ML20212D904
| ML20212D904 | |
| Person / Time | |
|---|---|
| Site: | Kewaunee, Point Beach, Haddam Neck, 05000000 |
| Issue date: | 12/29/1986 |
| From: | Hebdon F NRC OFFICE FOR ANALYSIS & EVALUATION OF OPERATIONAL DATA (AEOD) |
| To: | Jordan E NRC OFFICE OF INSPECTION & ENFORCEMENT (IE) |
| Shared Package | |
| ML20212D903 | List: |
| References | |
| AEOD-E613, NUDOCS 8701050127 | |
| Download: ML20212D904 (3) | |
Text
T DN g g3 AE0D/E613 MEMORANDUM FOR: Edward L. Jordan, Director Division of Emergency Preparedness and Engineering Response Office of Inspection and Enforcement Hugh L. Thompson, Jr., Director Division of PWR Licensing-A Office of Nuclear Reactor Regulation FROM:
Frederick J. Hebdon, Deputy Director Office for Analysis and Evaluation of Operational Data
SUBJECT:
LOCALIZED R00 CLUSTER CONTROL ASSEMBLY (RCCA) WEAR AT PWR PLANTS A recently completed AE0D engineering evaluation report on operational data involving degradation of rod cluster control assemblies (RCCA) is enclosed for your information and use. Our evaluation found that the available data (three reports) were for RCCA events that occurred at Westinghouse designed PWRs.
There was no data to ascertain whetbar similar wear should be anticipated at PWRs designed by Babcock and Wilcox and Combustion Engineering. The study concludes that RCCA degradation is generic for the Westinghouse design and will occur on all RCCAs (shutdown and control banks). The de to be related to plant operating time (number of fuel cycles) gradation appears and whether plant operation involved load following. There are potential safety concerns related to RCCA rodlet clad integrity, rod insertion, or loss of absorber material.
The safety aspects relate to degradation mechanisms that could affect rodlet cladding structural integrity due to wall thinning, through-wall perforations, and cracking.
This may adversely impact RCCA insertion into the core or lead to possible loss of absorber material with reduced shutdown margin or reduced negative reactivity worth.
It appears that the condition of the RCCAs, including the extent of degradation, can only be determined by inspection of the RCCAs during a refueling outage.
In addition, the reports about the RCCA degradation indicated that they were submitted on a voluntary basis because RCCA wear was considered not reportable by either an LER or to the NPRDS.
Even though Westinghouse has provided some information about the RCCA wear problem, it is not clear that licensee awareness of the RCCA degradation is adequate to assure appropriate licensee action for detection and replacement of degraded RCCAs.
Because of the generic aspect of the problem, we recommend that IE issue an Information Notice to alert licensees about the RCCA degrada-tion and the need to plan and schedule inspections to determine the condition of all RCCAs.
8701050127 861229 PDR ADOCK 05000213 P
Addresses In addition, the report suggests that NRR consider whether there is a need to i
establish periodic inspections (such as a 10-year ir)ferval inspection).of RCCAs and assess the feasibility of reactor water chemistry monitoring procedures to detect severe, through-wall rodlet degradation.
j If you'have any questions regarding the enclos,e'd report, please contact Earl J.
Brown of my staff. Dr. Brown can be reached on x24437.
/
.C. J. Heltemes, Jr., Director
/0ffice for Analysis and Evaluation j'
of Operational Data i
Enclosure:
As Stated
/
/
cc w/ enclosure:
/
D. Humenansky, OCM
./
i
.J.
Sniezek, DEDROGR
/
T. Novak, NRR
/
F. Miraglia, NRR
/
T. Colburn, NRR
/
R. Newton, WEPC j
M. Fairtile, NRR D. Nalepka, WPSC
/
F.'Akstulewicz, NRR
/
J. Drago, CYAPC
/
-J. Powers, CYAPC M. Beaumont, Westinghouse J. Woodcock, Westinghouse C. Brinkman, CE E. Dzenis, Westinghouse R. Borsum, B&W
'G. Arlotto, RES
/
L. Gifford, GE DISTRIBUTION:
/ OAB CF SRubin MWilliams AE00 CR
/ EBrown WLanning FHebdon AE00 SF
/ MChiramal KBlack CHeltemes, Jr.
~
Plam
/
SSalah
/
1
/
4
' 0FC
- ROAB
- SC:ROAB BC ROAB DD:AE00
- D:AE0D
_____:..._((__:-___....b_::.___:_______::.__4,._____:.. f
- ..___
- ___________:.______...__:._______G__)N.,____________:...________.:___
NAME : EBrown.as
- MChiramal
- SRubin
- FHebdon
- C temes 18 86 r2/T/86
/
- 13/lT /86
- 12/2.t/86
- Q/ <tT86
- DATE
- 11/
OFFICIAL RECORD COPY
Addressees In addition, the report suggests that NRR consider whether there is a need to establish periodic inspections (such as a 10-year interval inspection) of RCCAs and assess the feasibility of reactor water chemistry monitoring procedures to detect severe, through-wall rodlet degradation.
If you have any questions regarding the enclosed report, please contact Earl J.
Brown of my staff.
Dr. Brown can be reached on x24437.
Frederick J. Hebdon, Deputy Director Office for Analysis and Evaluation of Operational Data
Enclosure:
As Stated cc w/ enclosure:
D. Humenansky, OCM J. Sniezek, DEDR0GR T. Novak, NRR F. Miraglia, NRR T. Colburn, NRR R. Newton, WEPC M. Fairtile, NRR D. Nalepka, WPSC F. Akstulewicz, NRR J. Drago, CYAPC J. Powers, CYAPC M. Beaumont, Westinghouse J. Woodcock, Westinghouse C. Brinkman, CE E. Dzenis, Westinghousa R. Borsum, B&W G. Arlotto, RES L. Gifford, GE DISTRIBUTION:
PDR ROAB CF SRubin MWilliams AE00 CR EBrown WLanning FHebdon AEOD SF MChiramal KBlack CHeltemes, Jr.
Plam SSalah
- See next sheet for previous concurrence OFC : ROAB
- SC:ROAB
- BC:ROAB
- DD:AEOD
- D:AEOD
..___:__...______:____...__.__:......._____:___.._______:__ g... __:______..____:.......____
NAME : EBrown:as
- MChiramal
- SRubin
- FHebdon
- CHQtemes DATE : 12/18/86*
- 12/18/86*
- 12/18/86* : 12/22/86*
- 12/12/86 OFFICIAL RECORD COPY