Javier Quiñones | Universidad Complutense de Madrid (original) (raw)
Papers by Javier Quiñones
MRS Proceedings, 2004
This paper presents the results obtained from coprecipitation experiments of uranyl solutions in ... more This paper presents the results obtained from coprecipitation experiments of uranyl solutions in the presence of metallic iron and/or its alteration phases in synthetic bentonitic-granitic composition water. Experiments were done under oxidising conditions at room temperature. The pH range covered was 7.4 – 8.8. Changes in the uranium concentrations and the characterisation of the secondary phases formed in the experiments were done using XRD and SEM-EDS and are presented herein.Final uranium concentration values were in the range of 2·10−5 – 5·10−4 mol (kg of H2O)−1. In all cases, results from these experiments did not show evidence of a clear effect due to the presence of iron (metallic or previously corroded) on the uranium concentration. These data were similar to those obtained by coprecipitation in similar conditions but in absence of iron material. Boltwoodite was observed [K2(UO2)2(SiO3)2(OH)2·3H2O] in iron surface materials and characterized in all experiments. Based on the...
European Physical Journal Plus, 2021
The objective of nuclear forensic science is to link an event that involves a radioactive or nucl... more The objective of nuclear forensic science is to link an event that involves a radioactive or nuclear material with the personal and material means that have facilitated it. This implies the collection and analysis of any physical evidence of the scene, both radioactive and nuclear material for its characterization as well as classical evidence like DNA, hair, fingerprints or blood. Collecting evidence in these circumstances can be potentially dangerous for the respondent due to the risk of radiation or radioactive contamination, so studying the stability of forensic evidence in the presence of radiation will allow taking a reasonable decision whether the probative utility that the evidence may have exceeds the dangers involved in its collection. In this context, this work addresses the resistance of classical forensic evidences to radiation. Thus, gamma post-irradiation results of DNA profiling from relevant biological samples are presented and discussed providing threshold values o...
The European Physical Journal Plus, 2021
Chemical and radiological emergences can be caused by terrorist attacks, such as the use of CWA, ... more Chemical and radiological emergences can be caused by terrorist attacks, such as the use of CWA, as well as from industrial accidents. Whatever the trigger, these events often involve the rapid dispersal of toxic chemical agents that, depending on the scenario and level of exposure, can compromise security and human health. These risks and the associated alarm in the population justify the interest in the development of systems and processes for the efficient capture of toxics airborne released in these incidents. The countermeasure proposed in this work is based on the use of fog (i.e. water dissolution with several additives such as isopropanol, Ag+ compounds even so metallic sorbents solid in suspension). The different combinations of these countermeasures were tested and evaluated in order to achieve maximum cleaning efficiency and speed of action. These tests were performed at different scales comprising laboratory scale, pilot plant, and inside a large building. The effect of the combined countermeasure studied is much greater than that of each of the measures separately, since, as has been shown, the joint interaction favours the reduction of the concentration of the dispersed radiochemical agent in the atmosphere. The capability at real scale of the propounded system for minimising the effect of chemical and/or radionuclide dispersion in the atmosphere has been confirmed.
Energy Procedia, 2011
Direct geological disposal of spent fuel from nuclear energy production is a waste management str... more Direct geological disposal of spent fuel from nuclear energy production is a waste management strategy of many European member states. Disposal safety must be ensured for thousands to millions of years. If one wants to put the highly radioactive used nuclear fuel within a thick-walled metallic canister directly into a repository, corrosion of the canister will occur and access of deep groundwater will eventually take place. What happens if deep groundwater comes into contact with the fuel? Research has been ongoing for more than 25 years to create a large experimental data base to simulate the long-term performance of the waste thus disposed of. Further, there has been a substantial effort to develop descriptive and predictive modeling procedures. The evaluation of the long term performance of the spent fuel relies on the development of theoretical and sometimes semi-empirical models which can be combined with more general safety assessment models allowing repository barrier performance predictions for overall repository performance assessment (PA). The coordinated action MICADO has recently assessed the uncertainties in models describing the dissolution processe s of spent nuclear fuel in a repository for geological time periods. Coordinated by SUBATECH/ARMINES, this international coordinated action combines the efforts of many European waste management agencies, technical support organisations for regulators , universities and research organisations. Participating organisations are CEA, ANDRA and IRSN from France, SCK.CEN and BEL-V form Belgium, KIT Karlsruhe (former FZK-INE), ITU and GRS from Germany, ENRESA, UPC, CIEMAT and AMPHOS21 from Spain, SKB, SSM, Stu dsvik and KTH from Sweden, NAGRA from Switzerland and Quintessa from the United Kingdom. Essentially most worldwide leading experts participate in the project, representing different approaches to the assessment of the performance of disposed spent fuel for very long times: based on electrochemical, geochemical and/or radiolytical modeling approaches. Based on inputs from such models and the associated experimental studies, simplified operational models for spent fuel dissolution are developed and used by waste management and regulating organisations for the safety assessments in more complex systems. The objective was to find out whether international research has now provided sufficiently reliable models to assess the corrosion behavior of spent fuel in groundwater and by this to contribute to answering the question whether the highly radioactive used fuel from nuclear reactors can be disposed of safely in a geological repository. Principal project results are described in the paper.
MRS Proceedings, 2004
Any environmental performance assessment of spent nuclear fuel disposal requires a prediction of ... more Any environmental performance assessment of spent nuclear fuel disposal requires a prediction of the spent fuel matrix alteration rate when contact with groundwater is established. Taking into account the disposal design, the groundwater at the expected depth of the repository are generally reducing. These reducing redox conditions near the spent fuel surface may be changed to oxidising conditions by the radiolysis of water, due to radiation associated with the waste. This study is focussed on determining the influence of the γ radiation on the spent fuel matrix alteration rate under simulated repository conditions. A series of sequential leaching experiments under controlled conditions have been done. The experiments simulate the repository environmental conditions when engineering barriers are degraded and groundwater arrives at the surface of the spent fuel. In these experiments SIMFUEL (SIMulated FUEL) was used as analogue of spent fuel. Two types of leachant (i.e., granitic wat...
Journal of Nuclear Materials, 2005
Enhancing CBRNE Safety & Security: Proceedings of the SICC 2017 Conference
COUNTERFOG is a new, rapid response system for collapsing all kinds of dispersed agents (smoke, f... more COUNTERFOG is a new, rapid response system for collapsing all kinds of dispersed agents (smoke, fog, spores, etc.) by using a fog made of a solution that could eventually contain any kind of neutralizing component. It will be a permanent installation in large public buildings like railway stations or critical infrastructure but also a portable COUNTERFOG for use outdoors, used to counteract a CBRN attack in its earliest stages, greatly reducing the number of potential fatalities. In fact, COUNTERFOG uses the same “weapon” as a CBRN attack: a dispersed state with a large surface/volume ratio. Under certain conditions, it can penetrate all the intricate holes CBRN agents are able to infiltrate. As it needs a minimum quantity of decontaminant, it is intrinsically an environment-friendly and electric-compatible system. It has several benefits: firstly, to neutralize and collapse the CBRN cloud quickly limiting its extension and, secondly, to rapidly decontaminate all the affected area and any equipment. Prototypes have been developed and tested with agent surrogates in a specifically developed Fog Dynamics Laboratory. The results show that COUNTERFOG is effective against chemical, biological, and radiological surrogates and has a potential to be used both to counteract and to decontaminate. This work has been funded by FP7-SEC-2012-1 program of the EU Commission under grant number 312804.
<jats:title>Abstract</jats:title> <jats:p>A model to study the stability of the... more <jats:title>Abstract</jats:title> <jats:p>A model to study the stability of the spent fuel under repository conditions has been developed. The fuel-water interface is a dynamic redox system, where oxidising conditions due to the radiolysis of water can lead to the release of the uranium and the radionuclides embedded in the fuel matrix. Both kinetic and thermodynamic processes have been taken into account. Special attention is given to the unit rate of matrix oxidation/dissolution, which has been the subject of a specific radiolytic model. The findings of this work have important implications for the applicability of solubility limits in establishing source term models.</jats:p>
Faced with the new options for the high level waste management, the “Partitioning and Transmutati... more Faced with the new options for the high level waste management, the “Partitioning and Transmutation (P&T)” of the radio nuclides contained in the irradiated nuclear fuel appear as a promising option from different points of view, such as environmental risk, radiotoxic inventory reduction, economic, etc. The present work is part of a research project called “PYROREP” of the 5 FWP of the EU that studied the feasibility of the actinide separation from the rest of fission products contained in the irradiated nuclear fuel by pyrometallurgical processes with the aim of their transmutation. In order to design these processes it is necessary to determine basic thermodynamic and kinetic data of the radionuclides contained in the nuclear fuel in molten salt media. The electrochemical study of uranium, samarium and molybdenum in the eutectic melt LiCl – KCl has been performed at a tungsten electrode in the temperature range of 450 – 600C in order to obtain these basic properties.
COUNTERFOG is a new, rapid response system for collapsing all kinds of dispersed agents (smoke, f... more COUNTERFOG is a new, rapid response system for collapsing all kinds of dispersed agents (smoke, fog, spores, etc.) by using a fog made of a solution that could eventually contain any kind of neutralizing component. It will be a permanent installation in large public buildings like railway stations or critical infrastructure but also a portable COUNTERFOG for use outdoors, used to counteract a CBRN attack in its earliest stages, greatly reducing the number of potential fatalities. In fact, COUNTERFOG uses the same “weapon” as a CBRN attack: a dispersed state with a large surface/volume ratio. Under certain conditions, it can penetrate all the intricate holes CBRN agents are able to infiltrate. As it needs a minimum quantity of decontaminant, it is intrinsically an environment-friendly and electric-compatible system. It has several benefits: firstly, to neutralize and collapse the CBRN cloud quickly limiting its extension and, secondly, to rapidly decontaminate all the affected area a...
In this work a description of the new radioactive facility (Characteristics, scheme, projects inv... more In this work a description of the new radioactive facility (Characteristics, scheme, projects involved, techniques, ...) is presented. This facility was designed for performing R&D+i studies and/or projects related to characterize the physicochemical properties of the spent fuel, an its stability and behaviour under repository conditions. Furthermore, this facility has the capability for carrying out chemical analysis with ICP-MS and HPLC techniques. Due to these reasons, nowadays, this laboratory is involved in several National and International projects related to spent fuel stability. The paper reviews the manufacture and description of the laboratory, analytical techniques, the experimental work (leaching and coprecipitation experiments) and modelling performed for extrapolating to the repository conditions.
Nowadays, the threat of a terrorist attack with CBRNE (chemical, biological, radiological, nuclea... more Nowadays, the threat of a terrorist attack with CBRNE (chemical, biological, radiological, nuclear, and explosive) agents is very real, as can be seen in the increasing appearance of news related to the use of CWA (chemical warfare agent) in criminal acts. In light of these new threats, there are no countermeasures available that can respond quickly and automatically to mitigate the consequences. Therefore, the need arises to develop new countermeasure systems that will act against CBRNE agents.
The European Physical Journal Plus
Abstract.Nowadays, radioactive materials are widely used in medicine, agriculture, industry and s... more Abstract.Nowadays, radioactive materials are widely used in medicine, agriculture, industry and scientific research. This implies a growing accessibility and their potential use for criminal or terrorist purposes, i.e. as Radioactive Dispersion Device (RDD) or as Radiation Emission Device (RED). In light of these new threats, currently there are no countermeasures available that can respond quickly and automatically to mitigate their possible consequences. Therefore, the need arises to design and to implement new countermeasure systems that will act in the face of a CBRNE (Chemical, Biological, Radiological, Nuclear and Explosives) incident, even in the presence of fire. This is the main goal of the COUNTERFOG project, which proposed a countermeasure system based on the generation of a fog that interact with the dispersed aerosols. The objectives of the project range from the design and manufacture of nozzles able to generate the required fog, to planning and execution of the experimental procedure to evaluate its effectiveness. This work presents the results of the application of the COUNTERFOG system to the cleaning of RN surrogates, dispersed in the environment simulating the detonation of a RDD device.
11th International Conference on Environmental Remediation and Radioactive Waste Management, Parts A and B, 2007
From the Spanish point of view, one of the key issues related to the HLW performance assessment i... more From the Spanish point of view, one of the key issues related to the HLW performance assessment is knowing and predicting, or modelling, the behaviour of spent fuel under geological repository conditions. Taking into account this objective, several experiments have been performed in order to split and determine the influence of different variables on the final stability of the spent fuel matrix in the geological repository. This paper presents some of the leaching results obtained with spent fuel and chemical analogues (UO2, alpha doped – UO2, SIMFUEL,) their application to extrapolate the corrosion behaviour for a long period of time and compare with corresponding data obtained using models. This procedure allows pointing out some of the uncertainties whose minimization is necessary to improve the models useful for performance assessment studies.
MRS Proceedings, 2004
... simulation, the composition of the solution is identical to those that could be obtained diss... more ... simulation, the composition of the solution is identical to those that could be obtained dissolving SIMFUEL (SIMulated FUEL) [4] specimens which simulates a burnup of 50 MWd/kg U (ie, Ba, Sr, Mo, Pd, Ru, Rh, Y, Zr, La, Ce, Nd and U). Table I summarises the mole fraction ratio ...
Journal of Alloys and Compounds, 2007
The main objective of this paper is to study the role of groundwater radiolysis in the spent fuel... more The main objective of this paper is to study the role of groundwater radiolysis in the spent fuel matrix alteration process. In order to split the influence of each radiation field, the paper focuses on the ␣-radiation field effect. For this reason the system selected was U-Pu in a synthetic granitic-bentonitic groundwater (carbonate media) in order to simulate the environmental conditions of the Spanish repository scenario [ENRESA, Publicación Técnica ENRESA 03/99 ]. The experimental procedure used allows both the influence of the ␣-radiation field on the U secondary phase formed (and its solubility) and the Pu concentration in solution under simulated environmental conditions to be studied and makes it possible to determine whether any co-precipitation process takes place under these environmental conditions. Previous experimental evidence provided by Haschke et al. [J.M. Haschke, T.H. Allen, L.A. Morales, Science 287 285] pointed to a reaction cycle between Pu 0 and water vapor (at 250 • C) generating PuO 2+x (s) for the first time. Taking this work into account, the objective is to check whether this reaction mechanism will have any influence under the environmental conditions considered.
9th ASME International Conference on Radioactive Waste Management and Environmental Remediation: Volumes 1, 2, and 3, 2003
Radiolytic models have been usually considered useful tools for studying the behaviour of complex... more Radiolytic models have been usually considered useful tools for studying the behaviour of complex chemical systems under the presence of a radiation field. However, they still don&#x27;t have a wider acceptance due to limited availability of kinetic data, difficulty to handle heterogeneous ...
MRS Proceedings, 2006
ABSTRACT This paper focuses on how to extrapolate current knowledge of spent fuel matrix alterati... more ABSTRACT This paper focuses on how to extrapolate current knowledge of spent fuel matrix alteration processes from laboratory to repository conditions, i.e., the influence of changes in both the environmental conditions and the range of time scale considered. Therefore, a spent fuel matrix alteration model allowing the alteration rate evolution to be predicted as a function of both the host rock considered and evaluation time scale of interest is described.At present, the model assumes that alteration of the spent fuel will start when the groundwater reaches the solid surface and that only the radiolytic species of the groundwater (oxidants generated by α-radiation of spent fuel) will produce the surface oxidation process and subsequent matrix dissolution; O2, H2O2 and OH· are the species that react with UO2(s) for oxidation of the pellet surface. The dissolution process of the surface sites that are oxidized is modelled in two steps: first, a surface co-ordination of the oxidized layer with aqueous ligands and, second, detachment (dissolution) of the product species. Taking this mechanism into account, the model gives the evolution of the spent fuel matrix alteration rate over periods as long as 1,000,000 years.In this work the matrix alteration rate results obtained for two repository environments, granitic and argillaceous, will be presented. Furthermore, a sensitivity analysis study has been performed on the influence of the following variables: type of spent fuel considered, α-dose rate evolution, α-range in groundwater, carbonate and iron concentration in groundwater, H2 partial pressure, container time failure and specific surface area of the pellet.
To determine the concentration controlling solid phases and coprecipitation process for elements ... more To determine the concentration controlling solid phases and coprecipitation process for elements contained in spent nuclear fuel, SIMFUEL coprecipitation trials under simulated bentonitic-granitc groundwater were performed. These experiments were carried out under oxidizing conditions at pH values ranging from 5 to 10. In this work an effort to determine whether solubility of pure phases could predict the behaviour of each element or whether it would be necessary to consider the formation of mixed solid phases was made.
MRS Proceedings, 2004
This paper presents the results obtained from coprecipitation experiments of uranyl solutions in ... more This paper presents the results obtained from coprecipitation experiments of uranyl solutions in the presence of metallic iron and/or its alteration phases in synthetic bentonitic-granitic composition water. Experiments were done under oxidising conditions at room temperature. The pH range covered was 7.4 – 8.8. Changes in the uranium concentrations and the characterisation of the secondary phases formed in the experiments were done using XRD and SEM-EDS and are presented herein.Final uranium concentration values were in the range of 2·10−5 – 5·10−4 mol (kg of H2O)−1. In all cases, results from these experiments did not show evidence of a clear effect due to the presence of iron (metallic or previously corroded) on the uranium concentration. These data were similar to those obtained by coprecipitation in similar conditions but in absence of iron material. Boltwoodite was observed [K2(UO2)2(SiO3)2(OH)2·3H2O] in iron surface materials and characterized in all experiments. Based on the...
European Physical Journal Plus, 2021
The objective of nuclear forensic science is to link an event that involves a radioactive or nucl... more The objective of nuclear forensic science is to link an event that involves a radioactive or nuclear material with the personal and material means that have facilitated it. This implies the collection and analysis of any physical evidence of the scene, both radioactive and nuclear material for its characterization as well as classical evidence like DNA, hair, fingerprints or blood. Collecting evidence in these circumstances can be potentially dangerous for the respondent due to the risk of radiation or radioactive contamination, so studying the stability of forensic evidence in the presence of radiation will allow taking a reasonable decision whether the probative utility that the evidence may have exceeds the dangers involved in its collection. In this context, this work addresses the resistance of classical forensic evidences to radiation. Thus, gamma post-irradiation results of DNA profiling from relevant biological samples are presented and discussed providing threshold values o...
The European Physical Journal Plus, 2021
Chemical and radiological emergences can be caused by terrorist attacks, such as the use of CWA, ... more Chemical and radiological emergences can be caused by terrorist attacks, such as the use of CWA, as well as from industrial accidents. Whatever the trigger, these events often involve the rapid dispersal of toxic chemical agents that, depending on the scenario and level of exposure, can compromise security and human health. These risks and the associated alarm in the population justify the interest in the development of systems and processes for the efficient capture of toxics airborne released in these incidents. The countermeasure proposed in this work is based on the use of fog (i.e. water dissolution with several additives such as isopropanol, Ag+ compounds even so metallic sorbents solid in suspension). The different combinations of these countermeasures were tested and evaluated in order to achieve maximum cleaning efficiency and speed of action. These tests were performed at different scales comprising laboratory scale, pilot plant, and inside a large building. The effect of the combined countermeasure studied is much greater than that of each of the measures separately, since, as has been shown, the joint interaction favours the reduction of the concentration of the dispersed radiochemical agent in the atmosphere. The capability at real scale of the propounded system for minimising the effect of chemical and/or radionuclide dispersion in the atmosphere has been confirmed.
Energy Procedia, 2011
Direct geological disposal of spent fuel from nuclear energy production is a waste management str... more Direct geological disposal of spent fuel from nuclear energy production is a waste management strategy of many European member states. Disposal safety must be ensured for thousands to millions of years. If one wants to put the highly radioactive used nuclear fuel within a thick-walled metallic canister directly into a repository, corrosion of the canister will occur and access of deep groundwater will eventually take place. What happens if deep groundwater comes into contact with the fuel? Research has been ongoing for more than 25 years to create a large experimental data base to simulate the long-term performance of the waste thus disposed of. Further, there has been a substantial effort to develop descriptive and predictive modeling procedures. The evaluation of the long term performance of the spent fuel relies on the development of theoretical and sometimes semi-empirical models which can be combined with more general safety assessment models allowing repository barrier performance predictions for overall repository performance assessment (PA). The coordinated action MICADO has recently assessed the uncertainties in models describing the dissolution processe s of spent nuclear fuel in a repository for geological time periods. Coordinated by SUBATECH/ARMINES, this international coordinated action combines the efforts of many European waste management agencies, technical support organisations for regulators , universities and research organisations. Participating organisations are CEA, ANDRA and IRSN from France, SCK.CEN and BEL-V form Belgium, KIT Karlsruhe (former FZK-INE), ITU and GRS from Germany, ENRESA, UPC, CIEMAT and AMPHOS21 from Spain, SKB, SSM, Stu dsvik and KTH from Sweden, NAGRA from Switzerland and Quintessa from the United Kingdom. Essentially most worldwide leading experts participate in the project, representing different approaches to the assessment of the performance of disposed spent fuel for very long times: based on electrochemical, geochemical and/or radiolytical modeling approaches. Based on inputs from such models and the associated experimental studies, simplified operational models for spent fuel dissolution are developed and used by waste management and regulating organisations for the safety assessments in more complex systems. The objective was to find out whether international research has now provided sufficiently reliable models to assess the corrosion behavior of spent fuel in groundwater and by this to contribute to answering the question whether the highly radioactive used fuel from nuclear reactors can be disposed of safely in a geological repository. Principal project results are described in the paper.
MRS Proceedings, 2004
Any environmental performance assessment of spent nuclear fuel disposal requires a prediction of ... more Any environmental performance assessment of spent nuclear fuel disposal requires a prediction of the spent fuel matrix alteration rate when contact with groundwater is established. Taking into account the disposal design, the groundwater at the expected depth of the repository are generally reducing. These reducing redox conditions near the spent fuel surface may be changed to oxidising conditions by the radiolysis of water, due to radiation associated with the waste. This study is focussed on determining the influence of the γ radiation on the spent fuel matrix alteration rate under simulated repository conditions. A series of sequential leaching experiments under controlled conditions have been done. The experiments simulate the repository environmental conditions when engineering barriers are degraded and groundwater arrives at the surface of the spent fuel. In these experiments SIMFUEL (SIMulated FUEL) was used as analogue of spent fuel. Two types of leachant (i.e., granitic wat...
Journal of Nuclear Materials, 2005
Enhancing CBRNE Safety & Security: Proceedings of the SICC 2017 Conference
COUNTERFOG is a new, rapid response system for collapsing all kinds of dispersed agents (smoke, f... more COUNTERFOG is a new, rapid response system for collapsing all kinds of dispersed agents (smoke, fog, spores, etc.) by using a fog made of a solution that could eventually contain any kind of neutralizing component. It will be a permanent installation in large public buildings like railway stations or critical infrastructure but also a portable COUNTERFOG for use outdoors, used to counteract a CBRN attack in its earliest stages, greatly reducing the number of potential fatalities. In fact, COUNTERFOG uses the same “weapon” as a CBRN attack: a dispersed state with a large surface/volume ratio. Under certain conditions, it can penetrate all the intricate holes CBRN agents are able to infiltrate. As it needs a minimum quantity of decontaminant, it is intrinsically an environment-friendly and electric-compatible system. It has several benefits: firstly, to neutralize and collapse the CBRN cloud quickly limiting its extension and, secondly, to rapidly decontaminate all the affected area and any equipment. Prototypes have been developed and tested with agent surrogates in a specifically developed Fog Dynamics Laboratory. The results show that COUNTERFOG is effective against chemical, biological, and radiological surrogates and has a potential to be used both to counteract and to decontaminate. This work has been funded by FP7-SEC-2012-1 program of the EU Commission under grant number 312804.
<jats:title>Abstract</jats:title> <jats:p>A model to study the stability of the... more <jats:title>Abstract</jats:title> <jats:p>A model to study the stability of the spent fuel under repository conditions has been developed. The fuel-water interface is a dynamic redox system, where oxidising conditions due to the radiolysis of water can lead to the release of the uranium and the radionuclides embedded in the fuel matrix. Both kinetic and thermodynamic processes have been taken into account. Special attention is given to the unit rate of matrix oxidation/dissolution, which has been the subject of a specific radiolytic model. The findings of this work have important implications for the applicability of solubility limits in establishing source term models.</jats:p>
Faced with the new options for the high level waste management, the “Partitioning and Transmutati... more Faced with the new options for the high level waste management, the “Partitioning and Transmutation (P&T)” of the radio nuclides contained in the irradiated nuclear fuel appear as a promising option from different points of view, such as environmental risk, radiotoxic inventory reduction, economic, etc. The present work is part of a research project called “PYROREP” of the 5 FWP of the EU that studied the feasibility of the actinide separation from the rest of fission products contained in the irradiated nuclear fuel by pyrometallurgical processes with the aim of their transmutation. In order to design these processes it is necessary to determine basic thermodynamic and kinetic data of the radionuclides contained in the nuclear fuel in molten salt media. The electrochemical study of uranium, samarium and molybdenum in the eutectic melt LiCl – KCl has been performed at a tungsten electrode in the temperature range of 450 – 600C in order to obtain these basic properties.
COUNTERFOG is a new, rapid response system for collapsing all kinds of dispersed agents (smoke, f... more COUNTERFOG is a new, rapid response system for collapsing all kinds of dispersed agents (smoke, fog, spores, etc.) by using a fog made of a solution that could eventually contain any kind of neutralizing component. It will be a permanent installation in large public buildings like railway stations or critical infrastructure but also a portable COUNTERFOG for use outdoors, used to counteract a CBRN attack in its earliest stages, greatly reducing the number of potential fatalities. In fact, COUNTERFOG uses the same “weapon” as a CBRN attack: a dispersed state with a large surface/volume ratio. Under certain conditions, it can penetrate all the intricate holes CBRN agents are able to infiltrate. As it needs a minimum quantity of decontaminant, it is intrinsically an environment-friendly and electric-compatible system. It has several benefits: firstly, to neutralize and collapse the CBRN cloud quickly limiting its extension and, secondly, to rapidly decontaminate all the affected area a...
In this work a description of the new radioactive facility (Characteristics, scheme, projects inv... more In this work a description of the new radioactive facility (Characteristics, scheme, projects involved, techniques, ...) is presented. This facility was designed for performing R&D+i studies and/or projects related to characterize the physicochemical properties of the spent fuel, an its stability and behaviour under repository conditions. Furthermore, this facility has the capability for carrying out chemical analysis with ICP-MS and HPLC techniques. Due to these reasons, nowadays, this laboratory is involved in several National and International projects related to spent fuel stability. The paper reviews the manufacture and description of the laboratory, analytical techniques, the experimental work (leaching and coprecipitation experiments) and modelling performed for extrapolating to the repository conditions.
Nowadays, the threat of a terrorist attack with CBRNE (chemical, biological, radiological, nuclea... more Nowadays, the threat of a terrorist attack with CBRNE (chemical, biological, radiological, nuclear, and explosive) agents is very real, as can be seen in the increasing appearance of news related to the use of CWA (chemical warfare agent) in criminal acts. In light of these new threats, there are no countermeasures available that can respond quickly and automatically to mitigate the consequences. Therefore, the need arises to develop new countermeasure systems that will act against CBRNE agents.
The European Physical Journal Plus
Abstract.Nowadays, radioactive materials are widely used in medicine, agriculture, industry and s... more Abstract.Nowadays, radioactive materials are widely used in medicine, agriculture, industry and scientific research. This implies a growing accessibility and their potential use for criminal or terrorist purposes, i.e. as Radioactive Dispersion Device (RDD) or as Radiation Emission Device (RED). In light of these new threats, currently there are no countermeasures available that can respond quickly and automatically to mitigate their possible consequences. Therefore, the need arises to design and to implement new countermeasure systems that will act in the face of a CBRNE (Chemical, Biological, Radiological, Nuclear and Explosives) incident, even in the presence of fire. This is the main goal of the COUNTERFOG project, which proposed a countermeasure system based on the generation of a fog that interact with the dispersed aerosols. The objectives of the project range from the design and manufacture of nozzles able to generate the required fog, to planning and execution of the experimental procedure to evaluate its effectiveness. This work presents the results of the application of the COUNTERFOG system to the cleaning of RN surrogates, dispersed in the environment simulating the detonation of a RDD device.
11th International Conference on Environmental Remediation and Radioactive Waste Management, Parts A and B, 2007
From the Spanish point of view, one of the key issues related to the HLW performance assessment i... more From the Spanish point of view, one of the key issues related to the HLW performance assessment is knowing and predicting, or modelling, the behaviour of spent fuel under geological repository conditions. Taking into account this objective, several experiments have been performed in order to split and determine the influence of different variables on the final stability of the spent fuel matrix in the geological repository. This paper presents some of the leaching results obtained with spent fuel and chemical analogues (UO2, alpha doped – UO2, SIMFUEL,) their application to extrapolate the corrosion behaviour for a long period of time and compare with corresponding data obtained using models. This procedure allows pointing out some of the uncertainties whose minimization is necessary to improve the models useful for performance assessment studies.
MRS Proceedings, 2004
... simulation, the composition of the solution is identical to those that could be obtained diss... more ... simulation, the composition of the solution is identical to those that could be obtained dissolving SIMFUEL (SIMulated FUEL) [4] specimens which simulates a burnup of 50 MWd/kg U (ie, Ba, Sr, Mo, Pd, Ru, Rh, Y, Zr, La, Ce, Nd and U). Table I summarises the mole fraction ratio ...
Journal of Alloys and Compounds, 2007
The main objective of this paper is to study the role of groundwater radiolysis in the spent fuel... more The main objective of this paper is to study the role of groundwater radiolysis in the spent fuel matrix alteration process. In order to split the influence of each radiation field, the paper focuses on the ␣-radiation field effect. For this reason the system selected was U-Pu in a synthetic granitic-bentonitic groundwater (carbonate media) in order to simulate the environmental conditions of the Spanish repository scenario [ENRESA, Publicación Técnica ENRESA 03/99 ]. The experimental procedure used allows both the influence of the ␣-radiation field on the U secondary phase formed (and its solubility) and the Pu concentration in solution under simulated environmental conditions to be studied and makes it possible to determine whether any co-precipitation process takes place under these environmental conditions. Previous experimental evidence provided by Haschke et al. [J.M. Haschke, T.H. Allen, L.A. Morales, Science 287 285] pointed to a reaction cycle between Pu 0 and water vapor (at 250 • C) generating PuO 2+x (s) for the first time. Taking this work into account, the objective is to check whether this reaction mechanism will have any influence under the environmental conditions considered.
9th ASME International Conference on Radioactive Waste Management and Environmental Remediation: Volumes 1, 2, and 3, 2003
Radiolytic models have been usually considered useful tools for studying the behaviour of complex... more Radiolytic models have been usually considered useful tools for studying the behaviour of complex chemical systems under the presence of a radiation field. However, they still don&#x27;t have a wider acceptance due to limited availability of kinetic data, difficulty to handle heterogeneous ...
MRS Proceedings, 2006
ABSTRACT This paper focuses on how to extrapolate current knowledge of spent fuel matrix alterati... more ABSTRACT This paper focuses on how to extrapolate current knowledge of spent fuel matrix alteration processes from laboratory to repository conditions, i.e., the influence of changes in both the environmental conditions and the range of time scale considered. Therefore, a spent fuel matrix alteration model allowing the alteration rate evolution to be predicted as a function of both the host rock considered and evaluation time scale of interest is described.At present, the model assumes that alteration of the spent fuel will start when the groundwater reaches the solid surface and that only the radiolytic species of the groundwater (oxidants generated by α-radiation of spent fuel) will produce the surface oxidation process and subsequent matrix dissolution; O2, H2O2 and OH· are the species that react with UO2(s) for oxidation of the pellet surface. The dissolution process of the surface sites that are oxidized is modelled in two steps: first, a surface co-ordination of the oxidized layer with aqueous ligands and, second, detachment (dissolution) of the product species. Taking this mechanism into account, the model gives the evolution of the spent fuel matrix alteration rate over periods as long as 1,000,000 years.In this work the matrix alteration rate results obtained for two repository environments, granitic and argillaceous, will be presented. Furthermore, a sensitivity analysis study has been performed on the influence of the following variables: type of spent fuel considered, α-dose rate evolution, α-range in groundwater, carbonate and iron concentration in groundwater, H2 partial pressure, container time failure and specific surface area of the pellet.
To determine the concentration controlling solid phases and coprecipitation process for elements ... more To determine the concentration controlling solid phases and coprecipitation process for elements contained in spent nuclear fuel, SIMFUEL coprecipitation trials under simulated bentonitic-granitc groundwater were performed. These experiments were carried out under oxidizing conditions at pH values ranging from 5 to 10. In this work an effort to determine whether solubility of pure phases could predict the behaviour of each element or whether it would be necessary to consider the formation of mixed solid phases was made.