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Title: Benchmark Evaluation of the NRAD Reactor LEU Core Startup Measurements

Abstract

The Neutron Radiography (NRAD) reactor is a 250-kW TRIGA-(Training, Research, Isotope Production, General Atomics)-conversion-type reactor at the Idaho National Laboratory; it is primarily used for neutron radiography analysis of irradiated and unirradiated fuels and materials. The NRAD reactor was converted from HEU to LEU fuel with 60 fuel elements and brought critical on March 31, 2010. This configuration of the NRAD reactor has been evaluated as an acceptable benchmark experiment and is available in the 2011 editions of the International Handbook of Evaluated Criticality Safety Benchmark Experiments (ICSBEP Handbook) and the International Handbook of Evaluated Reactor Physics Benchmark Experiments (IRPhEP Handbook). Significant effort went into precisely characterizing all aspects of the reactor core dimensions and material properties; detailed analyses of reactor parameters minimized experimental uncertainties. The largest contributors to the total benchmark uncertainty were the 234U, 236U, Er, and Hf content in the fuel; the manganese content in the stainless-steel cladding; and the unknown level of water saturation in the graphite reflector blocks. A simplified benchmark model of the NRAD reactor was prepared with a keff of 1.0012 ± 0.0029 (1σ). Monte Carlo calculations with MCNP5 and KENO-VI and various neutron cross section libraries were performed and compared with themore » benchmark eigenvalue for the 60-fuel-element core configuration; all calculated eigenvalues are between 0.3 and 0.8% greater than the benchmark value. Benchmark evaluations of the NRAD reactor are beneficial in understanding biases and uncertainties affecting criticality safety analyses of storage, handling, or transportation applications with LEU-Er-Zr-H fuel.« less

Authors:
 [1];  [1];  [1]
  1. Idaho National Lab. (INL), Idaho Falls, ID (United States)
Publication Date:
Research Org.:
Idaho National Lab. (INL), Idaho Falls, ID (United States)
Sponsoring Org.:
USDOE National Nuclear Security Administration (NNSA), Nuclear Criticality Safety Program (NCSP)
OSTI Identifier:
1031653
Report Number(s):
INL/CON-11-20775
TRN: US1200145
DOE Contract Number:  
AC07-05ID14517
Resource Type:
Conference
Resource Relation:
Conference: ICNC '11: 9. International Conference on Nuclear Criticality, Edinburgh, Scotland (United Kingdom), 19-22 Sep 2011; Related Information: https://www.oecd-nea.org/science/meetings/ICNC2011/programme.html
Country of Publication:
United States
Language:
English
Subject:
21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS; 73 NUCLEAR PHYSICS AND RADIATION PHYSICS; 97 MATHEMATICAL METHODS AND COMPUTING; BENCHMARKS; CONFIGURATION; CRITICALITY; CROSS SECTIONS; DIMENSIONS; EIGENVALUES; FUEL ELEMENTS; GRAPHITE; ISOTOPE PRODUCTION; MANGANESE; NEUTRON RADIOGRAPHY; NEUTRONS; REACTOR CORES; REACTOR PHYSICS; SAFETY; STAINLESS STEELS; STORAGE; WATER SATURATION; INEEL; Nuclear Criticality Safety Program (NCSP); Benchmark; ICSBEP; IRPhEP; NRAD; TRIGA

Citation Formats

Bess, John D., Maddock, Thomas L., and Marshall, Margaret A. Benchmark Evaluation of the NRAD Reactor LEU Core Startup Measurements. United States: N. p., 2011. Web.
Bess, John D., Maddock, Thomas L., & Marshall, Margaret A. Benchmark Evaluation of the NRAD Reactor LEU Core Startup Measurements. United States.
Bess, John D., Maddock, Thomas L., and Marshall, Margaret A. 2011. "Benchmark Evaluation of the NRAD Reactor LEU Core Startup Measurements". United States. https://www.osti.gov/servlets/purl/1031653.
@article{osti_1031653,
title = {Benchmark Evaluation of the NRAD Reactor LEU Core Startup Measurements},
author = {Bess, John D. and Maddock, Thomas L. and Marshall, Margaret A.},
abstractNote = {The Neutron Radiography (NRAD) reactor is a 250-kW TRIGA-(Training, Research, Isotope Production, General Atomics)-conversion-type reactor at the Idaho National Laboratory; it is primarily used for neutron radiography analysis of irradiated and unirradiated fuels and materials. The NRAD reactor was converted from HEU to LEU fuel with 60 fuel elements and brought critical on March 31, 2010. This configuration of the NRAD reactor has been evaluated as an acceptable benchmark experiment and is available in the 2011 editions of the International Handbook of Evaluated Criticality Safety Benchmark Experiments (ICSBEP Handbook) and the International Handbook of Evaluated Reactor Physics Benchmark Experiments (IRPhEP Handbook). Significant effort went into precisely characterizing all aspects of the reactor core dimensions and material properties; detailed analyses of reactor parameters minimized experimental uncertainties. The largest contributors to the total benchmark uncertainty were the 234U, 236U, Er, and Hf content in the fuel; the manganese content in the stainless-steel cladding; and the unknown level of water saturation in the graphite reflector blocks. A simplified benchmark model of the NRAD reactor was prepared with a keff of 1.0012 ± 0.0029 (1σ). Monte Carlo calculations with MCNP5 and KENO-VI and various neutron cross section libraries were performed and compared with the benchmark eigenvalue for the 60-fuel-element core configuration; all calculated eigenvalues are between 0.3 and 0.8% greater than the benchmark value. Benchmark evaluations of the NRAD reactor are beneficial in understanding biases and uncertainties affecting criticality safety analyses of storage, handling, or transportation applications with LEU-Er-Zr-H fuel.},
doi = {},
url = {https://www.osti.gov/biblio/1031653}, journal = {},
number = ,
volume = ,
place = {United States},
year = {Mon Sep 19 00:00:00 EDT 2011},
month = {Mon Sep 19 00:00:00 EDT 2011}
}

Conference:
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