Lessons learned from TMI and how it changed the regulatory framework in the US

A brief description of the Three Mile Island accident with an emphasis on the in-plant radiological challenges that impacted occupational radiation protection is presented. Several official investigations into the accident identified many deficiencies and weaknesses in plant design, operations, and management; internal and external communications; human performance, and the facilities' overall preparedness to respond to the accident. The Lessons Learned and the resulting NRC Action Plan items related to occupational radiation protection are reviewed. The role of the plant's radiation protection program (and the core competencies of plant staff) during normal operations are discussed, with respect to their impact on adequate worker radiation protection during unanticipated off-normal events. (author)