Earnings rose significantly at BWX Technologies (BWXT), Lynchburg, Va., in the third quarter, which the company attributed to its “differentiating nuclear credentials” and some multi-year, special materials contracts it received. “The demand environment for nuclear solutions in defense, clean energy, and medical markets is unprecedented,” Rex Geveden, president and CEO of BWXT, said in the company’s earnings release published after the market closed Monday. “With that demand, we are seeing new opportunities across the market spectrum for BWXT.” Net earnings…