Evaluation of LMR Design Options for Reduction of Sodium Void Worth

Technical Report · Sat Sep 01 04:00:00 EDT 1990

DOI:https://doi.org/10.2172/2349069· OSTI ID:2349069

Khalil, H. S. ^[1]; Hill, R. N. ^[1]

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1. Argonne National Laboratory (ANL), Argonne, IL (United States)

Systematic analyses of alternative methods for reducing the sodium void worth for plutonium-fueled liquid metal reactors (LMRs) have been performed. The focus has been on core designs of recent interest in the U.S. LMR program, i.e., designs in the 450 to 1200 MWt size range that make use of metal alloy fuel. The design alternatives encompass changes in composition and geometry. A self-consistent and comprehensive evaluation is made of the void worth reduction achievable by various methods and of the associated core physics performance tradeoffs. We quantify the performance penalties (e.g., the reduced breeding efficiency and the increases in burnup reactivity loss and fissile mass requirement) caused by design changes that significantly reduce the void worth and assess the relative merits of each design option. Our results indicate that the penalties in burnup reactivity loss and fissile requirement can be minimized by use of a "tightly-coupled" radially heterogeneous configuration of minimum volume consistent with fuel rating limits and by adjusting the core height-to-diameter ratio to a value sufficiently small to yield an acceptable void worth. The reactor breeding ratio penalty, however, is minimized by the use of loosely coupled heterogeneous cores or annular cores with a large central blanket zone. Penalties in core radius and volume can be minimized by core composition changes, specifically replacement of a fraction of the fuel (or steel) by sodium or a moderating material.

• Research Organization: Argonne National Laboratory (ANL), Argonne, IL (United States)
• Sponsoring Organization: USDOE Office of Nuclear Energy (NE)
• DOE Contract Number: AC02-06CH11357
• OSTI ID: 2349069
• Report Number(s): ANL-IFR--138; 188121
• Country of Publication: United States
• Language: English

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