‘In the event of the worst happening to a single reactor, a major portion of the United Kingdom would have to be evacuated, and evacuated within hours. This would be impossible. Air-raid shelters might be some solution, but air-raid shelter filter-systems cannot filter out all the very fine particles of fall-out that would come from a power station. Their filters would be effective against fall-out from nuclear bombs, but not as effective against nuclear reactor fall-out. The basic difference is that nuclear reactor fall-out is much finer. It actually dissolves into the air itself, making it very hard – in fact, impossible – for filtration systems to keep it out. Wherever air, however finely filtered, gets in, so will nuclear reactor fall-out. Only those places with their own internal air supplies would be completely protected. The second problem is that after a bomb attack the fall-out level would subside to the point where people could come back out into the open within a few weeks. But with reactor fall-out, this period would be very much longer. Within twenty-four hours downwind, they would have to stay in their shelters for a year. And in any event, we are only talking about a tiny minority who would have any shelter protection at all. For the majority, we would have an insurmountable problem in that nothing could be grown on massive areas of British soil for years. We know it is impossible to evacuate the population, but it may well be equally impossible to feed the people if they stay – and survive.

‘And this would be the result of blowing up one, just one, of the forty-two reactors in the sixteen nuclear power stations on this island.’ He tapped the ash off his cigar.

‘I have read out to you the worst that could happen. With conventional explosives, or with an explosion caused by malfunction due to sabotage, the radiation hazards would be considerably reduced. But we should think in terms of the worst, and if something less bad happens, we can regard it as a bonus. There are plenty of people who say it is not possible to blow up a reactor and cause a serious radiation leakage; so far as I am concerned, they are the direct descendants of those people who knew the Titanic could never sink.

‘It is my opinion, from the evidence that has been presented to me, that somewhere out beyond these walls people are plotting against one or more of our nuclear power stations – and not only against our power stations, but those of other countries as well. There are three nuclear power stations on the north coast of France. If any of these were blown up when there was a southerly wind, great tracts of this country would be in grave danger.

‘We cannot take the kidnapping of Sir Isaac by the Russians too seriously. We must examine all the possible motives, and take every possible step to safeguard ourselves.’