Differences into HT and HTO concentrations in air into the Western Mediterranean Basin and Continental Europe and Safety Related Issues.

Real time Tritium concentrations in air in two chemical forms, HT and HTO, coming from an ITER-like fusion reactor as source were coupled the European Centre Medium Range Weather Forecast (ECMWF) numerical model with the Lagrangian Atmospheric-particle dispersion model FLEXPART. This tool was analyzed in nominal tritium discharge operational reference and selected incidental conditions affecting the Western Mediterranean Basin during 45 days during summer 2010 together with surface “wind observations” or weather data based in real hourly observations of wind direction and velocity providing a real approximation of the tritium behavior after the release to the atmosphere from a fusion reactor. From comparison with NORMTRI - a code using climatologically sequences as input - over the same area, the real time results have demonstrated an apparent overestimation of the corresponding climatologically sequence of Tritium concentrations in air outputs, at several distances from the reactor. For this purpose two development patterns were established. The first one was following a cyclonic circulation over the Mediterranean Sea and the second one was based on the plume delivered over the Interior of the Iberian Peninsula and Continental Europe by another stabilized circulation corresponding to a High Pressure System. One of the important remaining activities defined then, was the qualification tool. In order to validate the model of ECMWF/FLEXPART we have developed of a new complete data base of tritium concentrations for the months from November 2010 to March 2011 and defined a new set of four patterns of HT transport in air, in each case using real boundary conditions: stationary to the North, stationary to the South, fast and very fast displacement. Finally the differences corresponding to those four early patterns (each one in assessments 1 and 2) has been analyzed in terms of the tuning of safety related issues and taking into account the primary phase o- - f tritium modeling, from its discharge to the atmosphere to the deposition on the ground, will affect to the complete tritium environmental pathway altering the chronic dose by absorption, reemission and ingestion both from elemental tritium, HT and from the oxide of tritium, HT

Resistivity Recovery curves of electron-irradiated FeCr alloys with Object Kinetic Monte Carlo: influence of Cr interctions.

An Object Kinetic Monte Carlo model is being developed for dilute (less than 1% Cr) FeCr alloys. The model includes the effects of Cr on the mobility of radiation effects, using information obtained either from density functional theory or molecular dynamics calculations. The results are compared to experimental measurements of electric resistivity for different Cr concentrations. We analyse the dependence of Cr on the first two observed peaks: ID2 and IE and the influence of parameters such as the interaction radius between Cr and an Fe self-interstitial

Environmental impact assessment of tritium release over the Western

The environmental impact of systems managing large (kg) tritium amount represents a public scrutiny issue for the next coming fusion facilities as DEMO. Furthermore, potentially new dose limits imposed by international regulations (ICRP) shall impact next coming devices designs and the overall costs of fusion technology deployment. Refined environmental tritium dose impact assessment schemes are then overwhelming. Detailed assessments can be procured from the knowledge of the real boundary conditions of the primary tritium discharge phase into atmosphere and into soils. Lagrangian dispersion models using real-time meteorological and topographic data provide strong refinement. Advance simulation tools are being developed in this sense. The tool integrates modeled numerical records from European Centre for Medium range Weather Forecast (ECMWF) with a lagrangian atmospheric dispersion model (FLEXPART). The model results can be coupled with tritium dose secondary phase pathway assessment tools. Nominal tritium discharge operational reference and selected incidental ITER-like plant systems tritium form source terms have been assumed. The real-time daily data and mesh-refined records together with lagrangian dispersion model approach provide accurate results for doses to population by inhalation or ingestion in the secondary phase

Consequences of different meteorological scenarios in the environmental impact assesment of tritium release

The environmental impact of systems managing large (kg) tritium amount represents a public scrutiny issue for the next coming fusion facilities as ITER and DEMO. Furthermore, potentially new dose limits imposed by international regulations (ICRP) shall impact next coming devices designs and the overall costs of fusion technology deployment. Refined environmental tritium dose impact assessment schemes are then overwhelming. Detailed assessments can be procured from the knowledge of the real boundary conditions of the primary tritium discharge phase into atmosphere (low levels) and into soils. Lagrangian dispersion models using real-time meteorological and topographic data provide an strong refinement. Advance simulation tools are being developed in this sense. The tool integrates a numerical model output records from European Centre for Medium range Weather Forecast (ECMWF) with a lagrangian atmospheric dispersion model (FLEXPART). The composite model ECMWF/FLEXTRA results can be coupled with tritium dose secondary phase pathway assessment tools. Nominal tritium discharge operational reference and selected incidental ITER-like plant systems tritium form source terms have been assumed. The realtime daily data and mesh-refined records together with lagrangian dispersion model approach provide accurate results for doses to population by inhalation or ingestion in the secondary phase

Consequences of different meteorological scenarios in the environmental impact assessment of tritium in air

The environmental impact of systems managing large (kg) tritium amount represents a public scrutiny issue for the next coming fusion facilities as ITER and DEMO. Furthermore, potentially new dose limits imposed by international regulations (ICRP) shall impact next coming devices designs and the overall costs of fusion technology deployment. Refined environmental tritium dose impact assessment schemes are then overwhelming. Detailed assessments can be procured from the knowledge of the real boundary conditions of the primary tritium discharge phase into atmosphere (low levels) and into soils. Lagrangian dispersion models using real-time meteorological and topographic data provide a strong refinement. Advance simulation tools are being developed in this sense. The tool integrates a numerical model output records from European Centre for Medium range Weather Forecast (ECMWF) with a lagrangian atmospheric dispersion model (FLEXPART). The composite model ECMWF/FLEXTRA results can be coupled with tritium dose secondary phase pathway assessment tools. Nominal tritium discharge operational reference and selected incidental ITER-like plant systems tritium form source terms have been assumed. The realtime daily data and mesh-refined records together with lagrangian dispersion model approach provide accurate results for doses to population by inhalation or ingestion in the secondary phas

Validation of real time dispersion of Tritium clouds over the Western Mediterranean Basin in different assesments

Real time Tritium concentrations in air coming from an ITER-like reactor as source were coupled the European Centre Medium Range Weather Forecast (ECMWF) numerical model with the lagrangian atmospheric dispersion model FLEXPART. This tool ECMWF/FLEXPART was analyzed in normal operating conditions in the Western Mediterranean Basin during 45 days at summer 2010. From comparison with NORMTRI plumes over Western Mediterranean Basin the real time results have demonstrated an overestimation of the corresponding climatologically sequence Tritium concentrations in air outputs, at several distances from the reactor. For these purpose two clouds development patterns were established. The first one was following a cyclonic circulation over the Mediterranean Sea and the second one was based in the cloud delivered over the Interior of the Iberian Peninsula by another stabilized circulation corresponding to a High. One of the important remaining activities defined then, was the tool qualification. The aim of this paper is to present the ECMWF/FLEXPART products confronted with Tritium concentration in air data. For this purpose a database to develop and validate ECMWF/FLEXPART tritium in both assessments has been selected from a NORMTRI run. Similarities and differences, underestimation and overestimation with NORMTRI will allowfor refinement in some features of ECMWF/FLEXPAR

Interstitial defects stability in FeCr alloys vs Cr concentration

Finding adequate materials to withstand the demanding conditions in the future fusion and fission reactors is a real challenge in the development of these technologies. Structural materials need to sustain high irradiation doses and temperatures that will change the microstructure over time. A better understanding of the changes produced by the irradiation will allow for a better choice of materials, ensuring a safer and reliable future power plants. High-Cr ferritic/martensitic steels head the list of structural materials due to their high resistance to swelling and corrosion. However, it is well known that these alloys present a problem of embrittlement, which could be caused by the presence of defects created by irradiation as these defects act as obstacles for dislocation motion. Therefore, the mechanical response of these materials will depend on the type of defects created during irradiation. In this work, we address a study of the effect Cr concentration has on single interstitial defect formation energies in FeCr alloys

He production and induced swelling in KOYO-F

From preliminary results[1] of neutron fluxes and energy spectra obtained for the vacuum vessel of the Fast Ignition Fusion Reactor KOYO-F, the distribution of Primary Knock-on Atoms (PKA), necessary to quantify defect production, has been calculated. In the presence of He these defects could induce swelling through nucleation of voids and bubbles. Kinetic Monte Carlo models are being developed to predict the evolution of these defects in different metals. As a first study we have focused on He in Ni, since there are systematic experimental results available

The Importance of the Interaction Radius Between Cr and Self-interstitial Fe in Object Kinetic Monte Carlo Calculations of Irradiated FeCr Diluted Alloys

We have studied electron irradiation and annealing of FeCr alloys in the dilute limit ( less than 1% Cr) using Object kinetic Monte Carlo (OKMC) with input from density functional theory calculations and empirical potentials. The results are compared to experimental measurements of electric resistivity for different Cr concentrations. We analyse the dependence of Cr on the first two observed peaks: ID2 and IE and the influence of parameters such as the interaction radius between Cr and an Fe self-interstitial

Simulations of Resistivity Recovery curves of electron-irradiated dilute FeCr alloys using an Object Kinetic Monte Carlo Model.

An Object Kinetic Monte Carlo model is being developed for dilute (less than 1% Cr) FeCr alloys. The model includes the effects of Cr on the mobility of radiation effects using information obtained either from density functional theory or effects of Cr on the mobility of radiation effects, using information obtained either from density functional theory or molecular dynamics calculations. The results are compared to experimental measurements of electric resistivity for different Cr concentrations. We analyse the dependence of Cr on the first two observed peaks: ID2 and IE and the influence of parameters such as the interaction radius between Cr and an Fe self-interstiti