Carbon-14 is not the type of nuclear waste anyone is worried about. It's barely radioactive, with a long half life and very low decay energy. Disposing of it doesn't pose any issues because it is unable to make anything else radioactive.

You want to make a long lasting low power nuclear battery? Go for it. But don't try to trick people into thinking you are doing anything about nuclear waste.

The nuclear waste that causes problems is the type with neutron decay that is able to activate nearby elements. That is tricky to dispose of, and difficult to store.