It ocurred to me that India has nuclear weapons. Not easy with a CANDU so I read up. My statements are way outta date! From Wiki...

In terms of safeguards against nuclear proliferation, CANDU reactors meet a similar level of international certification as other reactor designs. However, there is a common misconception that the plutonium for India's first nuclear detonation, conducted in 1974 Operation Smiling Buddha, was produced in a CANDU design. In fact, the plutonium was produced in the unsafeguarded CIRUS reactor whose design is based on the NRX, a Canadian research reactor. In addition to its two CANDU reactors, India has some unsafeguarded pressurised heavy water reactors (PHWRs) based on the CANDU design, and two safeguarded light-water reactors supplied by the United States. Plutonium has been extracted from the spent fuel from all of these sources in the PREFRE reprocessing facility.[18] While all of these reactors could in principle be used for plutonium production, India uses an Indian designed and built military reactor for plutonium production called Dhruva. It is believed that the Dhruva reactor design is derived from the CIRUS reactor, with the Dhruva being scaled-up for more efficient plutonium production. It is this reactor which is thought to have produced the plutonium for India's more recent (1998) Operation Shakti nuclear tests.[19]