Abstract: In an embodiment of a method of evaluating robustness of a proposed solution to a constraint problem, operational output data for at least first and second modified versions of the proposed solution is generated. The first modified version has at least one control variable of the proposed solution perturbed in a first direction and the second modified version has the at least one control variable of the proposed solution perturbed in a second direction. At least a portion of the generated operation output data is then presented such as on a graphical user interface.

Abstract: In a method of determining an operating margin to a given operating limit in a nuclear reactor, operational plant data from an on-line nuclear reactor plant is accessed, and reactor operation is simulated off-line using the operational plant data to generate predicted dependent variable data representative of the given operating limit. The predicted dependent variable data is normalized for evaluation with normalized historical dependent variable data from stored operating cycles of plants having a similar plant configuration to the on-line plant. A time-dependent average bias and a time-dependent uncertainty value for the predicted dependent variable data are determined using the normalized historical dependent variable data, and a risk-tolerance level for the on-line plant is obtained.

Abstract: A method of fuel bundle consideration in a reactor. The method includes creating or editing bundle groups including fuel bundles.

Abstract: The apparatus for creating and editing a nuclear reactor core template includes a graphical user interface and a processor controlling the graphical user interface to allow a user to selectively populate a loading map with fuel bundles residing in at least one fuel pool.

Abstract: A method of evaluating constraint functions, the evaluation being based at least in part on a control blade movement criteria.

Abstract: The apparatus for creating and editing a nuclear reactor core template includes a graphical user interface and a processor controlling the graphical user interface to allow a user to selectively populate a loading map with fuel bundles residing in at least one fuel pool.

Abstract: A method, arrangement and computer program is described for generating a database of selectable fresh fuel bundle designs usable in one or more nuclear reactors. In an example, an initial population of candidate fresh fuel bundle designs may be generated and a set of rod-type changes to make to a given candidate in the initial population may be established. A given candidate fresh fuel bundle may be modified by making at least one rod-type change from the set therein. A core loaded with the modified bundle design may be simulated to generate bundle performance outputs. The bundle performance outputs may be ranked based on a plurality of user-input limits. The modified candidate fresh fuel bundle design may be stored, if the bundle performance outputs meet, or are within an accepted margin to, the user-input limits, so as to generate the database.