Automated core design code development for a lead‐cooled fast reactor and its core optimization

Abstract

Summary Based on the favorable neutronic performance, T/H (thermal‐hydraulic) characteristics and inherent safety of the lead‐cooled fast reactor (LFR), University of Science and Technology of China performed a preliminary design of the 1000Mth medium‐power modular lead‐cooled fast reactor M2LFR‐1000. To solve the core optimization problem of M2LFR‐1000, an automatic core design code named CODOPT (core design and optimization) was developed, considering geometry, neutronics and thermal‐hydraulics. CODOPT starts from setting a number of the core design schemes, then evaluates their key neutronic and T/H characteristics automatically and finally finds the design schemes satisfying the design constraints. Using this code, the sensitivity analysis of the key design parameters (fuel rod diameter, pitch diameter ratio, and inlet coolant velocity) is carried out. Under the neutronic and T/H design constraints, the optimization problem of the core has been studied using a multi‐objective function, which tries to find an optimal design with larger Keff, flatter power distribution, and minimum temperature of cladding and pellet. Current results show that the overall neutronic and T/H performance of M2LFR‐1000 can be improved by choosing the design parameters presented in this paper. The automatic core design ideas adopted currently can also provide some reference for future LFR designs.

A Design and Optimization Methodology for Liquid Metal Fast Reactors

“…The LFCC for this core design break-even with the original design LFCC of $6.98/MW e .hr occurs at a cost of 15 N enrichment of about $14/g. This cost is at least 40% higher than the reported [190, 250] Inner core enrichment (%) [9,11] Middle core enrichment (%) [11,13] Outer core enrichment (%) [12,15] value in Wallenius [33] for a fast reactor, which means the ENLFR is competitive at a higher enriched nitrogen cost. The ENLFR core lasts for a shorter cycle length compared to the natural nitride-fueled core (i.e., the WLFR).…”

“…It should be noted that the improvement on the LFCC introduced to the WLFR using DOM is relatively small because the WLFR was already an optimized design. The strength of DOM is in the design of new cores, where no [11,12] Outer core enrichment (%) [12,15] 10 International Journal of Energy Research "good" starting guess is available. This will be demonstrated in the next section.…”

“…Another methodology for the design and optimization of the LMFR core was suggested and implemented in the core design and optimization (CODOPT) code [11]. CODOPT iterates between three modules.…”