Patent ID: 6091790
Filing Date: 2000-07-18
Classification: G21C,Y02E

Abstract:
In a nuclear power plant having a nuclear reactor core and a multiplicity of control rods arranged for movement through the core for controlling the reactor power, the control rods being arranged in groups for movement through the core in staggered sequence, and wherein each said group has imposed thereon an administrative limit of cumulative exposure in the core while each group is situated within a pre-established position range in the core, said administrative limit being in the form of a limit index W:X, defined by a maximum of W hours of accumulated effective exposure on the sum S of effective exposure occurrences w.sub.1,w.sub.2 . . . during a X hour reference period, a method of monitoring compliance with said administration limit comprising the steps of:displaying at least one scale of X uniform intervals, marked with a plurality of numeric values indicative of an initial zero value and a final value X;displaying an indicator configuration for each group, each indicator configuration having a scale associated therewith, and consisting of an indicator for each component w of said sum S, each indicator initially appearing at the zero representation of the scale and growing in size toward the scale value X to span the number of scale intervals corresponding to the ratio of effective exposure of component w to the reference period X;independently of but simultaneously with said indicator growth, advancing each indicator along said scale toward the scale value X, at a uniform rate;displaying the sum S of all components w during the immediately preceding period X;displaying an instantaneous margin value M=W-S;whereby at any given moment, the operator can visually recognizethe number of and effective exposure for each component w during the immediately preceding period X,the total exposure S during the immediately preceding period X, andthe margin M.