Oldbury is “an absolutely prime site” for private firms to sweep in, he told MPs in February. “We have lots of companies from the U.S. working with U.K. companies on these other routes to market,” he said.  Easing planning rules to build nuclear closer to urban centers could open up another site, Heysham in north-west England, to future development. That site is owned by French energy giant EDF but it, too, has been eyed for potential U.S. development.  “If we have clear action, if the government were able to give clarity and certainty on Heysham, it certainly would be a site U.S. investors would look at,” the second industry figure said, citing technical advantages like its proximity to grid connections and local transport access.     Warming up Warren and Whitehall Any such moves could win over Stephens, the ambassador, who jumped on X last year to express his “extreme disappointment” when Miliband’s decision to build mini-nukes in north Wales deprived U.S. nuclear giant Westinghouse of the chance to build a full-size nuclear power plant on the same site.  There are still hurdles to clear, insiders argued, whatever the political intent behind Friday’s decision.  “The tricky thing with the Fingleton Review is not just the political acceptance of it, it’s the officials’ acceptance of it,” feared a third industry figure, citing supposed skepticism about …