P2M Simulation Exercise on Past Fuel Melting Irradiation Experiments

Journal Article · 22 May 2023 · Nuclear Technology

DOI: https://doi.org/10.1080/00295450.2023.2194270 · OSTI ID:2204969

D’Ambrosi, V.  ^[1]; Sercombe, J. ^[1]; Bejaoui, S. ^[1]; Chaieb, A. ^[2]; Baurens, B. ^[3]; Largenton, R. ^[2]; Ambard, A. ^[2]; Boer, B. ^[4]; Bonny, G. ^[4]; Ševeček, M. ^[5]; Herranz, L. E. ^[6]; Marquez, F. Feria ^[6]; Inagaki, K. ^[7]; Ohta, H. ^[7]; Boldt, F. ^[8]; Sappl, J. ^[8]; Armstrong, R. ^[9]; Mohamad, A. ^[10]; Udagawa, Y. ^[10]; Cozzo, C. ^[11] ; Klouzal, J. ^[12]; Vitezslav, M. ^[12]; Corson, J. ^[13]; Peltonen, J. ^[14]

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1. CEA, DES, IRESNE, DEC, Saint-Paul-lez-Durance (France)
2. EDF R&D, Moret-sur-Loing (France)
3. EDF Direction Technique, Lyon (France)
4. Belgian Nuclear Research Centre (SCK·CEN), Mol (Belgium)
5. ALVEL, a.s., Prague (Czech Republic)
6. Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas (El CIEMAT), Madrid (Spain)
7. Central Research Institute of Electric Power Industry (CRIEPI), Tokyo (Japan)
8. Gesellschaft für Anlagen- und Reaktorsicherheit (GRS), Garching (Germany)
9. Idaho National Laboratory (INL), Idaho Falls, ID (United States)
10. Japan Atomic Energy Agency (JAEA), Tokai (Japan)
11. Paul Scherrer Institute (PSI), Villigen (Switzerland)
12. Nuclear Research Institute Řež (ÚJV Řež) (Czech Republic)
13. US Nuclear Regulatory Commission (NRC), Washington, DC (United States)
14. VTT Technical Research Centre of Finland, Espoo (Finland)

This paper presents the results of the Power To Melt and Maneuverability (P2M) Simulation Exercise on past fuel melting irradiation experiments, organized within the Organisation for Economic Co-operation and Development/Nuclear Energy Agency Framework for IrraDiation ExperimentS (FIDES) framework by the Core Group (CEA, EDF, and SCK·CEN) and open to all FIDES members. The exercise consisted in simulating two past power ramps where fuel melting was detected: (1) the xM3 staircase power transient [ramp terminal level (RTL) 70 kW·m^-1, average burnup 27 GWd·tU^-1], carried out in 2005 in the R2 reactor at Studsvik (Sweden), where the rodlet maintained its integrity, and (2) the HBC4 fast power transient (RTL 66 kW·m^-1, average burnup 48 GWd·tU^-1), carried out in 1987 in the BR2 reactor at SCK·CEN (Belgium), where the cladding failed during the experiment. The exercise was joined by 13 organizations from 9 countries using 11 different fuel performance codes. In this paper, the main results of the Simulation Exercise are presented and compared to available postirradiation examinations (PIE) or on-line measurements during the power ramps (fuel and clad diameters, rod elongation, pellet-clad gap, and fission gas release). Since the focus of the Simulation Exercise is on fuel melting assessment, determination of the boundary between melted/nonmelted fuel and the consequent definition of a melting radius from PIE are first discussed. During the HBC4 ramp, fuel melting was predicted by most of the codes despite differences in the melting models. Higher discrepancies were observed for the xM3 rod that can be attributed partly to power uncertainty and partly to the limited capability of the models to describe partial melting of the fuel during this ramp. Finally, possible code developments to improve simulation results are presented.

• Research Organization: Idaho National Laboratory (INL), Idaho Falls, ID (United States)
• Sponsoring Organization: USDOE
• Grant/Contract Number: AC07-05ID14517
• OSTI ID: 2204969
• Report Number(s): INL/JOU--23-74112-Rev000; {"","Journal ID: ISSN 0029-5450"}
• Journal Information: Nuclear Technology, Journal Name: Nuclear Technology Journal Issue: 2 Vol. 210; ISSN 0029-5450
• Publisher: Taylor & FrancisCopyright Statement
• Country of Publication: United States
• Language: English