ATLANTA — Regulators should cut Georgia Power’s profits as the cost of its new nuclear plant rises, making it a less attractive financial deal for the public, an environmental group said. The Southern Alliance for Clean Energy asked state regulators Friday to trim back Georgia Power’s legally permitted profits on money shareholders invest in the project. Trimming those returns would punish the company for poor performance and reduce the overall costs for the company’s 2.4 million customers, SACE attorney Robert Baker said.