3 ms·

Waste heat? Evaporating the water? Nuclear power plants are steam engines. All their heat goes to evaporating water. Come to think of it, I wonder if you could

Waste heat? Evaporating the water? Nuclear power plants are steam engines. All their heat goes to evaporating water. Come to think of it, I wonder if you could harvest the steam from a nuclear plant, run it through a condenser or distiller, and in that way produce electricity and purify water at the same time.

cpeterso 11y ago
Harvesting the steam is a clever idea, but I don't know if the average consumer is ready for what would be spun as "radioactive Franken-water".
logfromblammo 11y ago
Not all fission reactors use the same cycles to turn heat from the nuclear reaction into usable power. Most existing reactors in the US use the reactor core as the heat source, a convection cooling tower as the heat sink, and water/steam as the working fluid. Using salt water as the working fluid in a BWR or SCWR would probably be dangerous, as it circulates around the reactor core. In a PWR, the working fluid and the fluid circulating past the reactor core are separated via heat exchangers in the steam generator, so that's probably the only widely used reactor type that could do distillation-based desalination without heavy modification. But probably the most useful way to go about doing it is to keep the rest of the reactor as it is, and just attach the reverse osmosis desalinator pumps to the same driveshaft as the electricity generator. Even though boiling and condensing water is an integral part of steam engine operation, it really works best when that water has been completely demineralized already. Otherwise, your boiler fills with salt sludge, and your condenser gets clogged with mineral scale. You're saving efficiency by taking out the two conversions between electrical and mechanical work and the transmission loss between generator and pump motor. The purified water and waste brine could also carry heat away from the steam engine's heat sink if it can go out hotter than the ocean water that comes in. I'm thinking that you'd heat the waste brine as hot as possible before dumping it in a solar evaporation pond. The infrastructure required to pump pre-heated water to the nearest community along with cold is probably not going to pay off unless you're supplying high-rises or a university campus.

cpeterso 11y ago

Harvesting the steam is a clever idea, but I don't know if the average consumer is ready for what would be spun as "radioactive Franken-water".

logfromblammo 11y ago

Not all fission reactors use the same cycles to turn heat from the nuclear reaction into usable power. Most existing reactors in the US use the reactor core as the heat source, a convection cooling tower as the heat sink, and water/steam as the working fluid. Using salt water as the working fluid in a BWR or SCWR would probably be dangerous, as it circulates around the reactor core. In a PWR, the working fluid and the fluid circulating past the reactor core are separated via heat exchangers in the steam generator, so that's probably the only widely used reactor type that could do distillation-based desalination without heavy modification. But probably the most useful way to go about doing it is to keep the rest of the reactor as it is, and just attach the reverse osmosis desalinator pumps to the same driveshaft as the electricity generator. Even though boiling and condensing water is an integral part of steam engine operation, it really works best when that water has been completely demineralized already. Otherwise, your boiler fills with salt sludge, and your condenser gets clogged with mineral scale. You're saving efficiency by taking out the two conversions between electrical and mechanical work and the transmission loss between generator and pump motor. The purified water and waste brine could also carry heat away from the steam engine's heat sink if it can go out hotter than the ocean water that comes in. I'm thinking that you'd heat the waste brine as hot as possible before dumping it in a solar evaporation pond. The infrastructure required to pump pre-heated water to the nearest community along with cold is probably not going to pay off unless you're supplying high-rises or a university campus.