Hacker Newsnew | past | comments | ask | show | jobs | submitlogin

Ah yes, the old “what will we do in 10000 years when the Uranium runs out” problem.


Easily mined uranium will deplete in less than 100 years unless we start using breeder or thorium reactors that are more efficient in using up fuel.


100,000 years supply is dissolved in the ocean. Breeder technology, and (thorium fuel cycle) are pretty well understood at this point. In fact, CANDU reactors widely deployed already support thorium fuel cycle. The reason we don't use them is because with all the uranium available, it's not necessary.


We could say the same about lithium supplies. It turns out 'mining' something measured in the parts per billion is enormously damaging to environments and quite expensive to the point of impracticality


Early stages, but current state of the art involves putting fabric out that captures the uranium passively. [1]

> Mining of underground uranium has environmental challenges not encountered with extracting it from the oceans. And Wai says the fibers, which have affinity for more heavy metals than just uranium, can likely be used one day to clean up toxic waterways themselves. He says the fibers have potential to extract vanadium, an expensive metal used in large scale batteries, from the oceans instead of mining it from the ground.

[1] https://www.pnnl.gov/news/release.aspx?id=4514


Yes, filtering ocean water for material is a well known technique. You need a massive throughput of ocean water for a small output and you also filter salts, other metals, polymers, and sea life. You must further refine those materials to get the stuff you want. You also change the ph of the filtered water in a way that would be disastrous if reinjected, and you consume filter media quickly. That all adds up to a huge waste and massive ecological damage.its simply not practical at scale.


I'm curious why you think deploying some of these fabrics would change the pH of the ocean? There are geological processes which replenish dissolved uranium in the ocean per the article I linked. I haven't seen any particular waste or sustainability concerns. The nice thing about uranium is that it's so incredibly energy dense that you don't really need to pull out all that much. I'm not ready to be so defeatist.

I defer to the researcher.

> "We have chemically modified regular, inexpensive yarn, to convert it into an adsorbent which is selective for uranium, efficient and reusable," said Chien Wai, president of LCW Supercritical Technologies. "PNNL's capabilities in evaluating and testing the material, have been invaluable in moving this technology forward."


> 100,000 years supply is dissolved in the ocean.

Yes, but that's not so easily mined. Point being that the cost of nuclear power will go up once the easily mined material is consumed.


Surprisingly not really. The cost of fissile material is extremely small relative to the cost of generated electricity. Raw uranium contributes $0.0015/kWh to the cost of nuclear power. In breeders it’s $0.000015/kWh. The article I linked suggested that even today sweater extraction costs just double what mining costs, so 3/10th of a cent per kWh.

This is why we don’t use breeder reactors right now. The cost of uranium is a rounding error relative to the value of the generated electricity.


"Suggested cost" is speculative. We won't know what it will really cost to scale until we actually start doing it.

There are also reasons to use breeders beyond fuel cost, such as dramatically decreasing the amount of waste and the time the waste is hazardous; both are reduced by 100x each IIRC.


Agreed on both counts.


This is from the 2020 IAEA world's uranium resources report [0];

"Meeting high case demand requirements through 2040 would consume about 28% of the total 2019 identified resource base recoverable at a cost of < USD 130/kgU (USD 50/lb U3O8) and 87% of identified resources available at a cost of < USD 80/kgU (equivalent USD 30/lb U3O8)."

Apply some exponential growth to that, and those allegedly 10.000 years would actually end up looking more like not even 50 years.

[0] https://www.iaea.org/newscenter/pressreleases/worlds-uranium...


The 10,000 years refers to the 4 billion tons dissolved in the ocean. However consider that its possible to dramatically extend the useful life of supplies with breeder reactors - and also to use thorium in existing designs such as the CANDU.




Guidelines | FAQ | Lists | API | Security | Legal | Apply to YC | Contact

Search: