost self-sufficient.

I think the key short-term/feasible solution at this point is conservation in NA since we use more oil relative to other nations for non-essential uses. A good start is in the vehicles we drive. No matter how much I like an H2 I can't bring myself to buy one since my conscience would nag me too much We can't count on people conserving by concience but by pain at the pumps. What is the pain threshold that forces people to use public transport more and/or buy a scooter/bike instead of an SUV? $5/gallon or? Therefore if we don't start conserving now the market will eventually force us to conserve. A nudge from government right now simply asking people to conserve may be a good thing. I think rationing at this point is overboard but if we see oil return to 1970's levels (~$92 2005 dollars) then that may happen.

Mid-term (now-15 years), slow obsoletion of non-essential energy inefficient vehicles. Prices alone will force people away from the most oil inefficient anyways and we'll be mainly using.

Longer term we need to pour resources into developing efficient, non-environment harming renewable energy. Fusion is obviously the goal but harnessing fusion could take 100+ years of research or more. So long-near term nuclear energy for electricity and a push for personel vehicles that are hydrogen/electric based.

[RickTaylor]

Hello,

I have another question along the lines of the last one I asked. I read an essay by Alan AtKisson in which he said that because nuclear wastes are so poisionous, it was imperative for us to preserve our technological society for thousands of years so that we would be able to contain them.

Is this true? I don't know much about the problems of disposing of radioactive plutonium. Ignoring the NIMBY issues for a moment, are there feasible options for disposing of it in ways that don't require our continuing attention, so that it won't leak out even if we fall back into the stone age? If not, what are the likely consequences?

--Rick Taylor

[RonMN]

Sure...they dug a massive hole in the earth in nevada & are burrying it all in there...it's on a major fault line so if/when a big earthquake hits it should be all wide open to the atmosphere & we can all pretend we are the wicked witch of the west

"I'm MELTING...MELTING"

[RickTaylor]

Hmmmmm. I've found one answer to my question, a definite "maybe."

http://www.monbiot.com/archives/2004/09 ... ass-death/

$this->bbcode_second_pass_quote('', 'A')nd it may no longer be true to say that there is no safe means of disposing of nuclear waste. I have just read a technical report produced by the Finnish nuclear authority Posiva which, to my untrained eye, looks pretty convincing. The spent fuel is set in cast iron, which is then encased in copper and dropped down a borehole. The borehole is filled with saturated bentonite, a kind of clay. Posiva’s metallurgists suggest that under these conditions the copper barrier would be good for at least a million years.(9)

[earthman]

The solution is not in technology but in ourselves…we must grow up, change, evolve, etc. and humans tend to resist change (i.e., the Civil War-slavery was finally ended after a huge and bloody resistance). I am all for new energy technology that is sustainable and Earth-friendly. The fact is we are not using current methods of conservation and energy efficiency available to us.

New technology without a new mindset is not going to do us much good. Take the technology of war for example. We have developed increasingly sophisticated war technology over the last 100 years. But we have not dealt with the root cause of war, which is in us. More and better war technology will not end war. In a similar way, the energy crisis will not be solved by technology. The solution is available to us as an interior solution. But I regret to say that I do not think we (collectively) will embrace that solution.

Humans are not actually stupid, and there is much evidence for intelligence. What we are lacking is wisdom.

[mortifiedpenguin]

How come we can't just melt the stuff by tossing it back into the reactor? I know, stupid question, but why can't we?

[MonteQuest]

$this->bbcode_second_pass_quote('TrueKaiser', ' ')
good point. montequest(just using you as a example because you posted in this topic allot) for example uses eroei as the end all marker for anything, and as we know because of the focus on oil as a energy source oil has the highest erori then anything else. he uses this to rule out the effectiveness of other techs, which if had the same focus as oil might have the same or better eroei, as for which one of the other techs would have this potential if focused on at the same level that oil is today i don't know.

he then backs up his claims by going into the laws of thermodynamics(mainly the second law, which does follow the principals of scientific laws and i am not disputing this). since i have come here all i have seen him post in the new energy forum is either out right dismissal of a new technology citing eroei(though some are rather bad to begin with ex. the space convoys to titan) or the 2nd law of thermodynamics(though admittedly free energy is not true).

[Dezakin]

$this->bbcode_second_pass_quote('', 'W')hen nuclear energy was trotted out, they claimed "it would be so cheap, they wouldn't bother to meter it."

[TrueKaiser]

$this->bbcode_second_pass_quote('', 'T')hen it would seem you haven't understood anything I've written. EROEI is not the end all for evaluating energy technologies, but one needs to see some numbers to back up claims of viability. One also needs to see energy density numbers. One also needs to see scalability numbers. One also needs to see enviromental impact and sustainability numbers. ONe person stating in an article that K011 ethanol will be "competitive" with gasoline just doesn't cut it. I want hard science.

[dang1t]

While I do not feel nuclear energy is THE solution, I feel it is an important option that cannot be ignored. The biggest drawback to nuclear power, even with pebble bed reactors, is radioactive waste. Waste storage sites like Yucca Mountain are not only controversial, but extremely expensive. Moreover, they cannot guarantee that radioactive waste will not ever seep into the ground water table or that earthquakes will not destroy the facility, or that the material might fall into the wrong hands.

In my reading on the issue I came across an alternative permanent solution that seems quite reasonable to me, but is certainly worth discussing in this forum. It essentially entails encasing the waste in a stainless steel enclosure, designed to compensate for pressure and temperature, and dropping it into a subduction fault deep in the ocean.

Subduction faults are earthquake faults at the edge of a continental crust that are in collision with the adjoining oceanic crust. Since the former are lighter than the latter, such waste would find its way below the continental crust where it can sink even deeper toward the earth's core and securely wait out its radioactive lifespan without threatening humans, fish, or the evironment, and would be well out of reach of potential terrorists. There are at least 10 major subduction faults that would be viable candidates.

More details on this proposal can be found at:

http://home.earthlink.net/~dengelhardt/ ... steSol.pdf

This method of disposal would be much cheaper and safer than any other solution I have seen.

[Devil]

Firstly, reduce the quantity of waste by recycling the fuel. US reactors use the stuff once and are left with high level waste in large quantities. Many European and Japanese reactors recycle 96% of the fuel and the remaining 4% is medium level waste.

Secondly, the waste disposal is less of a problem than the ecopolitical greens make out. The secret is to store it in STABLE geologic structures which do not permit the ingress of water. A thick anhydrite stratum is ideal, because it is self-healing should a fissure be created and it is usually found in earthquake-free zones, because constant fissuring would metamorphise it into gypsum. Tests done in tunnels in anhydrite strata have revealed very high stability and no moisture.

I don't think I like the notion of subducted waste. Do we know enough about its future fate?

[Starvid]

Putting the "waste" in a subduction fault is a bad idea, at least if you use the single through cycle (as is done in Sweden and the US).

Why?
Because almost 99 % of the energy is left in the waste. The waste should be reprocessed and bred, or at least should the possibility be kept open. The best method so far seems to be deep geological storage, half a kilometer down in the bedrock, from where the burnt fuel can be retrieved if necessary . Contrary to popular opinion it is not expensive, not compared with the massive cash flows a nuke plant generate and the relatively minute amounts of waste.

[ozonehole]

Sorry for sounding repetitive, but I still think that avoiding the whole problem by using breeder reactors just makes more sense. And it offers the added bonus of being 50 times more efficient in terms of the energy that can be extracted (plus it uses U238 which is 140 times more common than U235).

But yes, we've got all this nuclear waste lying around, and we have to do something with it. So subduction, burial in geologically stable formations, and plutonium recycling might all need to play a part.

What about this technique of making the plutonium waste into a glass-like substance? How well does that resist wear?

cheers,
OZ