There are different estimates as to when South Africa started its nuclear weapons program. A 1983 U.S. intelligence report, indicated that South Africa formally launched a nuclear weapons program in 1973 in response to the country's growing isolationism and fears of Soviet meddling in the region.
In 1974, The International Atomic Energy Agency reported that Prime Minister John Vorster had approved a "limited program for the development of nuclear weapons as a deterrent" beginning that year. But according to Waldo Stumpf, head of the Atomic Energy Corporation, not until 1977 did the government officially decide to develop a nuclear deterrent capability.
According to Institute for Science and International Security analyst David Albright, South Africa's Atomic Energy Board (AEB) conducted tests between 1976-78 using depleted uranium and constructed two nuclear devices. In 1979 the government assigned the Armaments Corporation (Armscor) to design and build more devices using highly enriched uranium produced by the AEB. In July of that year, an action committee, created by Prime Minister P.W. Botha to develop plans for the production of nuclear devices, recommended production of a total of seven nuclear weapons.
Because of sanctions against it in the 1970s, South Africa also began to collaborate secretly with Israel for the transfer of arms and technology. According to a 2000 article in the South African Weekly Mail and Guardian, Dieter Gerhardt, a senior commander in the South African Navy said that Israel agreed in 1974 to arm eight Jericho II missiles with "special warheads" for South Africa. And, David Albright reported in 1994 that in 1977 South Africa traded 50 metric tons of yellowcake uranium for 30 grams of Israeli tritium, a radioactive isotope used as a component in triggering thermonuclear weapons.
According to Stumpf, in April 1982 Armscor produced its first nuclear explosive device, and in December of the same year completed its first deliverable nuclear weapon.
According to South African media reports, shortly after President F.W. de Klerk assumed office in 1989, he declared at a meeting of his senior political advisors and aides that in order for South Africa to end its isolationism, it must dismantle its nuclear weapons capability and end its political system of apartheid.
South Africa began to dismantle its nuclear weapons program in July 1990. The next year, on July 10, 1991, South Africa officially entered the NPT as a non nuclear-weapon state and later submitted its initial inventory of nuclear materials and facilities to the IAEA. By late 1994 the IAEA, after completing inspections, declared that it had verified that all of South Africa's nuclear weapons facilities had been dismantled.
South Africa is the first and only country with nuclear capability to willingly dismantle its nuclear program and accede to the nuclear Non-Proliferation Treaty.