The Sellafield nuclear reprocessing site is close to the village of Seascale on the coast of the Irish Sea in Cumbria, The Independent daily reported.
The area has been hit by snow and strong winds.
A site spokesman told the BBC "a site incident has been declared and the plants on the site have been moved to a controlled, safe, shut down state".
A statement said there was no reason to believe that there will be any off-site nuclear, environmental or conventional safety issues associated with the incident.
Government agencies have issued warnings to the public to take care on the roads amidst snow and heavy rain.
In Devon and Cornwall, a number of homes have flooded and drivers have had to be rescued from their cars.
A house in Looe collapsed and police have said one resident, Susan Norman, aged in her 60s, was missing.
In Northern Ireland, more than 28,000 homes and businesses were left without power Friday after snow and winds brought down power lines.
The George Best City Airport said its runway was closed, while Belfast international airport warned that the weather could cause some disruption to flights.
In Yorkshire, the Leeds Bradford international airport suspended all flights due to "adverse weather conditions".
London: A nuclear site in Britain was shut down Friday as rain and snow swept across the country causing transport chaos, floods and power failure, a media report said.
First Published: Friday, March 22, 2013, 21:44