Evaluation of Neutron Radiography Reactor LEU-Core Start-Up Measurements

Journal Article · Tue Nov 04 00:00:00 EST 2014 · Nuclear Science and Engineering

DOI:https://doi.org/10.13182/NSE14-12· OSTI ID:1177618

Bess, John D. ^[1]; Maddock, Thomas L. ^[1]; Smolinski, Andrew T. ^[1]; Marshall, Margaret A. ^[1]

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1. Idaho National Lab. (INL), Idaho Falls, ID (United States)

Benchmark models were developed to evaluate the cold-critical start-up measurements performed during the fresh core reload of the Neutron Radiography (NRAD) reactor with Low Enriched Uranium (LEU) fuel. Experiments include criticality, control-rod worth measurements, shutdown margin, and excess reactivity for four core loadings with 56, 60, 62, and 64 fuel elements. The worth of four graphite reflector block assemblies and an empty dry tube used for experiment irradiations were also measured and evaluated for the 60-fuel-element core configuration. Dominant uncertainties in the experimental k_eff come from uncertainties in the manganese content and impurities in the stainless steel fuel cladding as well as the ²³⁶U and erbium poison content in the fuel matrix. Calculations with MCNP5 and ENDF/B-VII.0 neutron nuclear data are approximately 1.4% (9σ) greater than the benchmark model eigenvalues, which is commonly seen in Monte Carlo simulations of other TRIGA reactors. Simulations of the worth measurements are within the 2σ uncertainty for most of the benchmark experiment worth values. The complete benchmark evaluation details are available in the 2014 edition of the International Handbook of Evaluated Reactor Physics Benchmark Experiments.

• Research Organization: Idaho National Lab. (INL), Idaho Falls, ID (United States)
• Sponsoring Organization: USDOE Office of Nuclear Energy (NE)
• Grant/Contract Number: AC07-05ID14517
• OSTI ID: 1177618
• Report Number(s): INL/JOU-13-30828; TRN: US1600442
• Journal Information: Nuclear Science and Engineering, Vol. 178, Issue 4; ISSN 0029-5639
• Publisher: American Nuclear Society
• Country of Publication: United States
• Language: English

Related Subjects

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
97 MATHEMATICS AND COMPUTING
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS
NEUTRON RADIOGRAPHY
COMPUTERIZED SIMULATION
STAINLESS STEELS
BENCHMARKS
SLIGHTLY ENRICHED URANIUM
TRIGA TYPE REACTORS
NEUTRONS
ERBIUM
NUCLEAR FUELS
GRAPHITE
MANGANESE
CLADDING
EIGENVALUES
EVALUATION
MONTE CARLO METHOD
REACTOR START-UP
FUEL ELEMENTS
REACTOR PHYSICS
LOADING
MANUALS
CONTROL ROD WORTHS
NUCLEAR DATA COLLECTIONS
CONFIGURATION
COST
CRITICALITY
IMPURITIES
REACTIVITY
REACTOR SHUTDOWN
TUBES
Benchmark
IRPhEP
NRAD
TRIGA