The Nuclear Regulatory Commission (NRC) is amending its regulations governing licenses and radiation safety requirements for well logging. The final rule modifies NRC regulations dealing with: low activity energy compensation sources; tritium neutron generator target sources;specific abandonment procedures in the event of an immediate threat; changes to requirements for inadvertent intrusion on an abandoned source; the codification of an existing generic exemption; the removal of an obsolete date; and updating regulations to be consistent with the Commission's metrication policy. The amendments to NRC's regulations are necessary to improve, clarify, update, and reflect current practices in the well logging industry.