PhD Position – Investigation of the stability and corrosion behavior of uranium nitrides

Your Job:
Innovative nuclear reactor concepts are currently intensively discussed internationally.
For the operation of most of these concepts novel fuels are envisaged, in particular materials with a matrix of uranium nitride (UN) due to their good thermophysical properties. In addition to their suitability as nuclear fuel, the stability of the materials in contact with aqueous solutions, among other things, is of great interest for the safety assessment of a repository.

At IEK-6, such investigations are being carried out to maintain competence as part of the European collaborative project FREDMANS.
The work is carried out in close cooperation with European partners.

One focus is on the investigation of the oxidation behavior under conditions relevant for interim storage, as well as the conversion of the nitride matrix into an oxide matrix.

• Investigation of the oxidation of UN based materials
• Complete oxidation of the nitride matrix to an oxide matrix
• Influence of certain fission product types (Ln, PGM) on the oxidation of UN
• Influence of atmospheric composition on the oxidation of UN
• Development of thermodynamic and kinetic models to describe the oxidation of UN in collaboration with project partners
• Preparation of data and scientific interpretation of results
• Independent presentation of the results at scientific conferences and in scientific publications

Your Profile:
• Completed university studies (Master) in natural sciences, chemistry, physics, or related discipline
• Experience in the fields of radiochemistry, analytics, and materials science
• Practical experience with laboratory work, as well as willingness and ability to learn and develop these skills are essential
• Experience in handling radioactive materials is desirable
• Ability to work in an international multidisciplinary team
• Willingness to travel nationally and internationally on official business
• Strong motivation to complete the PhD within 3 years
• Very good command of written and spoken English

Last application date: 2023-05-31

A detailed description can be found HERE

PhD student in applied nuclear physics, nuclear safeguards for SMR

Duties

This project is devoted to research on non-proliferation and safeguards aspects related to the introduction and possibly deployment of SMR:s in Sweden. Of particular interest is accounting for and verification of the nuclear material, which means that the reactors themselves are central, but that also that other issues related to e.g. the transportation and storage of fuel could become relevant. In this context, potential challenges include geographically distributed and even transportable reactor systems, systems located at non-traditional sites, and nuclear materials and reactor operations that differ from current commercial large-scale light water reactors. Safeguards solutions need to be comprehensive, cost-efficient, robust, make efficient use of safeguards resources and be as non-intrusive as possible on plant operations. The main objective of this project is to provide safeguards concepts and solutions to ensure that safeguards requirements can be met during development, assessment and licensing of SMRs. The project will also research methods and equipment suitable for safeguards verification of the fuel cycle activities for modular reactor systems. Although this project focuses on the introduction of SMRs in Sweden, the research is highly relevant for the implementation of safeguards on an international level, through the International Atomic Energy Agency (IAEA) as well as on a regional and national level.

Research tasks include studies of selected SMR concepts to better understand safeguards considerations and challenges associated with all parts of the fuel cycle. This may include aspects related to national legislation, deployment scenarios, operation modes, logistic and storage considerations and fuel recycling. The objective is to better understand what implications the deployment of SMRs and or Advanced Modular Reactors could have on nuclear safeguards, from both a technical and non-technical perspective. This work could benefit from considering proliferation assessment studies, diversion pathway analysis or studies on material attractiveness. The research is furthermore expected to include analysis of (national) needs in terms of e.g. new facilities, new logistical solutions and new instruments/approaches/methods. This part of the project is related to the societal impacts of deployment of SMRs, and the work is foreseen to be done in collaboration with other partners and working groups in ANItA.

Another major part of this project is research on the characterization of material flows of fresh and irradiated fuels, and assessments related to future fuel use in the SMRs, as well as safeguards-relevant process materials streams. It is expected that the PhD student will model and simulate for instance used nuclear fuel as well as the detection of radiation from the fuel in order to draw conclusions about how to best verify the nuclear material. This research is expected to also include the use of machine learning methods for data analysis. Also this part of the project will be executed in collaboration and cooperation with other partners and working groups in ANItA.

Placement: Department of Physics and Astronomy

Type of employment: Full time , Temporary position

Pay: Fixed salary

Number of positions: 1

Working hours: 100 %

Town: Uppsala

County: Uppsala län

Country: Sweden

Union representative: ST/TCO tco@fackorg.uu.se
Seko Universitetsklubben seko@uadm.uu.se
Saco-rådet saco@uadm.uu.se

Number of reference: UFV-PA 2023/1069

Last application date: 2023-05-02

A detailed description can be found HERE

Detailed title of the PhD thesis:
Contributions to the design and performance evaluation of an actinide converter type molten
salt reactor

Description of the subject
Molten salt nuclear reactors (MSRs) have great potential in terms of safety and flexibility. These are reactors in which the fuel is dissolved in a mixture of molten salts (liquid), acting also as the coolant. The salt circulates in the fuel circuit through an area called the “core” where it is made critical by geometry, producing heat, which is extracted by passing through a heat exchanger, thus allowing the energy produced to be used, either in the form of heat (heat-generating role) or electricity (power-generating role). This type of reactor is characterized by its intrinsically core stable behavior, and its versatility (choice of the cycle, choice of neutron spectrum, choice of salt composition, etc.) and therefore the versatility of its applications (power reactor on a range from very small to very large power, burner of high activity and long-life waste by transmutation, etc.). As these qualities are sought after in the current nuclear context, it is attracting renewed interest in France, in Europe and in the world.

For about twenty years, the CNRS, through the MSFR (Molten Salt Fast Reactor) team of LPSC (Laboratoire de Physique Subatomique et de Cosmologie), has been studying this type of reactor in various forms, and in particular the so-called reference MSFR, a high-power breeder reactor operating in the Thorium cycle and with a fluoride salt. The SEN (Structure and Nuclear Energy) team of SUBATECH (Laboratoire de Physique SUBAtomique et TECHnologies Associées) joined this theme a few years ago with a particular interest in the aspects of neutronics and associated calculations of residual power.

Taking into account the renewed interest for this promising technology, new collaborations have been set up, and new studies are in progress, in particular, those around the MSR concepts of chloride salt actinide converter: among which the ARAMIS (Advanced Reactor for Actinides Management in Salt) reactor carried by the CEA and studied in the framework of the national ISAC (Innovative System for Actinides Conversion) project which began in the first half of 2022 and whose partners are: CEA, CNRS, EDF, FRAMATOME and ORANO. The ISAC project aims to study the capacity of a breakthrough technology, in this case the MSR, to reduce the inventory of actinides from the existing reactor fleet via the transmutation of minor actinides, by carrying out a sketch study (evaluation of design options, performances of the concept, operational and safety analysis) and by associating with it the first small-scale experiments on the main barriers of this technology: the chemistry of the salts, treatment/recycling, and the prevention of corrosion applied to the materials making up the primary circuit. Scenario studies will be associated in order to evaluate the final impact on the inventory and the type of waste to be stored according to different hypotheses.

The subject of the PhD thesis proposed here will contribute to the definition of the outline in collaboration with the different partners of the consortium, via the neutronic studies of the ARAMIS reactor. The thesis will focus on the calculation of the core and cycle performances, on the sensitivities to nuclear data, as well as on the study of the residual power. Other studies may be undertaken by the PhD student, depending on the progress of the thesis and of the ISAC project, particularly in connection with safety studies: core behavior in accident situations, participation in risk analysis in collaboration with EDF and Framatome. The thesis, which will be supported by the two laboratories LPSC and SUBATECH, will be carried out 50% in Nantes at SUBATECH and 50% in Grenoble at LPSC.

The neutronic studies will be performed with the SERPENT evolution code for core characterization taking into account the on-line fuel processing scheme for the defined concept. Developments of the SERPENT code, specific to the MSR technology (constraints on the reactivity and/or the fuelcomposition during evolution) are currently underway at the SUBATECH laboratory. The results of these studies will also be compared to those obtained with the REM code developed in Grenoble since more than 20 years and which is currently the reference evolution code for the MSR concepts. Sensitivity studies to nuclear data will be performed with the Coconust and Cocodrilo codes developed at SUBATECH and LPSC. A work on the needs for improvement of nuclear data related to residual power will be carried out in the framework of the thesis. The PhD student may also use the coupled multiphysics codes developed at LPSC for the calculation of normal and accidental transients of MSR, in particular the coupled 3D code TFM-OpenFOAM and the system code LiCore. Also, part of the studies could focus on the optimization of the fuel circuit of the ARAMIS concept, with the LPSC multicriteria
optimization code Songe.

In addition, the LPSC and SUBATECH laboratories are collaborating in the European projects SAMOSAFER (Simulation Models and Safety Assessment for Fluid-fuel Energy Reactors) and MIMOSA (MultI-recycling strategies of LWR SNF focusing on MOlten SAlt technology), and the PhD student will have the opportunity to present his/her work in these European frameworks and also to contribute to the working groups of these projects in relation to the PhD thesis subject.

Context of the work
The PhD student under CNRS contract will be based during the first half of the thesis at the SUBATECH laboratory in Nantes and during the second half at the LPSC laboratory in Grenoble.

The research work will be multidisciplinary, ranging from reactor physics, nuclear data and safety analysis.

The candidate must have a Master’s degree in nuclear or reactor physics or equivalent. He or she must:
– Have a good knowledge of reactor physics (neutronics, thermal-hydraulics, safety…)
– Have a good knowledge of the use of an evolving neutronic code, dealing with the coupling of Boltzmann (neutron transport) and Bateman (material evolution) equations
– Be able to work in a team in the context of a wide range of collaborations
– Be used to developing computer code, especially in Python and Java
– Ability to produce large amounts of data
– Fluency in scientific English, both spoken and written
– Basics in French and will to learn!
– Be rigorous: know how to report, and respect deadlines.

The position is foreseen to be fulfilled between March 2023 and October 2023.

Both students who are already graduated or are looking for a PhD for the new fall semester are invited to apply.

The application (CV, cover letter, reference letters, transcript of Master’s results) is to be sent first via email to

Axel Laureau (axel.laureau@cnrs.fr)

Elsa Merle (elsa.merle@lpsc.in2p3.fr)

Lydie Giot (giot@subatech.in2p3.fr).

A detailed description can be downloaded HERE (French first and English follows)

SCK CEN is welcoming PhD Applications until MARCH 23, 2023

Fields are diverse: radiochemistry, reactor engineering, nuclear technology, materials, radiation protection, waste & disposal, decommissioning, etc…

The list of available topics:

• A whole-body physiologically based pharmacokinetic model for personalized 161Tb-PRRT

  Research in Dosimetric Applications

  More details

• Application of Lemna-based technologies to remediate radioactively polluted water and investigation of valorisation potential of residual phases

  Biosphere Impact Studies

  More details

• Changing of the Guard: Managing safety and security interactions in a context of nuclear technological innovation

  Nuclear Science and Technology Studies

  More details

• Developing flexible matrices for transmutation targets

  Fuel Materials

  More details

• Development of a molten salt electrorefining process suited for the recycling of HALEU fuel production scraps

  Radiochemistry

  More details

• Development of a novel laser spectroscopy apparatus for high-precision studies of radioactive isotopes at ISOL@MYRRHA

  Physics and Target Research

  More details

• Development of organ-on-chip sensors to monitor cardiac tissue

  Radiobiology

  More details

• Evaluation of the corrosion rate and mechanism of metallic uranium (BR1 fuel) in highly alkaline and anaerobic conditions

  R&D Waste Packages

  More details

• First generation targets for the ISOL facility of MYRRHA – A Si/Ti target for Al and Mg isotopes

  Physics and Target Research

  More details

• In vivo and in silico assessment of circular RNAs as novel long-term biomarkers of radiation exposure for biodosimetry

  Radiobiology

  More details

• Innovative detector set-ups for the robust quantification of radiological data acquired with Unmanned Aerial Vehicles

  Crisis Management and Decision Support

  More details

• Neutronic experiments at VENUS-F in support of lead-cooled small modular reactor deployment

  Nuclear Systems Measurements

  More details

• Novel assays of ‘difficult-to-measure’ radionuclides in the context of a sustainable waste management

  Low-level Radioactivity Measurements

  More details

• Oxidation and corrosion mechanisms in actinide oxide systems

  Fuel Materials

  More details

• Personal online dosimetry of astronauts using computational methods

  Research in Dosimetric Applications

  More details

• Screening of airborne radioxenon measurements for Nuclear-Test-Ban Treaty verification

  Crisis Management and Decision Support

  More details

• Separation and purification of medical radioisotopes by solvent extraction in milliflow reactors

  Radiochemistry

  More details

• Shape controlled thorium dioxide precipitation routes

  Fuel Materials

  More details

• Super-resolved analysis of lamin-mediated DNA damage repair after high LET irradiation and its applicability to predictive modelling of individual radiation sensitivity in cancer patients

  Radiobiology

  More details

• Towards insights of formation, growth and degradation of thin oxide films on steels in liquid lead as applied for Lead-cooled Small Modular Reactors (SMRs)

  Reactor Research & Engineering

  More details

• Understanding the RNA regulatory interactome landscape of radiation response in glioblastoma.

  Radiobiology

  More details

University of Pisa (Unipi) is looking for strong and motivated PhD candidates from international Universities.

This year, Unipi offers over 300 PhD scholarships many of which will be in collaboration with or co-funded by companies. The PhD scholarship is for three years and no fees are requested by the University of Pisa for its PhD programs.

The proposed research topics of the PhD projects will be aligned with the most innovative research fields including green revolution and ecological transition, renewable energy, digital transition, circular economy, sustainable mobility, etc.

The University organizes transversal didactic activities every year, allowing to acquire competencies that go beyond the specialized notions of the individual PhD course. Moreover, abroad periods will be strongly encouraged for all PhD Students and further funds for travelling, accommodation, conference fees and other research budgets will be available.

On 20^th July 2022 a second call has been open and the deadline will be on 23^rd August at 1:00 p.m.

A third call will be open in September.

For all the information about the application, admission process etc., please visit the website https://dottorato2022.webhost1.unipi.it/en/home-english/.

More information is available at the website of the Doctoral studies of Politecnico di Milano (https://www.dottorato.polimi.it/?id=442&L=1)

and on the NRG website (http://www.nuclearenergy.polimi.it/4-industrial-phd-fellowships/).

The Reactor Engineering Division of the Jožef Stefan Institute (Ljubljana, Slovenia) is searching for PhD candidates for young researcher positions on the topics of computational fluid dynamics and structural mechanics.

Potential PhD research topics:

– Heat transfer for the forced-convection film boiling conditions

– Material damage under fluid-induced loads

– Flow boiling at high heat fluxes

– Simulations of turbulent stratified flows

The deadline for application is July 31, 2022.

More information on the potential research topics is here.

Call CLOSED

Background: JRC is developing/optimizing methods for the analysis of the safety performance of a repository, through the investigation of materials and radionuclides relevant to the safety of a repository, or for the radiotoxicity of ¹⁴C.
After an initial period in which the student will receive general instructions on the mission of the JRC and in particular the role of the EURATOM activities carried out on the Karlsruhe site in the field of nuclear fission, his/her research activity on carbon-14 concentration determination using SCAR will start.

Activities will be focused on the following main tasks:

• Analysis and optimization of the optical setup in terms of laser beam;
• Development, characterisation and optimisation of carbon extraction and oxidation systems.
• Experimental campaign on graphite samples with different activation levels. Those samples are real decommissioning ones and thus very relevant for the mission of the JRC.
• Investigation and characterization of other samples, such as activated reactor structural material, irradiated cladding and spent nuclear fuel.

Timeframe of the PhD research in the Unit

The duration of the PhD project will be three years. The PhD will spend approximately two years at JRC and 1 year in total at UniPi.

Expected outputs of the PhD research/thesis

The expected output of the PhD project will be:

• optimization of the optical setup in terms of laser beam– resonance cavity coupling and stability of its locking;
• optimization of the CO2 extraction procedure including the development of an automatic system to interface the carbon extraction system to the CO2 cryogenic trap;
• validation and (possibly) certification of techniques used for the investigation of materials and radionuclides relevant for the safety of a repository, or for the radiotoxicity of ¹⁴C for which there is no consolidated procedure in literature.

Expected results of the collaboration

The project will increase the analytical capabilities of both the HEI and JRC laboratories, lead to a strong improvement in the knowledge of tools and methods used/to use for the quantification of radiocarbon in waste materials from nuclear decommissioning.
The research work will positively impact on the activities dedicated to nuclear decommissioning at both JRC and DICI.
Globally the project will enhance the collaboration between the two Parties and might produce increased knowledge in analytical and experimental techniques for nuclear decommissioning with potential benefits for the entire European system.

Contact Person: professor Rosa Lo Frano rosa.lo.frano@unipi.it

The subject of the PhD thesis proposed here will contribute to the definition of the outline in collaboration with the different partners of the consortium, via the neutronic studies of the ARAMIS reactor. The thesis will focus on the calculation of the core and cycle performances, on the sensitivities to nuclear data, as well as on the study of the residual power. Other studies may be undertaken by the PhD student, depending on the progress of the thesis and of the ISAC project, particularly in connection with safety studies: core behavior in accident situations, participation in risk analysis in collaboration with EDF and Framatome. The thesis, which will be supported by the two laboratories LPSC and SUBATECH, will be carried out 50% in Nantes at SUBATECH and 50% in Grenoble at LPSC.

The full description can be found HERE

A collaboration team of the IFIC Valencia (Spain) and Subatech (France) is offering a PhD position under the topic “Study of exotic nuclei interesting for applied and fundamental nuclear physics with Total Absorption Gamma Spectroscopy (TAGS)”.

The collaboration has two proposals accepted at the the JYFL facility (Jyväskÿla-Finland) for the measurements of nuclei interesting for applied and fundamental physics.

One of these experiments should be done in 2022. The selected candidate will participate to the preparation of the detector, the experiment and to the following data analysis. This analysis will allow to compute the beta feeding distribution and to deduce the subsequent beta strength toward the daughter nucleus, for each studied nucleus.

The fellowship is funded by the SANDA European Project and the student will work in both IFIC and Subatech laboratories.

Applications should be send before 1st of June 2022. The PhD will start around September 2022.

The full description can be found HERE

Applications CLOSED

Sensitivities of neutron transport modes with Monte Carlo Methods

Despite being the reference neutron transport method, Monte Carlo used to be limited in its capacity to calculate sensitivities (relative change in output associated with a change in input, such as a cross-section), or adjoint-based outputs, such as kinetics parameters (effective delayed neutron fractions, etc.). This has completely changed with the very fast development of perturbation methods and generalization in most of the codes in the last decade [1]. This field is still growing and few researchers have focused on the question of the statistical convergence of those new objects when compared to the large bibliography that exists for other parameters, such as eigenvalues, in particular for problems with high dominance ratios, i.e. when the second eigenvalue is very close from the first one, the inverse of k_eff. Another very active field of research related to Monte Carlo is its use for the calculation of higher modes than the first eigenvalue or for other modes types. Many applications are based on the use of the modes of different formalisms, which are often “matrix filled” formalisms, i.e. formalisms that use matrices built from Monte Carlo tallies such as “Fission Matrices”. Kinetics calculations are historically based on spectral analysis and can now rely on Monte Carlo associated parameters for which sensitivities are also available [2]. 

The convergence of local variables such as local fluxes in Monte Carlo may be much slower than global ones, e.g. k_eff. The convergence of their sensitivities with the number of histories simulated is not well known and their actual convergence may be doubtful as it depends on « new » parameters of the Monte Carlo method used for the calculations of sensitivities such as the number of « latent » generations [3]. We expect that the convergence speed of the sensitivities of the modes would be faster, if they could be calculated.

The objective of this project is to work on the combination of the two dynamic fields discussed above and extend the sensitivity capacities of Serpent2 [4] for the calculation of the sensitivities of modes to different perturbations, such as nuclide densities or nuclear data, and to study the convergence speed of those new output parameters.

This PhD is part of the joint “NEEDS” project called SUDEC (Sensitivity Uncertainty comparison for Depletion Calculations) in which CNRS, CEA and IRSN work together to study the propagation of uncertainty in fuel burn-up calculations. Those fuel burn-up calculations rely on the calculation of reaction rates that can be considered as local variables that could be projected on an adequate mode base. The student will then contribute to the project by developing a key component of it and will benefit from the collective work and competencies of the partners.

Indicative timeline

Year 1

Tools discovery. Convergence tests of sensitivities of existing Serpent 2 outputs.

Preliminary set up of innovative mode calculation sensitivities.

Year 2

Development and tests of the performance of the sensitivities of the modes.

Research and set up of reduced models of coupling, with TH and/or depletion.

Year 3

End of developments.

In depths studies with the tools developed.
Manuscript and defence preparations.

PhD Director

Adrien Bidaud has 20 years of experience in the field of nuclear data uncertainty and sensitivities. Besides this research and the associated teaching activities, he also teaches and develops interdisciplinary research projects in long term energy prospective with energy economists. He is the co-chair of the Energy and Nuclear Engineering program of the Engineering school PHELMA of Grenoble Institute of Technology.

Laboratoire de Physique Subatomique et Cosmologie (http://lpsc.in2p3.fr)

The aim of the research at LPSC is to improve our knowledge about the most elementary particles and about the forces that govern their interactions. It helps to broaden our understanding of the universe, its structure and its evolution. These activities require the development of sophisticated, state-of-the-art instrumentation, a strong theoretical research activity as well as strong modelling competencies that support the experiments during the preparatory stages and during the data analysis.

The research also affects our everyday lives; for example, it enables to come up with innovative solutions in the field of nuclear power or cancer treatment and to train a new generation of researchers, teachers and engineers.

Candidates interested in teaching activities may be offered to contribute to the nuclear engineering curriculum of Grenoble Institute of Technologie (school PHELMA) and Université Grenoble Alpes, which include for instance electronics, mathematics, signal processing, nuclear instrumentation lab sessions, numerical methods, numerical methods projects etc.

Bibliography

[1] “Review of Early 21st-Century Monte Carlo Perturbation and Sensitivity Techniques for k- Eigenvalue Radiation Transport Calculations”, Brian Kiedrowski, Nuclear Science and Engineering, 2017, 185:3, 426-444, https://doi.org/10.1080/00295639.2017.1283153

[2] “Perturbation and sensitivity calculations for time eigenvalues using the Generalized Iterated Fission Probability, Alexis Jinaphanh, Andrea Zoia,

2019, Annals of Nuclear Energy, 133, 678-687, https://doi.org/10.1016/j.anucene.2019.06.062

[3] « Sensitivity Analysis and Its Convergence Through Monte Carlo Calculations for the UAM GEN-III Benchmark: Application to Power Distributions », Pamela Lopez and Adrien Bidaud, Proceedings of the Conference: Mathematics and Computational Methods Applied to Nuclear Science and Engineering, Raleigh, North Carolina, USA, April 2021

[4] “A collision history-based approach to sensitivity/perturbation calculations in the continuous energy Monte Carlo code SERPENT”, Manuele Aufiero et al., Annals of Nuclear Energy, 2015, https://doi.org/10.1016/j.anucene.2015.05.008.

Key-words: Neutronics, Nuclear Data sensitivity, Uncertainty analysis, Monte Carlo, Perturbation Theory.

Profile: Candidates must have a background in Reactor Physics, with a demonstrated knowledge of Neutron Transport. Some experience in Monte Carlo codes would be an asset.

Contact

Adrien Bidaud

LPSC – Groupe Physique des Réacteurs

Téléphone : 0476284045 email : bidaud@lpsc.in2p3.fr

THE PHD SHALL START IN: FALL 2022 – TO APPLY, CONTACT PROF. BIDAUD As  Soon As Possible

Studying in Grenoble

https://www.univ-grenoble-alpes.fr/education/why-choose-uga/why-choose-uga-713448.kjsp

https://international.univ-grenoble-alpes.fr/getting-organized/the-steps-of-your-stay/the-practical-guide-for-international-doctoral-students-795458.kjsp?RH=1611732328710