Massachusetts Gov. Michael S. Dukakis is going to court to try to block the restart of the Pilgrim nuclear power plant and promises more legal fights if federal regulators issue a low-power license for the Seabrook plant in neighboring New Hampshire.

The Nuclear Regulatory Commission, in unanimous votes Wednesday, cleared the way for the $5.7 billion Seabrook reactor to receive a long-sought low-power testing permit - perhaps within several weeks - and ruled that the Pilgrim plant in Plymouth, Mass., can slowly begin operations after a shutdown of nearly three years.In a related development, NRC Chairman Lando W. Zech Jr. said the commission will not rule until next year on whether the state and local governments in New York have legal standing in the licensing procedure for the idled Shoreham nuclear plant on Long Island, under fire for reasons similar to those cited by critics of Seabrook.

Dukakis, who says it is impossible to evacuate the seacoast towns around Seabrook and who argues that Pilgrim should not be restarted without an approved evacuation plan, called the commission votes "irrational" and "irresponsible."

The state's lawsuit, filed in U.S. Circuit Court of Appeals just hours after the vote, calls the NRC action on Pilgrim "arbitrary and capricious" and urges an immediate injunction to halt the plant from getting up to 25 percent power.

Zech said Seabrook could get its low-power license, which permits testing at 5 percent power, as early as Jan. 6 if it can set aside $72.1 million. The NRC said the owners must have that money on hand for decommissioning costs in case Seabrook receives the testing permit but never gets a full-power commercial license.

Seabrook also cannot receive the license, which it has sought for more than two years, until the Atomic Safety and Licensing Board rules on a request by Massachusetts officials to review alleged problems with the operators' response during a June exercise of the plant's emergency plans.

But Seabrook officials said the commission's staff already has recommended that the licensing board reject the state's request and that they expected the issue to be resolved shortly.