[en] For the past two years Alan Swain and Henry E. Guttmann, of the Statistics, Computing, and Human Factors Division, Sandia Laboratories, have been developing a handbook to aid qualified persons to evaluate the effect of human error on the availability of engineered safety systems and features in nuclear power plants. The handbook includes a mathematical model, procedures, derived human failure data, and principles of human behavior and ergonomics. The handbook is expanding the human error analyses which were presented in WASH--1400. The work, under the sponsorship of Probabilistic Analysis Staff, NRC Office of Nuclear Regulatory Research (Dr. M.C. Cullingford, NRC Program Manager), is about half completed. An outline of the handbook contents is given in copies of vugraphs (attached), followed by copies of human performance model abstractors (also attached). A first draft of the handbook is scheduled for NRC review by July 1, 1979