he Nuclear Regulatory Commission needs to subject New York's Indian Point nuclear plant to a stringent test of its ability to cope with a terrorist attack as soon as possible. There is no other way to determine whether the plant's security forces are blessed with Rambo-like powers, as the industry claims, or are more like the Keystone Kops, as an assessment from some of the guards themselves suggests.

The ads on nuclear plant security that the industry ran earlier this year depicted tough-looking men with big guns protecting unidentified nuclear plants. "Meet Steve Yancey, formerly of the 82nd Airborne and the U.S. Marine Corps," one ad said. It described Steve and his colleagues as highly committed, exactingly trained and physically fit and as expert marksmen with an array of weaponry.

Too bad the guards at Indian Point, some 35 miles north of Times Square, do not quite fit that image. According to a leaked report submitted to the plant's owners early this year, only 19 percent of the guards, who are supplied by the Wackenhut Corporation, felt that they could adequately defend the plant. Some guards estimated that half the force might not be physically able to meet the demands. As for marksmanship, some guards require multiple tries to pass their annual tests.

These revelations were contained in a report prepared by a former N.R.C. investigator who interviewed more than 50 guards at the plant. In follow-up interviews, Richard Prez-Pea of The Times reported, guards told of minimal training, of some guards' reporting to duty drunk and having to be sent home, and of fatigue from working 70 to 80 hours a week or more.

Entergy, the company that owns and operates Indian Point, says that most of the guards' concerns have been addressed. A new fence, barriers and security cameras have been installed, for example, and 30 new guards will report in January to help protect both Unit 2, where the survey was done, and the adjacent Unit 3. National Guardsmen and state police provide additional protection. Entergy remains convinced that Indian Point's defenses are robust and that they could pass any test.

Security at Indian Point has passed muster with both the N.R.C., which considers the site well protected against terrorists, and Gov. George Pataki's own Office of Public Security. But the guards' assessment is so jarringly at odds with those judgments, and with the industry's tough-guy reassurances, that a closer look is needed.

Senator Hillary Rodham Clinton has urged both Entergy and the N.R.C. to schedule a mock terrorist attack at Indian Point early next year to see whether the security force can handle it. Entergy says it is willing. The drill should use realistic assumptions about the size of an attacking force and the likelihood that it would strike without warning. If the regulators cannot ensure that the private guards are competent and ready, it may be time to federalize the security force at nuclear plants.