Philadelphia Electric Co., whose Peach Bottom nuclear plant was ordered closed four months ago because operators slept while on duty, was fined $50,000 for violations of fire protection rules at the plant. The Nuclear Regulatory Commission, which imposed the fine, said it knew of no fires at the plant since the violations came to light last year. But NRC regional administrator William Russell said the violations "are of significant concern." The utility has 30 days to either pay the fine or to request in writing that part or all of it be withdrawn. The company must also say whether it admits or denies the allegations and detail any corrective action it is taking.