A Nuclear Regulatory Commission board denied an operating license to New York's Shoreham Nuclear Power Station because of inadequate emergency plans for handling a radiation disaster.

In an order likely to be appealed, the board said the plan's shortcomings were largely the fault of state and Suffolk County officials, who have refused to cooperate with the Long Island Lighting Co. in developing an emergency plan for the 809-megawatt reactor, located 50 miles east of New York City.

Suffolk County officials concluded two years ago that the area near the plant could not be safely evacuated in an emergency and have opposed issuing an operating license.

LILCO has spent $4.2 billion on the reactor, which it began building in 1973, making it the nation's most expensive nuclear plant per unit of generating power. Company officials had no comment on the decision.

In another action, the NRC issued a full-power operating license for the second reactor at the $5.6 billion Diablo Canyon nuclear plant near San Luis Obispo, Calif. The 30-year license was approved by the panel Aug. 1, but its conveyance was delayed until the plant's owner, Pacific Gas & Electric Co., completed some tests.