Granular flow in pebble bed reactors: Dust generation and scaling

Conference · Sun Jul 01 04:00:00 EDT 2012

OSTI ID:22105969

Rycroft, C. H.; Lind, T. ^[1]; Guentay, S.; Dehbi, A. ^[2]

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1. Dept. of Mathematics, Univ. of California, Berkeley, CA 94720 (United States)
2. Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland)

In experimental prototypes of pebble bed reactors, significant quantities of graphite dust have been observed due to rubbing between pebbles as they flow through the core. At the high temperatures and pressures in these reactors, little data is available to understand the frictional properties of the pebble surfaces, and as a result, the Paul Scherrer Institut (Switzerland) proposes a conceptual design of a scaled-down version of a pebble bed reactor to investigate this issue in detail. In this paper, simulations of granular flow in pebble bed reactors using the discrete-element method are presented. Simulations in the full geometry (using 440,000 pebbles) are compared to those in geometries scaled down by 3:1 and 6:1. The simulations show complex behavior due to discrete pebble packing effects, meaning that pebble flow and dust generation in a scaled-down facility may be significantly different. The differences between velocity profiles, packing geometry, and pebble wear at the different scales are discussed. The results can aid in the design of the prototypical facility to more accurately reproduce the flow in a full-size reactor. (authors)

• Research Organization: American Nuclear Society, 555 North Kensington Avenue, La Grange Park, IL 60526 (United States)
• OSTI ID: 22105969
• Country of Publication: United States
• Language: English

Related Subjects

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
DESIGN
DUSTS
GRANULAR MATERIALS
GRAPHITE
PACKINGS
PEBBLE BED REACTORS
SCALING
SIMULATION
SURFACES
TEMPERATURE RANGE 0400-1000 K
WEAR