Heat left in nuclear spent fuel ?

[Externet]

Hi. Not a subject I know enough about.

 

One kilogram of typical spent nuclear fuel; as put aside to cool and later to storage by the energy industry, if had to be used to warm-up a dwelling in winter...

 

How many Watts would produce for how long?

 

( If its radioactivity was properly and safely contained, only releasing safe heat, in a world populated with only good angels and no risk of falling onto crooked minds )

[Moontanman]

WOW! This brings back old memories of pro nuclear forum that had plans they put up on how to build a stove out of nuclear waste or use it as a source. Ten years ago at least, I have looked all over my favs list but I'll keep looking. If I remember correctly it wasn't a really large lump of spent waste, maybe a cubic foot or so... Just a cubic foot in every home in america.. it wasn't a bad idea....

[EdEarl]

Maybe not a bad idea for retrofitting existing homes, but new homes can be built to use solar heat with nearly zero other other energy needed. Air conditioning is another issue not addressed by either spent nuclear or solar for heat. Both can generate electricity, of course.

[swansont]

from http://jol.liljenzin.se/KAPITEL/CH21NY3.PDF

 

At 1 day, it's 193 W/kg of Uranium (though the enrichment detail is not given)

at 90 days, 30 W/kg

at 180 days 19 W/kg

at 1 year, 10.8W/kg

at 5 years, 2.1 W/kg

 

That's a combination of fission product decay and the actinides formed from neutron absorption

[Externet]

Thanks.

With those small figures, it is not worth the trouble at all. Good for puttting the speculative question to rest; shows that solar collectors on a roof are far better choice; and that the nuclear industry is doing the proper action in guarding and putting away the spent material.

[Enthalpy]

One plant in China uses residual heat to distribute hot water to homes. Which is not something I'd like to see everywhere, due to the obvious risks made worse by the connecting pipes.

 

Many people are tempted by the residual heat of fission waste after the elements are separated, especially strontium 90.

http://en.wikipedia.org/wiki/Strontium-90

Some radioisotopic thermal generators (RTG) were built in the Soviet Union using ⁹⁰Sr.

http://en.wikipedia.org/wiki/Radioisotope_thermoelectric_generator

Though, it emits gamma rays, by bremsstrahlung and by the beta emission of the daughter ⁹⁰Y, as opposed to the painstakingly produced ²³⁸Pu which is a pure alpha emitter.

http://en.wikipedia.org/wiki/Plutonium-238

These ⁹⁰Sr RTG were used to power remote lighthouses and they created accidents, for instance two Siberian hunters who slept near one for warmth and died few days later.

 

One Lunar exploration programme by South Korea plans to use a ⁹⁰Sr-powered generator, and frankly, I would not use an RTG on the Moon. Risks before and during launch are just too big; Solar panels work well on the Moon. There are supposedly reasons like operation during the long night, but I'd choose differently. Probes have used Sunlight at the asteroid belt recently; our Moon is 6 times easier.

[NATO]

I'm pro nuclear. Sure it's dangerous when things go wrong, but so is air travel. As long as you don't forget the dangers, it's an amazing power sourse.

[Enthalpy]

An aeroplane crash doesn't need to evacuate a province for centuries. The designers at Westinghouse (Fukushima's technology) did not forget the dangers; it's nuclear power that's inherently too dangerous. We have cheaper power sources, so "not forget the danger" means "don't make it".

[imatfaal]

!

Moderator Note

NATO & Enthalpy. The safety of nuclear power per se is offtopic - please do not continue in this vein.

[J.C.MacSwell]

Thanks.

With those small figures, it is not worth the trouble at all. Good for puttting the speculative question to rest; shows that solar collectors on a roof are far better choice; and that the nuclear industry is doing the proper action in guarding and putting away the spent material.

Well...those small figures represent a lot of energy per kg. Compare it with wood, oil or propane. If it really was safe it would be worthwhile.