With precautions in place for air attack, some worry plants remain at risk of ground assault

If there is one bright spot in the anti-terrorism picture, it may be nuclear power.

Preliminary results from new studies suggest that if a Boeing 757 airliner crashed into a reactor building, it would not penetrate the 4-foot-thick concrete walls and the grid of 2-inch-thick steel reinforcing bars, according to Steve Floyd of the Nuclear Energy Institute, an industry group. The still-thicker walls of nuclear waste storage buildings would also hold up.

Even if terrorists produced a radioactive leak, the damage might not be great, says Michael Weber of the Nuclear Regulatory Commission. “It’s not as catastrophic as one might imagine. You have to have a combination of severe conditions to have significant off-site consequences.”

As for ground attacks, critics argue that requirements for guards are still inadequate. Few have the training, heavy weapons or numbers needed to repel a commando assault, they say.

Industry officials insist many plants are much better defended.

“The worst case for us would be a highly trained terrorist organization with multiple team members and sophisticated weapons and detailed plans of our sites,” says Mark Findlay, security director of Nuclear Management Co., which has six plants in the Midwest.

To meet such assaults, some plants are installing more electronic sensors and expanding their defensive perimeters. Huge rocks and concrete Jersey barriers can deter vehicle attacks. Guards, many now armed with automatic weapons, patrol the no-man’s land between the old and new lines.

“It very much looks like a fort or a military base now,” Findlay says of one of his plants.