In the test at the Bushehr nuclear power plant, "dummy" fuel rods were used, so no nuclear reaction began.

CNN: U.S.: Iran has material for nuclear bomb but still 'not close'

The unencrypted USB pen drive, containing a 'stress test' safety assessment of the Hartlepool plant, was lost by an employee of the Office for Nuclear Regulation (ONR).

BBC: USB stick with nuclear plant data lost by ONR official