Nuclear proliferation remains a nightmare for all of us. What would happen if terrorists or rogue states were to get there hands on the plutonium produced by nuclear reactors?

The nuclear industry must therefore keep a close watch on the nuclear waste they produce. Strict auditing processes must be observed to ensure plutonium does not fall into the wrong hands.

Take the Cadarache nuclear facility in France, which is currently being decommissioned, for example. How much plutonium does it have? Easy, it has eight kilogrammes of plutonium. Sorry, make that 22 kilogrammes. Yes, that’s right. No, wait a minute, it could be ‘in the region’ of 39 kilogrammes. In fact, the amount of plutonium at Cadarache has been massively underestimated.

France’s Nuclear Safety Authority has suspended decommissioning at the site, saying the ‘underestimation of the quantities of plutonium reduces safety margins calculated to prevent criticality accidents’. The underestimation was found by Cadarache’s owners, the Atomic Energy Commission, in June this year but they didn’t report it until October. You can tell they put a premium on transparency, trust and public confidence, can’t you?

So, how much of this plutonium may have been stolen to make nuclear weapons or is otherwise unaccounted for? We’ll never know – until it’s too late, obviously – because the operators of Cadarache (which has 19 nuclear installations) have absolutely no idea how much plutonium they were supposed to be safeguarding.