Atomic Weapons Establishment leaks tritium gas into stream
15 October 2013 Last updated at 00:03 BST
The Atomic Weapons Establishment (AWE) in Aldermaston has been criticised for leaking radioactive gas into a stream.
There was an increase in levels of tritium in Aldermaston Stream after AWE turned off a ventilation fan in a radioactive waste storage unit.
The Environment Agency said the low levels of radiation in the stream did not represent an environmental hazard.
However, it said AWE had not adequately assessed the environmental impact of its modifications to the storage unit.