There is little unknown information or new data on the South African Military Nuclear program. However, the story of the inception of this program is still fascinating because it remains rare among other similar military ventures around the world. Apart from the publicly declared nuclear powers India, France, the United States, Pakistan, Russia, and China (and not forgetting the semi-declared power of Israel and the state of North Korea), quite a few countries have the experience and know-how to put together such an ambitious program. And we are not speaking here about dirty bombs or low yield bulky crude devices. Among those countries are Brazil, Argentina, Ukraine and even a country like Switzerland who very early on was contemplating a nuclear arsenal and even went as far as feasibility studies, which is quite a contradiction for a country so proud of their neutrality. However, South Africa completed a full program.
The motivation to achieve this was provided by the fact that the Pretoria Regime was living in an understandable state of paranoia surrounded by countries which had vowed its destruction. In that sense, it shared the same geopolitical environment of another country, the State of Israel. The two strange, newfound allies then agreed to share information and scientific cooperation. It has been said that, concerning this union, South Africa has the money and Israel has the brains. It is simply a cheap explanation.
“the Pretoria Regime was living in an understandable state of paranoia surrounded by countries which had vowed its destruction.”
Contrary to general beliefs, it is not that hard to produce a nuclear device—the science has been known since the 1940's and if there is one thing about science, it’s not that easy to keep it hidden in a box. These assertions that can be found on the net are simply another page in the compendium of examples of the nefarious habit of considering what comes out of Africa as evidently not worth consideration. With an open mind and a touch of historical knowledge, one can easily see that no country can claim the total paternity of these cataclysmic devices, which strangely have been the only guarantee of "peace" since WW2.
The Soviet's first nuclear bomb was a carbon copy of the American one, and Stalin was well aware of the Manhattan project as his numerous spies there provided him with firsthand data. That is why he did not show any surprise or emotion when the then US President informed him that the United States had in its arsenal a weapon of unequal destructive power. By then, Soviet scientists had already started the race and were helped by the vital information that was delivered to them by a more than competent intelligence service. They succeeded in exploding their first nuke in 1948. The Manhattan project, which is one that no one in his right mind will dispute for the breadth of scope and achievements, unequalled to that day by any other scientific project, was awash with foreign scientists. This factor alone let the US provide the finance and though the brains were not theirs, the still claim (carefully) their superiority in technological innovation. At the same time, it allowed Stalin and his network as well as other countries to collect information.
“Stalin was well aware of the Manhattan project as his numerous spies there provided him with firsthand data.”
The Republic of France helped Israel and Pakistan and has been a key disseminator of nuclear technology and the means of their delivery. So asserting that the government of Pretoria was able to put up only the money is nonsensical and certainly offensive . Furthermore even during this early period, the scientific literature available was sufficient for even a terrorist group to be able to attempt such a project. South Africa had already demonstrated their technological might in heart surgery, astronomy, and missile technology.
Whatever the case, we know now that these developments permitted the production of six fission type gun bombs of the same type as the American Little Boy that destroyed Hiroshima. There was a seventh device but apparently, this one was not completed. Despite the South African advances in missile technology, their nuclear bombs were still too bulky to be delivered by any of their missiles which explains why their deployment in case of conflict would have to be achieved by bombers such as the English Electric Canberra or the Blackburn Buccaneer. However one question remains: did the South African military make a test to validate their weapon's design?
And here comes along the mysterious Vela incident. To enforce the partial nuclear test ban, the Americans put Vela Hotel Satellites in orbit to detect any suspicious detonations. There were reasons to worry as history tells us that a previously planned test in a mine was aborted only because the Russians, who had detected the preparations, warned their American counterparts who confirmed the South African's intentions with a flight over the suspected mine made by the famous spy plane sr-71 Blackburn. Since their launch in 1969 from Vandenberg Air Force base, Vela did not detect any contraventions to the treaty.
Then, on September 22 in 1979 at 00:53 Universal Time, one satellite, Vela-5B, picked up the characteristic double flash signature of a nuclear detonation in the ocean located between South Africa and Antarctica. Here, we will not discuss the nature of the flash but let's say that any scientist would be hard pressed to find another explanation for this deflagration. Some have suggested that it could be a false positive from an impactor on one of the panels of the satellite but the probability of such an event is negligible. Of course the United States sent detection planes to enable confirmation by collecting any by-products of fission materials produced by such an event truly occurring but nothing was confirmed.
“However one question remains: did the South African military make a test to validate their weapon's design?”
The International Outsider
So can we say that here, we have the conclusion of this affair. The United States Air Force accepts that during this period of time, their system of detection and confirmation in this zone of the ocean was unreliable. This was a fact certainly known to the Israeli intelligence services with whom the American intelligence services have a strangely incestuous type of relationship. The yield of the suspected device was around the 3 kilotons. To date, there is no final conclusion to this incident but the chances are high that the Vela Incident or Operation Phoenix (sometimes called Alert 747) really took place.
If you want to further your research, a good start will be the Skeptoid website where you can find a pretty good account of the Vela Incident with the audio of the podcast under the title Alert 747: The Vela incident. Concerning the South African Nuclear Weapon Program, you could also check out the course work for PH241, Stanford University by Gil Kornberg. Wikipedia of course, South Africa and weapons of mass destruction has some reliable data and is an opportunity to compile data on this subject. There you can discover what Commodore Dieter Gerhardt, former commander of South Africa's Simon's Town Naval Base (who was later convicted of spying for the USSR) was reported to have said on the Vela Incident with many other interesting sources, all to be consumed without moderation. You are also invited to read the interview of Frederic De Klerk on The Atlantic: Why One President Gave up His Country's Nukes . In dealing with North Korea, said F.W. de Klerk, remember that "inner conviction weighs heavier on the scale than international pressure."