ML25227A109
| ML25227A109 | |
| Person / Time | |
|---|---|
| Issue date: | 08/15/2025 |
| From: | Raj Iyengar NRC/RES/DE |
| To: | Christian Araguas Office of Nuclear Regulatory Research |
| Chris Ulmer | |
| References | |
| Download: ML25227A109 (3) | |
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MEMORANDUM TO:
Christian Araguas, Director Division of Engineering Office of Nuclear Regulatory Research FROM:
Raj Iyengar, Branch Chief Reactor Engineering Branch Division of Engineering Office of Nuclear Regulatory Research
SUBJECT:
SUMMARY
OF JULY 29, 2025, PUBLIC MEETING FAVPRO USER GROUP MEETING On July 29, 2025, U.S. Nuclear Regulatory Commission (NRC) staff from the Office of Nuclear Regulatory Research (RES) held a public meeting to discuss the NRCs reactor pressure vessel (RPV) integrity code Fracture Analysis of Vessels - Probabilistic (FAVPRO). The meeting allowed NRC staff to discuss the latest updates to FAVPRO and provide an opportunity for users in attendance to share their experiences and feedback. Potential stakeholders including international regulatory, research, and commercial organizations attended. FAVPRO user group meetings allow for a more collaborative relationship with users through regular information exchanges.
Opening remarks were given by Christian Araguas, the Director of the Division of Engineering (DE) in RES. During the meeting, NRC staff and non-NRC users presented information about FAVPRO-related activities.
David Dijamco, NRC staff from the Vessels and Internals Branch in the Office of Nuclear Reactor Regulations Division of New and Renewed Licenses, presented regulatory perspectives on FAVPRO. He noted regulations that are based on precursor codes to FAVPRO and discussed how FAVPRO may be leveraged to potentially address upcoming regulatory needs.
Christopher Ulmer, NRC staff from the Reactor Engineering Branch (REB) in RES/DE, presented an overview of the recently released FAVPRO v1.1. He described FAVPRO and its development, and highlighted the key changes in v1.1 including the addition of the Master Curve toughness model and changes to embrittlement trend correlations.
Ellie Cohn, NRC staff from RES/DE/REB, gave a live demonstration of FAVPRO usage, including input file generation using the Excel tool, FAVPRO command line execution, and visualization of output using the provided Python visualization tool. She highlighted and emphasized the toughness model new to FAVPRO v1.1.
CONTACT:
Christopher Ulmer, RES/DE/REB 301-415-3883 August 15, 2025 Signed by Iyengar, Raj on 08/15/25
C. Araguas 2
Jens Arndt, from Gesellschaft für Anlagen-und Reaktorsicherheit (GRS) in Germany, presented a case study on a German RPV using FAVPRO. He benchmarked FAVPRO against results from the International Comparative Assessment Study of Pressurized Thermal-Shock (PTS) in RPVs.
Marko Kosonen, from Fortum in Finland, discussed the use of FAVPRO for safety analysis at the Loviisa nuclear power plant. He presented the specific design information and analysis needs for the VVER-440 pressurized water reactor, including consideration of an external cooling PTS event.
Steven Xu, from Kinectrics in Canada, outlined activities to introduce constraint effects on fracture toughness into FAVPRO. He discussed how a Master Curve based toughness adjustment method with an index temperature shift can be used to adjust for constraint conditions.
In addition to the presentations, the attendees discussed the usage of embrittlement trend correlations with the Master Curve model. Elliot Long from the Electric Power Research Institute (EPRI) provided information on the development of a method to account for embrittlement and referenced proposed American Society of Mechanical Engineers (ASME) Code Case N-914 and the associated EPRI Technical Basis Report, MRP-462, which are currently being revised to address comments. Additionally, there was a general discussion of the capabilities and limitations of FAVPRO, including suggestions for potential enhancement of FAVPRO such as modeling external cooling transients, unit selection in the output visualization tool, and additional options for embrittlement models.
The meeting was attended by over 40 people, with over 20 non-NRC attendees from various international organizations. The meeting announcement (ML25164A313) and presentation slides (ML25210A023) can be found on the Agencywide Documents Access and Management System (ADAMS).
Please direct any inquiries to Christopher Ulmer at 301-415-3883 or via email at Christopher.Ulmer@nrc.gov.
Enclosure:
Attendance List
C. Araguas 3
FAVPRO User Group Meeting Attendance List July 29, 2025 Name Organization Name Organization Amy Hull NRC Satoshi Miyashiro Central Research Institute of Electric Power Industry (CRIEPI)
Angie Buford NRC Markus Burkardt Dominion Engineering Carolyn Fairbanks NRC Emmanuel Ardillon
Électricité de France SA (EDF)
Chip Becker NRC Sofia Bouhrizi EDF Christopher Nellis NRC Elliot Long EPRI Christopher Ulmer NRC Nathan Palm EPRI Dan Widrevitz NRC Marko Kosonen Fortum David Rudland NRC Jarmo Harju Fortum Ellie Cohn NRC Bogdan Wasiluk Framatome Emma Haywood NRC Martin Kolar Framatome Eric Focht NRC Yifan Huang Framatome Jay Wallace NRC Jens Arndt GRS Jeff Poehler NRC Oriol Costa Jozef Stefan Institute John Tsao NRC Steven Xu Kinectrics Marlena Tatkowski NRC Koenraad Freytag Paul Scherrer Institute Mekonen Bayssie NRC Martin Berglund Vattenfall On Yee NRC Alexandria Scott Westinghouse Raj Iyengar NRC Anees Udyawar Westinghouse Robert Tregoning NRC Lukas Wilson Westinghouse Todd Hilsmeier NRC Ramesh Kumar
- Not provided Shah Malik
- Not provided
Memo ML25227A109 OFFICE RES/DE/REB RES/DE/CIB NAME CUlmer RIyengar DATE Aug 15, 2025 Aug 15, 2025