New Improved Nuclear Data for Nuclear Criticality and Safety

Conference · Mon Sep 19 00:00:00 EDT 2011

OSTI ID:1025850

Guber, Klaus H. ^[1]; Leal, Luiz C. ^[1]; Lampoudis, C. ^[2]; Kopecky, S. ^[3]; Schillebeeckx, P. ^[3]; Emiliani, F. ^[3]; Wynants, R. ^[3]; Siegler, P. ^[3]

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1. Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
2. Institute for Reference Materials and Measurements (IRMM), Geel (Belgium).
3. Institute for Reference Materials and Measurements (IRMM), Geel (Belgium). European Commission Joint Research Center

The Geel Electron Linear Accelerator (GELINA) was used to measure neutron total and capture cross sections of ^{182,183,184,186}W and ^63,65Cu in the energy range from 100 eV to {approx}200 keV using the time-of-flight method. GELINA is the only high-power white neutron source with excellent timing resolution and ideally suited for these experiments. Concerns about the use of existing cross-section data in nuclear criticality calculations using Monte Carlo codes and benchmarks were a prime motivator for the new cross-section measurements. To support the Nuclear Criticality Safety Program, neutron cross-section measurements were initiated using GELINA at the EC-JRC-IRMM. Concerns about data deficiencies in some existing cross-section evaluations from libraries such as ENDF/B, JEFF, or JENDL for nuclear criticality calculations were the prime motivator for new cross-section measurements. Over the past years many troubles with existing nuclear data have emerged, such as problems related to proper normalization, neutron sensitivity backgrounds, poorly characterized samples, and use of improper pulse-height weighting functions. These deficiencies may occur in the resolved- and unresolved-resonance region and may lead to erroneous nuclear criticality calculations. An example is the use of the evaluated neutron cross-section data for tungsten in nuclear criticality safety calculations, which exhibit discrepancies in benchmark calculations and show the need for reliable covariance data. We measured the neutron total and capture cross sections of ^{182,183,184,186}W and ^63,65Cu in the neutron energy range from 100 eV to several hundred keV. This will help to improve the representation of the cross sections since most of the available evaluated data rely only on old measurements. Usually, these measurements were done with poor experimental resolution or only over a very limited energy range, which is insufficient for the current application.

• Research Organization: Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA), Nuclear Criticality Safety Program (NCSP)
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 1025850
• Resource Relation: Conference: 9. International Conference on Nuclear Criticality Safety (ICNC 2011), Edinburgh (United Kingdom), 19-22 Sep 2011
• Country of Publication: United States
• Language: English

Related Subjects

43 PARTICLE ACCELERATORS
97 MATHEMATICS AND COMPUTING
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
BENCHMARKS
CRITICALITY
CROSS SECTIONS
ELECTRONS
ENERGY RANGE
LINEAR ACCELERATORS
NEUTRON SOURCES
NEUTRONS
RESOLUTION
SAFETY
SENSITIVITY
TIME-OF-FLIGHT METHOD
TUNGSTEN
WEIGHTING FUNCTIONS
Nuclear Criticality Safety Program (NCSP)
Geel Electron Linear Accelerator (GELINA)
High-Power White Neutron Source
Neutron Total