These are fast reactors and operate on different principles. The coolant there is sodium and while hard to design and run, it’s doable. French had similar reactor but only one and it was shut down. Nice thing about fast reactors is that these can burn even-numbered isotopes of plutonium, useless in water moderated reactor, and give fresh mostly 239Pu plutonium of good quality. weapons grade even, and IAEA doesn’t like it. But who cares since nonproliferation is dead anyway?