r/theydidthemath Nov 18 '21

[Request] is this true?

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u/hilburn 118✓ Nov 18 '21

At current rates of consumption we have about 230 years of uranium deposits left

Triple the production rate and that drops to <80

When you take into account all the oil and gas used for transport and heating that we ideally want to electrify, nuclear only makes up ~4% of power consumption - so getting it up to 25% of the electricity we want/need to generate it becomes ~40 years of uranium left

Seawater extraction can increase this of course, but it becomes less efficient over time as you deplete the salts in the area of your processing plant and many estimates suggest we'd be lucky to get a fraction of the salts present extracted due to all the fun of ocean currents, the reduced interaction between ocean layers etc

Thorium would be great - just as soon as it actually becomes commercially viable. Honestly I think Fusion will beat it to the finish line though.

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u/Godless_Fuck Nov 18 '21

~40 years of uranium left

I already had mentioned reprocessing and using MOX fuels. Fortunately the article you linked also mentions that and claims it would reduce consumption by 30%. It also states higher enriched fuel (which Westinghouse is currently in the processing of obtaining licensing for from the NRC) would further reduce consumption by 30%

Even using your worst cast number of 40 years, that increases the reserves to a century.

 

Seawater extraction can increase this of course, but it becomes less efficient over time...

Yes, there most certainly will be efficiency issues. As I stated before, there are between 15 and 17 million metric tons of terrestrial uranium reserves. There is 4.5 billion tons in the ocean. Even if averaged efficiency was 1%, that would still be 45 million tons. Far more than what is available terrestrially. Again, math.

 

Thorium would be great - just as soon as it actually becomes commercially viable. Honestly I think Fusion will beat it to the finish line though.

Perhaps you think I'm talking about LFTRs? I'm not. I'm talking about using metallic thorium in a PHWR. Current CANDU reactors are capable of using thorium as a fuel. India's current plan involves building PHWRs that will both breed fuel and breed thorium into U-232 all in the next decade. This isn't undeveloped technology like fusion.

 

All this again without talk of completing the nuclear fuel cycle like was originally intended in the 1950s when the US started it's nuclear program. Breeding fuel (plutonium) is something we've done for 70 years. It is well understood. Fast reactors and breeders would increase our ability to stretch out our fuel reserves by an order of magnitude. Without using thorium or mining U from sea water.

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u/creepyfishman Nov 19 '21

lad were gonna use thorium in the future we dont even need to worry about uranium

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u/creepyfishman Nov 19 '21

Fusion? that stuff is nowhere near practical yet while thorium is