WASHINGTON – All 107 nuclear reactors in the United States are inadequately protected from terrorist attacks, according to a Defense Department-commissioned report released Thursday.

The report, by the Nuclear Proliferation Prevention Project at the University of Texas at Austin, warns that the current security required of civilian-operated reactors fails to safeguard against airplane attacks, rocket-propelled grenades and more than a small handful of attackers.

The research highlights the 11 most vulnerable reactors, including plants near Southport, N.C.; Port St. Lucie, Fla.; Columbia, Mo.; and Gaithersburg, Md., less than 25 miles from the White House.

It doesn’t mention the specific security plans because they aren’t publicly available and the report contains classified material.

Instead, it highlights the broader regulations that would apply to each type of plant.

There are 104 nuclear power plant reactors and three research reactors, none of which is protected against a 9/11-style terrorist attack, Alan J. Kuperman, an associate professor at the university who co-authored the report, said Thursday.

He said current policies leave U.S. nuclear facilities vulnerable to credible terrorist threats of theft of bomb-grade material and sabotage that could cause a massive meltdown and release of radiation.

Kuperman made multiple references to the 9/11 Commission’s finding that al-Qaida had considered targeting a nuclear power reactor during the Sept. 11, 2001, attacks.

Three organizations control the safety of nuclear materials: The Nuclear Regulatory Commission oversees civilian reactors, the Department of Energy looks after its research reactors and the Department of Defense controls nuclear weapons and fuel, with the help of the DOE.

Because each group creates its own threat assessment, referred to as the design basis threat, instead of being uniform, security standards vary.