But this would need to be a fail save type of reactor and with a clear plan(s) all the way down to how the waste is handled till it's no longer active.
Only about one percent of high-level nuclear waste is fission products, the broken-apart atoms left after fission. The rest is U238, unused U235, plutonium, and other transuranics produced by absorbing neutrons without fissioning. Fast reactors can fission all of these. That's why they can run on nuclear waste.
For the same reason, they can get over a hundred times as much energy from the same amount of uranium ore. Conventional reactors can only use the U235, which is 0.7% of natural uranium.
That's a great start, but with such efficient use, it's practical to get the uranium from seawater. We can do that now at five times the cost of mining; if we only need 1% as much uranium, then total fuel cost would be 5% as much as nuclear reactors spend on fuel today. Fast reactors fueled from seawater would last for millions of years.
TLDR: Its all just theoretical.
"TerraPower planned to build a 600 MWe demonstration Plant, the TWR-P, by 2018–2022 followed by larger commercial plants of 1150 MWe in the late 2020s.[15] However, in January 2019 it was announced that the project had been abandoned due to technology transfer limitations placed by the Trump administration."