‘Their aim is that we accept a capacity of ten thousand separative work units which is equivalent to ten thousand centrifuges of the older type that we already have,’ Ali Khamenei, Iran’s supreme leader, said on 4 June. ‘Our officials say we need 190,000 SWU. Perhaps this is not a need this year or in two years or five years, but this is the country’s absolute need.’
Vol. 36 No. 18 · 25 September 2014
In the LRB of 31 July I discussed the concept of separative work units, SWUs, which are used to measure the amount of enriched uranium that a centrifuge can produce. Around 200 SWUs are needed to produce one kilogram of 95 per cent enriched uranium, weapons grade. It seems that the proposal apparently being negotiated is to limit Iranian SWU production to 10,000 per year. There are now 18,000 centrifuges operating some of the time in Iran. Since each produces about one SWU per year – probably somewhat less – the programme would have some plausibility. But a recent report issued by the Institute for Science and International Security contains a disturbing bit of news: Iran has claimed that it has produced a new centrifuge 16 times more powerful than the existing ones. There is no plausible need for this centrifuge. Its development once again makes it clear that when it comes to nuclear power, actions in Iran must be scrutinised with great care.