[photochemsyn]

Fact-Checking the Fact-Checkers initiates infinite recursion... Specifically, the section on the 'audacious claim' that small modular reactors generate more long-term waste (per unit of energy generated) than much larger traditional reactors does seem to have some support [1], based on issues like irradiation of the support structure (possibly more support structure is needed for many small reactors vs. one big reactor, plus the small structure might get a higher net flux of neutrons), and cases where sodium metal coolant is used as it becomes lowishly radioactive. The tradeoff I suppose is less risk of meltdown in the small modular designs?

The latest pebble-bed SMR designs avoid some of these problems as they use helium as the coolant, but similar efforts in South Africa failed several decades ago as the graphite pebbles broke down and graphite dust (and fuel particles) clogged the system. Now several plants in China and Canada using pebble-bed are currently in the works or operational (notably the one in China passed a natural-cooldown-after-loss-of-power test, i.e. no need to fire up a diesel generator to keep the coolant flowing to prevent meltdown[2]). However, there could be other catastrophic scenarios, as graphite is flammable and when hot reacts with water to form hydrogen. Loss-of-coolant >20% seems bad[3].

[1] https://thebulletin.org/2022/06/interview-small-modular-reac...

[2] https://www.modernpowersystems.com/news/chinas-htr-pm-reacto...

"Three-dimensional modeling and loss-of-coolant accident analysis of high temperature gas cooled reactor" [3] https://www.sciencedirect.com/science/article/abs/pii/S03064...