DASS: A decision aid integrating the safety parameter display system and emergency functional recovery procedures. Final report

Using a stand-alone developmental test-bed consisting of a minicomputer and a high-resolution color graphics computer, displays and supporting software incorporating advanced on-line decision-aid concepts were developed and evaluated. The advanced concepts embodied in displays designed for the operating crew of a PWR plant include: (1) an integrated display format which supports a top-down approach to problem detection, recovery planning, and control; (2) introduction of nonobservable plant parameters derived from first principles mass and energy balances as part of the displayed information; and (3) systematic processing and display of key success path (plant safety system) attributes. The prototype system, referred to as the PWR-DASS (Disturbance Analysis and Surveillance System), consists of 18 displays targeted for principal use by the control room systems manager. PWR-DASS was conceived to fulfill an operational void not fully supported by safety parameter display systems or reformulated emergency procedure guidelines. The results from the evaluation by licensed operators suggest that organization and display of desired critical safety function and success path information as incorporated in the PWR-DASS prototype can support the systems manager's overview. The results also point to the need for several refinements required for a field grade system, and to the need for a simulator-based evaluation of the prototype or its successor. (author)