ML18003A577
| ML18003A577 | |
| Person / Time | |
|---|---|
| Site: | PROJ0728, 99902041 |
| Issue date: | 04/30/2018 |
| From: | Rowley J NRC/NRR/DLP/PLPB |
| To: | Dennis Morey NRC/NRR/DLP/PLPB |
| Rowley J | |
| Shared Package | |
| ML18003A576 | List: |
| References | |
| Download: ML18003A577 (4) | |
Text
April 30, 2018 MEMORANDUM TO: Dennis C. Morey, Chief Licensing Processes Branch Division of Licensing Projects Office of Nuclear Reactor Regulation FROM: Jonathan G. Rowley, Project Manager /RA/
Licensing Processes Branch Division of Licensing Projects Office of Nuclear Reactor Regulation
SUBJECT:
SUMMARY
OF DECEMBER 5, 2017, CLOSED MEETING WITH AREVA INC. REGARDING PART LENGTH FUEL ROD BURNUP On December 5, 2017, a closed meeting was held between the U.S. Nuclear Regulatory Commission (NRC) staff and AREVA Inc. (AREVA) to discuss the applicability of the fuel rod burnup limit to part length fuel rods in boiling water reactors (BWR). The existing burnup limit is based on the average of fuel exposure over the entire length of the fuel rod. During the meeting, AREVA described significant differences in calculated rod average burnup between adjacent full length and part length fuel rods (exposed to the same axial power distribution).
Part length fuel rods tend to have higher average burnup due to their truncation within the high flux core region. Full length fuel rods have lower enriched fuel pellets in the lower flux, upper core region which achieve lower burnup. These lower burnup pellets drive down the rod average burnup.
The AREVA position is that the limit on fuel rod average burnup applies solely to full length rods and that differences between calculated rod average burnup in part length fuel rods are already accounted for in safety analyses. AREVA is concerned that application of the existing rod average burnup limit to part length fuel rods will force utilities to restrict fuel management and this will increase fuel cost.
The NRC staffs main concern is that burn-up dependent factors (e.g., thermal conductivity degradation, fission gas release) need to be properly accounted for in fuel mechanical design and accident analyses and that an established limit(s) on fuel burnup is necessary to ensure the continued applicability of analytical models, inputs, assumptions, and results.
CONTACT: Jonathan G. Rowley, NRR/DLP/PLPB (301) 415-4053
D. Morey During the meeting, NRC and AREVA staff discussed potential generic means to disposition this issue. Potential solutions include the following:
- NRC issued generic communications or a revision to Regulatory Guide 1.187 stating that application of Table 3 fission product gap inventories is acceptable to part length fuel rods provided these rods are treated as full length fuel rods in dose calculation.
- AREVA submitted supplement to RODEX4 topical report requesting approval of a specific part length rod burnup limit and/or peak nodal burnup limit.
An alternate approach would be to have licensees request a license amendment seeking separate full length and part length fuel rod burnup limits with appropriate justification.
A follow-up meeting was discussed as necessary to resolve this issue, but not scheduled.
A list of attendees is enclosed. The AREVA presentation material can be found in the Agencywide Documents Access and Management System at Accession Nos. ML17360A040 (proprietary) and ML17360A039 (non-proprietary).
Project No. 728 Docket No. 99902041
Enclosure:
As stated
ML18003A577 (Summary); ML18003A576 (Package);
ML17334B105 (Notice); ML17360A040, ML17360A039 (Presentations) NRC-001 OFFICE PLPB/PM PLPB/BC PLPB/PM NAME JRowley DMorey JRowley DATE 4/26/2018 4/30/2018 4/30/2018 List of Attendees Meeting with AREVA Regarding Part Length Fuel Rod Burnup Limits December 5, 2017 Name Organization Jeff Morris AREVA Thongchai patchana AREVA Alan Meginnis AREVA Ioan Arimescu AREVA Jerald Holm AREVA Jonathan Rowley U.S. Nuclear Regulatory Commission (NRC)
Robert Lukes NRC Paul Clifford NRC Mirela Gavrilas NRC Enclosure