I suspect refurbishing decades old PWR reactors would be far more expensive than just building new ones, for example a SpaceX Merlin engine costs $1 million and a Blue Origin BE-4 costs $15 million. Nasa argued it would be 'cheaper' to reuse Shuttle components for the Space Launch System (SLS). Refurbishing Shuttle RS-25 engines has cost Nasa $50 million dollars per engine, restarting a production line is costing $100 million for each new RS-25 engine.