It is the regular beeping that grates. But if it stops, prepare to be scared. The signal audible every second in every corridor of the high-level toxic nuclear waste plant on Britain's sprawling Sellafield site is a sign all the alarms are working. If it stops, or changes tone, something has gone very wrong. "The people who work here every day tell me they get used to it. But it tends to get on the nerves of everyone who visits the plant," Sellafield information officer Ben Chilton told Reuters on a tour of the site 480 km (300 miles) northwest...