(CBS NEWS)-- Every commercial nuclear reactor in the United States is insufficiently protected against "credible" terrorist threats, according to a new report (PDF) from the Nuclear Proliferation Prevention Project at the University of Texas at Austin.
The report found that facilities were vulnerable to the theft of bomb-grade nuclear materials and sabotage attacks designed to cause a meltdown.
While all 107 commercial nuclear power reactors were thought to be vulnerable, the report spotlighted 11 that were most at risk. That included eight reactors that were deemed unprotected from attacks from the sea: Diablo Canyon in California, St. Lucie in Florida, Brunswick in North Carolina, Surry in Virginia, Indian Point in New York, Millstone in Connecticut, Pilgrim in Massachusetts, and the South Texas Project.
Three civilian reactors fueled with bomb-grade uranium were also deemed particularly vulnerable. They are housed at the University of Missouri in Columbia, the Massachusetts Institute of Technology in Cambridge, and the National Institute of Standards and Technology - which is within 25 miles of the White House. Unlike military facilities that hold bomb-grade uranium, the report found, these facilities are not sufficiently defended against a credible terrorist threat.
As a release announcing the report notes, the Sept. 11 hijackers considered flying a passenger get into a New York City-area nuclear reactor.
"More than 10 years have come and gone since the events of September 2001, and America's civilian nuclear facilities remain unprotected against a terrorist attack of that scale," said report co-author Alan J. Kuperman. "Instead, our civilian reactors prepare only against a much smaller-scale attack."
The facility near the White House, Kuperman added, is not required to even protect against the smaller-scale attack, known as "design basis threat."
"We know where the weak spots are when it comes to nuclear facilities, so it would be the height of irresponsibility to fail to take action now," he said.
The report found that some U.S. government nuclear facilities are protected against most or all threats, but others remain unprotected because they are seen as having little appeal to terrorists or because officials believe an attack would not be catastrophic.
The report's authors take issue with that calculation, saying it is impossible to know which sites terrorists favor or which could be used to cause the most harm. They recommend that all facilities be upgraded to defend against a maximum credible terrorist attack.
© 2013 CBS Interactive Inc. All Rights Reserved.