Scaling analysis for the direct reactor auxiliary cooling system for FHRs

Journal Article · Wed Apr 01 04:00:00 EDT 2015 · Nuclear Engineering and Design

DOI:https://doi.org/10.1016/j.nucengdes.2014.12.035· OSTI ID:1177634

Lv, Q. ^[1]; Kim, I. H. ^[1]; Sun, X. ^[1]; Christensen, R. N. ^[1]; Blue, T. E. ^[1]; Yoder, G. ^[2]; Wilson, D. ^[2]; Sabharwall, P. ^[3]

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1. The Ohio State Univ., Columbus, OH (United States). Nuclear Engineering Program, Dept. of Mechanical & Aerospace Engineering
2. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
3. Idaho National Lab. (INL), Idaho Falls, ID (United States)

The Direct Reactor Auxiliary Cooling System (DRACS) is a passive residual heat removal system proposed for the Fluoride-salt-cooled High-temperature Reactor (FHR) that combines the coated particle fuel and graphite moderator with a liquid fluoride salt as the coolant. The DRACS features three natural circulation/convection loops that rely on buoyancy as the driving force and are coupled via two heat exchangers, namely, the DRACS heat exchanger and the natural draft heat exchanger. A fluidic diode is employed to minimize the parasitic flow into the DRACS primary loop and correspondingly the heat loss to the DRACS during reactor normal operation, and to activate the DRACS in accidents when the reactor is shut down. While the DRACS concept has been proposed, there are no actual prototypic DRACS systems for FHRs built or tested in the literature. In this paper, a detailed scaling analysis for the DRACS is performed, which will provide guidance for the design of scaled-down DRACS test facilities. Based on the Boussinesq assumption and one-dimensional flow formulation, the governing equations are non-dimensionalized by introducing appropriate dimensionless parameters. The key dimensionless numbers that characterize the DRACS system are obtained from the non-dimensional governing equations. Based on the dimensionless numbers and non-dimensional governing equations, similarity laws are proposed. In addition, a scaling methodology has been developed, which consists of a core scaling and a loop scaling. The consistency between the core and loop scaling is examined via the reference volume ratio, which can be obtained from both the core and loop scaling processes. The scaling methodology and similarity laws have been applied to obtain a scientific design of a scaled-down high-temperature DRACS test facility.

• Research Organization: Idaho National Laboratory (INL), Idaho Falls, ID (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC07-05ID14517
• OSTI ID: 1177634
• Report Number(s): INL/JOU--15-34850
• Journal Information: Nuclear Engineering and Design, Journal Name: Nuclear Engineering and Design Vol. 285; ISSN 0029-5493
• Publisher: Elsevier
• Country of Publication: United States
• Language: English

Related Subjects

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
22 GENERAL STUDIES OF NUCLEAR REACTORS
AFTER-HEAT REMOVAL
DESIGN
DIMENSIONLESS NUMBERS
Direct Reactor Auxiliary Cooling System DIRECT REACTOR AUXILIARY COOLING SYSTEM
HEAT EXCHANGERS
Molten Salt Cooled Reactors
NATURAL CONVECTION
ONE-DIMENSIONAL CALCULATIONS
RHR SYSTEMS
Scaling Laws
TEST FACILITIES