There are unlikely to be any nuclear waste trains, although there's the possibility of constructions materials being brought in if anything ever happened at Trawsfynydd.
Waste trains have stopped running to Sizewell now that the A station has been largely decommissioned, nothing runs in relation to the newer B station - it has never sent a single flask of waste in 20 years of use, it is all stored on site and a new store was recently opened that will hold a further 20 years spent fuel.
Martin