Pakistan has begun building a new nuclear power plant in Punjab province.
AQ Khan sparked concern with his nuclear confession
Prime Minister Shaukat Aziz launched work on the 325-megawatt plant in Chashma, which is the second to be built at the site with Chinese help.
It was "a milestone" in the history of nuclear technology in Pakistan, Mr Aziz told officials from both countries.
The construction follows concern aroused by the confession of a leading Pakistani last year that he leaked nuclear secrets.
Dr AQ Khan shocked the nation and sparked international alarm when he publicly confessed to sharing nuclear technology with North Korea, Libya and Iran.
Officials say Chashma-2, south of the capital Islamabad, is for peaceful purposes and will follow International Atomic Energy Agency safeguards.
Pakistan has a parallel nuclear establishment, which runs its nuclear-weapon and missile technology programme.
Pakistan's first nuclear power plant was built in 1972 in Karachi with Canadian assistance.
Western nations later ceased nuclear co-operation with Islamabad, after it was alleged Pakistan was developing nuclear weapons.
Pakistan conducted nuclear weapons tests in 1998. Its rival India launched its first nuclear weapon more than a decade earlier.