Here's why the siren's been going off at Heysham 1 power station today

A reader contacted us saying: “The siren keeps going off at the power station this morning. It's not normal for it to sound on a Wednesday as the test day is Thursday.”

A spokesman for EDF said: “Heysham 1 is this morning running one of its regularly programmed emergency exercises.

"This includes testing site alarms and sirens and is something we routinely test as part of our arrangements.

"Emergency services and a number of local businesses have been warned we would be running an exercise of this nature this morning.”