Radiological Materials Security Act

Radiological Materials Security Act - Amends the Homeland Security Act of 2002 to direct the Secretary of Homeland Security to enhance domestic preparedness for and collective response to terrorism by conducting a risk assessment regarding the threat of, vulnerability to, and consequences of theft or other procurement of radiological materials that could be used by a terrorist in a radiological dispersion device.

Requires the Secretary to: (1) disseminate the findings of, and specific risk information developed in, the assessment to participants in the radiological sources security system; (2) develop a classification system for information regarding radiological materials and classify the assessment under such system; (3) share the assessment with participants with appropriate clearances; (4) develop a terrorism risk self-assessment tool for facilities to ascertain risk and provide it to the Nuclear Regulatory Commission (NRC), which shall disseminate it to system facilities; (5) issue recommended practices for securing high-risk radiological materials; and (6) make available infrastructure protection grants to owners and operators of facilities with approved facility security plans.

Directs the NRC to: (1) update, promulgate, and enforce regulations for the security of radiological materials; (2) maintain and update a nuclear materials events database and a database to track regulated radiological materials and orphaned, lost, or stolen radiological materials; and (3) issue regulations requiring the owner or operator of a facility containing high-risk radiological material to create, submit to the NRC and certain states, and implement facility security plans to address vulnerabilities.

Directs the Secretary of Energy to provide technical assistance for securing high-risk radiological materials to the Department of Homeland Security (DHS), the NRC, state and local authorities, and participating facilities.