2002. 7. 22. KIM, UNG-SOO Dept. of Nuclear and Quantum Engineering Axially Variable Strength Control Rods for The Power Maneuvering of PWRs 2002. 7. 22. KIM, UNG-SOO Dept. of Nuclear and Quantum Engineering

Table of Contents Introduction Optimization of AVSCRs Conclusion and Further Study

Introduction Optimization for the axially varying strength of the AVSCRs Obtaining the optimal performance for power maneuvering Minimizing AO variation and power deviation during power maneuvering Objective function for optimization of the AVSCRs Relationship between AO variation(or power deviation) and worth shape Analytic objective function does not exist. Response for input can only be evaluated by computer simulation. Simulation optimization

Optimization of AVSCRs The optimization indexes are modified and improved. In order to reflect the requirements of AVSCRs Do the indexes have consistency with optimization objectives? Correspond to objectives ! Correspond to past index !

Optimization of AVSCRs Optimization of AVSCRs through simulation optimization Response surface methodology as an optimization strategy 3-in-a-row stopping rule is used. Objective function (Optimization index) The degree of violation of AO target boundary Power deviation from reference target power Initial AO (for AVSCR1)

Optimization of AVSCRs Evaluated by computer simulation (ONED94)

Optimization of AVSCRs Multiple objectives (The use of many responses) Desirability function The researcher’s own priorities and desires on the response value are built into the optimization procedure. One- and two- sided functions are used.(maximization, minimization, assigned target value) For assigned target value,

Optimization of AVSCRs For maximization, For minimization,

Optimization of AVSCRs Single composite response Geometric mean of the desirabilities of the individual responses Maximization of D implies that all responses are in a desirable range simultaneously.

Optimization of AVSCRs In this experiment Optimization of AVSCR1 Index1 : The degree of violation of AO target boundary Index2 : Initial AO

Optimization of AVSCRs Single composite response

Optimization of AVSCRs Results of Optimization (AVSCR1) Optimized shape of AVSCR1 : [3.1903, 0.5, 1.2255]

Optimization of AVSCRs Results of Optimization (AVSCR1)

Optimization of AVSCRs Results of Optimization (AVSCR1) At initial shape After optimization

Optimization of AVSCRs Application to the power maneuvering Initial power variation vs. the step of the AVSCR1 Initial step of AVSCR1 = 20

Optimization of AVSCRs Initial AO variation vs. the step of the AVSCR1 Desirable AO line

Optimization of AVSCRs Initial AO variation vs. the step of the AVSCR2 with the AVSCR1 on the initial position Desirable AO line Initial step of AVSCR2 = 73

Optimization of AVSCRs Application to the power maneuvering : 100-50-100%, 2-6-2-14h

Optimization of AVSCRs Application to the power maneuvering : 100-50-100%, 2-6-2-14h (cont’d)

Conclusion and Further Study Obtaining optimum worth shape of AVSCRs Safety related analysis Enhancement of the operation strategy for the AVSCRs to extract optimal performance of the AVSCRs to be developed applying T_avg signal