The emergency services will be tested today during an exercise at Wylfa nuclear power station on Anglesey.
The test will check the response of all the emergency services in the event of an incident involving the transport of radioactive material.
More top news
Winter sunshine with cloud creeping in during the afternoon and a frosty night ahead.
The Revd Canon Joanna Penberthy has been consecrated as Bishop of St Davids in "an historic" day for the Church in Wales.
Temperatures will tumble under clear skies tonight with a widespread frost developing.