the new-clear age
There's been some friendly banter around SFB about the merits of nuclear energy, or lack thereof. By "friendly banter", I of course mean "everyone else thinks I'm crazy."
Well, apparently I'm not the only one who sees nuclear power as our society's best chance to kick the energy-by-fossil-fuels habit without majorly curbing our electricity-guzzling ways. This paper, for example, shows that the cost of nuclear energy is comparable to that of fossil fuels depending on location - for Canada in particular, nuclear is second to coal in terms of cost. That's including maintenance, waste disposal and decomissioning costs. When the "cost" of venting carbon dioxide is factored in, through a tariff on gas emissions a la Kyoto, nuclear energy is more economic than coal.
As for uranium availibility, this page puts known recoverable uranium ore at 3,107,000 tonnes. This page agrees. It takes approximately 8kg of ore to produce one kg of usable fuel, which produces 315,000 kWh of energy per kilogram. Nuclear energy is responsible for about 2500 TWh of energy annually. Crunch those numbers, and you come out with about 50 years worth of uranium at present consumption levels. This is a huge underestimate for many reasons. First, because it doesn't take into account spent-fuel reprocessing, which recycles unburned uranium. Second, the 8kg ore per 1kg fuel figure assumes about 1% "good" uranium (U235) in the ore, while over 15% of the world's stores (mostly in Canada) are high grade and contain 10-20% U235. Third, it doesn't take into account the many tonnes of weapons-grade stockpiles held by Russia and the States that are now being sold off. These are already mined and highly-enriched fuels that actually have to be diluted 30:1 before they can be used in reactors. Fourth, and most importantly, this is only the uranium that we know for sure is out there and economically available with current methods. I doubt even the most optimistic oil forecasts involving dubious "likely oil here" and "tear up a national park there" schemes could give us another 50 years of burning oil at our current rate.
There has also been some buzz about pebble-bed reactors. These new designs use helium-gas turbines to reach much higher operating temperatures and efficiencies, while being inherently meltdown-proof. And not just the many-redundant-cooling-systems safety of conventional reactors: tests have shown pebble beds with all control systems switched off, all coolant flow stopped, reaching their maximum design temperature and happily staying there for hours. While they won't be ready for commercial use for another 10 years, these next-generation reactors will provide more bang for your nuclear buck with thermal efficiencies of around 50%, compared to 30% for today's reactors.
Waste disposal is a tough issue. Even if you take the cost of proper disposal into account, you can't get around the fact that more nuclear power means more radioactive spent fuel slowly decaying underneath a mountain somewhere. Until we finally build a space elevator, there'll be no economic way to completely get rid of the stuff, and there's always the chance that an earthquake, flood, terrorist attack, or some other force of nature will leach radioactive toxins into our soil and kill us all. To this, I can only say that I'd rather have hundreds of tonnes of vitrified uranium to bury than millions of tons of carbon dioxide venting into my atmosphere. Until wind and solar power lower their costs by an order of magnitude and somehow solve that pesky problem of not working when the sun don't shine and the wind don't blow, nuclear's all we got, baby.
Well, apparently I'm not the only one who sees nuclear power as our society's best chance to kick the energy-by-fossil-fuels habit without majorly curbing our electricity-guzzling ways. This paper, for example, shows that the cost of nuclear energy is comparable to that of fossil fuels depending on location - for Canada in particular, nuclear is second to coal in terms of cost. That's including maintenance, waste disposal and decomissioning costs. When the "cost" of venting carbon dioxide is factored in, through a tariff on gas emissions a la Kyoto, nuclear energy is more economic than coal.
As for uranium availibility, this page puts known recoverable uranium ore at 3,107,000 tonnes. This page agrees. It takes approximately 8kg of ore to produce one kg of usable fuel, which produces 315,000 kWh of energy per kilogram. Nuclear energy is responsible for about 2500 TWh of energy annually. Crunch those numbers, and you come out with about 50 years worth of uranium at present consumption levels. This is a huge underestimate for many reasons. First, because it doesn't take into account spent-fuel reprocessing, which recycles unburned uranium. Second, the 8kg ore per 1kg fuel figure assumes about 1% "good" uranium (U235) in the ore, while over 15% of the world's stores (mostly in Canada) are high grade and contain 10-20% U235. Third, it doesn't take into account the many tonnes of weapons-grade stockpiles held by Russia and the States that are now being sold off. These are already mined and highly-enriched fuels that actually have to be diluted 30:1 before they can be used in reactors. Fourth, and most importantly, this is only the uranium that we know for sure is out there and economically available with current methods. I doubt even the most optimistic oil forecasts involving dubious "likely oil here" and "tear up a national park there" schemes could give us another 50 years of burning oil at our current rate.
There has also been some buzz about pebble-bed reactors. These new designs use helium-gas turbines to reach much higher operating temperatures and efficiencies, while being inherently meltdown-proof. And not just the many-redundant-cooling-systems safety of conventional reactors: tests have shown pebble beds with all control systems switched off, all coolant flow stopped, reaching their maximum design temperature and happily staying there for hours. While they won't be ready for commercial use for another 10 years, these next-generation reactors will provide more bang for your nuclear buck with thermal efficiencies of around 50%, compared to 30% for today's reactors.
Waste disposal is a tough issue. Even if you take the cost of proper disposal into account, you can't get around the fact that more nuclear power means more radioactive spent fuel slowly decaying underneath a mountain somewhere. Until we finally build a space elevator, there'll be no economic way to completely get rid of the stuff, and there's always the chance that an earthquake, flood, terrorist attack, or some other force of nature will leach radioactive toxins into our soil and kill us all. To this, I can only say that I'd rather have hundreds of tonnes of vitrified uranium to bury than millions of tons of carbon dioxide venting into my atmosphere. Until wind and solar power lower their costs by an order of magnitude and somehow solve that pesky problem of not working when the sun don't shine and the wind don't blow, nuclear's all we got, baby.
