Crappy reactors from the 1970s occasionally go boom. We have much better designs now, like the one in the article:

> The radioactive materials stay fully encased for their entire life and beyond. It's a very robust, strong fuel that's designed to make sure it indefinitely keeps the fuel safely inside the pellet.

> Some of the main differences that the MMR has from conventional nuclear plants is that the reactor cannot meltdown as the heat is passively released into the environment, does not need any active systems to remove heat, and requires no on-site fuel storage, handling, or processing.

This reactor would have been completely unaffected by the events at Fukushima.