The Nuclear Regulatory Commission (NRC) is amending its regulations to include jurisdiction over discrete sources of radium- 226, accelerator-produced radioactive materials, and discrete sources of naturally occurring radioactive material, as required by the Energy Policy Act of 2005 (EPAct), which was signed into law on August 8, 2005. The EPAct expanded the Atomic Energy Act of 1954 definition of Byproduct material to include any discrete source of radium-226, any material made radioactive by use of a particle accelerator, and any discrete source of naturally occurring radioactive material, other than source material, that the Commission, in consultation with other Federal officials named in the EPAct, determines would pose a similar threat to the public health and safety or the common defense and security as a discrete source of radium-226, that are extracted or converted after extraction for use for a commercial, medical, or research activity. In so doing, these materials were placed under the NRC's regulatory authority. The EPAct also mandated that the Commission, after consultation with the States and other stakeholders, issue final regulations establishing requirements that the Commission determines necessary under the EPAct. This rulemaking effort has been undertaken in response to that mandate and includes significant contributions from many States that have regulated the naturally occurring and accelerator-produced radioactive material, the Organization of Agreement States, Inc., the Conference of Radiation Control Program Directors, Inc. (CRCPD), and other stakeholders. In addition, this final rule was informed and guided by the CRCPD's applicable Suggested State Regulations for the Control of Radiation. Licensees, individuals, and other entities who are engaged in activities involving the newly defined byproduct material in both Agreement States and non-Agreement States and United States Territories will be affected by this rulemaking.