Keen to bolster a domestic nuclear industry that’s built just three reactors this century, the is opting to use a government-investment strategy it’s applied to the mining, steel and semiconductor industries. Under a pact Tuesday, the administration is committing more than $80 billion to buy reactors from Westinghouse Electric Co. It follows moves to take in chip giant and The goal: help ease financing concerns that have deterred project development — even as enthusiasm for new reactors mounts.