ENTHALPY Final Summary Report FINAL SUMMARY REPORT EUROPEAN NUCLEAR THERMODYNAMIC DATABASE (ENTHALPY Project) CO ORDINATOR Dr A DE BREMAECKER Detached from SCK CEN Mol at IRSN/DRS/SEMAR CEN de Cadarac[.]
FINAL SUMMARY REPORT EUROPEAN NUCLEAR THERMODYNAMIC DATABASE (ENTHALPY Project) CO-ORDINATOR Dr A DE BREMAECKER Detached from SCK.CEN-Mol at IRSN/DRS/SEMAR CEN de Cadarache Bât 702 BP F - 13108 Saint-Paul-lez-Durance FRANCE Tel.: + 33 4225 3501 Fax: + 33 4225 2929 LIST OF PARTNERS IRSN/DRS, Cadarache, France CEA/DRN-Grenoble, France AEA-Technology,Harwell, United Kingdom THERMODATA, Grenoble, France FRAMATOME-ANP, Erlangen, Germany CEA-DRN-DTP, Cadarache, France EdF, Clamart, France AEKI-KFKI, Budapest, Hungary SKODA-UJP, Praha, Czech republic 10 SCK.CEN, Mol, Belgium 11 ULB, Université Libre de Bruxelles, Brussels, Belgium 12 UCL, Université Catholique de Louvain, Louvain-la-Neuve, Belgium CONTRACT N°: FI3S-CT1999-00001 EC Contribution: Partners Contribution: Starting Date: Euro 600 000 Euro 1.125.000 February 2000 Duration: 36 months FINAL SUMMARY REPORT "ENTHALPY" SAM(ENTHA)04-P019 January 2004 CONTENTS LIST OF ABBREVIATIONS AND SYMBOLS EXECUTIVE SUMMARY A OBJECTIVES AND SCOPE B WORK PROGRAMME C B.1 Assembling of the two existing databases & extension to new elements B.2 Separate Effect tests B.3 Improvement and validation of the database B.4 Evaluation of the consequences of the uncertainties B.5 Methodologies of coupling the database with SA codes B.6 Edition of the database WORK PERFORMED AND RESULTS C.1 State of the Art Report C.2 Assembling and extension of the database (WP 1) C.2.1 Introduction C.2.1.1 C.2.1.2 C.2.1.3 C.2.1.4 Selection of the elements to be included in NTD Modelling and merging procedure Selection of the systems to be included in NTD Critical assessment work C.2.2 Critical assessment and assembling (Task 1.1) C.2.3 Extension of the database (Task 1.2) C.2.3.1 C.2.3.2 C.2.3.3 Extension of NTDIV01 to Boron and Carbon and assembling of the final In-Vessel Nuclear Thermodynamic database : NTDIV02 Extension of NTDIV02 to concrete elements (Al, Ca, Mg, Si) Assembling of the final In/ex Vessel Nuclear Thermodynamic Database : NUCLEA Comparison calculations FINAL SUMMARY REPORT "ENTHALPY" SAM(ENTHA)04-P019 January 2004 C.2.4 State of the validation C.3 Separate Effect Tests (WP 2) C.3.1 Solidus – Liquidus temperatures for (U,Zr)O2+x (Task 2.1) C.3.1.1 C.3.1.2 C.3.2 Tliq in Zr-Fe-O & Zr – Cr – O systems (Task 2.2) C.3.2.1 C.3.2.2 C.3.3 Experimental Results Experimental Results Tliq in B2O3 + FeOx/ZrO2/UO2 systems (Task 2.3) C.3.3.1 C.3.3.2 C.3.3.2.1 C.3.3.2.2 C.3.3.2.3 Experimental Results Fe2O3-B2O3 system ZrO2-B2O3 system UO2-B2O3 system C.3.4 Tliq in UO2-ZrO2-FeOx-CaO-Al2O3-SiO2 systems (Task 2.4) C.3.5 Experimental study of (sub)system(s) in UO2-ZrO2-BaO-MoOx (Task 2.5) C.3.5.1 C.3.5.1.1 C.3.5.1.2 C.3.5.1.3 C.3.5.1.5 Direct determination of the phase diagram (Task 2.5.2.1) Experimental Results in the ternary system BaO-ZrO2-MoO3 Results in the quaternary system UO2-BaO-ZrO2-MoO3 in reducing atmosphere at 1480°C and 1600°C Results in the quaternary system UO2-BaO-ZrO2-MoO3 in oxidising atmosphere at 1600°C Conclusion C.3.5.2 C.3.5.2.1 C.3.5.2.2 Release in thermal gradient (Task 2.5.2.3) Experimental results C.3.5.3 Review of the U-Zr-Mo-Ba-O system including in irradiated fuel pins (Task 2.5.2.4) Solid solubility and precipitation of FP Molybdenum Solid solubility and precipitation of FP Baryum and Zirconium Post-irradiation observations Review of equilibria established at the Mo/MoOé equilibrium Conclusions C.3.5.1.4 C.3.5.3.1 C.3.5.3.2 C.3.5.3.3 C.3.5.3.4 C.3.5.3.5 FINAL SUMMARY REPORT "ENTHALPY" SAM(ENTHA)04-P019 January 2004 C.4 Validation and Improvement of the database (WP 3) C.4.1 Validation based on fuel experiments and empirical models (Task 3.1) C.4.2 Validation based on experiments (task 3.2) C.4.3 Validation based on VULCANO/CEA and COMETA/NRI experiments (Task 3.3) C.4.3.1 C.4.3.2 C.4.3.3 C.4.4 Improvement by literature review (task 3.4) C.4.4.1 C.4.4.2 C.4.5 VULCANO VE-U3 experiment VULCANO VE-U7 COMETA / NRI test Boiling points and vapour pressures of the elements Thermodynamic properties of UxOy gaseous species Validation based on Tliq and Tsol measurements in UO2+x-ZrO2 (AEA-T) and Fe-Zr-O (SKODA), and global experiments (VERCORS, Hofmann) (Task 3.5) C.4.5.1 C.4.5.2 C.4.5.3 C.4.5.4 UO2+x-ZrO liquidus and solidus measurements Fe-Zr-O liquidus and solidus measurements Fission Products release (Vercors tests) Corium pool stratification involving Fe-O-U-Zr (+ Cr, Ni) C.5 Influence of uncertainties C.6 Coupling methodologies to SA codes C.6.1 Coupling methodology of thermodynamic databases to SA codes (CROCO and ICARE/CATHARE) (Task 5.1) C.6.1.1 C.6.1.2 C.6.1.3 C.6.1.4 C.6.1.5 C.6.2 Tabulation of the phase diagram Interface with the thermochemical code Generation of the library, research and interpolation in the library Applications Time consuming and coupling aspects Recalculation of TMI2 with MAAP4 and the database (Task 5.2) C.6.2.1 C.6.2.2 C.6.2.3 Thermo-chemistry of the U-Zr-O domain Recalculation of the U-Zr-O diagram using the NUCLEA database Recalculation of TMI-2 using the new Tliq and Tsol C.6.3 Simplification of the database and/or of the equilibrium code and adaptation to SA codes (Task 5.3) C.7 Edition of the NUCLEA database FINAL SUMMARY REPORT "ENTHALPY" SAM(ENTHA)04-P019 January 2004 CONCLUSION REFERENCES TABLES FIGURES LIST OF ABBREVIATIONS & SYMBOLS CIT Corium Interactions and Thermochemistry COLOSS Core Loss DTA Differential Thermal Analysis EDX Energy Dispersive Microanalysis EPMA Electron Probe Micro Analysis FP Fission Product ICP Inductively Coupled Plasma LOCA Loss of Coolant Accident MDB Material Data Bank ( module of the ASTEC System Code) MCCI Molten Corium-Concrete Interaction NTD Nuclear Thermodynamic Database SA Severe Accident SEM Scanning Electron Microscopy SGTE Scientific Group Thermodata Europe TDBCR-IV Thermodynamic Data Base Corium - In Vessel THMO Thermo-chemical Modeling and data TMI-2 Three Mile Island Unit VPA Visual Polythermal Analysis XRD X-Ray Diffraction FINAL SUMMARY REPORT "ENTHALPY" SAM(ENTHA)04-P019 January 2004 EXECUTIVE SUMMARY ENTHALPY is a shared-cost action where 11 partners from countries succeeded to pro- duce one unique well validated thermodynamic database for in- & ex-vessel applications The first step was the critical assessment and merging of the two thermodynamic databases (THERMODATA/Grenoble and AEA-Technology/Harwell) in one database called "NTDiv" (for Nuclear Thermodynamic Database in-vessel) The second step was the extension of the database to Boron and Carbon, leading to the edition of the NTDiv0201 version (14 elements) In a third step, four ex-vessel elements and four new oxides components were added All together, the final database is based on 20 elements : O-U-Zr-Ag-In-Fe-Cr-Ni-Ba-La-Ru-Sr-B-C-Al-Ca-Mg-Si + Ar-H and includes in particular the 15 oxides system : UO2-ZrO2-FeO-Fe2O3-Cr2O3-NiO-In2O3-BaO-La2O3-SrO-B2O3-Al2O3-CaO-MgO-SiO2 In view of the extension to Boron, AEKI determined experimentally new phase diagrams namely ZrO2-FeOx, ZrO2-B2O3 and B2O3 – UO2 About the open question of the solubility of zirconia in Zr-Fe, SKODA tests on Tliq and Tsol in the corner of low oxygen in the Zr-Fe-O system confirmed the large solubility The influence of the hyperstoichiometry of UO2 on Tliq and Tsol of typical corium (U,Zr)O2 was tested by AEA-T and the results confirmed the model used in the database The direct construction of the complex phase diagram U-Zr-Ba-Mo-O was made in different atmospheres (reducing conditions, and in air) as an exploratory research and showed that in rather oxidizing atmospheres, the stability of the Ba zirconates decreases in favour of Ba molybdates or scheelite (BaMoO4) This was confirmed by tests in thermal gradients at UCL and by PIE at SCK.CEN on irradiated fuel pins at high burn-up Tliq of 10 ex-vessel mixtures (sub-systems in UO2-ZrO2-FeOx-CaO-Al2O3-SiO2) measured by different techniques, confirmed or validated points of the ex-vessel database The database was further improved by THERMODATA The thermodynamic properties of 11 gaseous elements and of the UxOy species were specially revisited and reassessed The database was validated by pre- and post-calculations of experimental tasks, and by (semi)global tests : FP release (VERCORS tests), in-vessel corium pool stratification (SASCHA), and ex-vessel corium spreading (VULCANO) The influence of uncertainties on the corium physical properties was studied on the point of view of the variability of key properties from different versions of the database A strategy was developed by IRSN to couple the database to severe accident codes, through tabulation of the phase diagram, generation of a library by GEMINI2 and interpolation This was proven to be efficient for the elements system U-Zr-Fe-O A reactor calculation (TMI2) on the new subsystem U-Zr-O did by EdF with MAAP4 concluded that the calculation must be enlarged to a subsystem including at least iron The “NUCLEA” database, edited by Thermodata is now commercially available FINAL SUMMARY REPORT "ENTHALPY" SAM(ENTHA)04-P019 January 2004 A OBJECTIVES and SCOPE For the prevention, mitigation and management of severe accidents, many problems related to core melt have to be solved : fuel degradation, melting and relocation, convection in the core melt(s), coolability of the core melt(s), fission product release, hydrogen production, ex-vessel spreading of the core melt(s), etc To solve these problems such properties like thermal conductivity, heat capacity, density, viscosity, evaporation or sublimation of melts, the solidification behavior, the tendency to trap or to release the fission products, the stratification of melts, must be known However most of these properties are delicate to measure directly at high temperature and/or in the radioactive environment produced by the fission products Therefore some of them must be derived by calculations from the physical-chemical description of the melt : number of phases, phase compositions, proportions of solids and liquids and their respective oxidation state, miscibility of the liquids, solubility of one phase in another, etc This information are given by the phase diagrams of the materials in presence The phase diagrams can be experimentally determined in specific tests, or they can be constructed by calculations made on the basis of measurements of the Gibbs energies, binary or ternary interaction parameters, and models (the « associated » model or the « ionic » model) and in a second step validated by application to global tests Results of the “CIT” & “THMO” projects (4th R&D-FW Program) were previously obtained in this field but had to be confirmed and broadly enlarged In this frame, the general objective of “ENTHALPY” was to obtain one unique European commonly agreed thermodynamic database for in- and ex-vessel applications, well validated and with methodologies able to couple the database to Severe Accident codes used by end-users like utilities, safety Authorities and nuclear designers B WORK PROGRAMME The work programme was organised in Work Packages (WP) described below (see also Table I) Each WP contains one or more tasks Each task was performed by one partner At the mid-term assessment meeting it was agreed to merge two tasks (formerly named "Task 2.2.3 : Tliq and Tsol in UO2-ZrO2-FeO-Cr2O3" and "Task 2.4 : UO2-ZrO2/(CaO+Al2O3) both performed by FRAMATOME ANP) , in one task named "Task 2.4 : Tliq in UO2-ZrO2-FeOxCaO-Al2O3-SiO2" entirely performed by FRAMATOME ANP, and task 2.2.2 and 3.2 in order to re-in force the effort on the key Zr-Fe-O system (Task 2.2.1) B.1 : Assembling of the two existing databases and extension to new elements (WP1) The two existing nuclear thermodynamic databases had to be merged in one database, with agreed thermodynamic models, covering the entire field from metal to oxide (borides/carbides) for a complex multi-component chemical system) FINAL SUMMARY REPORT "ENTHALPY" SAM(ENTHA)04-P019 January 2004 B.2 : Separate Effect Tests (WP2) Tests were performed in the key U-Zr-Fe-O (sub)systems and in other in- & ex-vessel subsystems (B2O3, B, Pu, PuO2, Mo ; Si, SiO2, Ca, CaO, Al2O3 etc) including FPs with high decay heat (Ba), in such a way that thermodynamic results (Tliq, Tsol, enthalpies, solubility limits) were obtained B.3 : Improvement and validation of the database (WP 3) This WP included the improvement and validation of the new database against global tests B.4 : Evaluation of the consequences of the uncertainties (WP 4) This WP envisaged the consequences of uncertainties on Corium physical properties B.5 : Methodologies of coupling the database with SA codes (WP 5) Methodologies were developed to effectively couple the database to severe accidents codes, and a recalculation of TMI2 with MAAP4 was made B.6 : Edition of the database (WP 6) This WP included the documentation, the discussion of an agreement on property rights and the diffusion of the database C WORK PERFORMED AND RESULTS C.1 State of the Art Report Before the start of ENTHALPY, THERMODATA, had developed the specific TDBCR thermodynamic database for nuclear safety applications It covered the entire field from metal to oxide domains in the following multi-component system : O-U-Zr-Fe-Cr-Ni-Ag-In-Ba-La-Ru-Sr-Al-Ca-Mg-Si + Ar-H and was able to be used for both in- or ex- Vessel applications AEA-T, through external collaborations, had developed a large oxide thermodynamic database, more oriented to Ex- Vessel applications, based on the following oxides : UO2-ZrO2-Fe2O3-BaO-La2O3-CeO2-Ce2O3-SrO-Al2O3-CaO-MgO-SiO2 Specific databases were also available (metal domain : U-Fe-Zr-Si-Ba-Sr-Ce-La-Ru-Te where Cerium was introduced for simulating Plutonium ; metal oxide field : U-O-Zr-Si) These two databases needed to be improved, specially in some key-subsystems (U-O, Zr-FeO for instance), to be extended to the absorber elements Boron and Carbon, and to be more largely validated The coupling of the database to SA codes was also weak Faster and more efficient methodologies of coupling were needed FINAL SUMMARY REPORT "ENTHALPY" SAM(ENTHA)04-P019 January 2004 C.2 Assembling of the database (WP 1) C.2.1 Introduction The development of a common database, based on the CALPHAD method, involved the definition of a precise methodology to assemble the data coming from the two sources An inventory of the content of the two databases was made and discussed Important decisions were taken concerning : - the elements to be included in the database, - the subsystems (binary, quasi-binary, ternary, quasi-ternary) to be critically assessed, - the standards to be adopted (thermodynamic data for unary systems, thermodynamic models) C.2.1.1 Selection of the elements to be included in NTD The following elements (18 + 2) were selected for being included in NTD : O-U-Zr-Fe-Cr-Ni-Ag-In-Ba-La-Ru-Sr-B-C-Al-Ca-Mg-Si + Ar-H These are the elements of the main materials involved in a severe accident : UO2 (fuel), Zr (zircaloy cladding), Fe-Cr-Ni (steel of the structural components), SIC and B4C (control rods), Ba-La-Ru-Sr (selected fission products), Al2O3-CaO-MgO-SiO2 (concrete), H2O (water), O (air, oxides) Argon was added only as a neutral species in the gas phase Hydrogen has not been taken into account in non stoichiometric solution phases As any metallic element can be oxidised at a given oxygen potential, the multicomponent (15) oxide system is also a subset of the whole database : UO2-ZrO2-FeO-Fe2O3-Cr2O3-NiO-In2O3-BaO-La2O3-SrO-B2O3-Al2O3-CaO-MgO-SiO2 (AgO and RuO2 are two oxides decomposed before melting.) C.2.1.2 Modelling and merging procedure The development of a thermodynamic database for multi-component system is based on the critical assessment of the most relevant sub-systems (binary, ternary, …) i.e the compilation of the available experimental data (phase diagram and thermodynamic properties), the inventory of all possible phases, the choice of suitable thermodynamic models for each phase, and finally, the optimisation of Gibbs energy parameters The whole subset of Gibbs energy parameters for a given sub-system is also called a thermodynamic database, and allows the user to re-calculate the whole phase diagram The list of all possible condensed solution phases was commonly built, and for each identified solution phase, a thermodynamic model was proposed and agreed Common standards were also adopted for unary systems (pure elements and oxides) C.2.1.3 Selection of the systems to be included in NTD The thermodynamic modelling of the selected multi-component system was based on the critical assessment of all the possible binary (153) or pseudo-binary (105) systems Only the most important ternary or pseudo-ternary systems (metal, metal-oxygen, oxide) were critically assessed, due to the very high number of possible ternary systems C.2.1.4 Critical assessment work For each system, the following points were carefully treated : - The list of bibliographic references has been up-dated - The set of experimental data was re-checked FINAL SUMMARY REPORT "ENTHALPY" SAM(ENTHA)04-P019 January 2004 - The new experimental information was included in the optimisation process - The heat capacity of stoichiometric compounds was estimated, in order to produce fundamental values for substances (H°298.15 K, S° 298.15 K, Cp(T), G - HSER) - A new optimisation was performed in order to correct any evident disagreement between calculated and experimental values - The calculated and experimental temperatures and compositions of the invariant reactions or specific points have been compared in numeric tables - The phase diagram and specific thermodynamic properties were calculated and compared to experimental values taken from literature on figures - A new set of optimised Gibbs energy parameters has been produced and included in the new nuclear thermodynamic databases (NTDIV01, NTDIV02, NTD) - The lack of experimental knowledge was identified - Finally, a new quality criterion was proposed for each sub-system C.2.2 Critical assessment and assembling (Task 1.1) (Assembling of a first partial In-Vessel Nuclear Thermodynamic Database : NTDIV01) A partial thermodynamic database for In-Vessel applications, named NTDIV01, was first assembled, based on 14 elements : O-U-Zr-Ag-In-Fe-Cr-Ni-Ba-La-Ru-Sr + Ar-H It included in particular the 10 oxides system : UO2-ZrO2-FeO-Fe2O3-Cr2O3-NiO-In2O3-BaO-La2O3-SrO Then the Gibbs energy parameters of all possible phases were assembled by using the thermodynamic modelling of the Gibbs energy from the assessed binary and ternary subsystems in the GEMINI2 code format (Ref [1] & [2]) NTDIV01 is composed of three different files : The Gibbs energy parameters of the « lattice-stabilities », i.e the Gibbs energy difference of each element of the multi-component system in a given structure and a reference one (SER = Standard Element Reference) The Gibbs energy parameters of all possible substances referred to any chosen reference state, provided that it is present in the first file The Gibbs energy parameters of solution phases C.2.3 Extension of the Database (Task 1.2) C.2.3.1 Extension of NTDIV01 to Boron and Carbon and Assembling of the final InVessel Nuclear Thermodynamic Database : NTDIV02 NTDIV01 was extended firstly to two new elements B and C and one oxide B2O3 to the database After assembling, the final thermodynamic database for In-Vessel applications, named NTDIV02,was thus based on 16 elements (O-U-Zr-Ag-In-Fe-Cr-Ni-Ba-La-Ru-Sr-B-C + Ar-H), and included in particular the following 11 oxides system (UO2-ZrO2-FeO-Fe2O3Cr2O3-NiO-In2O3-BaO-La2O3-SrO-B2O3) This extension involved the thermodynamic modelling of new systems Some of them were already accepted : B-Fe, B-Ni, C-Cr, C-Fe, C-Ni, C-Zr, C-Cr-Fe, C-Cr-Ni, C-Fe-Ni, CrFe-Ni, C-Cr-Fe-Ni Other ones, as B-Cr, B-O, B-U, C-U, B-Zr, B-C, B-C-Fe, B-C-U, B-C-Zr, B-Fe-U, B-Fe-Zr, C-O-U, C-O-Zr, C-U-Zr, C-O-U-Zr, were modelled by THERMODATA FINAL SUMMARY REPORT "ENTHALPY" SAM(ENTHA)04-P019 January 2004 10