JAMES D LITTLE
Real Estate Commission in Pittsburgh, PA

4675147, Jun 23, 1987

Apr 6, 1983

6/482641

William F. Schaefer - North Huntingdon PA
James L. Little - Pittsburgh PA
Kenneth F. Cooper - Pittsburgh PA
James R. Easter - Pittsburgh PA

Westinghouse Electic Corp. - Pittsburgh PA

G21C 1700

376245

The real time actual and reference values of parameters pertinent to the key safety concerns of a pressurized water reactor nuclear power plant are used to generate an integrated graphic display representative of the plant safety status. This display is in the form of a polygon with the distances of the vertices from a common origin determined by the actual value of the selected parameters normalized such that the polygon is regular whenever the actual value of each parameter equals its reference value despite changes in the reference value with operating conditions, and is an irregular polygon which visually indicates deviations from normal otherwise. The values of parameters represented in analog form are dynamically scaled between the reference value and high and low limits which are displayed as tic marks at fixed distances along spokes radiating from the common origin and passing through the vertices. Multiple, related binary signals are displayed on a single spoke by drawing the associated vertice at the reference value when none of the represented conditions exist and at the high limit when any such condition is detected. A regular polygon fixed at the reference values aids the operator in detecting small deviations from normal and in gauging the magnitude of the deviation.