The construction of the power station, which was undertaken by a consortium of AEI and John Thompson began in 1956. It had two Magnox reactors producing 276 megawatts (MW) in total. The reactors were supplied by The Nuclear Power Group (TNPG) and the turbines by AEI.
Reactor 2 was shut down in October 1988, followed by Reactor 1 in March 1989. Berkeley was the first commercial nuclear power station in the United Kingdom to be decommissioned following its closure in 1989. So far the nuclear decommissioning process has involved the removal of all fuel from the site in 1992, and the demolition of structures such as the turbine hall in 1995 and cooling ponds in 2001. The next step of decommissioning will be the care and maintenance stage of the nuclear reactor structures until radioactive decay means that they can be demolished and the site completely cleared.
Berkeley is one of four stations located close to the mouth of the River Severn and the Bristol Channel, the others being Oldbury, Hinkley Point A and Hinkley Point B.