Absolutely, and even the new designs are multiple decades old. (But even those are a huge improvement over what we have from the 60s/70s). Many of existing pla

Absolutely, and even the new designs are multiple decades old. (But even those are a huge improvement over what we have from the 60s/70s). Many of existing plants were at the time they were built considered to be important for national security (read: nuclear arsenal), which is much of why they're using the fuel they use and have the designs they have. Civilian nuclear never really materialized in it's own right, which is certainly a shame.