scholarly journals Testing Oxygen Nuclear Data Libraries in Research Center Rez

2020 ◽  
Vol 7 (2) ◽  
Author(s):  
Martin Schulc ◽  
Michal Košťál ◽  
Evžen Novák ◽  
Jan Šimon ◽  
Luiz Leal
Keyword(s):  
Fast Neutron ◽  
Neutron Source ◽  
Nuclear Data ◽  
Light Water ◽  
Neutron Spectra ◽  
Active Core ◽  
252Cf Neutron Source ◽  
Data Libraries ◽  
Nuclear Data Libraries ◽  
Fast Neutron Spectrum

Abstract Oxygen belongs to the group of the most important isotopes in the nuclear data field. The aim of this paper is validate various oxygen nuclear data libraries in different scenarios with high content of oxygen. For this purpose, fast neutron spectra were measured by a stilbene scintillation detector in the region of 1–10 MeV in the three model cases involving 252Cf neutron source and light water reactor. The cases include measurements of leakage spectra using 252Cf neutron source placed in the centers of the light water and heavy water spheres of 0.30 m diameter. Following measurements were carried out inside the concrete biological shielding of the VVER-1000 mock-up simulator in the LR-0 reactor and in the dry channel located in the center of the special core placed in the LR-0 reactor. In the case of the special core, symmetric active core consisted of six standard fuel assemblies which surround the experimental dry module, where the fast neutron spectrum was measured. The measured neutron spectra were compared with MCNP6 transport code calculations in ENDF/B-VII.1, ENDF/B-VIII.0, JENDL-4.0, and IRSN 16O nuclear data evaluations. Experimental results for all cases follow similar trend. All considered libraries underestimate experimental measurement in the region of 3–4 MeV in all cases.

Investigation of 127I(n,2n)126I and 23Na(n,2n)22Na Reactions Using 252Cf Neutron Source

2019 ◽  
Vol 5 (3) ◽  
Author(s):  
Martin Schulc ◽  
Michal Košťál ◽  
Evžen Novák ◽  
Jan Šimon ◽  
Nicola Burianová
Keyword(s):  
Neutron Source ◽  
Cross Sections ◽  
Nuclear Data ◽  
Reaction Rates ◽  
Fission Neutron ◽  
High Energy ◽  
High Energy Tail ◽  
252Cf Neutron Source ◽  
Data Libraries ◽  
Nuclear Data Libraries

This work deals with 23Na(n,2n)22Na and 127I(n,2n)126I reactions in the 252Cf spontaneous fission neutron source. 252Cf neutron source with approximate emission of 6·× 108 n/s was employed for the irradiation of sodium iodide. The spectrum-averaged cross sections (SACS) were then inferred from experimentally determined reaction rates and compared with calculations in MCNP6 using various nuclear data libraries. The experimental reaction rates were derived from the net peak areas (NPAs) measured using the high purity germanium spectroscopy. The measured SACS for the 23Na(n,2n)22Na reaction in the 252Cf spectrum was determined as equal to (8.98±0.32)·× 10−6 b. The resulting SACS for the 127I(n,2n)126I reaction in the 252Cf spectrum was derived as (2.044±0.0072)·× 10−3 b. These experimental data can be used for nuclear data libraries validation and to specify high energy tail of the 252Cf neutron spectrum.

scholarly journals Generation of the 1H in H2O neutron thermal scattering law covariance matrix of the CAB model

2018 ◽  
Vol 4 ◽  
pp. 32
Author(s):  
Juan Pablo Scotta ◽  
Gilles Noguère ◽  
Jose Ignacio Marquez Damian
Keyword(s):  
Covariance Matrix ◽  
Nuclear Data ◽  
Water Model ◽  
Dynamic Simulations ◽  
Light Water ◽  
Thermal Scattering ◽  
Data Libraries ◽  
Hydrogen Bound ◽  
Nuclear Data Libraries ◽  
Evaluated Nuclear Data

The thermal scattering law (TSL) of 1H in H2O describes the interaction of the neutron with the hydrogen bound to light water. No recommended procedure exists for computing covariances of TSLs available in the international evaluated nuclear data libraries. This work presents an analytic methodology to produce such a covariance matrix-associated to the water model developed at the Atomic Center of Bariloche (Centro Atomico Bariloche, CAB, Argentina). This model is called as CAB model, it calculates the TSL of hydrogen bound to light water from molecular dynamic simulations. The performance of the obtained covariance matrix has been quantified on integral calculations at “cold” reactor conditions between 20 and 80∘ C. For UOX fuel, the uncertainty on the calculated reactivity ranges from ±71 to ±155 pcm. For MOX fuel, it ranges from ±110 to ±203 pcm.

scholarly journals Measurement of leakage neutron spectra with D-T neutrons and evaluated nuclear data

2020 ◽  
Vol 239 ◽  
pp. 18009
Author(s):  
Rui Han ◽  
Zhiqiang Chen ◽  
Guoyu Tian ◽  
Yangbo Nie ◽  
Fudong Shi ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Nuclear Data ◽  
Neutron Spectra ◽  
Neutron Reaction ◽  
Partial Energy ◽  
Reaction Channels ◽  
Neutron Leakage ◽  
Data Libraries ◽  
Nuclear Data Libraries ◽  
Evaluated Nuclear Data

Benchmarking of evaluated neutron nuclear data libraries was performed for ∼14.8 MeV neutrons on the several targets, such as gallium, graphite, silicon carbide, uranium and tungsten samples. The experiments were performed at China Institute of Atomic Energy (CIAE). The neutron leakage spectra from the samples were measured at 60◦ and 120◦ by a TOF technique with a BC501A scintillation detector. The measured spectra are rather well reproduced by MCNP-4C simulations with the CENDL3.1, JENDL-4.0 and the new release ENDF/B-VIII.0, JEFF-3.3 evaluated nuclear data libraries and so on. There have some difference between experiments and simulations for the elastic and inelastic contributions in the partial energy range. And the discrepancies of the neutron leakage spectra in the MCNP simulations originate simply from the differences in the spectra distributions of the neutron reaction channels in the evaluated nuclear data libraries.

Criticality Calculations and Basic Sensitivity/Uncertainty Investigation of LR-0 Benchmark Core

2019 ◽  
Vol 5 (3) ◽  
Author(s):  
Tomáš Czakoj ◽  
Evžen Losa
Keyword(s):  
Lithium Fluoride ◽  
Three Dimensional ◽  
Reactor Core ◽  
Nuclear Data ◽  
Monte Carlo Code ◽  
Multiplication Factor ◽  
Reference Case ◽  
Energy Version ◽  
Data Libraries ◽  
Nuclear Data Libraries

Three-dimensional Monte Carlo code KENO-VI of SCALE-6.2.2 code system was applied for criticality calculation of the LR-0 reactor core. A central module placed in the center of the core was filled by graphite, lithium fluoride-beryllium fluoride (FLIBE), and lithium fluoride-sodium fluoride (FLINA) compounds. The multiplication factor was obtained for all cases using both ENDF/B-VII.0 and ENDF/B-VII.1 nuclear data libraries. Obtained results were compared with benchmark calculations in the MCNP6 using ENDF/B-VII.0 library. The results of KENO-VI calculations are found to be in good agreement with results obtained by the MCNP6. The discrepancies are typically within tens of pcm excluding the case with the FLINA filling. Sensitivities and uncertainties of the reference case with no filling were determined by a continuos-energy version of the TSUNAMI sequence of SCALE-6.2.2. The obtained uncertainty in multiplication factor due to the uncertainties in nuclear data is about 650 pcm with ENDF/B-VII.1.

Sensitivity to Nuclear Data Libraries in the Physics Core Characteristics of Conceptual Thorium Breeders

2011 ◽  
Vol 59 (2(3)) ◽  
pp. 1361-1364
Author(s):  
V. Jagannathan ◽  
U. Pal ◽  
R. Karthikeyan ◽  
A. Srivastava ◽  
S. A. Khan
Keyword(s):  
Nuclear Data ◽  
Data Libraries ◽  
Core Characteristics ◽  
Nuclear Data Libraries
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