Are there any MSR designs that require NO reprocessing (whether online, batch or other)?
I'd love to find actual data but, anecdotally, it seems like a large amount (vast majority?) of the nuclear legacy costs for countries like the UK, at least, come from the back-end - ie reprocessing. If you just store used rods (in perpetuity) near the reactor they were used in then the overall legacy footprint is pretty modest. Indeed, I think that's what the UK does now - our reprocessing facilities are now in decommissioning mode and the US did the same a long time ago.
Yes - part of the decision to stop reprocessing was proliferation risk. But I think it's also because reprocessing is so insanely messy and so easy to get wrong.
This is because if you 'reprocess' fuel, the waste problem just balloons... the rods have to be chopped up, dissolved in nitric acid, taken through a complex chemical process and you end up with vast amounts of liquid waste, various bits of undissolved gunk, a fiendishly difficult-to-decommission reprocessing facility and all the rest. Reprocessing plants are some of the most complicated chemical plants in the world... and when they go wrong (eg the UK's Thorp leak) they're almost impossible to repair owing to the radioactivity.
In the past, the purpose of the early reactors was to generate plutonium for weapons and so reprocessing was, in reality, the key activity, with the reactors just the tedious thing you had to build to provide feedstuff for this extraction process.
But if we don't want any new plutonium then there's no need to reprocess and the waste problem just becomes insanely easier.
To see what I mean, google the history of the UK's Sellafield (specifically the B.205 and Thorp plants) or Russia's Mayak or France's La Hague. So many leaks and accidents, all totally unnecessary if they hadn't been trying to reprocess the fuel. The idea of taking something small and stable (a rod) and turning it into a dangerous liquid and then trying to run it through a fiendishly complex chemical plant just seems nuts on its face.
Hence my question about MSRs... can you build one that doesn't require any of this tricky chemical engineering, whether 'online' or otherwise? If so, great. If not, why isn't this whole avenue just shut down as DOA?
> Are there any MSR designs that require NO reprocessing (whether online, batch or other)?
I think the Terrestrial IMSR (which is probably the one closest to commercializing in the West) is designed for a once-through uranium cycle, similar to current LWR plants. The idea, IIRC, is to replace the entire reactor vessel (including the fuel salt) every 7 years.
Not sure what the plan is for dealing with the spent fuel. If the fuel salt is water soluble (not sure, but salts tend to be, right?) I'd think some form of processing is necessary before geological disposal. But maybe that can be a cleaner and simpler process than a full PUREX.
I'd love to find actual data but, anecdotally, it seems like a large amount (vast majority?) of the nuclear legacy costs for countries like the UK, at least, come from the back-end - ie reprocessing. If you just store used rods (in perpetuity) near the reactor they were used in then the overall legacy footprint is pretty modest. Indeed, I think that's what the UK does now - our reprocessing facilities are now in decommissioning mode and the US did the same a long time ago.
Yes - part of the decision to stop reprocessing was proliferation risk. But I think it's also because reprocessing is so insanely messy and so easy to get wrong.
This is because if you 'reprocess' fuel, the waste problem just balloons... the rods have to be chopped up, dissolved in nitric acid, taken through a complex chemical process and you end up with vast amounts of liquid waste, various bits of undissolved gunk, a fiendishly difficult-to-decommission reprocessing facility and all the rest. Reprocessing plants are some of the most complicated chemical plants in the world... and when they go wrong (eg the UK's Thorp leak) they're almost impossible to repair owing to the radioactivity.
In the past, the purpose of the early reactors was to generate plutonium for weapons and so reprocessing was, in reality, the key activity, with the reactors just the tedious thing you had to build to provide feedstuff for this extraction process.
But if we don't want any new plutonium then there's no need to reprocess and the waste problem just becomes insanely easier.
To see what I mean, google the history of the UK's Sellafield (specifically the B.205 and Thorp plants) or Russia's Mayak or France's La Hague. So many leaks and accidents, all totally unnecessary if they hadn't been trying to reprocess the fuel. The idea of taking something small and stable (a rod) and turning it into a dangerous liquid and then trying to run it through a fiendishly complex chemical plant just seems nuts on its face.
Hence my question about MSRs... can you build one that doesn't require any of this tricky chemical engineering, whether 'online' or otherwise? If so, great. If not, why isn't this whole avenue just shut down as DOA?