What are some things that are in the US that use or need radium to operate?

Radium has very few commercial uses these days, it formerly was used in luminous watch dials, and used in cancer treatment. However, both those uses have stopped because of the environmental dangers. Very little radium is produced nowadays.

That is too bad I need to do a repot on Marie Curie and I don't know what to say for my introduction do you have any ideas?

Do some atomic clocks use Radium ? I think they use Cesium, but I got the same guess from 2 people