The 17th EMUG was held by VTT in Espoo, Finland on 20th – 24th April, 2026.
Presentations:
Day 1: Monday, 20th of April – MACCS / MELCOR meeting
| Time | Title | Speaker | |||
| 9:00 – 9:30 | Registrations | ||||
| 9:30 – 9:35 | 17th EMUG - WELCOME | Mateusz MALICKI (PSI) | |||
| 9:35 – 9:40 | Safety and security advice to visitors | Tuomo SEVÓN (VTT) | |||
| 9:40 – 10:00 | Introduction VTT | Jani Halinen, Vice President Nuclear Energy (VTT) | |||
| Session 1: CSARP program & SNL introduction | |||||
| 10:00 – 10:30 | U.S. NRC Research Activities on Severe Accident Progression and Source Term Analysis | Shawn CAMPBELL (U.S. NRC) | |||
| 10:30 – 11:00 | Coffee Break | ||||
Session 2: SNL introduction | Chairperson: SEVÓN Tuomo (VTT) | ||||
| 11:00 – 12:00 | MELCOR Overview | David Luxat (SNL) | |||
| 12:00 – 12:30 | MELCOR Overview | David Luxat (SNL) | |||
| 12:30 – 13:45 | Lunch | ||||
| Session 3: MACCS | Chairperson: Elena YEGOROVA (U.S. NRC) | ||||
| 13:45 – 14:30 | MACCS: Overview and Recent Analysis Enhancements | AJ NOSEK (U.S. NRC) | |||
| 14:30 – 15:00 | MACCS–ADDAM Atmospheric Transport and Dispersion Benchmarking for Cold-Region Applications | Elena YEGOROVA (U.S. NRC) | |||
| 15:00 – 15:30 | Quantitative Evaluation of Potassium Iodide Implementation Strategies Using the MACCS Code | Mariah GARCIA (SNL) RECORDED | |||
| 15:30 – 16:00 | Coffee Break | ||||
| 16:00 – 16:30 | Newbuild plans in Finland: Related siting and EPZ studies by offsite dispersion and dose codes | Mikko Ilvonen (VTT) | |||
| 16:30 – 17:00 | A Methodology for using MACCS as a Tool for the Licensing of Non-Light Water Reactors | Etter Noah (NCSU/NRC) | |||
17:00 | Adjourn | ||||
Day 2: Tuesday, 21st of April – MELCOR meeting
| Time | Title | Speaker | |
| 8:30 – 9:00 | Registrations | ||
| Session 4: Users - SA codes experience | Chairperson: Michela Angelucci (UNIPI) | ||
| 9:00 – 9:30 | Use of the NUCLEA Database to Verify Thermodynamic Properties for Fuel Cladding | Jeremy Bittan (EDF) | |
| 9:30 – 10:00 | MELCOR-related Activities at Framatome | Matthias Braun (Framatome) | |
| 10:00 – 10:15 | Latest Experiences with MELCOR 2.2: An Overview of Applications, Issues and Challenges | Monica Garcia (CIEMAT) | |
| 10:15 – 10:30 | MELCOR research activities | Mateusz Malicki (PSI) | |
10:30 – 11:00 | Coffee Break + group photo | ||
| Session 5: Users – SA codes experience -ATF modeling | Chairperson: Michela Angelucci (UNIPI) | ||
| 11:00 – 11:30 | Insights into MELCOR modeling of QUENCH-15 bundle experiment and ATF coatings | Lukas Hamrik (BUT) | |
| 11:30 – 11:55 | Simulating the QUENCH-19 FeCrAl Bundle Test with MELCOR: Modeling Insights from KIT/UNIPI collaboration | Michela Angelucci (UNIPI) | |
| 11:55 – 12:20 | MELCOR 2.2 Analysis of the QUENCH-19 FeCrAl Bundle Test | Mauricio Cazado (KIT) | |
| 12:20 – 12:30 | discussion | ||
| 12:30 – 13:45 | Lunch | ||
| Session 6: Users – SA codes experience | Chairperson: Štěpán Foral (TES) | ||
| 13:45 – 14:15 | Liner modelling in CVTR | Karel Nečas (TES) | |
| 14:15 – 14:30 | RadSIM. An open-source python tool to evaluate in-containment doses during a Severe Accident for MELCOR. | Kevin Fernandez-Cosials (UPM) | |
| 14:30 – 14:50 | Approach to MELCOR sensitivity to initial conditions | Björn Engström (KTH) | |
| 15:00 – 15:30 | Coffee Break | ||
| 15:30 – 15:50 | Simplified neutron-kinetics model for severe accident recriticality assessment | Björn Engström (KTH) | |
| 15:50 – 16:10 | Machine Learning-Based Condensation Heat Transfer Coefficients for Containment Analysis in MELCOR-TNG | Rainer Kelk (PSI) | |
| 16:10 – 17:00 | Discussion / 18th EMUG announcement | ||
| 17:00 | Adjourn | ||
Day 3: Wednesday, 22nd of April – MELCOR meeting
| Time | Title | Speaker | |
| 8:30 – 9:00 | Registrations | ||
| Session 7: SNL Workshop – Ex-vessel and Lower Head Modeling | Chairperson: David Luxat (SNL) | ||
| 9:00 – 9:30 | Bradley Beeny (SNL) | ||
| 9:30 – 10:00 | Bradley Beeny (SNL) | ||
| 10:00 – 10:30 | Bradley Beeny (SNL) | ||
| 10:30 – 11:00 | Coffee Break | ||
| Session 7: SNL Workshop - TOPIC TBD | Chairperson: David Luxat (SNL) | ||
| 11:00 – 11:30 | Bradley Beeny (SNL) | ||
| 11:30 – 12:00 | Lower Head Modeling (1/2) | David Luxat (SNL) | |
| 12:00 – 12:30 | Lower Head Modeling (2/2) | David Luxat (SNL) | |
| 12:30 – 13:45 | Lunch | ||
| Session 8: SNL Workshop – Non-LWR Validation | Chairperson: David Luxat (SNL) | ||
| 13:45 – 14:30 | Non-LWR Validation (1/2) | Edward Duchnowski (SNL) | |
| 14:30 – 15:00 | Non-LWR Validation (2/2) | Edward Duchnowski (SNL) | |
| 15:00 – 15:30 | Coffee Break | ||
Session 9: SNL Workshop – MELCOR modernization | Chairperson: David Luxat (SNL) | ||
| 15:30 – 16:30 | Modernizing the MELCOR Experience (1/2): The VS Code Extension and Integrated Toolkit | Brandon De Luna (SNL) | |
| 16:30 – 17:00 | Modernizing the MELCOR Experience (2/2): AI‑Assisted Modeling and Intelligent Interfaces | Brandon De Luna (SNL) | |
| 17:00 | Adjourn | ||
Day 4: Thursday, 23rd of April – MELCOR meeting
| Time | Title | Speaker | ||||
8:30 – 9:00 | Registrations | |||||
| Session 10: Users – NPP simulations | Chairperson: Mateusz MALICKI (PSI) | |||||
| 9:00 – 9:30 | Lessons learned from past work with MELCOR at NUBIKI | Rebeka Molnár (NUBIKI) | ||||
| 9:30 – 10:00 | Modelling the Reactor Cavity Flooding in a VVER-440 Plant with Ice Condensers Using MELCOR 2.2 | Aapo Harju (Fortum) | ||||
| 10:00 – 10:30 | Impact of Safety Response Delays on IVMR Performance in VVER-440 Reactors | Barbora Lužná (SURO) | ||||
10:30 – 11:00 | Coffee Break | |||||
| Session 11: Users - SMR | Chairperson: Mateusz MALICKI (PSI) | |||||
| 11:00 – 11:20 | Lessons learned and challenges identified in modeling integral PWRs in the EU SASPAM-SA project | Tuomo Sevón (VTT) | ||||
| 11:20 – 11:40 | MELCOR analyses on LDR-lite | Marcello Principato (PSI) | ||||
| 11:40 – 12:00 | Sensitivity and Uncertainty Analyses of the LDR-Lite MELCOR Model | Sara Ojalehto (VTT) | ||||
12:00 – 13:15 | Lunch | |||||
| Session 12: Users - fusion | Chairperson: Matteo D’Onorio (UNIROMA) | |||||
| 13:15 – 13:45 | Tritium and Dust Transport Analyses in DEMO HCPB VVPSS | Mazzini Guido (CVR) | ||||
| 13:45 – 14:05 | Analysis of loss of cryostat vacuum in DEMO fusion reactor due to large ingress of He gas | Matjaž Leskovar (JSI) | ||||
| 14:05 – 14:25 | System-Level Multi-Fluid Modelling of the ITER Water-Cooled Lead-Lithium TBM with MELCOR for fusion | Matteo D’Onorio (UNIROMA) | ||||
| 14:25 – 14:45 | Deterministic Safety analyses of PIEs impacting DEMO Tokamak building | Danilo Dongiovanni (ENEA) | ||||
| 14:45 - 15:05 | Hydrogen isotopes transport analyses with MELCOR-TMAP. Verification & Validation against fusion-relevant applications | Tommaso Glingler (UNIROMA) | ||||
15:05 – 15:30 | Coffee Break | |||||
Session 13: SNL – fusion | Chairperson: Matteo D’Onorio (UNIROMA) | |||||
| 15:30 – 16:30 | Development of MELCOR for Fusion | David Luxat/ Bradley Beeny (SNL) | ||||
| 16:30 – 17:00 | NRC Fusion Activities | Ed Harvey (U.S.NRC) | ||||
| 17:00 | Adjourn | |||||