5 ms·
How is nuclear renewable?
by zerostar07 14y ago
How is nuclear renewable?
- jules 14y agoIt depends on the kind of nuclear. For example thorium, while finite, is quite abundant. Note that the sun's energy is finite as well, so "renewable" is not black and white.
- dredmorbius 14y agoIt's not renewable, but it is essentially zero-impact as far as atmospheric carbon dioxide emissions are concerned. I'm hedging only because someone will come along and cite fossil-fuel based ancillary activities related to nuclear fuel mining, processing, transport, and disposal if I say "zero". But for all intents, zero. There are breeder reactor designs which convert far more abundant non-fissile isotopes to fuel-grade fissible isotopes, usually starting with U-238 or Th-232. While not technically "renewable", these do off a theoretically sustainable energy supply, with projections suggesting over 5 billion years' supply at forseable energy consumption rates (that's long enough for solar stability to be the principle limiting factor). https://en.wikipedia.org/wiki/Breeder_reactor https://en.wikipedia.org/wiki/Breeder_reactor
- danielharan 14y agoYes, all the things you mentioned, plus building the actual plant. As far as new breeder designs, it's a bit too late. Nuclear promised us "energy too cheap to meter" and construction and maintenance costs have kept going down. Meanwhile solar and wind have been regularly going down in price with each doubling of production. The case against nuclear isn't environmental; it's economic.
- sliverstorm 14y agoThe case against nuclear isn't environmental; it's economic. No, it's mostly just fear.
- cygx 14y agoJust because some of the popular resistance to nuclear energy production is based on fear doesn't mean there aren't rational arguments against it. Personally, I consider the current generation of fission reactors technologically unsound: Neither the problem of radiactive waste nor shutdown in case of catastrophic failures are adequately solved. Research in Thorium reactors is worthwhile considering the growing energy needs of China and India, but smarter transnational grids with more efficient load balancing can probably make renewable energy production viable in Europe.
- dredmorbius 14y agoThere are a number of arguments against nuclear. I'm not an uncritical fan, but I'm not a absolute opponent either. Nuclear represents high risks at multiple areas of operation: - The fuel, waste, and plants are all radioactive, in some cases for geological time periods, presenting unprecedented disposal issues. Perhaps not insurmountable, but very, very significant. - Scale of operations of nuclear plants means that the plants themselves, their operations, and their revenues are immense. A large nuclear plant generates over $2 billion worth of electricity (retail) annually. As we've learned with other large financial systems, profit maximization can skew risk management objectives. - Risks of scale include management, financial, terrorist, natural disaster, labor action, and other factors. Any of these could put, at the least, power reliability at risk, and at worst, health and safety for millions of people. One consequence of the 2011 Tōhoku earthquake and tsunami in Japan was TEPCO's loss of 27% of its generating capacity (http://www.pcworld.idg.com.au/article/379610/japan_facing_major_electricity_supply_problems_blackouts/ http://www.pcworld.idg.com.au/article/379610/japan_facing_ma...). Exacerbated by Japan's dual-cycle grids (eastern and western Japan operate on 50 and 60 Hz respectively: http://www.wired.com/gadgetlab/2011/03/tech-legacy-tokyo/ http://www.wired.com/gadgetlab/2011/03/tech-legacy-tokyo/). - The timescale and emergent phenomena associated with nuclear power mean that risks aren't known, appreciated, and/or understood at construction time. Chernobyl, TMI, and Fukushima all exhibited fundamental engineering and/or operational flaws. Siting of the Fukushima plant turned out to be problematic. Several California plants are now known to be on or near active seismic zones. We still don't have a permanent waste disposal solution in the US (and much of the rest of the world). Most alternate forms of renewable / sustainable power are much more diverse and distributed. Though this means higher capital and maintenance costs per MWh of generation, it also means vastly smaller risks of any individual plant failure, and far lower likelihood of cascade failures. Interesting times.
- ktizo 14y agoPebble bed reactors are nice - http://en.wikipedia.org/wiki/Pebble_bed_reactor http://en.wikipedia.org/wiki/Pebble_bed_reactor But my major problem with most forms of nuclear is that from a geopolitical standpoint, if you are proposing a technology for clean global power, it has to by definition be something you would be able to share freely with a potential enemy. Most current nuclear power technologies, including the pebble bed, conspicuously fail at this.
- beefman 14y agoDefine "technically renewable" and "theoretically sustainable".
- dredmorbius 14y agoA technically renewable resource would be one that renews itself naturally, at a rate exceeding that of consumption. Solar, wind, and hydro are renewable in the sense that we consume them as they are produced. Agriculturally-based power sources (wood, ethanol, biomass, algae oil generation) are renewable in the sense that the biological source grows back after it's harvested (assuming sustainable harvesting). A sustainable consumptive resource is one which, at projected rates of consumption, would be sufficient for forseable demand until the end of time on Earth. In 4-5 billion years, the sun will expand to the point that it encompasses Earth's orbit. Somewhat sooner than that, increased solar radiation will boil off the oceans and atmosphere. We'll have bigger things to worry about than sources of electricity. https://en.wikipedia.org/wiki/Timeline_of_the_far_future https://en.wikipedia.org/wiki/Timeline_of_the_far_future
- beefman 14y ago"Renews itself naturally at a rate exceeding that of consumption" Over what period of time (or is the rate of consumption fixed?) and what region of space? "at projected rates of consumption, would be sufficient for forseable demand until the end of time on Earth" Not sure I believe 4B-year forward demand projections... Isn't the amount of energy expended (and/or mass of raw materials mixed) per TWh produced what we really care about?
- dredmorbius 14y agoIf you want to dig into the specifics of any given model, well, you'd have to dig into the specifics of the model. If you look at the Timeline of the Far Future, somewhere between 100m and 800m years from now life as we know it on Earth becomes untenable (asteroid impacts, solar flux), if not before (other effects). There are some practical upper long-term limits to human population on Earth. I suspect it's anywhere between a few hundred millions to low billions (I don't believe present populations are long-term sustainable). There are other resource constraints which may serve to set an upper limit on energy consumption per capita. From this we can establish long-term energy demands, available supplies, and feasibility of these supplies. 4 billion year forecasting is rather more fantasy than science, so far as human endeavors go.
- beefman 14y agoHow is hydro renewable?