ML23352A274
| ML23352A274 | |
| Person / Time | |
|---|---|
| Issue date: | 01/03/2024 |
| From: | King D Licensing Processes Branch |
| To: | Gerond George Licensing Processes Branch |
| References | |
| Download: ML23352A274 (1) | |
Text
January 3, 2024 MEMORANDUM TO:
Gerond A. George, Chief Licensing Projects Branch Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation FROM:
Daniel G. King, ATF Project Manager
/RA/
Licensing Projects Branch Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation
SUBJECT:
SUMMARY
OF THE DECEMBER 4 TO 7, 2023, PHENOMENON IDENTIFICATION AND RANKING TABLE PANEL DISCUSSION ON HIGH BURNUP FUEL DISPERSAL AND ITS CONSEQUENCES PUBLIC MEETING From December 4, 2023, to December 7, 2023, the U.S. Nuclear Regulatory Commission (NRC) staff and Information System Laboratories, Inc. (ISL) held a hybrid phenomenon identification and ranking table (PIRT) panel public meeting with representatives from the nuclear industry to discuss high burnup uranium dioxide fuel fragmentation, relocation, and dispersal. The purpose of the meeting was to provide an opportunity for the PIRT panel to ask questions of the NRC staff or make comments about issues related to the scope of the PIRT. The meeting notice can be found in the Agencywide Documents and Management System (ADAMS) under Accession No. ML23338A042.
Key observations from the meeting discussions:
The PIRT panelists agreed that core coolability is the main concern associated with fuel dispersal during a postulated loss-of-coolant accident (LOCA).
o The panelists stated that fuel dispersal is not likely to lead to recriticality during the postulated accident and that this could be verified utilizing existing computational methods and bounding assumptions.
o The NRC staff noted that the impact of fuel dispersal on fission product releases during a LOCA has been evaluated, in Regulatory Guide 1.183, Revision 1, Alternative Radiological Source Terms for Evaluating Design Basis Accidents at Nuclear Power Reactors (ADAMS Accession No. ML23082A305).
The impacts of fuel dispersal are highly dependent on total mass and size distribution of particles that could be released from fuel rods that burst during a LOCA. The particle size distribution is in turn influenced by a range of parameters, including the fuel burnup and the temperature reached during the postulated accident.
Contact:
Daniel G. King James Corson 301-415-1233 301-415-2458
Spacer grids may influence fuel dispersal and its consequences. Spacer grids may reduce the mass that could be dispersed because they are expected to reduce cladding strain near grids. However, spacer grids may also influence the transport of fuel particles in the core.
The knowledge level of phenomena related to the transport of fuel through the reactor coolant system is low. Bounding approaches may be useful to assess the potential consequences of fuel dispersal on core coolability, but more work is needed to develop and validate more realistic models.
The following schedule going forward was agree upon by the NRC staff, ISL, and panelists.
Note that the panelists will be performing their own rankings individually with a consolidated table being constructed in January 2024. The second PIRT panel meeting will take place in January 2024, at which time the need for additional meetings will be assessed.
January 2024 Panel members complete ranking remaining phenomena, individually.
January 2024 Second panel meeting will be held, to discuss and consolidate rankings.
February 2024 ISL distribute draft report capturing outcomes to NRC staff and panelists for comment.
February 2024 ISL submits draft final report to NRC for publication.
No comments were received during the public comment portion of the meeting. Additional information on Accident Tolerant Fuel PIRTs can be found at:
https://www.nrc.gov/reactors/power/atf/pirt.html No regulatory decisions were made in the meeting.
Enclosure:
List of Attendees
Enclosure List of Attendees PHENOMENON IDENTIFICATION AND RANKING TABLE PANEL DISCUSSION ON HIGH BURNUP FUEL DISPERSAL AND ITS CONSEQUENCES PUBLIC MEETING December 4 to 7, 2023 U.S. Nuclear Regulatory Commission (NRC)
First Name Last Name Steve Bajorek Matthew Bernard Andrew Bielen Kristy Bucholtz Shawn Campbell Alice Chung James Corson Elijah Dickson Joseph Donoghue Richard Fu Kevin Heller Lois James Daniel King Scott Krepel Michael Mahoney Don Marksberry Sandra McClure Joseph Messina Donald Palmrose Mathew Panicker Carla Roque-Cruz Michael Salay Ashley Smith Joseph Staudenmeier Chris Van Wert Josh Whitman Zhe Yuan Non-NRC First Name Last Name Organization (if provided)
Birol Aktas TerraPower Colleen Armoruso Information System Laboratories (ISL)
Kevin Barber Westinghouse Electric Company (Westinghouse)
Carl Beyer Pacific Northwest National Laboratory Francis Bolger Electric Power Research Institute (EPRI)
Michael Bradbury ISL Nathan Capps Oak Ridge National Laboratory Thomas Eichenberg Tennessee Valley Authority Jeffrey Kobelak Westinghouse Dave Kropaczek Veracity Nuclear Samuel Lafountain Scott Luchau Wade Marcum Oregon State University Brian Mount Dominion Energy Natalie Morgan Kurshad Muftuoglu EPRI Vesselin Palazov ISL Baris Sarikaya Constellation Nuclear Jay Spore Los Alamos National Laboratory Nadejda Todorova Constellation Nuclear
Gretar Tryggvason Johns Hopkins University Michael Tudisco Constellation Nuclear W.
Wiesenack Halden Jason Williams ISL Zefeng Yu Westinghouse Note: Attendance list based on Microsoft Teams participant list and in person attendee sign in sheet. This list does not include individuals who did not provide their last name either in registering for the meeting or by a follow-up email.
ML23352A274 (Meeting Summary)
ML23338A042 (Meeting Notice)
OFFICE NRR/DORL/LLPB PM RES/DSA/FSCB NRR/DORL/LLPB LA RES/DSA/FSCB BC NAME DKing JCorson DHarrison HEsmaili DATE 12/18/2023 12/19/2024 1/2/2024 1/3/2024 OFFICE NRR/DORL/LLPB BC NRR/DORL/LLPB PM NAME GGeorge DKing DATE 1/2/2024 1/3/2024