ML17325B299
| ML17325B299 | |
| Person / Time | |
|---|---|
| Site: | Cook  |
| Issue date: | 11/01/1989 |
| From: | Alexich M INDIANA MICHIGAN POWER CO. (FORMERLY INDIANA & MICHIG |
| To: | Murley T NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| AEP:NRC:1069C, IEB-88-008, IEB-88-8, NUDOCS 8911070301 | |
| Download: ML17325B299 (4) | |
Text
ACCEIZRA REGULATO+ZNFORMATZON DISTRIBUTION STEM (RIDE)
ACCESSION NBR:8911070301 DOC.DATE: 89/11/01 NOTARIZED: YES DOCKET FACIL:50-315 Donald C.
Cook Nuclear Power Plant, Unit 1, Indiana 05000315 50-316 Donald C.
Cook Nuclear Power Plant, Unit 2, Indiana 6
05000316 AUTH.NAME AUTHOR AFFILIATION ALEXICH,M.P.
Indiana Michigan Power Co. (formerly Indiana
& Michigan Ele RECIP.NAME RECIPIENT AFFILIATION MURLEY,T.E.
Document Control Branch (Document Control Desk)
SUBJECT:
Provides addi response to NRC Bulletin 88-008 addressing thermal fatigue impact on auxiliary pressurizer spray line.
DISTRIBUTION CODE:
IE16D COPIES RECEIVED:LTR ENCL SIZE:
TITLE: Bulletin Response 88-08 Thermal Stress in Piping to RCS.
NOTES:
RECIPIENT ID CODE/NAME PD3-1 LA-GIITTER,J.
INTERNAL: AEOD/DOA NRR HARTZMANFM NRR REEVES,E.A.
NRR/DEST/MEB 9H NRR/DOEA/GCB ll N
S ILRB12 EG FILE 02 RG FILE 01 COPIES LTTR ENCL RECIPIENT ID CODE/NAME PD3-1 PD AEOD/DSP/TPAB NRR HUMFM NRR/DEST/ADS 7E NRR/DOEA/EAB 11 NRR/DREP/EPB 10 NUDOCS-ABSTRACT
,'RES/DSIR/EIB COPIES
-LTTR NCL 1
1 1
1 1
1 1
1 1
h EXTERNAL: LPDR NSIC NRC PDR D
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TOTAL NUMBER OF COPIES REQUIRED:
LTTR 21 ENCL
Indiana Michigan Power Company P.O. Box 16631 Coiumbus, OH 43216~
g INDIANA NICHIGAN POWER AEP:NRC:1069C Donald C.
Cook Nuclear Plant Units 1 and 2
Docket Nos.
50-315 and 50-316 License Nos.
DPR-58 and DPR-74 NRC BULLETIN NO.
88-.08:
FINAL RESPONSE ON AUXILIARY PRESSURIZER SPRAY LINE U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D.C.
20555 Attn: T. E. Hurley:
November 1, 1989
Dear Dr. Hurley:
This additional response to NRC Bulletin No. 88-08 addresses the further evaluation required to determine the thermal fatigue impact on the auxiliary pressurizer spray line due to a specific operating concern for the Donald C.
Cook Nuclear Plant.
Our prior submittal,,
AEP:NRC:1069A dated August 8, 1989, identified that this line has an overall minimum potentialfor fatigue failure.
However, further review was required to address the unusual condition of low leakage (less than or equal to 0.2 gpm) from a normally-closed auxiliary pressurizer spray valve without the presence of fully developed turbulent flow from the normal pressurizer spray line.
Fully developed turbulent flow from the normal pressurizer spray valves, which would mix any existing thermal stratification, cannot be assured when these valves are partially" opened.
Only partial
'pening of the normal pressurizer spray valves is required to provide the necessary flows during the various modes of unit operation.
A revised fatigue crack growth analysis was performed by Westinghouse Electric Corporation to evaluate the impact on the auxiliary pressurizer spray line with a low leakage flow and no turbulent mixing.
This analysis was based on the time that the normal pressurizer spray valves are required to be open.
Since these valves are opened only during power changes, unit startup and'ooldown, a conservative time of three months or 20% of power operation during a typical fuel cycle was used.
The results of the analysis indicate that if the auxiliary pressurizer spray lines are subjected to "worst-case" thermal fatigue stresses, pipe integrity SVli07030i 99ii0i PDR ADOCI( 050003i5 G
PNU
Dr. T. E.
Murley
" AEP:NRC:1069C will be maintained'or at least 30 months of power operation.
This is based. on the time needed to propagate an initial 10% through-wall crack to 608 of the wall thickness.
"Vorst-case" conditions reflect the conservative stress cycle frequencies identified in the Farley 2 failure.
Continuous unit operation is therefore acceptable contingent on examination of potential high stress points within this 30-month operating period.
The long-term assurance program for the auxiliary pressurizer spray
" line will consist of non-destructive examination (NDE) of the appropriate welds/bends on a refueling outage basis for each unit.
This frequency establishes a conservative margin to further ensure the integrity of the auxiliary pressurizer, spray lines at Cook Nuclear Plant.
This letter is being submitted under oath pursuant to the provisions of Section
- 182a, Atomic Energy Act of 1954, as amended.
Sincerely, M. P. Alexich Vice President ldp cc:
D. H. Williams, Jr.
A. A. Blind - Bridgman R.
C. Callen G. Charnoff A. B. Davis
- Region III NRC Resident Inspector
- Bridgman NFEM Section Chief
COUNTY OF FRANKLIN Milton P. Alexich, being duly sworn, deposes and says that he is the Vice President of licensee Indiana Michigan Power Company, that he has read the foregoing Response to NRC Bulletin No. 88-08: Final Response on Auxiliary Pressurizer Spray Line and knows the contents thereof; and that said contents are true to the best of his knowledge and belief.
Subscribed and sworn co before me chis ~n day of 198 e
NOTARY PUBLIC RITA D HILL IIOTART PUBI.IC. STATE Qf QHIQ