Coupled CFD-DEM Analysis of Molten Salt-Cooled Pebble-Bed Reactor Experiment

Journal Article · Sat Jul 01 04:00:00 EDT 2017 · Transactions of the American Nuclear Society

OSTI ID:23050427

Mardus-Hall, Robert; Timchenko, Victoria ^[1]; Ho, Mark ^[2]; Yeoh, Guan ^[1]

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1. The School of Mechanical and Manufacturing Engineering, UNSW, High St, Kensington, NSW 2052, Australia (Australia)
2. Nuclear Analysis Section, Australian Nuclear Science and Technology Organisation, New Illawarra Rd, Menai, NSW 2234, Australia (Australia)

The development of new nuclear reactor designs is an area of ongoing investigation, and a focus of dedicated work for various laboratories around the world. Despite the steadfast and reliable service of Light Water Reactors (LWR), the ideal power reactor, with a combination of high operational temperature, passive safety, proliferation resistance, economic build and waste minimization remains elusive. One promising design that might address these diverse, and at times contradictory requirements, is the Molten Salt Reactor (MSR). In its most radical form, a liquid fueled (LF) MSR has the nuclear fuel dissolved in the molten-salt primary coolant itself, as demonstrated by Oak Ridge National Lab (ORNL) in 1965 to 1969. An alternative fuel arrangement is to retain conventional, solid fuel elements. A proposed method is to implement pebble fuel elements, as have been used in previous gas-cooled reactors, with the gas coolant being replaced with a molten salt. This is referred to as pebble-bed, molten-salt reactor (PB-MSR). The spherical fuel pebbles used within PB-MSRs contain TRISO particles dispersed throughout the pebble's graphite matrix. Many pebbles are constrained to form a porous bed within the core region of a reactor. Coolant molten-salt passes through the pebble bed to remove heat produced due to the nuclear fission taking place within the fuel pebbles' TRISO particles. Various benefits are apparent with the PB-MSR design. When considering the choice of fuel elements, they are a geometry that has been produced and utilized in a similar way in the past, within gas-cooled reactors. The fuel pebbles are also able to be added to, and removed from, the core during operation, enabling on-line refueling. When considering the coolant choice, molten-salts have much higher boiling points (1703 K at 1 atm. for FLiBe) than conventional coolants such as water (630 K at 150 atm.), and are capable of reaching these temperatures at atmospheric pressure. This in turn removes the need for high pressure containment that is present in light water reactors and gas-cooled reactors. The future implementation of new reactors, and the search for improvements in efficiency and safety in current designs, require the advancement of simulation tools, which this work ultimately aims to address.

• OSTI ID: 23050427
• Journal Information: Transactions of the American Nuclear Society, Journal Name: Transactions of the American Nuclear Society Vol. 116; ISSN 0003-018X
• Country of Publication: United States
• Language: English

Related Subjects

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS
21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
42 ENGINEERING
ALTERNATIVE FUELS
BOILING POINTS
FISSION
FLIBE
FUEL ELEMENTS
MOLTEN SALT REACTORS
NUCLEAR FUELS
ORNL
PEBBLE BED REACTORS
POROUS MATERIALS
POWER REACTORS
PRIMARY COOLANT CIRCUITS
REACTOR DESIGN
SOLID FUELS
SPHERICAL CONFIGURATION
WATER COOLED REACTORS
WATER MODERATED REACTORS