The Dungeoness reactor had a partial meltdown in 2004 (mentioned in London, Shadows of Europe, detailed in Sixth World Almanac, p. 13). It resulted in over 6,000 dead, including about a third of 800 gamers attending a nearby convention. By 2052, nearby lands were called the Kentish Habitable Zone, and was already steadily shrinking, allowing new housing to go up in the area. From the maps in London sourcebook, it doesn't look like Canterbury is part of the 2051 zone.