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International audience ; This article focuses on spallation reactions, i.e. interactions of energetic nucleons, basically with a kinetic energy in the 100 MeV to a few GeV range, with a target nucleus. These processes are described rather successfully by the so-called Intranuclear Cascade (INC) plus evaporation models. They can be viewed as a first stage of nucleon-nucleon collisions, ejecting fast particles, followed by evaporation of slow particles from the target remnant. These cascade + evaporation models have, now, globally reached a high level of predictive power, owing in particular to successive research programs. The present work, which is an outcome of one of these programs, the recent European Union ANDES research program, deals with a set of reactions (or observable quantities), which can be due to a single collision, such as the one-nucleon removal reactions or the quasi-elastic elastic process. A survey of the experimental data is presented, which allows to clearly point out that, often, the INC models are unsatisfactory for the description of these peculiar events, whereas they are rather successful for the rest of the experimental data. This paradoxical situation is tentatively related to quasi-particle effects which are neglected in INC models.

International audience ; This article focuses on spallation reactions, i.e. interactions of energetic nucleons, basically with a kinetic energy in the 100 MeV to a few GeV range, with a target nucleus. These processes are described rather successfully by the so-called Intranuclear Cascade (INC) plus evaporation models. They can be viewed as a first stage of nucleon-nucleon collisions, ejecting fast particles, followed by evaporation of slow particles from the target remnant. These cascade + evaporation models have, now, globally reached a high level of predictive power, owing in particular to successive research programs. The present work, which is an outcome of one of these programs, the recent European Union ANDES research program, deals with a set of reactions (or observable quantities), which can be due to a single collision, such as the one-nucleon removal reactions or the quasi-elastic elastic process. A survey of the experimental data is presented, which allows to clearly point out that, often, the INC models are unsatisfactory for the description of these peculiar events, whereas they are rather successful for the rest of the experimental data. This paradoxical situation is tentatively related to quasi-particle effects which are neglected in INC models.

International audience ; This article focuses on spallation reactions, i.e. interactions of energetic nucleons, basically with a kinetic energy in the 100 MeV to a few GeV range, with a target nucleus. These processes are described rather successfully by the so-called Intranuclear Cascade (INC) plus evaporation models. They can be viewed as a first stage of nucleon-nucleon collisions, ejecting fast particles, followed by evaporation of slow particles from the target remnant. These cascade + evaporation models have, now, globally reached a high level of predictive power, owing in particular to successive research programs. The present work, which is an outcome of one of these programs, the recent European Union ANDES research program, deals with a set of reactions (or observable quantities), which can be due to a single collision, such as the one-nucleon removal reactions or the quasi-elastic elastic process. A survey of the experimental data is presented, which allows to clearly point out that, often, the INC models are unsatisfactory for the description of these peculiar events, whereas they are rather successful for the rest of the experimental data. This paradoxical situation is tentatively related to quasi-particle effects which are neglected in INC models.

International audience ; In case of a severe accident in a light water nuclear reactor, hydrogen would be produced duringreactor core degradation and released into the reactor building. The stratification of the released hydrogen in the reactor containment could lead to local pockets of gas mixtures of high hydrogen concentration and, in case ofcombustion, to high pressure loads which might challenge the containment structural integrity.The objectives of ERCOSAM and SAMARA projects, co-funded by the European Union and the Russia, are to investigate hydrogen concentration build-up and break-up due to safety components operations, as sprays, coolers and Passive Auto-catalytic Recombiners (PARs).For this purpose, various experiments addressing accident scenarios scaled down from existing plant calculations to different thermal-hydraulics facilities (TOSQAN, MISTRA, PANDA, SPOT) are considered. This paper describes the work performed in framework of the workpackage WP1 of the ERCOSAM project and presents theadopted methodology to scale down the real plant calculations results, provided by the projects partners, to the experimental facilities.

International audience ; In case of a severe accident in a light water nuclear reactor, hydrogen would be produced duringreactor core degradation and released into the reactor building. The stratification of the released hydrogen in the reactor containment could lead to local pockets of gas mixtures of high hydrogen concentration and, in case ofcombustion, to high pressure loads which might challenge the containment structural integrity.The objectives of ERCOSAM and SAMARA projects, co-funded by the European Union and the Russia, are to investigate hydrogen concentration build-up and break-up due to safety components operations, as sprays, coolers and Passive Auto-catalytic Recombiners (PARs).For this purpose, various experiments addressing accident scenarios scaled down from existing plant calculations to different thermal-hydraulics facilities (TOSQAN, MISTRA, PANDA, SPOT) are considered. This paper describes the work performed in framework of the workpackage WP1 of the ERCOSAM project and presents theadopted methodology to scale down the real plant calculations results, provided by the projects partners, to the experimental facilities.

International audience ; In case of a severe accident in a light water nuclear reactor, hydrogen would be produced duringreactor core degradation and released into the reactor building. The stratification of the released hydrogen in the reactor containment could lead to local pockets of gas mixtures of high hydrogen concentration and, in case ofcombustion, to high pressure loads which might challenge the containment structural integrity.The objectives of ERCOSAM and SAMARA projects, co-funded by the European Union and the Russia, are to investigate hydrogen concentration build-up and break-up due to safety components operations, as sprays, coolers and Passive Auto-catalytic Recombiners (PARs).For this purpose, various experiments addressing accident scenarios scaled down from existing plant calculations to different thermal-hydraulics facilities (TOSQAN, MISTRA, PANDA, SPOT) are considered. This paper describes the work performed in framework of the workpackage WP1 of the ERCOSAM project and presents theadopted methodology to scale down the real plant calculations results, provided by the projects partners, to the experimental facilities.

International audience ; Sodium-cooled Fast Reactors (SFR) is one of the Generation IV reactor concepts selected to secure the nuclear fuel resources and to manage radioactive waste. In the frame of the June 2006 French act on sustainable management of radioactive materials and wastes, French Government entrusted CEA (French Commission for Atomic Energy and Alternative Energy) to conduct design studies of ASTRID (Advanced Sodium Technological Reactor for Industrial Demonstration) prototype in collaboration with fourteen industrial partners.After 6 years of Conceptual Design phase, the Project is involved since January 2016 in Basic Design with a reference for the power conversion systems (PCS) in Brayton gas cycle in order to benefit from the use of a gas (pure nitrogen) non-reactive with sodium.The first 10 months of 2016 were dedicated to a Confirmation of Configuration Phase (P2C) whose objectives were to revisit and optimize the different technical options considered as the reference configuration during the AVP phase.The P2C was closed in October 2016 by a review which defined the new reference configuration for the Basic Design studies to be done. In addition, Balance Of Plant (BOP) studies considering the French reference site are going on.This paper presents the status of the ASTRID architecture including a synthesis of the specificities of the site. The main items of the reference P2C configuration will be detailed: design of Na secondary loops and heat exchangers according to the Brayton cycle, handling fuel route including an external storage vessel in the reactor building, symmetric design of the nuclear buildings with two exchangers gas buildings and independent turbine associated.Finally, the conditions of integration of the nuclear island buildings in the site and the general layout will also be exposed.Items addressed in this document include 3D views of nuclear island buildings which have been designed by the industrial Partners and managed by CEA which acts as the industrial architect of the project.

International audience ; Sodium-cooled Fast Reactors (SFR) is one of the Generation IV reactor concepts selected to secure the nuclear fuel resources and to manage radioactive waste. In the frame of the June 2006 French act on sustainable management of radioactive materials and wastes, French Government entrusted CEA (French Commission for Atomic Energy and Alternative Energy) to conduct design studies of ASTRID (Advanced Sodium Technological Reactor for Industrial Demonstration) prototype in collaboration with fourteen industrial partners.After 6 years of Conceptual Design phase, the Project is involved since January 2016 in Basic Design with a reference for the power conversion systems (PCS) in Brayton gas cycle in order to benefit from the use of a gas (pure nitrogen) non-reactive with sodium.The first 10 months of 2016 were dedicated to a Confirmation of Configuration Phase (P2C) whose objectives were to revisit and optimize the different technical options considered as the reference configuration during the AVP phase.The P2C was closed in October 2016 by a review which defined the new reference configuration for the Basic Design studies to be done. In addition, Balance Of Plant (BOP) studies considering the French reference site are going on.This paper presents the status of the ASTRID architecture including a synthesis of the specificities of the site. The main items of the reference P2C configuration will be detailed: design of Na secondary loops and heat exchangers according to the Brayton cycle, handling fuel route including an external storage vessel in the reactor building, symmetric design of the nuclear buildings with two exchangers gas buildings and independent turbine associated.Finally, the conditions of integration of the nuclear island buildings in the site and the general layout will also be exposed.Items addressed in this document include 3D views of nuclear island buildings which have been designed by the industrial Partners and managed by CEA which acts as the industrial architect of the ...

International audience ; In the framework of the successive 1991 and 2006 Waste Management Act, French government supported a very significant RandD program on partitioning and transmutation of minor actinides (MA). This program aims to study potential solutions for still minimizing the quantity and the hazardousness of final waste, by MA recycling. Indeed, MA recycling can reduce the heat load and the half-life of most of the waste to be buried to a couple of hundred years, overcoming the concerns of the public related to the long-life of the waste.Within this framework, this paper aims to present the most recent progress obtained in CEA on the development of innovative actinide partitioning hydrometallurgical processes in support of their recycling, either in an homogeneous mode (MA are recycled at low concentration in all the standard reactor fuel) or in an heterogeneous mode (MA are recycled at higher concentration in specific targets, at the periphery of the reactor core). Recovery performances obtained on recent tests in high active conditions of the so-called GANEX and DIAMEX-SANEX process will be presented and discussed in light of the potential PetT scenarios. Finally, recent developments regarding the recycling of the sole Am will be presented as well as the results obtained on highly active solutions for this so-called EXAM process.This set of results gives to the French government a portfolio of potential recycling processes which could be separately and progressively implemented if decided.

International audience ; In the framework of the successive 1991 and 2006 Waste Management Act, French government supported a very significant RandD program on partitioning and transmutation of minor actinides (MA). This program aims to study potential solutions for still minimizing the quantity and the hazardousness of final waste, by MA recycling. Indeed, MA recycling can reduce the heat load and the half-life of most of the waste to be buried to a couple of hundred years, overcoming the concerns of the public related to the long-life of the waste.Within this framework, this paper aims to present the most recent progress obtained in CEA on the development of innovative actinide partitioning hydrometallurgical processes in support of their recycling, either in an homogeneous mode (MA are recycled at low concentration in all the standard reactor fuel) or in an heterogeneous mode (MA are recycled at higher concentration in specific targets, at the periphery of the reactor core). Recovery performances obtained on recent tests in high active conditions of the so-called GANEX and DIAMEX-SANEX process will be presented and discussed in light of the potential PetT scenarios. Finally, recent developments regarding the recycling of the sole Am will be presented as well as the results obtained on highly active solutions for this so-called EXAM process.This set of results gives to the French government a portfolio of potential recycling processes which could be separately and progressively implemented if decided.

In the european political field, the challenge consists in organizing a political debate on the scale of the Union whereas the citizens of this one do not speak the same language, ignore the Community institutions, live in different institutional systems and, during nearly 50 years, lived Wall on both sides, in opposite ideological universes. Television can help to take up this challenge in condition of being put in perspective in its right place: neither obsolete and diabolic object manipulating the masses, nor democratic fairy bringing the rational light to the individuals

In the european political field, the challenge consists in organizing a political debate on the scale of the Union whereas the citizens of this one do not speak the same language, ignore the Community institutions, live in different institutional systems and, during nearly 50 years, lived Wall on both sides, in opposite ideological universes. Television can help to take up this challenge in condition of being put in perspective in its right place: neither obsolete and diabolic object manipulating the masses, nor democratic fairy bringing the rational light to the individuals

In the european political field, the challenge consists in organizing a political debate on the scale of the Union whereas the citizens of this one do not speak the same language, ignore the Community institutions, live in different institutional systems and, during nearly 50 years, lived Wall on both sides, in opposite ideological universes. Television can help to take up this challenge in condition of being put in perspective in its right place: neither obsolete and diabolic object manipulating the masses, nor democratic fairy bringing the rational light to the individuals

In the european political field, the challenge consists in organizing a political debate on the scale of the Union whereas the citizens of this one do not speak the same language, ignore the Community institutions, live in different institutional systems and, during nearly 50 years, lived Wall on both sides, in opposite ideological universes. Television can help to take up this challenge in condition of being put in perspective in its right place: neither obsolete and diabolic object manipulating the masses, nor democratic fairy bringing the rational light to the individuals

In the european political field, the challenge consists in organizing a political debate on the scale of the Union whereas the citizens of this one do not speak the same language, ignore the Community institutions, live in different institutional systems and, during nearly 50 years, lived Wall on both sides, in opposite ideological universes. Television can help to take up this challenge in condition of being put in perspective in its right place: neither obsolete and diabolic object manipulating the masses, nor democratic fairy bringing the rational light to the individuals