I'd be interested in seeing information that counters the features of the 'Generation IV' nuclear reactors[0]. Among other promises, they purportedly can consum

I'd be interested in seeing information that counters the features of the 'Generation IV' nuclear reactors[0]. Among other promises, they purportedly can consume existing waste from Generation I-III reactors, and reduce the total nuclear waste on the planet, rather than increasing it. Some purported advantages (there are different technologies): - Nuclear waste that remains radioactive for a few centuries instead of millennia - 100–300 times more energy yield from the same amount of nuclear fuel - Broader range of fuels, and even un-encapsulated raw fuels (non-pebble MSR, LFTR). - In some reactors, the ability to consume existing nuclear waste in the production of electricity, that is, a closed nuclear fuel cycle. This strengthens the argument to deem nuclear power as renewable energy. - Improved operating safety features, such as (depending on design) avoidance of pressurized operation, automatic passive (unpowered, uncommanded) reactor shutdown, avoidance of water cooling and the associated risks of loss of water (leaks or boiling) and hydrogen generation/explosion and contamination of coolant water. Any information filling out this picture is appreciated. [0] https://en.wikipedia.org/wiki/Generation_IV_reactor https://en.wikipedia.org/wiki/Generation_IV_reactor