French TEAM MSFR LPSC Grenoble CNRSIN 2 P

French TEAM MSFR LPSC Grenoble (CNRS-IN 2 P 3, UGA, Grenoble INP), IPN Orsay (CNRSIN 2 P 3), LRC MANON (UPMC-CNRS / CEA-DEN-DM 2 S), SIMa. P Grenoble (CNRS, Grenoble INP, UGA), Subatech Nantes (CNRS-IN 2 P 3) Elsa MERLE – merle@lpsc. in 2 p 3. fr Atelier Bilan NEEDS 2018, Grenoble French Team MSFR

Concept of Molten Salt Fast Reactor (MSFR) ü Homogeneity of the fuel (no loading plan) ü Heat produced directly in the heat transfer fluid ü Possibility to reconfigure quickly and passively the geometry of the fuel (gravitational draining) ü Possibility to reprocess the fuel without stopping the reactor: – Safety: negative feedback coefficients – Sustainability: reduce irradiation damages in Neutronic Optimization of MSR the core – Deployment: good breeding of the fuel + (Gen 4 criteria) : reduced initial fissile inventory 2008: Definition of an innovative MSR concept based on a fast neutron spectrum, and called MSFR (Molten Salt Fast Reactor) by the GIF Policy Group Ø All feedback thermal coefficients negative Ø No solid material in the high flux area: reduction of the waste production of irradiated structural elements and less in core maintenance operations ØGood breeding of the fissile matter thanks to the fast neutron spectrum Ø Actinides burning improved thanks to the fast neutron spectrum Atelier Bilan NEEDS 2018, Grenoble 2 French Team MSFR

Description of the Molten Salt Fast Reactor (MSFR) system General characteristics: • • • Fuel = coolant Liquid circulating fuel Thermal yield: 45% Fast neutron spectrum Breeder reactor Atelier Bilan NEEDS 2018, Grenoble Three circuits: Fuel salt circuit French Team MSFR

Description of the Molten Salt Fast Reactor (MSFR) system General characteristics: • • • Liquid circulating fuel Fuel = coolant Thermal yield: 45% Fast neutron spectrum Breeder reactor Three circuits: Fuel salt circuit Intermediate circuit cs, i s y h l Thermal conversion cir rp nacuit o o t i t c a a + Draining / storage (re a n tanks. OL e n i s t r n e EV +o Processing ratio units tom y exp r b ra a a l u n l i E l o ( p C isci )– ean ) frame d p … i o s l t r l a he u A ri t Eu E e m f / t A : o ) I a s F its IF, , m itie ED G m n v , i ( i l g t i N e c s e S a e id R SFR th M y f l i l t R&D safety, d AREVA, I worldw en ma d n) S i / , o , i d ) y – s t r s n e t a t h i a s z c t t i i i e W ial ns) r G o t i s 3 t chem , Univers FAR proj ( u a r ind gu SFR S i O f o R M t n M N ’ s o A C e c p ( and S ‘referenc ceptable fy the ste ac ns: nti e e o i h d s t i r ne ve t+ Two pt + defi d concep e conc simplifie – R M S ( M. Allibert, M. Aufiero, M. Brovchenko, S. Delpech, V. Ghetta, D. Heuer, A. Laureau, E. Merle-Lucotte, “Chapter 7 - Molten Salt Fast Reactors”, Handbook of Generation IV Nuclear Reactors, Woodhead Publishing Series in Energy (2015) Atelier Bilan NEEDS 2018, Grenoble French Team MSFR

R&D Activities in Reactor Physics, Design and Safety Concepts considered: • Large scale MSFR: called “reference MSFR” and studied since around 10 years first at CNRS and now in European and national programs – Objective: defining a large power reactor to identify the challenges of such a concept + define the acceptable configurations • Small-size MSFR: called “S-MSFR” and studies foreseen in the coming years – Objective: see how to simplify the MSFR concept + define the steps and a R&D roadmap up to industrialization of such a reactor R&D Common thematics • Neutronics and reactor physics studies based on multiphysics (code ref = TFM-Open. FOAM coupling code) and evolutive Monte-Carlo calculations + a system code (basic principle simulator) under development • Experimental studies of the salt operation, salt control and processing • Safety analysis and evaluations using classical safety tools (FFMEA, MLD, Lo. D) + Resistance to proliferation preliminary analysis Atelier Bilan NEEDS 2018, Grenoble French Team MSFR

Fuel depletion calculations for the MSFR concept with the MURE and SERPENT codes - Contact: lydie. giot@subatech. in 2 p 3. fr Draining Tank of the MSFR / g heat Decay Heat (DH) for MSFR - Draining tank to empty the fuel out of the core if accident - Decay heat codes and associated libraries validated mostly for BWR/PWR reactors on U/Pu cycle => need also to be tested for MSFR concept - Volume of the fuel salt is small compared to the total volume of the draining tank - Moreover, some fission products are biased by the Pandemonium effect 1) New TAS measurements were included in JEFF 3. 3 => g radiation : important mode of energy transport, need to assess g heat deposited out the salt Example of g spectrum emited by the MSFR for a time step - Foreseen in 2018: Comparison on gamma transport between MURE and new 2018 SERPENT version (dedicated develp for g) April-August 2017: M 1 internship Bordeaux Univ. Atelier Bilan NEEDS 2018, Grenoble => estimate their impact on DH for MSFR 2) But also need to identify key FP as a function of time and study if they suffer from Pandemonium effect for a non PWR/BWR concept => List of potential key nuclei for MSFR to re-measure with Total Absorption Spectroscopy technique - Study on MSFR core for cylindrical configuration in Th/U cycle with the SERPENT code - Development of PYTHON macros associated to nuclear structure criteria to automatically go through decay data libraries Mai-August 2018: M 1 internship from INP-Phelma French Team MSFR

Proliferation Resistance & Physical Protection (PR&PP) methodology Atelier Bilan NEEDS 2018, Grenoble French Team MSFR

Choice of a threat: fissile diversion • Application of the Proliferation Resistance methodology on the threat “fissile diversion” for the whole MSFR system (reactor and processing units) Proliferation resistance Actor type Host state Actor capability Unlimited Objectives Weapon grade 233 U Strategy a few SQ (as given by IAEA) Concealed diversion & remote clandestine facility MSFR Pu contains 8% to 70% 238 Pu MSFR U contains 232 U (the reason why the Th-U cycle is said PR) → 2. 6 Me. V (suitable for nuclear explosive but detectable and detrimental to electronic devices and humans) Atelier Bilan NEEDS 2018, Grenoble French Team MSFR

Target identification: Inventory Th/U cycle Atelier Bilan NEEDS 2018, Grenoble French Team MSFR

Pathway identification: reactor versus processing units Physical Separation (in core? ) Ø Gas Processing Unit through bubbling extraction Ø Extract Kr, Xe, He and particles in suspension Chemical Separation (by batch) Ø Pyrochemical processing Unit Ø Located on-site, but outside the reactor vessel Dose rate for unprotected 40 l of fuel (µSv/h) after U extraction at 99% and partial Th extraction Atelier Bilan NEEDS 2018, Grenoble French Team MSFR

Estimation of measures – Preliminary conclusions Th-based reactors are not an absolute non-proliferent technology The non-proliferation barriers should be included in the design to raise as much as possible its non-proliferation level NEXT to come: Identify and analyze other PR threats related to the MSFR system Need for interactions with the PR&PP WG (GIF), with IAEA and other experts Atelier Bilan NEEDS 2018, Grenoble French Team MSFR

Etude de l’iode et de l’uranium dans les sels FLi. Na. K et Li. F-Th. F 4 Contact: sylvie. delpech@ipno. in 2 p 3. fr Etude de l’iode et de l’uranium dans les sels FLi. Na. K (500 et 650°C) et Li. F-Th. F 4 (650°C) Mise en évidence de comportements différents du fait de la fluoroacidité différente. - U(IV) et I(-I) plus stables dans FLi. Na. K Présence d’un oxyfluorure de thorium Th. OF 2 qui augmente le pouvoir oxydant de O 2 En présence de traces d’oxygène dans la phase gazeuse, on observe l’oxydation de I - et U(IV) qui s’accompagne de la formation de Th. OF 2 - U(IV) alors oxydé en UO 2 F 2 Atelier Bilan NEEDS 2018, Grenoble French Team MSFR

Etude de l’iode et de l’uranium dans les sels FLi. Na. K et Li. F-Th. F 4 Contact: sylvie. delpech@ipno. in 2 p 3. fr Etude de l’iode et de l’uranium dans les sels FLi. Na. K (500 et 650°C) et Li. F-Th. F 4 (650°C) En cours: • Etude du zirconium dans FLi. Na. K et Li. F-Th. F 4 • Mise au point de la synthèse de Th. F 4 • Comportement de plusieurs matériaux de structure (dont Si. C) en sel inactif et actif Membres permanents: 1 (S. Delpech) Post-doctorants: 1, 5 (G. Duran-Klie (sept. 2020) et D. Rodrigues (nov. 2018)) Master 2: 1 (Ivan Gao) Demande de bourse de thèse CSC pour Ivan Gao (réponse en mai) Atelier Bilan NEEDS 2018, Grenoble French Team MSFR

Couplage entre la thermohydraulique et la neutronique - Contacts: Stéphane Dellacherie, Erell Jamelot, Olivier Lafitte (LRC Manon) Nouveaux objectifs après obtention d’une solution modèle • Obtenu, avec données réalistes (sections efficaces tabulées issues d’un cas réel) dans un cas très simplifié 1 D stationnaire de couplage entre un problème de la neutronique et les équations de l’hydrodynamique couplée avec la thermique • Peut aussi être vu comme une méthode de tir pour un problème à paramètre keff - solution analytique donnée par une intégrale de Jacobi Travaux réalisés en 2017 • Analyse du schéma numérique couplant les deux problèmes : identification d’un critère de convergence très difficile à obtenir (une condition drastique sur la constante de couplage) • Prise en compte du cas 2 d : début de l’analyse • Ecriture du schéma numérique intrusif (ne couplant pas les schémas) Perspectives • Tester le schéma numérique pour le système couplé qui ne soit pas le couplage des schémas • Etudier le cas instationnaire pour faire la relation entre la valeur de keff et la stabilité du système couplé autour d’une solution nominale • Etudier la sensibilité aux incertitudes sur les données tabulées issues de la neutronique Atelier Bilan NEEDS 2018, Grenoble French Team MSFR

Framatome contribution on MSFR components design Contact: alain. gerber@framatome. com • Framatome contributed to preliminary assessments of main components design – 6 -month internship of Sophie Roussel in 2017, managed by Alain Gerber (component design team in Framatome advanced projects – GEN IV) – Potential solutions for main heat exchangers design have been studied • Potential current solution recommended by Framatome is PSHE (Plate Stamped Heat Exchanger) because of its capability to answer to several requirements better than other designs (as PCHE Printed Circuit Heat Exchanger, Tubular Heat Exchanger) – Reduced dimensions requests – Low pressure losses on both sides – Manufacturing capabilities (in particular concern of minimum material thickness) – Thermomechanical resistance. • Geometrical parameters have been optimized – Plate thickness – Plate dimension – Corrugation angles – Number of plates for the 3 rd dimension Alfa Laval figures Géométrie des plaques corruguées – GRETh (1999) – Solution currently discussed with partners Atelier Bilan NEEDS 2018, Grenoble Diffusion Limitée Framatome French Team MSFR

Framatome contribution on MSFR components design Contact: alain. gerber@framatome. com • Parametric studies have also been performed to get sensitivity to parameters : – intermediate fluid : temperatures level, nature of fluid – Plate : thickness, material • Fluids distribution of both fluids within the HX has also been investigated (in the PSHE configuration) – Recommendation: • • • “Z” configuration for primary fluid “U” Configuration for intermediate fluid Framatome also performed a review of primary pumps – Type Centrifugal or Helical or Mixed • • Fuel According to operating parameters, in particular pressure head and pressure losses (NPSH, cavitation) Highlight of the concerns on: pump position (above / below the HX) ; on the material issue especially for upper position (high temperatures, corrosion) ; leaktightness problems at shaft crossing ; • Other items investigated: intermediate fluid comparison, thermomechanical methodology for plate type HX • From now on Framatome will carry on these studies in the European frame (H 2020) Atelier Bilan NEEDS 2018, Grenoble Diffusion Limitée Framatome Intermediate French Team MSFR

Atelier Bilan NEEDS 2018, Grenoble French Team MSFR

French Team MSFR 2018 : 8 1 0 2 R F S M S D à E 8 E 1 N 0 r 2 e i Atel ébut juin Saclay / y D a s r O / y s s a M Atelier Bilan NEEDS 2018, Grenoble French Team MSFR

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Some Ph. D Thesis in France on MSR Gabriela DURAN, "Étude du comportement de l'uranium et de l'iode dans le mélange de fluorures fondus Li. F-Th. F 4 à 650°C", Ph. D Thesis, Université Paris Saclay, France (2017) Axel LAUREAU, "Développement de modèles neutroniques pour le couplage thermohydraulique du MSFR et le calcul de paramètres cinétiques effectifs", Ph. D Thesis, Grenoble Alpes University, France (2015) Davide RODRIGUES, "Solvatation du thorium par les fluorures en milieu sel fondu à haute température : application au procédé d'extraction réductrice pour le concept MSFR", Ph. D Thesis, Paris Sud University (2015) Mariya BROVCHENKO, "Etudes préliminaires de sûreté du réacteur à sels fondus MSFR", Ph. D Thesis, Grenoble Institute of Technology, France (2013) Xavier DOLIGEZ, “Influence du retraitement physico-chimique du sel combustible sur le comportement du MSFR et sur le dimensionnement de son unité de retraitement”, Ph. D Thesis, Grenoble Institute of Technology and EDF, France (2010) Elsa MERLE-LUCOTTE, “Le cycle Thorium en réacteurs à sels fondus peut-il être une solution au problème énergétique du XXIème siècle ? Le concept de TMSR-NM”, Habilitation à Diriger les Recherches, Grenoble INP, France (2008) Ludovic MATHIEU, “Cycle Thorium et Réacteurs à Sel Fondu: Exploration du champ des Paramètres et des Contraintes définissant le Thorium Molten Salt Reactor”, Ph. D Thesis, Grenoble Institute of Technology and EDF, France (2005) Jorgen FINNE, “Chimie des mélanges de sels fondus - Application à l'extraction réductrice d'actinides et de lanthanides par un métal liquide”, Ph. D Thesis, EDF-CEA-ENSCP, Paris, France (2005) Fabien PERDU, “Contributions aux études de sûreté pour des filières innovantes de réacteurs nucléaires”, Ph. D Thesis, Grenoble Institute of Technology, France (2003) Alexis NUTTIN, “Potentialités du concept de réacteur à sels fondus pour une production durable d’énergie nucléaire basée sur le cycle thorium en spectre épithermique”, Ph. D Thesis, Grenoble I University and EDF, France (2002) David LECARPENTIER, “Le concept AMSTER, aspects physiques et sûreté”, EDF and CNAM, Paris, France (2001) Available on http: //lpsc. in 2 p 3. fr/index. php/fr/38 -activites-scientifiques/physique-des-reacteurs -nucleaires/183 -msfr-bibliographie or ‘MSFR LPSC’ in google search Atelier Bilan NEEDS 2018, Grenoble French Team MSFR

Some documents mentioning the MSRF MSR-Safety White Paper, Gen 4 International Forum, SSC-MSR, review process (2018) M. Allibert, M. Aufiero, M. Brovchenko, S. Delpech, V. Ghetta, D. Heuer, A. Laureau, E. Merle-Lucotte, "Chapter 7 - Molten Salt Fast Reactors", Handbook of Generation IV Nuclear Reactors, Woodhead Publishing Series in Energy (2015) “Introduction of Thorium in the Nuclear Fuel Cycle”, Nuclear Science 2015, NEA website https: //www. oecd-nea. org/science/pubs/2015/7224 -thorium. pdf (2015) J. Serp, M. Allibert, O. Beneš, S. Delpech, O. Feynberg, V. Ghetta, D. Heuer, D. Holcomb, V. Ignatiev, J. L. Kloosterman, L. Luzzi, E. Merle-Lucotte, J. Uhlíř, R. Yoshioka, D. Zhimin, “The molten salt reactor (MSR) in generation IV: Overview and Perspectives”, Prog. Nucl. Energy, 1 -12 (2014) H. Boussier, S. Delpech, V. Ghetta, D. Heuer, D. E. Holcomb, V. Ignatiev, E. Merle-Lucotte, J. Serp, “The Molten Salt Reactor in Generation IV: Overview and Perspectives”, Proceedings of the Generation 4 International Forum Symposium, San Diego, USA (2012) CEA, Rapport sur la gestion durable des matières nucléaires - Tome 4 : Les autres filières à neutrons rapides de 4ème génération (2012) C. Renault, S. Delpech, E. Merle-Lucotte, R. Konings, M. Hron, V. Ignatiev, "The molten salt reactor: R&D status and perspectives in Europe", Poceedings of FISA 2009: 7 th European Commission conference on EURATOM research and training in reactor systems, Prague, Tchéquie (2009) See also the annex on Molten Salt Reactor Systems of the Strategic Research Agenda (published in January 2012) Agenda of the SNETP (Sustainable Nuclear Energy Technology Platform of Europe) here: http: //www. snetp. eu/www/snetp/. . . /sra_annex-MSRS. pdf Atelier Bilan NEEDS 2018, Grenoble 21 French Team MSFR

Blablatitre - Contact: olivier. doche@simap. grenoble-inp. fr Atelier Bilan NEEDS 2018, Grenoble French Team MSFR