Summary: A September 1978 GAO report revealed that Nuclear Regulatory Commission (NRC) inspectors: (1) did little independent testing of nuclear powerplant construction work but relied heavily upon utility companies' self evaluations; (2) spent little time observing construction work; and (3) did not communicate routinely with the people who did the actual construction work. NRC inspectors spent much of their onsite inspection time reviewing documentation and assessing utilities' audit reports to test the utilities' quality assurance programs. Construction contractors normally decided what corrective actions were needed when construction problems were identified; performed the corrective actions; and reinspected and accepted the rework. Thus, quality assurance rested primarily with construction contractors, and only secondarily with licensees and NRC. The problem was compounded by the fact that NRC inspectors spent only about 50 days per year at construction sites and only about 4 of these days were spent observing tests by the utility or its contractors. GAO recommended that NRC provide a more thorough and independent evaluation of the quality of construction work by increasing independent measurements and direct observations, initiating private interviews with craftsmen, and requiring utilities to train craftsmen in the principles of quality assurance. GAO found that a program to review vendors who supply safety-related components for nuclear powerplants which was begun in 1974 was having a positive effect, but needed further improvement. NRC had not identified all vendors of safety-related equipment, nor had it set up a systematic method of selecting these vendors for inspection. GAO concluded that NRC needed to initiate these actions and to assign more inspectors to vendor inspections. GAO also found that NRC inspection and reporting practices needed to be improved as they contained errors, lacked details about the scope of work performed, and did not have adequate supporting documentation. GAO recommended several changes to NRC inspection performance and reporting practices aimed at correcting these weaknesses. The continuing problems with construction quality at many of the Nation's nuclear powerplants clearly demonstrate the need for an effective regulatory program for inspecting powerplant construction.