1,721,019 research outputs found
ANITA-2000 activation code package - updating of the decay data libraries and validation on the experimental data of the 14 MeV Frascati Neutron Generator
No full textANITA-2000 is a code package for the activation characterization of materials exposed to neutron irradiation released by ENEA to OECD-NEADB and ORNL-RSICC. The main component of the package is the activation code ANITA-4M that computes the radioactive inventory of a material exposed to neutron irradiation. The code requires the decay data library (file fl1) containing the quantities describing the decay properties of the unstable nuclides and the library (file fl2) containing the gamma ray spectra emitted by the radioactive nuclei. The fl1 and fl2 files of the ANITA-2000 code package, originally based on the evaluated nuclear data library FENDL/D-2.0, were recently updated on the basis of the JEFF-3.1.1 Radioactive Decay Data Library. This paper presents the results of the validation of the new fl1 decay data library through the comparison of the ANITA-4M calculated values with the measured electron and photon decay heats and activities of fusion material samples irradiated at the 14 MeV Frascati Neutron Generator (FNG) of the NEA-Frascati Research Centre. Twelve material samples were considered, namely: Mo, Cu, Hf, Mg, Ni, Cd, Sn, Re, Ti, W, Ag and Al. The ratios between calculated and experimental values (C/E) are shown and discussed in this paper
ANITA-IEAF activation code package – updating of the decay and cross section data libraries and validation on the experimental data from the Karlsruhe Isochronous Cyclotron
Full text linkANITA-IEAF is an activation package (code and libraries) developed in the past in ENEA-Bologna in order to assess the activation of materials exposed to neutrons with energies greater than 20 MeV. An updated version of the ANITA-IEAF activation code package has been developed. It is suitable to be applied to the study of the irradiation effects on materials in facilities like the International Fusion Materials Irradiation Facility (IFMIF) and the DEMO Oriented Neutron Source (DONES), in which a considerable amount of neutrons with energies above 20 MeV is produced. The present paper summarizes the main characteristics of the updated version of ANITA-IEAF, able to use decay and cross section data based on more recent evaluated nuclear data libraries, i.e. the JEFF-3.1.1 Radioactive Decay Data Library and the EAF-2010 neutron activation cross section library. In this paper the validation effort related to the comparison between the code predictions and the activity measurements obtained from the Karlsruhe Isochronous Cyclotron is presented. In this integral experiment samples of two different steels, SS-316 and F82H, pure vanadium and a vanadium alloy, structural materials of interest in fusion technology, were activated in a neutron spectrum similar to the IFMIF neutron field
Nuclear assessment of the IFMIF-DONES lithium target system
No full textIn the framework of the Work Package Early Neutron Source (WPENS) of the EUROfusion Consortium, the engineering design of the IFMIF-DONES (International Fusion Material Irradiation Facility - Demo Oriented Neutron Source) lithium target system has been accomplished. The development of the design required that new neutronic calculations had to be performed in ENEA, in order to update those already achieved in the past for the previous geometrical layout. The aim of these evaluations is to provide quantities, such as power deposition, dpa and gas production, useful for the thermo-mechanical analysis that is required for assessing the structural behavior of the system subjected to irradiation. Coupled neutron-gamma transport calculations have been carried out by using the MCNP6.2 code integrated with the McDeLicious-17 neutron source. The geometrical input for MCNP used in the calculations was provided by KIT. Neutron activation calculations have been also performed by means of the FISPACT-II activation code package in order to provide radioactive quantities, such as decay heat and contact dose rates, in various parts of the system, useful for thermo-mechanical analysis and safety purposes, like waste management considerations. This paper presents the main results obtained from the above analyses
Engineering design and steady state thermomechanical analysis of the IFMIF European lithium target system
No full textIn the framework of the current IFMIF Engineering Validation and Engineering Design Activities (IFMIF/EVEDA) phase, ENEA is responsible for the design of the European concept of the IFMIF lithium target system which foresees the possibility to periodically replace only the most irradiated and thus critical component (i.e., the backplate) while continuing to operate the rest of the target for a longer period (bayonet backplate concept). In this work, the results of the steady state thermomechanical analysis of the IFMIF EU target assembly are briefly reported highlighting the relevant indications obtained with respect to the fulfillment of the design requirements. © 2013 IEEE
BUGJEFF311.BOLIB (JEFF-3.1.1) and BUGENDF70.BOLIB (ENDF/B-VII.0) - Generation Methodology and Preliminary Testing of two ENEA-Bologna Group Cross Section Libraries for LWR Shielding and Pressure Vessel Dosimetry
No full textTwo broad-group coupled neutron/photon working cross section libraries in FIDO-ANISN format, dedicated to LWR shielding and pressure vessel dosimetry applications, were generated following the methodology recommended by the US ANSI/ANS-6.1.2-1999 (R2009) standard. These libraries, named BUGJEFF311.BOLIB and BUGENDF70.BOLIB, are respectively based on JEFF-3.1.1 and ENDF/B-VII.0 nuclear data and adopt the same broad-group energy structure (47 n + 20 γ) of the ORNL BUGLE-96 similar library. They were respectively obtained from the ENEA-Bologna VITJEFF311.BOLIB and VITENDF70.BOLIB libraries in AMPX format for nuclear fission applications through problem-dependent cross section collapsing with the ENEA-Bologna 2007 revision of the ORNL SCAMPI nuclear data processing system. Both previous libraries are based on the Bondarenko self-shielding factor method and have the same AMPX format and fine-group energy structure (199 n + 42 γ) as the ORNL VITAMIN-B6 similar library from which BUGLE-96 was obtained at ORNL. A synthesis of a preliminary validation of the cited BUGLE-type libraries, performed through 3D fixed source transport calculations with the ORNL TORT-3.2 SN code, is included. The calculations were dedicated to the PCA-Replica 12/13 and VENUS-3 engineering neutron shielding benchmark experiments, specifically conceived to test the accuracy of nuclear data and transport codes in LWR shielding and radiation damage analyses. © 2016 Owned by the authors, published by EDP Sciences
Hydro-thermo analysis of Li flow over IFMIF geometry
No full textA thermo-hydraulic analysis of high-speed free surface Li flow over a concave plate (IFMIF geometry) is performed. Simulations are done for bulk velocities between 10 and 20 m/s using ANSYS Fluent. A precomputed heat source was imposed at the center of the curved section to simulate the interaction of a dual deuteron beam with the Li jet. LES and k-ε models were used for turbulence modeling and Volume of Fluid and Level Set methods were used to model the free surface flow. Results reported are the variation of temperature, pressure and velocities across the Li jet at various locations along the curved region. Safety margins before Li starts boiling are also predicted. All cases predicted smooth surfaces without any waves
Materials activation induced by high-energy neutrons: A comparison of ANITA-IEAF calculation with measurements from the Karlsruhe Isochronous Cyclotron
No full textThe validation effort related to the comparison between the predictions of the new ANITA-IEAF code package and the activity measurements obtained from the Karlsruhe Isochronous Cyclotron is presented and discussed in this paper. The code, able to handle the numerous reaction channels for neutron energies higher than 20 MeV, has been set up for activation calculations in the frame of the IFMIF facility. The validation was possible thanks to the availability of new experimental data obtained with neutrons of energy greater than 20 MeV. In this experiment, a thick target of natural lithium was irradiated with 40 MeV deuterons. Samples of two different steels, SS-316 and F82H, pure vanadium and a vanadium alloy were irradiated in the resulting neutron spectrum and the specific activities of many radionuclides were measured at various cooling times. The results of the comparison are presented and discussed
ANITA-IEAF: A code package for performing fusion material transmutation and activation analysis induced by intermediate energy neutrons
No full textThis paper presents the ANITA-IEAF code package for the activation characterisation of materials exposed to neutrons with energies up to 150 MeV. It computes the radioactive inventories of materials exposed to neutron irradiation, continuous or stepwise. The activity, isotopic nuclide density, decay heat, biological hazard, clearance index and gamma ray source spectra are calculated at shutdown and at different cooling times. The code package is provided with a complete database that includes neutron activation data library, decay, hazard and clearance data library, and gamma library. The paper also presents an application of the ANITA-IEAF code package to the neutron exposure characterisation for the AISI 316 liner of the Test Cell area of the International Fusion Materials Irradiation Facility
Experimental fusion material photon and electron decay heat measurements: Its use for activation codes validation
No full textThis paper presents the summary of the results of the comparison between the calculated and measured photons and electrons decay heat and activations of material samples irradiated at the Fusion Neutron Generator of the ENEA Research Centre of Frascati that were used for activation code validation purpose. Samples material considered are: Mo, Cu, Hf, Mg, Ni, Cd, Sn, Re, Ti, W, Ag, and Al. Material decay heat (and activity) at various times after the end of the samples irradiation have been evaluated using the ANITA-2000 activation code, by considering three different neutron activation libraries (EAF-99, FENDL/A-2, and EAF-2003) and the results have been compared with the experimental ones. The ratios between calculated and experimental values have been obtained and they are discussed in this paper
The SCALENEA-1 multipurpose Sn calculation sequence for application in fusion field: Main features and its validation based on experimental data from a low-level waste repository
No full textThe paper presents the main features of the Sn calculation sequence SCALENEA-1 that has been extensively used for radioactive inventories, source terms, wastes and dose rates calculation for ITER, SEAFP and IFMIF fusion machines. As part of the validation process for the code package and for the calculation sequence, experimental-calculation comparison has been performed using the information and the measured isotope radioactive inventories and dose rate gathered from drum containers of a low-level waste repository. The agreement between calculation and gamma dose rates experimental data is good: discrepancies are lower than 50%. To guarantee a complete Quality Assurance for codes and calculation scheme, a simulation of the radioactive containers to evaluate the dose rates has done also by using the Monte Carlo MCNP-4C code. The discrepancies between the two calculation approaches are lower than 1%. The conclusion of the study confirms once again that the SCALENEA-1 calculation sequence is able to provide reliable results for various fusion machines safety analyses purposes
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