The "Equities & Terrorists" thread (http://early-retirement.org/cgi-bin..._board;action=display;num=1087657588;start=60) mentions a hydrogen economy and nuclear technology. Allow me to ramble for a few paragraphs.
The May 2004 Scientific American (http://www.sciam.com/article.cfm?chanID=sa006&colID=1&articleID=000600B1-1A4E-1085-94F483414B7F0000) looks at the hydrogen economy and concludes that it's tempting, but other technologies are closer to fiscal reality. Apparently the most economic process of producing hydrogen (from methanol or natural gas) also produces a tremendous amount of CO2-- a big greenhouse gas problem. The author concludes that fuel cells will start showing up in houses, cell phones, survival gear, & laptop computers... but that diesel and/or electric cars are much closer to economic success.
Hydrolysis is a BIG loser. Personally the logistics challenges of generating, transporting, storing, dispensing, & using hydrogen scare the heck outta me. Today submarines use oxygen generators that electrolyze pure water into H2 & O2. The O2 is stored in 3000-psi tanks and the H2 is vented overboard as soon as it can be disposed of. Submarines also use nuclear reactors and many varieties of highly explosive ordnance. I never had an emergency with the explosives or the reactor (other than "minor inconveniences") but I've had several emergencies with oxygen generators. Even under normal operation they're a PITA requiring extensive labor-intensive monitoring and expensive maintenance. British submariners enclose their generators in explosion-proof steel cases, and there's a reason that we all refer to them as "bombs". Even the manufacturer (http://www.treadwellcorp.com/index.html) has seen the light and is moving from electrolysis to proton-exchange membranes.
The new reactor technology that TH mentions is a pebble-bed reactor. (http://web.mit.edu/pebble-bed/) I believe it uses regular or enriched uranium and the heat is transferred to helium, which isn't easily made radioactive. The advantage of the pebble-bed design is that it'll shut itself down if it loses power or flow, something that's much more problematic (yet achievable!) in a pressurized-water reactor.
Fifty years of material science has taught us nukes a lot, and today's reactor components have radiation levels that are literally orders of magnitude lower than the bad old days. Practices that were routine to me as a "young nuke" would be horrific stone-age implements in today's Navy. So disposing of tomorrow's old fuel pebbles will be "no big deal" as long as they're accounted for. When the civilian industry can economically compete with cheap coal/oil/natural gas, the pebble-bed design will move out of the lab and become an industry standard.
If you've read this far and you're still awake, thanks for indulging me. My spouse really hates having to hold up her end of the conversation on these topics, and my kid still has trouble pronouncing "self-saturable burnable poisons"...
The May 2004 Scientific American (http://www.sciam.com/article.cfm?chanID=sa006&colID=1&articleID=000600B1-1A4E-1085-94F483414B7F0000) looks at the hydrogen economy and concludes that it's tempting, but other technologies are closer to fiscal reality. Apparently the most economic process of producing hydrogen (from methanol or natural gas) also produces a tremendous amount of CO2-- a big greenhouse gas problem. The author concludes that fuel cells will start showing up in houses, cell phones, survival gear, & laptop computers... but that diesel and/or electric cars are much closer to economic success.
Hydrolysis is a BIG loser. Personally the logistics challenges of generating, transporting, storing, dispensing, & using hydrogen scare the heck outta me. Today submarines use oxygen generators that electrolyze pure water into H2 & O2. The O2 is stored in 3000-psi tanks and the H2 is vented overboard as soon as it can be disposed of. Submarines also use nuclear reactors and many varieties of highly explosive ordnance. I never had an emergency with the explosives or the reactor (other than "minor inconveniences") but I've had several emergencies with oxygen generators. Even under normal operation they're a PITA requiring extensive labor-intensive monitoring and expensive maintenance. British submariners enclose their generators in explosion-proof steel cases, and there's a reason that we all refer to them as "bombs". Even the manufacturer (http://www.treadwellcorp.com/index.html) has seen the light and is moving from electrolysis to proton-exchange membranes.
The new reactor technology that TH mentions is a pebble-bed reactor. (http://web.mit.edu/pebble-bed/) I believe it uses regular or enriched uranium and the heat is transferred to helium, which isn't easily made radioactive. The advantage of the pebble-bed design is that it'll shut itself down if it loses power or flow, something that's much more problematic (yet achievable!) in a pressurized-water reactor.
Fifty years of material science has taught us nukes a lot, and today's reactor components have radiation levels that are literally orders of magnitude lower than the bad old days. Practices that were routine to me as a "young nuke" would be horrific stone-age implements in today's Navy. So disposing of tomorrow's old fuel pebbles will be "no big deal" as long as they're accounted for. When the civilian industry can economically compete with cheap coal/oil/natural gas, the pebble-bed design will move out of the lab and become an industry standard.
If you've read this far and you're still awake, thanks for indulging me. My spouse really hates having to hold up her end of the conversation on these topics, and my kid still has trouble pronouncing "self-saturable burnable poisons"...