'Nightline' Gains Exclusive Access to Search for Nuclear Material

An ABC News Investigation Has Found That Nuclear Reactors on 25 U.S. College Campuses Lack Security

ABC News Gets Exclusive Opportunity to Observe Teams Deployed to Detect Radioactive Material

Sites on College Campuses Among Those Vulnerable to Potential Attacks

An Obsessive Policy Wonk Has Started a Blog About Weapons Proliferation

But Only One Major Seaport Has Installed Critical Technology

ABC News Poll Shows Americans Concerned About Emergency Preparation for Nuclear Threat

ABC News Chief Investigative Correspondent

"Loose Nukes on Main Street: The New Terror Threat"

A nuclear blast is an explosion with intense light and heat, a damaging pressure wave and widespread radioactive material that can contaminate the air, water and ground surfaces...

Dangers Are More Likely to Stem From the Explosion Than from Radiaion

Sources of Radioactive Material

McClellan Nuclear Radiation Center -- Davis, Calif.

TRIGA Reactor; Corvallis, Ore.

Reed College Reactor Facility; Portland, Ore.

WSU Nuclear Radiation Center; Pullman, Wash.

Lillibridge Engineering Lab; Pocatello, Idaho

Center for Excellence in Nuclear Technology, Engineering and Research; Salt Lake City, Utah

Department of Chemistry; Irvine, Calif.

Engineering Building; Tucson, Ariz.

Chemical and Nuclear Engineering Department; Albuquerque, N.M.

Nuclear Engineering Teaching Lab; Austin, Texas

Texas Engineering Experiment Station; College Station, Texas

Lowell, Mass.

Nuclear Engineering and Engineering Physics Program; Troy, N.Y.

MITR-II; Cambridge, Mass.

Nuclear Reactor Facility; Worcester, Mass.

Breazeale Nuclear Reactor; University Park, Pa.

OSURR; Columbus, Ohio

School of Nuclear Engineering; West Lafayette, Ind.

UWNR; Madison, Wis.

TRIGA Mark II Nuclear Reactor Facility; Manhattan, Kan.

UMRR; Rolla, Mo.

MURR; Columbia, Mo.

MUTR; College Park, Md.

Department of Nuclear Engineering; Raleigh, N.C.

Department of Nuclear and Radiological Engineering; Gainesville, Fla.