The Defense Advanced Research Projects Agency (DARPA) is an office within the US government that develops military technology. One of their current projects is to design a nuclear reactor that can be sustained with human and animal waste:
Link via Fast Company | Photo: US Department of Agriculture
The military’s already working on using seawater to create fuel, but that’s more of an option for maritime operations. Without an endless supply of seawater, they’d need an alternative carbon source. Enter the massive quantities of sludge that inevitably accumulate around troop outposts. It’s been a problem for decades, according to environmental management expert Dr. James Lee. In an article for the Army’s Engineer School, he writes that the military spent upwards of $65,000 in annual fuel costs just to burn off human refuse at base camp in the Balkans.
So Darpa’s proposal would offer two major benefits: Less waste to treat and dispose of at bases, and fewer financial and tactical burdens around sourcing adequate fuel — whether to power jets and facilities or burn off heaps of odorous fecal matter. And with a single trooper stationed in Afghanistan using 22 gallons of fuel a day, that’d add up to major savings.
Link via Fast Company | Photo: US Department of Agriculture
Uranium from seawater is perfectly reasonable, something people have talked about for decades. Using human poop as a biofuel is equally reasonable.
I just learned that people ingest, on average, one to two micrograms a day of uranium via our food. The 'safe upper limit' is apparently 35ug. That's not much.From 1.5 micrograms of U, you get just over .01ug U-235. When you fission that, you release ~.1% of its rest mass energy. That's ~1000 J, per person, per day- or an eightieth of a watt (thermal). If you had a breeder reactor and could use the U-238 as well, you could up that to 1.5 watts thermal (.5 watts electric).
If you're already bringing a nuclear reactor with you somewhere, an extra few kg for fuel isn't going to be an issue. Even the smallest nuclear reactors mankind has developed have weights measured in tons. The military uses highly enriched fuel compared to civilian reactors (at least in naval reactors). That means 1 kg of fuel could provide 1-10 million kWh of electricity, depending on enrichment and efficiency. Why would anyone, even DARPA, not choose that?
http://en.wikipedia.org/wiki/Aachi_&_Ssipak