Ivan Kodeli - Academia.edu (original) (raw)

Papers by Ivan Kodeli

Research paper thumbnail of Overview of the JET results in support to ITER

Research paper thumbnail of On how sensitive the cross-section sensitivity calculations are to P_N order approximations

Research paper thumbnail of XSUN-2022/SUSD3D n/γ sensitivity-uncertainty code package with recent JEFF-3.3 and ENDF/B-VIII.0 covariance data

Epj Web of Conferences, 2023

Research paper thumbnail of Outcomes of WPEC SG47 on "Use of Shielding Integral Benchmark Archive and Database for Nuclear Data Validation

EPJ Web of Conferences

The Working Party on International Nuclear Data Evaluation Co-operation Subgroup 47 (WPECSG47) en... more The Working Party on International Nuclear Data Evaluation Co-operation Subgroup 47 (WPECSG47) entitled "Use of Shielding Integral Benchmark Archive and Database for Nuclear Data Validation" was organised from 2019 and 2022 with the objectives to promote more systematic and wider use of shielding benchmark experiments in nuclear data (ND) and transport code validation and development, to provide feedback on the Shielding Integral Benchmark Archive and Database (SINBAD), and to promote its further development in coordination with the Expert Group on Physics of Reactor Systems (EGPRS). Altogether 9 meetings, the large majority (8) held remotely, were organised during the past 3 years to discuss the experience on the use of SINBAD, evaluation of new benchmarks and improvements to be contributed to the database which was severely neglected and lacking maintenance over the past ⇠ 10+ years. Several proposals for new or updated benchmark evaluation were presented and discussed, ...

Research paper thumbnail of Nuclear data uncertainty propagation and implications for radioactive waste management of fusion steels

Fusion Engineering and Design

Research paper thumbnail of Nuclear Data and Code Testing Using the Radiation Shielding Experiments in SINBAD

Shielding benchmark experiments are valuable for validation of nuclear data and particle transpor... more Shielding benchmark experiments are valuable for validation of nuclear data and particle transport codes. They diversify and complement the information obtained using other measurements, such as critical benchmarks which dominate today in most nuclear data validation schemes. In order to preserve and make available the information on the performed radiation shielding benchmarks the Organisation for Economic Co-operation and Development’s Nuclear Energy Agency Data Bank (OECD/NEADB) and the Radiation Safety Information Computational Center (RSICC) at Oak Ridge National Laboratory (ORNL) started in the early 1990’s the Shielding Integral Benchmark Archive and Database (SINBAD) project. Currently, the SINBAD database comprises over 100 benchmark compilations and evaluations of relevance to reactor shielding, pressure vessel dosimetry, fusion blanket neutronics and accelerator shielding. The present status of the project, several examples of the use of selected benchmarks, and the futur...

Research paper thumbnail of SINBAD Database – Ongoing Activities

Research paper thumbnail of Recent Development and Examples of Use of the Windows Interface Environment XSUN-2016 for Transport and Sensitivity-Uncertainty Analysis

In 2013 the first version of the Windows interface XSUN-2013 facilitating the deterministic radia... more In 2013 the first version of the Windows interface XSUN-2013 facilitating the deterministic radiation transport and cross-section sensitivity-uncertainty (S/U) calculation was developed and submitted to OECD/NEA Data Bank Computer Code Collection and RSICC. The package allows the preparation of input cards, rapid modification and execution of the complete chain of codes including TRANSX, PARTISN and SUSD3D in a user-friendly way. A new version of the code, XSUN-2016, including several major modifications and improvements will be released this year. Description and few examples of the use of XSUN-2016 are presented, including: S/U intercomparison exercise using the SNEAK-7A & -7B benchmark experiments from the IRPhE database. The performance of the XSUN-2016 code system was compared with the codes such as TSUNAMI, SERPENT and MCNP6. Transport, sensitivity and uncertainty analysis of the keff and eff parameters for the MYRRHA accelerator driven system (ADS).

Research paper thumbnail of Computer Environment Integrating Several Deterministic Transport and Perturbation Codes Distributed by the NEA DB

The paper presents the development of a modern computer environment for the preparation and execu... more The paper presents the development of a modern computer environment for the preparation and execution of the deterministic neutron-gamma computer codes in a user friendly way, adopted for today standards and users. At present, the system integrates the codes for the nuclear cross-section preparation (TRANSX-2.15), the code PARTISN for 1-, 2-, and 3-dimensional neutron and gamma transport calculations and the SUSD3D code for the nuclear data sensitivity and uncertainty analysis. User-friendly plotting codes are also available for the 3-dimensional visualisation of neutron fluxes, spectra and sensitivity profiles. The system will be available through the OECD/NEA Data Bank

Research paper thumbnail of Analysis of DD, TT and DT Neutron Streaming Experiments with the ADVANTG Code

EPJ Web of Conferences, 2020

The paper presents an analysis of DD, TT and DT neutron streaming benchmark experiments with the ... more The paper presents an analysis of DD, TT and DT neutron streaming benchmark experiments with the recently released hybrid transport code ADVANTG (AutomateD VAriaNce reducTion Generator). ADVANTG combines the deterministic neutron transport solver Denovo with the Monte Carlo transport code MCNP via the principle of variance reduction. It automatically produces weight-window and source biasing variance reduction parameters based on the CADIS (Consistent Adjoint Driven Importance Sampling) methodology. Using this novel hybrid methodology Monte Carlo simulations of realistic complex fusion streaming geometries have become possible. In this paper the experimental results from the 2016 DD campaign using measurements with TLDs and activation foils up to 40 m from the plasma source are analyzed. New detailed models of the detector assemblies were incorporated into the JET 360°MCNP model for this analysis. In preparation of the TT and DTE2 campaigns at JET a pre-analysis for these campaigns is also presented.

Research paper thumbnail of ACTIVATION OF Mn, Li2O AND LiF IN JSI TRIGA REACTOR TO STUDY POTENTIAL TRITIUM PRODUCTION MONITORS FOR FUSION APPLICATIONS

Nuclear Fusion, 2019

Two series of measurements were performed in the JSI TRIGA research reactor in 2014 and 2017 to v... more Two series of measurements were performed in the JSI TRIGA research reactor in 2014 and 2017 to validate the 55Mn(n,γ)56Mn cross-sections and experimentally investigate the relationship between the 55Mn(n,γ)56Mn reaction and the rate of tritium production through the 6Li(n,t)4He reaction. Indeed, previously observed similarities between the sensitivity profiles of the neutron reaction of tritium production on lithium, 6Li(n,t)4He, and those of the 55Mn(n,γ)56Mn reaction in tritium breeder modules indicated that the latter reaction could be used as an effective monitor of tritium production, at least for short-term monitoring (the half-life of 56Mn being 2.579 h). However, experimental verification, improvements and validation of the 55Mn(n,γ)56Mn cross-sections are needed in order to meet the required accuracy. Foils of certified reference material Al–1%Mn, as well as LiF thermoluminescent detectors and Li2O samples were irradiated, both bare and under cadmium, to study the potentia...

Research paper thumbnail of Comments on the status of modern covariance data based on different fission and fusion reactor studies

EPJ Nuclear Sciences & Technologies, 2018

Both the availability and the quality of covariance data improved over the last years and many re... more Both the availability and the quality of covariance data improved over the last years and many recent cross-section evaluations, such as JENDL-4.0, ENDF/B-VII.1, JEFF-3.3, etc. include new covariance data compilations. However, several gaps and inconsistencies still persist. Although most modern nuclear data evaluations are based on similar (or even same) sets of experimental data, and the agreement in the results obtained using different cross-sections is reasonably good, larger discrepancies were observed among the corresponding covariance data. This suggests that the differences in the covariance matrix evaluations reflect more the differences in the (mathematical) approaches used and possibly in the interpretations of the experimental data, rather than the different nuclear experimental data used. Furthermore, “tuning” and adjustments are often used in the process of nuclear data evaluations. In principle, if adjustments or “tunings” are used in the evaluation of cross-section t...

Research paper thumbnail of Beta-effective sensitivity and uncertainty analysis of MYRRHA reactor for possible use in nuclear data validation and improvement

Annals of Nuclear Energy, 2018

New reactor concept studies, such as those of the MYRRHA Accelerator Driven System (ADS), with th... more New reactor concept studies, such as those of the MYRRHA Accelerator Driven System (ADS), with their extended nuclear data needs relaunched the interest in sensitivity and uncertainty (S/U) studies. S/U analysis play an essential role in assuring the accuracy and reliability of nuclear reactor computations and provide an insight in the physical phenomena involved in the neutron transport. This paper presents the study of the MYRRHA critical core, which is designed to operate at 100 MW thermal power. The previously presented analysis of the MYRRHA effective multiplication factor (k eff) was extended to study the sensitivity and uncertainty in kinetic parameters, such as the effective delayed neutron fraction (b eff). The sensitivity and uncertainty computations were performed by means of the SUSD3D code based on forward and adjoint-flux first-order perturbation theory. The sensitivity coefficients of b eff with respect to the basic nuclear data were calculated by the k-ratio derivation method proposed in 2011. The main components of the uncertainties in b eff were estimated using the JENDL-4.0u covariance data. The energy dependent sensitivity profiles of k eff and b eff with respect to nuclear data are compared in view of exploiting the differences among them for a physically more complete, comprehensive and consistent nuclear data validation and improvement procedure. The accuracy of the k eff and b eff measurements and calculations has to be carefully evaluated in order to conclude on the nuclear data status and possible improvements.

Research paper thumbnail of SUSD3D Computer Code as Part of the XSUN-2017 Windows Interface Environment for Deterministic Radiation Transport and Cross-Section Sensitivity-Uncertainty Analysis

Science and Technology of Nuclear Installations, 2017

A Windows interface XSUN-2017 facilitating the deterministic radiation transport and cross-sectio... more A Windows interface XSUN-2017 facilitating the deterministic radiation transport and cross-section sensitivity-uncertainty (S/U) calculation is presented. The package was developed to assist the users in the preparation of input cards, rapid modification, and execution of the complete chain of codes including TRANSX, PARTISN, and SUSD3D, all available from the OECD/NEA Data Bank and RSICC. The objective of this work was to make the input and output handling for these codes as user-friendly as possible, passing information among codes internally. XSUN-2017 allows a user-friendly viewing of results obtained from the PARTISN and SUSD3D programs. The first version of the Windows interface XSUN-2013 was developed in 2013 and submitted to OECD/NEA Data Bank Computer Code Collection and RSICC in early 2014. An updated version, XSUN-2017, will be released in 2017. The package includes also the new version of the SUSD3D code. The XSUN-2017 and SUSD3D code systems and recent improvements and ...

Research paper thumbnail of Combined use of k-effective and beta-effective measurements for nuclear data validation and improvement

EPJ Web of Conferences, 2017

Nuclear cross-sections are being re-evaluated time and again since decades, and in the recent yea... more Nuclear cross-sections are being re-evaluated time and again since decades, and in the recent years they are "tuned" to match better in particular the k e f f measurements. However, the k ef f parameter as a very global parameter provides simply too many possible combinations and variations, all more or less in agreement with the differential cross section data measurements and the associated uncertainties. Adding other types of integral measurements, such as shielding and kinetics benchmarks, on the cross-section evaluation menu is expected to provide a complementary and a more complete view on the problem. This paper discusses the advantages of exploiting the effective delayed neutron fraction (β ef f) measurements for nuclear data (ND) evaluation and testing. The cross-section sensitivity and uncertainty analysis revealed some crucial differences in the k e f f and β ef f sensitivity profiles which are favorable for ND validation.

Research paper thumbnail of Sensitivity and uncertainty in the effective delayed neutron fraction ()

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2013

ABSTRACT Precise knowledge of the effective delayed neutron fraction (βeff) and the corresponding... more ABSTRACT Precise knowledge of the effective delayed neutron fraction (βeff) and the corresponding uncertainty is important for nuclear reactor safety analysis. The interest in developing the methodology for estimating the uncertainty in βeff was expressed in the scope of the UAM project of the OECD/NEA. The sensitivity and uncertainty analysis of βeff performed using the standard first-order perturbation code SUSD3D is presented. The sensitivity coefficients of βeff with respect to the basic nuclear data were calculated by deriving Bretscher's k-ratio formula. The procedure was applied to several fast neutron benchmark experiments selected from the ICSBEP and IRPhE databases. According to the JENDL-4.0m covariance matrices and taking into account the uncertainties in the cross-sections and in the prompt and delayed fission spectra the total uncertainty in βeff was found to be in general around 3%, and up to ∼7% for the 233U benchmarks. An approximation was applied to investigate the uncertainty due to the delayed fission neutron spectra. The βeff sensitivity and uncertainty analyses are furthermore demonstrated to be useful for the better understanding and interpretation of the physical phenomena involved. Due to their specific sensitivity profiles the βeff measurements are shown to provide valuable complementary information which could be used in combination with the criticality (keff) measurements for the evaluation and validation of certain nuclear reaction data, such as for example the delayed (and prompt) fission neutron yields and interestingly also the 238U inelastic and elastic scattering cross-sections.

Research paper thumbnail of Use of Nuclear Data Sensitivity and Uncertainty Analysis for the Design Preparation of the HCLL Breeder Blanket Mockup Experiment for ITER

Science and Technology of Nuclear Installations, 2008

An experiment on a mockup of the test blanket module based on helium-cooled lithium lead (HCLL) c... more An experiment on a mockup of the test blanket module based on helium-cooled lithium lead (HCLL) concept will be performed in 2008 in the Frascati Neutron Generator (FNG) in order to study neutronics characteristics of the module and the accuracy of the computational tools. With the objective to prepare and optimise the design of the mockup in the sense to provide maximum information on the state-of-the-art of the cross-section data the mockup was pre-analysed using the deterministic codes for the sensitivity/uncertainty analysis. The neutron fluxes and tritium production rate (TPR), their sensitivity to the underlying basic cross-sections, as well as the corresponding uncertainties were calculated using the deterministic transport codes (DOORS package), the sensitivity/uncertainty code package SUSD3D, and the VITAMINJ/ COVA covariance matrix libraries. The cross-section reactions with largest contribution to the uncertainty of the calculated TPR were identified to be (n,2n) and (n,3...

Research paper thumbnail of Verification of Oxygen Cross Section Data for Oil Well Logging Applications

Journal of Nuclear Science and Technology, 2002

The carbon/oxygen logging tools used in the petroleum industry to determine the ratio of the numb... more The carbon/oxygen logging tools used in the petroleum industry to determine the ratio of the number of carbon to the number of oxygen nuclei in the formation surrounding the tool, and in this way the oil to water ratio, relies on a good knowledge on the oxygen and carbon cross sections in particular. The objective of this work is to investigate the importance of the oxygen cross section with respect to the needs of the oil well logging applications, and to state the quality of the presently available evaluations. For a few typical oil well logging geometries the radiation transport calculations combined with the cross section sensitivity analyses were performed. The sensitivity profiles of the 3 to 7 MeV gamma rays in the detectors (roughly corresponding to the energy windows used for carbon and oxygen logging) with respect to the major nuclear reaction types of oxygen very obtained, indicating the nuclear data important for oil well logging. Finally, the FNS/JAERI Liquid Oxygen Time-of-Flight benchmark experiment, involving the measurement of the angular neutron spectra leaking from a 20 cm liquid oxygen slab, and covering the energy range relevant for oil well logging applications, was analysed in order to determine the actual state-of-the-art of the oxygen nuclear data. The benchmark experiment was analysed using the discrete ordinates transport code DORT and compared to the results of the Monte Carlo code MCNP-4B.

Research paper thumbnail of Multidimensional Deterministic Nuclear Data Sensitivity and Uncertainty Code System: Method and Application

Nuclear Science and Engineering, 2001

In the nuclear industry, an increased demand exists to provide modeling results with credible con... more In the nuclear industry, an increased demand exists to provide modeling results with credible confidence bounds not only for simple but also for refined modeling. With the objective to facilitate and promote such analysis, a user-friendly and complete computer code package was developed comprising the multidimensional cross-section sensitivity and uncertainty code package SUSD3D, the secondary angular distribution (SAD) covariance data-processing

Research paper thumbnail of Analysis of computational problems expressing the overall uncertainties: photons, neutrons and electrons

Radiation Protection Dosimetry, 2008

In the frame of the EU Coordination Action CONRAD (coordinated network for radiation dosimetry), ... more In the frame of the EU Coordination Action CONRAD (coordinated network for radiation dosimetry), WP4 was dedicated to work on computational dosimetry with an action entitled 'Uncertainty assessment in computational dosimetry: an intercomparison of approaches'. Participants attempted one or more of eight problems. This paper presents the results from problems 4-8-dealing with the overall uncertainty budget estimate; a short overview of each problem is presented together with a discussion of the most significant results and conclusions. The scope of the problems discussed here are: the study of a (137)Cs calibration irradiator; the manganese bath technique; the iron sphere experiment using neutron time-of-flight technique; the energy response of a RADFET detector and finally the sensitivity and uncertainty analysis for the recoil-proton telescope discussed in the companion paper.

Research paper thumbnail of Overview of the JET results in support to ITER

Research paper thumbnail of On how sensitive the cross-section sensitivity calculations are to P_N order approximations

Research paper thumbnail of XSUN-2022/SUSD3D n/γ sensitivity-uncertainty code package with recent JEFF-3.3 and ENDF/B-VIII.0 covariance data

Epj Web of Conferences, 2023

Research paper thumbnail of Outcomes of WPEC SG47 on "Use of Shielding Integral Benchmark Archive and Database for Nuclear Data Validation

EPJ Web of Conferences

The Working Party on International Nuclear Data Evaluation Co-operation Subgroup 47 (WPECSG47) en... more The Working Party on International Nuclear Data Evaluation Co-operation Subgroup 47 (WPECSG47) entitled "Use of Shielding Integral Benchmark Archive and Database for Nuclear Data Validation" was organised from 2019 and 2022 with the objectives to promote more systematic and wider use of shielding benchmark experiments in nuclear data (ND) and transport code validation and development, to provide feedback on the Shielding Integral Benchmark Archive and Database (SINBAD), and to promote its further development in coordination with the Expert Group on Physics of Reactor Systems (EGPRS). Altogether 9 meetings, the large majority (8) held remotely, were organised during the past 3 years to discuss the experience on the use of SINBAD, evaluation of new benchmarks and improvements to be contributed to the database which was severely neglected and lacking maintenance over the past ⇠ 10+ years. Several proposals for new or updated benchmark evaluation were presented and discussed, ...

Research paper thumbnail of Nuclear data uncertainty propagation and implications for radioactive waste management of fusion steels

Fusion Engineering and Design

Research paper thumbnail of Nuclear Data and Code Testing Using the Radiation Shielding Experiments in SINBAD

Shielding benchmark experiments are valuable for validation of nuclear data and particle transpor... more Shielding benchmark experiments are valuable for validation of nuclear data and particle transport codes. They diversify and complement the information obtained using other measurements, such as critical benchmarks which dominate today in most nuclear data validation schemes. In order to preserve and make available the information on the performed radiation shielding benchmarks the Organisation for Economic Co-operation and Development’s Nuclear Energy Agency Data Bank (OECD/NEADB) and the Radiation Safety Information Computational Center (RSICC) at Oak Ridge National Laboratory (ORNL) started in the early 1990’s the Shielding Integral Benchmark Archive and Database (SINBAD) project. Currently, the SINBAD database comprises over 100 benchmark compilations and evaluations of relevance to reactor shielding, pressure vessel dosimetry, fusion blanket neutronics and accelerator shielding. The present status of the project, several examples of the use of selected benchmarks, and the futur...

Research paper thumbnail of SINBAD Database – Ongoing Activities

Research paper thumbnail of Recent Development and Examples of Use of the Windows Interface Environment XSUN-2016 for Transport and Sensitivity-Uncertainty Analysis

In 2013 the first version of the Windows interface XSUN-2013 facilitating the deterministic radia... more In 2013 the first version of the Windows interface XSUN-2013 facilitating the deterministic radiation transport and cross-section sensitivity-uncertainty (S/U) calculation was developed and submitted to OECD/NEA Data Bank Computer Code Collection and RSICC. The package allows the preparation of input cards, rapid modification and execution of the complete chain of codes including TRANSX, PARTISN and SUSD3D in a user-friendly way. A new version of the code, XSUN-2016, including several major modifications and improvements will be released this year. Description and few examples of the use of XSUN-2016 are presented, including: S/U intercomparison exercise using the SNEAK-7A & -7B benchmark experiments from the IRPhE database. The performance of the XSUN-2016 code system was compared with the codes such as TSUNAMI, SERPENT and MCNP6. Transport, sensitivity and uncertainty analysis of the keff and eff parameters for the MYRRHA accelerator driven system (ADS).

Research paper thumbnail of Computer Environment Integrating Several Deterministic Transport and Perturbation Codes Distributed by the NEA DB

The paper presents the development of a modern computer environment for the preparation and execu... more The paper presents the development of a modern computer environment for the preparation and execution of the deterministic neutron-gamma computer codes in a user friendly way, adopted for today standards and users. At present, the system integrates the codes for the nuclear cross-section preparation (TRANSX-2.15), the code PARTISN for 1-, 2-, and 3-dimensional neutron and gamma transport calculations and the SUSD3D code for the nuclear data sensitivity and uncertainty analysis. User-friendly plotting codes are also available for the 3-dimensional visualisation of neutron fluxes, spectra and sensitivity profiles. The system will be available through the OECD/NEA Data Bank

Research paper thumbnail of Analysis of DD, TT and DT Neutron Streaming Experiments with the ADVANTG Code

EPJ Web of Conferences, 2020

The paper presents an analysis of DD, TT and DT neutron streaming benchmark experiments with the ... more The paper presents an analysis of DD, TT and DT neutron streaming benchmark experiments with the recently released hybrid transport code ADVANTG (AutomateD VAriaNce reducTion Generator). ADVANTG combines the deterministic neutron transport solver Denovo with the Monte Carlo transport code MCNP via the principle of variance reduction. It automatically produces weight-window and source biasing variance reduction parameters based on the CADIS (Consistent Adjoint Driven Importance Sampling) methodology. Using this novel hybrid methodology Monte Carlo simulations of realistic complex fusion streaming geometries have become possible. In this paper the experimental results from the 2016 DD campaign using measurements with TLDs and activation foils up to 40 m from the plasma source are analyzed. New detailed models of the detector assemblies were incorporated into the JET 360°MCNP model for this analysis. In preparation of the TT and DTE2 campaigns at JET a pre-analysis for these campaigns is also presented.

Research paper thumbnail of ACTIVATION OF Mn, Li2O AND LiF IN JSI TRIGA REACTOR TO STUDY POTENTIAL TRITIUM PRODUCTION MONITORS FOR FUSION APPLICATIONS

Nuclear Fusion, 2019

Two series of measurements were performed in the JSI TRIGA research reactor in 2014 and 2017 to v... more Two series of measurements were performed in the JSI TRIGA research reactor in 2014 and 2017 to validate the 55Mn(n,γ)56Mn cross-sections and experimentally investigate the relationship between the 55Mn(n,γ)56Mn reaction and the rate of tritium production through the 6Li(n,t)4He reaction. Indeed, previously observed similarities between the sensitivity profiles of the neutron reaction of tritium production on lithium, 6Li(n,t)4He, and those of the 55Mn(n,γ)56Mn reaction in tritium breeder modules indicated that the latter reaction could be used as an effective monitor of tritium production, at least for short-term monitoring (the half-life of 56Mn being 2.579 h). However, experimental verification, improvements and validation of the 55Mn(n,γ)56Mn cross-sections are needed in order to meet the required accuracy. Foils of certified reference material Al–1%Mn, as well as LiF thermoluminescent detectors and Li2O samples were irradiated, both bare and under cadmium, to study the potentia...

Research paper thumbnail of Comments on the status of modern covariance data based on different fission and fusion reactor studies

EPJ Nuclear Sciences & Technologies, 2018

Both the availability and the quality of covariance data improved over the last years and many re... more Both the availability and the quality of covariance data improved over the last years and many recent cross-section evaluations, such as JENDL-4.0, ENDF/B-VII.1, JEFF-3.3, etc. include new covariance data compilations. However, several gaps and inconsistencies still persist. Although most modern nuclear data evaluations are based on similar (or even same) sets of experimental data, and the agreement in the results obtained using different cross-sections is reasonably good, larger discrepancies were observed among the corresponding covariance data. This suggests that the differences in the covariance matrix evaluations reflect more the differences in the (mathematical) approaches used and possibly in the interpretations of the experimental data, rather than the different nuclear experimental data used. Furthermore, “tuning” and adjustments are often used in the process of nuclear data evaluations. In principle, if adjustments or “tunings” are used in the evaluation of cross-section t...

Research paper thumbnail of Beta-effective sensitivity and uncertainty analysis of MYRRHA reactor for possible use in nuclear data validation and improvement

Annals of Nuclear Energy, 2018

New reactor concept studies, such as those of the MYRRHA Accelerator Driven System (ADS), with th... more New reactor concept studies, such as those of the MYRRHA Accelerator Driven System (ADS), with their extended nuclear data needs relaunched the interest in sensitivity and uncertainty (S/U) studies. S/U analysis play an essential role in assuring the accuracy and reliability of nuclear reactor computations and provide an insight in the physical phenomena involved in the neutron transport. This paper presents the study of the MYRRHA critical core, which is designed to operate at 100 MW thermal power. The previously presented analysis of the MYRRHA effective multiplication factor (k eff) was extended to study the sensitivity and uncertainty in kinetic parameters, such as the effective delayed neutron fraction (b eff). The sensitivity and uncertainty computations were performed by means of the SUSD3D code based on forward and adjoint-flux first-order perturbation theory. The sensitivity coefficients of b eff with respect to the basic nuclear data were calculated by the k-ratio derivation method proposed in 2011. The main components of the uncertainties in b eff were estimated using the JENDL-4.0u covariance data. The energy dependent sensitivity profiles of k eff and b eff with respect to nuclear data are compared in view of exploiting the differences among them for a physically more complete, comprehensive and consistent nuclear data validation and improvement procedure. The accuracy of the k eff and b eff measurements and calculations has to be carefully evaluated in order to conclude on the nuclear data status and possible improvements.

Research paper thumbnail of SUSD3D Computer Code as Part of the XSUN-2017 Windows Interface Environment for Deterministic Radiation Transport and Cross-Section Sensitivity-Uncertainty Analysis

Science and Technology of Nuclear Installations, 2017

A Windows interface XSUN-2017 facilitating the deterministic radiation transport and cross-sectio... more A Windows interface XSUN-2017 facilitating the deterministic radiation transport and cross-section sensitivity-uncertainty (S/U) calculation is presented. The package was developed to assist the users in the preparation of input cards, rapid modification, and execution of the complete chain of codes including TRANSX, PARTISN, and SUSD3D, all available from the OECD/NEA Data Bank and RSICC. The objective of this work was to make the input and output handling for these codes as user-friendly as possible, passing information among codes internally. XSUN-2017 allows a user-friendly viewing of results obtained from the PARTISN and SUSD3D programs. The first version of the Windows interface XSUN-2013 was developed in 2013 and submitted to OECD/NEA Data Bank Computer Code Collection and RSICC in early 2014. An updated version, XSUN-2017, will be released in 2017. The package includes also the new version of the SUSD3D code. The XSUN-2017 and SUSD3D code systems and recent improvements and ...

Research paper thumbnail of Combined use of k-effective and beta-effective measurements for nuclear data validation and improvement

EPJ Web of Conferences, 2017

Nuclear cross-sections are being re-evaluated time and again since decades, and in the recent yea... more Nuclear cross-sections are being re-evaluated time and again since decades, and in the recent years they are "tuned" to match better in particular the k e f f measurements. However, the k ef f parameter as a very global parameter provides simply too many possible combinations and variations, all more or less in agreement with the differential cross section data measurements and the associated uncertainties. Adding other types of integral measurements, such as shielding and kinetics benchmarks, on the cross-section evaluation menu is expected to provide a complementary and a more complete view on the problem. This paper discusses the advantages of exploiting the effective delayed neutron fraction (β ef f) measurements for nuclear data (ND) evaluation and testing. The cross-section sensitivity and uncertainty analysis revealed some crucial differences in the k e f f and β ef f sensitivity profiles which are favorable for ND validation.

Research paper thumbnail of Sensitivity and uncertainty in the effective delayed neutron fraction ()

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2013

ABSTRACT Precise knowledge of the effective delayed neutron fraction (βeff) and the corresponding... more ABSTRACT Precise knowledge of the effective delayed neutron fraction (βeff) and the corresponding uncertainty is important for nuclear reactor safety analysis. The interest in developing the methodology for estimating the uncertainty in βeff was expressed in the scope of the UAM project of the OECD/NEA. The sensitivity and uncertainty analysis of βeff performed using the standard first-order perturbation code SUSD3D is presented. The sensitivity coefficients of βeff with respect to the basic nuclear data were calculated by deriving Bretscher's k-ratio formula. The procedure was applied to several fast neutron benchmark experiments selected from the ICSBEP and IRPhE databases. According to the JENDL-4.0m covariance matrices and taking into account the uncertainties in the cross-sections and in the prompt and delayed fission spectra the total uncertainty in βeff was found to be in general around 3%, and up to ∼7% for the 233U benchmarks. An approximation was applied to investigate the uncertainty due to the delayed fission neutron spectra. The βeff sensitivity and uncertainty analyses are furthermore demonstrated to be useful for the better understanding and interpretation of the physical phenomena involved. Due to their specific sensitivity profiles the βeff measurements are shown to provide valuable complementary information which could be used in combination with the criticality (keff) measurements for the evaluation and validation of certain nuclear reaction data, such as for example the delayed (and prompt) fission neutron yields and interestingly also the 238U inelastic and elastic scattering cross-sections.

Research paper thumbnail of Use of Nuclear Data Sensitivity and Uncertainty Analysis for the Design Preparation of the HCLL Breeder Blanket Mockup Experiment for ITER

Science and Technology of Nuclear Installations, 2008

An experiment on a mockup of the test blanket module based on helium-cooled lithium lead (HCLL) c... more An experiment on a mockup of the test blanket module based on helium-cooled lithium lead (HCLL) concept will be performed in 2008 in the Frascati Neutron Generator (FNG) in order to study neutronics characteristics of the module and the accuracy of the computational tools. With the objective to prepare and optimise the design of the mockup in the sense to provide maximum information on the state-of-the-art of the cross-section data the mockup was pre-analysed using the deterministic codes for the sensitivity/uncertainty analysis. The neutron fluxes and tritium production rate (TPR), their sensitivity to the underlying basic cross-sections, as well as the corresponding uncertainties were calculated using the deterministic transport codes (DOORS package), the sensitivity/uncertainty code package SUSD3D, and the VITAMINJ/ COVA covariance matrix libraries. The cross-section reactions with largest contribution to the uncertainty of the calculated TPR were identified to be (n,2n) and (n,3...

Research paper thumbnail of Verification of Oxygen Cross Section Data for Oil Well Logging Applications

Journal of Nuclear Science and Technology, 2002

The carbon/oxygen logging tools used in the petroleum industry to determine the ratio of the numb... more The carbon/oxygen logging tools used in the petroleum industry to determine the ratio of the number of carbon to the number of oxygen nuclei in the formation surrounding the tool, and in this way the oil to water ratio, relies on a good knowledge on the oxygen and carbon cross sections in particular. The objective of this work is to investigate the importance of the oxygen cross section with respect to the needs of the oil well logging applications, and to state the quality of the presently available evaluations. For a few typical oil well logging geometries the radiation transport calculations combined with the cross section sensitivity analyses were performed. The sensitivity profiles of the 3 to 7 MeV gamma rays in the detectors (roughly corresponding to the energy windows used for carbon and oxygen logging) with respect to the major nuclear reaction types of oxygen very obtained, indicating the nuclear data important for oil well logging. Finally, the FNS/JAERI Liquid Oxygen Time-of-Flight benchmark experiment, involving the measurement of the angular neutron spectra leaking from a 20 cm liquid oxygen slab, and covering the energy range relevant for oil well logging applications, was analysed in order to determine the actual state-of-the-art of the oxygen nuclear data. The benchmark experiment was analysed using the discrete ordinates transport code DORT and compared to the results of the Monte Carlo code MCNP-4B.

Research paper thumbnail of Multidimensional Deterministic Nuclear Data Sensitivity and Uncertainty Code System: Method and Application

Nuclear Science and Engineering, 2001

In the nuclear industry, an increased demand exists to provide modeling results with credible con... more In the nuclear industry, an increased demand exists to provide modeling results with credible confidence bounds not only for simple but also for refined modeling. With the objective to facilitate and promote such analysis, a user-friendly and complete computer code package was developed comprising the multidimensional cross-section sensitivity and uncertainty code package SUSD3D, the secondary angular distribution (SAD) covariance data-processing

Research paper thumbnail of Analysis of computational problems expressing the overall uncertainties: photons, neutrons and electrons

Radiation Protection Dosimetry, 2008

In the frame of the EU Coordination Action CONRAD (coordinated network for radiation dosimetry), ... more In the frame of the EU Coordination Action CONRAD (coordinated network for radiation dosimetry), WP4 was dedicated to work on computational dosimetry with an action entitled 'Uncertainty assessment in computational dosimetry: an intercomparison of approaches'. Participants attempted one or more of eight problems. This paper presents the results from problems 4-8-dealing with the overall uncertainty budget estimate; a short overview of each problem is presented together with a discussion of the most significant results and conclusions. The scope of the problems discussed here are: the study of a (137)Cs calibration irradiator; the manganese bath technique; the iron sphere experiment using neutron time-of-flight technique; the energy response of a RADFET detector and finally the sensitivity and uncertainty analysis for the recoil-proton telescope discussed in the companion paper.