On May 18, 1974, India detonated a nuclear bomb made from plutonium manufactured by the CIRUS research reactor built by AECL in 1956, which was a commercial version of its NRX research reactor. In addition AECL built two power reactors in India based on the Douglas Point design, and many of India's other reactors are domestic variants of this design. The connection between India's nuclear weapons program and its CIRUS research reactor led to a severance of nuclear technological cooperation between Canada and India. [http://archives.cbc.ca/IDC-1-75-104-898/science_technology/candu/clip4]