In the late 1940s, when she was 8 years old, Packer helped her brothers dig a bomb shelter in the family's back yard in Murray. The shelter was just a hole with a board over it, but if there had actually been a nuclear war, she says, "I would have had better protection than 95 percent of people in the U.S. today."

When she grew up she received a master's degree in nuclear engineering from the University of Utah. She studied under Dr. Gary Sandquist, who is now secretary-treasurer of The American Civil Defense Association board. The president, Jay Whimpey, is also from Utah. The most famous former board member was "father of the hydrogen bomb," Edward Teller.

Private, nonprofit TACDA was incorporated in Florida in 1962 about the time of the Cuban missile crisis. Its headquarters is now in a small office park in Draper. Currently only 400 people are dues-paying members. For $36 a year they get the quarterly Civil Defense Journal as well as access to reports about topics such as thermal effects and water purification. Nonmembers can buy radiation monitoring devices and emergency supplies at TACDA's Web site.

"Civil defense" has a kind of nostalgic ring to it, reminiscent of what, in a sense, was a more innocent time, when there was a threat of nuclear holocaust, but nobody had yet flown planes into American buildings. These days, "civil defense" has been eclipsed by "homeland security."

But the Office of Homeland Security's recommendations for personal preparedness are "way too minimal," Packer says.

National and state government officials don't tell people about the danger from an EMP, because "they're not knowledgeable about its effects," she says. Recently, Packer traveled to New Jersey to address FEMA emergency management workers. Out of 200 people in the room, she says, only two knew anything about electromagnetic pulse effect.

Packer has recently posted, free of charge, the 2004 testimony of Lowell Wood before the House Armed Services Committee, at tacda.org. Wood, a Visiting Fellow at the Hoover Institution on War, Revolution and Peace at Stanford University, and a staff member of the Lawrence Livermore National Laboratory, testified that EMP "is a weapon of mass hardware destruction" that "could cripple much of the U.S. military machine and which also can lay waste to modern American civilization."

Wood testified that "even a modest, single-explosion EMP attack on the United States might well devastate us as a modern, post-industrial nation." He said that the cost of hardening mass-produced systems against EMP effects may be as low as 1 percent of the cost of each item.

"We have got to alarm people," Packer said. Not to scare them, but to "get them out of denial and inactivity and direct them toward a solution."