5 ms·

Energy density matters... a lot. As a matter of scale, nuclear can be shipped by plane to feed a plant (no Government would allow it, just for comparison sake).

Energy density matters... a lot. As a matter of scale, nuclear can be shipped by plane to feed a plant (no Government would allow it, just for comparison sake). Try doing it with coal or gas. How much digging you must do to have a sizeable quantity of radioactive ore to refine into nuclear fuel? Compare it to coal, lithium salt, bauxite (aluminium) and cobalt. Electrification of everything and mining every item above can take a greater toll on environment. Is Nuclear older tech? Light Water Reactors (LWRs) are from 1950s and used by the Navy. In the same time, Molten Salt Reactos (MSRs) were developed by Alvin Weinberg in the Oak Ridge National Labs (ORNL) and proved very successfull. Unfortunately, the US Gov't (Nixon) invested in Plutonium/Nuke tech and MSRs weren't developed further. Not all energy uses are electrical. MSRs can also be used on thermal processes (above 700 degrees Celsius) and thermal energy is crucial to dozens of industrial processes, currently moslty feeded by coal and gas. Current light water cooled nuclear plants just do at 350 degrees and requires tons of protection to contain gaseous water pressure (> 150 thousands Atm). MSRs can operate at 3 Atm and higher temps => low explosion risk. Radioactive waste: France is estimated to grow long term waste from 140,000 cubic meters (2019 - data from Statista) to 189,000 in 2040. Thats 2,200 40ft containers to 2,900. A 700 container size change in 20 years. All their current long term waste fills 11% of Evergreen, the infamous ship that clogged the Suez Canal. Compared to coal ash deposits, it is nothing. Current nuclear waste retains 97% of usable energy. With MSRs, it is estimated to reduce it to under 5%, with half-times around 50 years (very short). Imagine the waste reduction after recycling all that into those reactors. The most important component in solar panels is silicon with 99.999% purity. That consumes a lot or energy to produce. And China produces lots of them... fueled by coal plants. Nice for a carbon-free tech. Concrete is a carbon intensive material but you´ll use a lot less in a nuclear plant than a hidropower one. Concrete, aluminum, fertilizer are all thermal energy intensive industries and are carbon intensive with current tech. What do you think where their carbon footprint goes if you adapt them to use some nuclear thermo-electrical boost?

pfdietz 4y ago
All of the considerations you bring up are lame substitutes for the metric that actually matters... cost. If we had never built nuclear power plants or wind turbines or PV fields, maybe trying to get a handle on the cost by such indirect arguments could be useful. But why resort to such an unreliable methodology when we have the actual cost data? We know that nuclear is considerably more expensive than renewables, which is why nuclear is shut out of new construction in the US. Even around the world, renewables are dominating nuclear for new construction.
Schroedingersat 4y ago
> Energy density matters... a lot. As a matter of scale, nuclear can be shipped by plane to feed a plant (no Government would allow it, just for comparison sake). Try doing it with coal or gas. How much digging you must do to have a sizeable quantity of radioactive ore to refine into nuclear fuel? Compare it to coal, lithium salt, bauxite (aluminium) and cobalt. Electrification of everything and mining every item above can take a greater toll on environment. You're still just pointing out categories where renewables win. Glassless pv panels are available to anyone. Consider the Barrel 375W panel at 5kg. That's a power density of 18W/kg which is about on par with the mass of steel in most nuclear reactors and dwarfed by the mass of concrete. In a 25 year lifetime it has an energy output of 14GJ/kg. Compare to about 200GJ/kg of uranium fuel at typical burnup and thermal efficiency. It looks favourable for the uranium until you consider you have to have a huge amount of safety and shielding equipment around it. So this is fine unless you are arguing that LWRs have insufficient energy density? Solar also requires a little bit of silver and copper, but that is vastly easier to get than all the exotic elements required to keep a nuclear reactor running. > The most important component in solar panels is silicon with 99.999% purity. That consumes a lot or energy to produce. And China produces lots of them... fueled by coal plants. Nice for a carbon-free tech. How do you think that uranium is mined? This is captured hy eroi which is in the 20-100 range for current generation panels.

pfdietz 4y ago

All of the considerations you bring up are lame substitutes for the metric that actually matters... cost. If we had never built nuclear power plants or wind turbines or PV fields, maybe trying to get a handle on the cost by such indirect arguments could be useful. But why resort to such an unreliable methodology when we have the actual cost data? We know that nuclear is considerably more expensive than renewables, which is why nuclear is shut out of new construction in the US. Even around the world, renewables are dominating nuclear for new construction.

Schroedingersat 4y ago

> Energy density matters... a lot. As a matter of scale, nuclear can be shipped by plane to feed a plant (no Government would allow it, just for comparison sake). Try doing it with coal or gas. How much digging you must do to have a sizeable quantity of radioactive ore to refine into nuclear fuel? Compare it to coal, lithium salt, bauxite (aluminium) and cobalt. Electrification of everything and mining every item above can take a greater toll on environment. You're still just pointing out categories where renewables win. Glassless pv panels are available to anyone. Consider the Barrel 375W panel at 5kg. That's a power density of 18W/kg which is about on par with the mass of steel in most nuclear reactors and dwarfed by the mass of concrete. In a 25 year lifetime it has an energy output of 14GJ/kg. Compare to about 200GJ/kg of uranium fuel at typical burnup and thermal efficiency. It looks favourable for the uranium until you consider you have to have a huge amount of safety and shielding equipment around it. So this is fine unless you are arguing that LWRs have insufficient energy density? Solar also requires a little bit of silver and copper, but that is vastly easier to get than all the exotic elements required to keep a nuclear reactor running. > The most important component in solar panels is silicon with 99.999% purity. That consumes a lot or energy to produce. And China produces lots of them... fueled by coal plants. Nice for a carbon-free tech. How do you think that uranium is mined? This is captured hy eroi which is in the 20-100 range for current generation panels.