20 July 1970
The Prime Minister, Balthazar Johannes Vorster announced in the House of Assembly in Cape Town that South African scientists have succeeded in developing a new process for uranium enrichment. He also mentioned that a pilot plant for this process was under construction by the South African Atomic Board (AEB). Vorster described the success as ‘unequalled in the history of our country’. It is widely believed that the uranium was used to manufacture nuclear weapons by the South Africa government. The history of nuclear energy in South Africa dates back to 1959 when the country's first large-scale nuclear research and development project was initiated under the auspices of the AEB. In 1990, President F. W. de Klerk terminated the program and in 1991 South Africa signed the Nuclear Non-Proliferation Treaty (NPT).
References

Albright D. (2001) ‘South Africa's Nuclear Weapons Program’, from Massachusetts Institute of Technology, 04 March, [online], available at www.mit.edu(Accessed: 08 June 2012) | Cassuto A. ‘Can Uranium Enrichment Enrich South Africa?’, in The World Today Vol. 26, No. 10 (October 1970), pp. 419-427 | South African History Online, ‘Timeline: 1790s’, [online], available at www.sahistory.org.za(Accessed: 08 June 2012)