Hacker News Reader

Comment by ausjke | Hacker News Reader

can this be used for car/boat/etc-fuel somehow one day, then all gas-station will be run out of business and middle-east-plus-texas-oil-field all file for chapter-11?

not sure how to prevent radiation though.

View on HN

There's a few problems with making Highly-Enriched Uranium commercially available, even before we get to radiation.

Thorium reactors [1], on the other hand, might be more feasible due to their lack of weaponization potential, cheaper fuel, and reduced waste. However, Thorium reactors are much more complex, and will likely never approach the small scale of KiloPower; they also have significant startup costs, remain commercially unproven, and have a more dangerous fuel cycle (in terms of radioactivity).

[1] https://en.wikipedia.org/wiki/Thorium-based_nuclear_power

They have completed designs using low enriched Uranium. They're not quite as elegant or as small, but they should work fine.

https://fas.org/nuke/space/leu-reactor.pdf

Something that's often left out in the discussion of nuclear because it's not an issue yet, is that nuclear fissile materials are also rare. If nuclear became the standard for energy production, the rarity of these materials would, in the longrun, end up creating more stupid games similar to what we play with fossil fuels today.

'Time do bring democracy to Australia!'

'Wait guys... what?? We are a democracy!!'

'Sorry, can't hear you over the sounds of FREEDOM coming your way!'

It's usually left out of the discussion because it really is a non-issue long term as well. With breeder reactors (technology which already exists), Th in addition to U, U/Th extraction from seawater, we have enough fission fuel to power the entire planet at current levels for tens of thousands of years, if not indefinitely.

That's vastly understating the amount of Uranium and Thorium we can access. Without a breeder reactor it might only be tens of thousands but with a breeder reactor the amount of material we could use goes up by several orders of magnitude.

You can't just handwave away the economics or practical issues here. Seawater extraction is incredibly expensive. Breeder reactors are also expensive, ignoring the countless other technical and practical issues that they come with. For instance the output level for optimal efficiency with breeder reactors is quite low. You'd have literally thousands of breeder reactors spread around (with a proportional number of fuel reprocessing plants) when you run into the practical problem that, while failure rates are low, with the number of facilities scaled up by orders of magnitude they are currently intolerable due to the consequence of failure.

But back to cost your argument is like saying that "Bah, there's no concern about a lack of freshwater. We can just desalinate the sea!" You sure can, but that's completely irrelevant as the costs make it an unreasonable solution. Using conventionally obtained and utilized material, we only have enough nuclear material for about 200 years of consumption. [1] And in looking at the longrun it's obviously quite myopic to take as an assumption that humanity has reached the highest energy usage it will ever have.

[1] - https://www.scientificamerican.com/article/how-long-will-glo...

Reply on news.ycombinator.com