High-level fuel fabrication facility designs from discrete-event simulation

Highlights: • k_eff limits will not be a binding design constraint, as criticality never exceeds 0.566 in any alloy-geometry configuration. • Dose rates vary between 0.0272 and 554.0 mrem/h and are dependent on both alloy selection and which step in the fabrication process a worker is executing. • To adequately staff fuel production, anywhere from 28 to 63 individuals will need to be hired, depending on which set of design constraints are active. • Under baseline design constraints, the MNF fabrication facility is estimated to incur a total project cost of $777.7 M. • This total can be reduced by as much as $43.3 M if the production confidence constraint is relaxed to P(throughput − σ ≥ 40 assemblies/yr) = 0.95. Like other industrial processes, the production of metallic nuclear fuels (MNF) requires that fabrication facilities be able to reliably meet production demands, operate efficiently, and adhere to federal and local safety regulations. In turn, the set of design variables employed by such a facility, such as operations policies, infrastructure and machinery purchased, and the type and number of staff hired, directly impact a facility's ability to satisfy these goals. Therefore, facility designers must carefully determine which set of design variable values optimally satisfies these constraints. In this paper, we explore how values for these high-level design variables, namely hiring requirements, can be determined in the context of nuclear fuel manufacturing through the coupling of physics-based and discrete-event simulation technologies. Using the Versatile Test Reactor (VTR) program as a case study, we demonstrate how SCALE and MCNP nuclear physics model outputs can be integrated into ExtendSim discrete-event simulation (DES) models of the fuel fabrication process to determine the optimal number of staff hired to ensure fuel production goals are met, operations comply with effective dose limit regulations, and overall project costs are reduced.