The Koeberg nuclear plant near Cape Town requires about thirty tons of uranium fuel per year. Unlike a fuel such as coal, this uranium is not burnt up. It undergoes a nuclear reaction, which transforms it into other elements, some of which are highly radioactive. Burning or any other chemical process does not reduce the radioactivity.
That means that over thirty tons of spent nuclear fuel (SNF) are removed from the reactors each year. So far over a million kilograms of this SNF (over 2000 fuel elements) have accumulated since Koeberg began operating in 1984.
I am sitting in a conference in Stockholm about nuclear waste. There are speakers from organisations from all over the world including the International Atomic Energy Agency, the Japan Atomic Energy Agency, delegates from many non-governmental organisation, engineers, and academics studying subjects such as nuclear physics, ethics, and geology.
Gene Rowe of the US Nuclear Waste Technical Review Board gave a highly technical presentation about the prospects of dealing with nuclear spent fuel in the USA via a combination of reprocessing and disposal. I got chatting to him afterwards, and asked him about a claim I have heard repeated many times in South Africa.