CANDU

The CANDU power reactor is a pressurized heavy water reactor (PHWR), initially developed in the late 1950's in Canada. CANDU is an acronym for "CANada Deuterium Uranium".

This design is relatively safe from a nonproliferation standpoint, as it produces little plutonium, and that plutonium is rich in ²⁴⁰Pu, an isotope highly undesirable for bombs.