This report, part of GAO's performance and accountability series, discusses the major management challenges and program risks facing the Nuclear Regulatory Commission (NRC). GAO found that NRC must resolve issues related to its risk-informed regulatory approach for commercial power plants. NRC developed the Risk-Informed Regulation Implementation Plan to guide its efforts to transition from its traditional regulatory approach to a risk-informed approach. This plan, however, is not as comprehensive as it could be. GAO found that the plan lacks critical performance measures and does not address activities that cut across agency resources. NRC must also address the inherent difficulties in applying a risk-informed approach to nuclear material licensees. Other challenges facing NRC include strengthening its personnel management, developing an effective cost accounting system, and resolving financial management issues.