"Sir Michael Marsh: (Ignoring Matt) At the heart of any nuclear power station is a nuclear reactor. The reactor is basically a massive concrete box - and it is in here that our controlled explosion takes place. The uranium is surrounded by long sticks called control rods. When you lift up the control rods, the explosion starts. And the higher you lift them, the more powerful the explosion becomes. The reactor is the most dangerous part of the station. You have to remember what happened at Chernobyl, in Russia. One mistake here and you risk what is known as an excursion, an explosion which might kill hundreds or even thousands of people and destroy a vast area of land for years. When the government began to think about building nuclear stations, about fifty years ago, they set up a number of experimental stations where they could study reactors in action and make sure they were safe. Omega One was the first of these experiments and I helped design and build it. It ran for less than eighteen months. And after we'd finished with it, we shut it down and left it to rot in the pine forest thaty surrounds it."