I agree nationalisation has its place when needs must. See 2008, Thames Water risks, etc etc.
But this plant is utterly past its shelf life and will need to be decommissioned in 4 or 5 years (now at taxpayer cost). Feels very much a political decision to can kick that issue beyond the next election, and not give Farage any more fodder over newly nationalised railway tracks having to be replaced with foreign muck.
All the stuff about national interest and resilience is just cover for the above. There is no way they're building tanks and warships with steel from the plant. Too late now to have a change of heart and become european about ownership of industry and infrastructure. Even UK passports are still made in France as far as I know.