WISCASSET – Maine Yankee has beefed up security since the Sept. 11 terrorist attacks. But some say the now-closed nuclear power plant isn’t doing enough to protect its highly radioactive spent-fuel pool.

Concrete barriers and a booth manned around-the-clock now block the road to the facility, largely in response to Nuclear Regulatory Commission demands for more safeguards at all plants, said Maine Yankee spokesman Eric Howes.

Paula Craighead, nuclear adviser to Gov. Angus King, said plant officials have done “what they need for today’s conditions.” She said Maine Yankee staff has begun to post no-trespassing signs on the grounds, limiting access for hikers and hunters. Concrete barriers also line a second, less-traveled access road.

A group of public officials, anti-nuclear activists and citizens say they want to see more security surrounding the plant’s highly radioactive waste.

“I don’t think they’re doing enough,” said Stanley Lane, a selectman from Westport, which neighbors Wiscasset. His board this month wrote a letter to the NRC urging that safety measures at the plant be revised in light of the attacks. “I think of it as all window dressing.”

Maine Yankee has been taking necessary precautions to protect 1,432 spent fuel-rod assemblies ever since the attacks, Howes said.

Howes maintained that changes at Maine Yankee resulted from several general advisories from the NRC and conference calls with other nuclear plant managers throughout the Northeast.

King, who voiced concerns about safety at Maine Yankee in a letter to the NRC this month, has been satisfied with recent security improvements, said Craighead.

But King and his advisers remain “in an ongoing mode of examination,” she added.

Craighead said the public should be assured that there are armed guards at Maine Yankee and that plant officials have addressed the plant’s proximity to water and the Wiscasset airport.

Critics of security at Maine Yankee have pushed for a no-fly zone over the plant and the presence of National Guardsmen. Neither idea has received much support from state or plant officials.

Nationally, the NRC has asked plants to boost security patrols, restrict access to sensitive parts of the plant and limit the number of vehicles allowed on site, said agency spokesman Neil Sheehan.

Sheehan said NRC inspectors are visiting nuclear plants, including Maine Yankee, during the next several weeks to “make sure the plants are doing what they’re supposed to do.”

Even though Maine Yankee has been permanently closed since 1997, its spent-fuel pool “still warrants a high level of protection,” Sheehan said.