In a study commissioned by the U.S. Nuclear Regulatory Commission (NRC), Pacific Northwest Laboratory evaluated the costs and benefits of modifying regulatory requirements in the area of the turbine rotor design reviews and inspections. The basis for the analysis was presented in the Regulatory Analysis Guidelines and in the Handbook for Value-Impact Assessment. The effects of selected modifications to regulations were evaluated in terms of public risk and costs to industry and the NRC. The results indicate that substantial savings in operating costs may be realized by changing the interval of turbine rotor inspections.