13.4 IDENTIFICATION OF HUMAN-MACHINE INTERFACES
This section summarizes the safety SSCs requiring human- machine interfaces to
function, and the required human- machine interface. These are identified in
conjunction with the results of the hazard analysis and accident analysis in Chapter
3 that identifies safety SSCs. Include human- machine interfaces necessary for the
surveillance and maintenance of safety SSCs during normal operations, and the
human-machine interfaces required for ensuring safety function during normal,
abnormal, and emergency operations. Describe the actions identified so that the
reviewer can understand what the humans are expected to do (i.e., close isolation
valves) and the importance to facility safety of their action (e.g., ens ures
confinement, actuates a protective response system, etc.).
13.5 OPTIMIZATION OF HUMAN -MACHINE INTERFACES
This section summarizes a systematic inquiry into the optimization of human
machine interfaces with safety SSCs to enhance human performance. Che cklists
serve to document the systematic inquiry. Discussions will be proportionate to the
importance to safety and may consider the following design elements:
Furnished instrumentation, provisions for communication and operational
aids to support timely, reliable performance for safety functions.
Layout and design of controls and instrumentation, and provision for
labeling that apply the principles of ergonomics and human engineering.
Work environments, including physical access, need for protective
clothing or breathing apparatus, noise levels, temperature, humidity,
distractions, and other factors bearing upon physical comfort, alertness,
Staffing considerations (e.g., minimum staffing levels, allocation of
control functions, overtime restr ictions, facility status turnover between
shifts, procedures, training, etc.).
As necessary, reference documentation existing elsewhere in the DSA (i.e.,
Chapter 12, "Procedures and Training").