Search

In order to maximize both the life cycle and efficiency of a reactor core, it is essential to find the optimum loading pattern. In the case of research reactors, a loading pattern can also be optimized for flux at an irradiation site. Therefore, the development of a general-use methodology for core loading optimization would be very valuable. In this paper, general-use multiobjective core reloading pattern optimization is performed using modified genetic algorithms (MGA). The developed strategy can be applied for the constrained optimization of research and power reactor cores. For an optimal reactor core reloading design strategy, an intelligent technique GA is coupled with the Monte Carlo (MC) code SuperMC developed by the FDS team in China for nuclear reactor physics calculations. An optimal loading pattern can be depicted as a configuration that has the maximum keff and maximum thermal fluxes in the core of the given fuel inventory keeping in view the safety constraints such as limitation on power peaking factor. The optimized loading patterns for Pakistan Research Reactor-1 (PARR-1) have been recommended using the implemented strategy by considering the constraint optimization, i.e., to maximize the keff or maximum thermal neutron flux while maintaining low power peaking factor. It has been observed that the developed intelligent strategy performs these tasks with a reasonable computational cost. [ABSTRACT FROM AUTHOR]

The core cycle length is crucial parameter for effective and economic operation of a nuclear power plant. Nuclear industry has great emphasis on improving the feasibility and sustainability of nuclear power generation. The cost of the electricity can be reduced by increasing the cycle length without violating the safety margins. Various methods and strategies have been examined to extend a Pressurized Water Reactor (PWR) core cycle length with optimized loading patterns. The objective of this work is to analyse the feasibility of the system to extend the cycle length of Chashma Nuclear Power Generating Station (CNPGS) unit-3, currently operating in Pakistan from 12 months to ∼18 months. To achieve the objective, fuel enrichment is increased from 3.4% to 4.1% with Gd 2 O 3 as burnable poisons to suppress the excess reactivity. The multi-cycle analyses showed promising results and the core cycle length has been extended to ∼18-month for CNPGS unit-3 keeping power peaking factor, temperature coefficients and discharge burnup within design limits. The method can be confidently applied at any cycle of the power plant. Additionally, fuel and moderator temperatures at average and hot channels at beginning of life (BOL) and the end of life (EOL) are predicted using the 1-D steady state thermal hydraulic analysis. The peak to average temperatures at BOL and EOL are found well below the reference value (1.6875). • The cycle length of CNPGS unit-3 is extended from 12 months to ∼18 months. • The fuel enrichment is increased from 3.4% to 4.1% and Gd 2 O 3 is used as the burnable poison. • The multi-cycle analyses is performed using DRAGON5 and DONJON5 computer codes. • Various neutronic parameters are calculated under various core conditions and kept within design limits. • The 1-D steady state thermal hydraulic analysis is performed at average and hot channels at BOL and EOL. [ABSTRACT FROM AUTHOR]