The greater the gate length, the slower the transistor, since electrons passing through the channel in the transistor (which is the same length as the gate) have further to travel.
The opening of the new centre on Monday will see a group of local children swimming the equivalent length of the English Channel to raise money for charity.
Sea water will be pumped in via underground tunnels 2-3km (1.2 to 1.8 miles) in length to cool the two nuclear reactors and then back to the Bristol Channel.