ML17329A372
| ML17329A372 | |
| Person / Time | |
|---|---|
| Site: | Cook  |
| Issue date: | 01/31/1992 |
| From: | Fitzpatrick E AMERICAN ELECTRIC POWER CO., INC. |
| To: | Murley T NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| AEP:NRC:1069D, IEB-88-008, IEB-88-8, TAC-M69618, TAC-M69619, NUDOCS 9202060361 | |
| Download: ML17329A372 (7) | |
Text
ACCELERATED DRIBUTION DEMONSTRATION SYSTEM REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)
.'ACCESSION NBR:9202060361 DOC.DATE: 92/01/31 NOTARIZED: YES FACIL:50-315 Donald C.
Cook Nuclear Power Plant, Unit 1, Indiana M
50-316 Donald C.
Cook Nuclear Power Plant, Unit 2, Indiana M
AUTH.NAME AUTHOR AFFILIATION FITZPATRICK,E.
American Electric Power Co., Inc.
RECIP.NAME RECIPIENT AFFILIATION MURLEY,T.E.
Document Control Branch (Document Control Desk)
SUBJECT:
Forwards response to NRC Bulletin 88-088, "Thermal Stresses in Piping Connected to RCSs."
Data will be collewcted for 1 fuel cycle on possible fatigue cracking in PRZ auxiliary spray line by mounting RTDs near welds 6 bends.
DISTRIBUTION CODE:
IE16D COPIES RECEIVED:LTR ENCL SIZE:
TITLE: Bulletin Response 88-08 Thermal Stress in Pipe.ng to RCS.
NOTES'OCKET 05000315 05000316 D
RECIPIENT ID CODE/NAME PD3-1 LA STANG,J I 'ITERNAL: AEOD/DOA NRR HUM,M NRR/DET/EMEB 7E NRR/DOEA/OGCB11 NRR/DSTT~E REG AGE 2
RGN3 IGE 01 K'YTERNAL: 'NRC PDR COPIES LTTR ENCL 1
0 1
1 1
1 1
1 1
1 1
1 1
1 1
1 1
1 1
1 RECIPIENT ID CODE/NAME PD3-1 PD NRR HARTZMAN,M NRR MOZAFARI,B NRR/DOEA/OEAB11 NRR/DREP/PEPB9D NRR/PMAS/ILRB12 RES/DSIR/EIB NSIC COPIES LTTR ENCL 1
1 1
1 1
1 1
1 1'
1, 1
1 1
1 1
D D
NOTE TO ALL"RIDS" RECIPIENTS:
D D
PLEASE HELP US TO REDUCE lVASTE! CONTACT THE DOCUMENT CONTROL DESK, ROOivl Pl-37 (EXT. 20079) TO ELIMINATEYOUR NAME FROM DISTRIBUTION LISTS FOR DOCUMENTS YOU DON'T NEED!
TOTAL NUMBER OF COPIES REQUIRED'TTR 18 ENCL 17
American Electric Po~
Service Corporation~
1 Riverside Plaza Columbus, OH 43215 614 223 1000 ANMlCAR KLKC'MIC POWfM
'AEP:NRC:1069D 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, "THERMAL STRESSES IN PIPING CONNECTED TO REACTOR COOLANT SYSTEMS" U.
S. Nuclear Regulatory Commission Document Control -Desk Washington, D.
C.
20555
" Attn:
T.
E. Murley
- January 31, 1992
Dear Dr. Murley:
Reference
- Letter, W. D. Long (NRC) to E. E. Fitzpatrick (AEPSC),
"NRC Bulletin 88-08, "Thermal Stresses in Piping Connected to Reactor Coolant Systems" (TAC Nos @69618 and)%69619),
dated November 1, 1991.
Letter AEP:NRC:1069C, "NRC Bulletin No.
88-08:
Final
Response
on Auxiliary Pressurizer Spray Line,"
dated November 1, 1989.
This letter responds to a November 1, 1991, letter from W. D. Long to E.
E. Fitzpatrick (Reference
- 1) which requested that Indiana Michigan Power Company provide a method, other than in-service inspection,:for ensuring that the pressurizer auxiliary spray line is not susceptible to fatigue cracking as described in NRC Bulletin No. 88-08.
In response to the Bulletin, I&M had previously proposed the use of non-destructive examination (NDE) each refueling outage to detect the presence of cracks (Reference 2).
This proposal was based on a Westinghouse analysis which showed that a postulat:ed 10', through-the-wall crack would require 30 months to propagate to 60% of wall thickness.
Since a crack would require more than one fuel cycle to propagate to 60% of the wall thickness, the absence of a crack during NDE would provide assurance that failure of the auxiliary spray line would not occur during the following operational cycle.
The NRC found this method unacceptable as a
final resolution to the Bulletin's concerns because "the cynpn~p+p36 i q~p131 PDR ADOCK o PDR 8
Dr. T.
E. Murley AEP:NRC:1069D fundamental precept of the Bulletin is to prevent the initiation of cracks in piping, insqrvice inspection is not an acceptable technique identified in the Bulletin for preventing'such cracks."
We have discussed the concern with Westinghouse,
- and, of the acceptable methods listed in the acceptance criteria attached to Reference 1,
we are now proposing to monitor the Unit 1 auxiliary spray temperature.
It is Westinghouse's
- position, as, stated in the attachment, that the auxiliary spray line is not susceptible to high cycle thermal loads that produce fatigue cracks, and that the Unit 1 data will confirm this.
The program will consist of mounting RTDs near appropriate welds and bends and taking data for one fuel cycle.
Following the evaluation of the data, which will include the investigation of thermal hydraulic and structural response characteristics to determine susceptibility to fatigue-initiated cracks, we 'ill inform you of. the results and any further required actions.
Unit 1
was chosen for monitoring because installation of the instrumentation will require a unit outage, and sufficient time does not exist to install the instrumentation during the 1992 Unit 2 refueling outage.
In addition, because of the similarities in the design and operation of both* units, the Unit 1 data will be applicable to Unit 2.
As an interim measure until the monitoring program is concluded, NDE will be performed on Units 1
and 2
during the 1992 refueling outages to confirm that no cracks 'have developed. in the auxiliary spray line.
This letter is submitted pursuant to 10 CFR 50.54(f) and, as such, an oath of affirmation is enclosed.
Sincerely, E.
E. Fitzpatrick Vice President Attachment CC:
D. H. Williams, Jr.
A. A. Blind - Bridgman J.
R. Padgett G. Charnoff NFEM Section Chief A. B.'avis
- Region III NRC Resident Inspector
- Bridgman
COUNTY OF FRANKLIN E.
E. Fitzpatrick, being duly sworn, deposes and says that he is the Vice President of licensee Indiana Michigan Power
- Company, that he-has read the forgoing Response to NRC Bulletin 88-08, "Thermal Stresses in Piping Connected to Reactor Coolant Systems,"
and knows the contents thereof; and that said contents are true to the best, of his knowlege and belief.
E~C&-) >~~/
Subscribed and sworn to before me this ~~2~ '
day of 19~/
N TARY P BLIC
ATTACHMENT TO AEP:NRC:1069D
)
Westinghouse Electric Corporation Energy Systems Box 355 Pinsorrrgrr Pennsylvania 15230 0355 AEP-92-003 Hr.
R. A. Kadlec American Electric Power, Service Corporation P. 0.
Box 16631 One Riverside Plaza
- Columbus, OH 43216
Dear Hr. Kadlec:
Ref: HT-DHT-449(91)
WCAP--12143, Supp.
1 AMERICAN ELECTRIC POWER SERVICE CORPORATION DONALD C.
COOK UNITS 1
AND 2 TECHNICAL REVIEW OF WCAP-12143 SUPPLEMENT 1
In accordance with your request, a review of the technical basis of WCAP-12143, Supplement 1,
has been performed.
The purpose of this review was to determine the amount of conservatism in the transient loads postulated for an 88-08 type valve leakage scenario in the Donald C.
Cook auxiliary spray valves.
After completing that review, it is judged that a
considerable amount of conservatism exists in the postulated valve leakage transients.
Specifically, the transient postulated is considered
'onservative for the following reasons:
a)
Spray flow in the main spray line is considerably less energetic than primary loop flow
- hence, turbulent penetration produced by normal spray flow would be relatively small and is considered to have an insufficient energy level to promote thermal cycling in the branch line.
b)
The fact that flow will exist in the main spray line will promote mixing of any cooler fluid that enters the main spray line from the auxiliary spray line for low to moderate leak rates.
Hence, for low to moderate leak rates no significant thermal stratification of the main spray line is expected.
c)
For moderate to large leak rates, the available cold water source would be quickly depleted and replaced with water heated by the regenerative heat exchanger.
- Hence, the cold water source would run out before any significant.cycles could be experienced by the spray line.
In summary, the spray lines at Donald C. Cook units one and two are considered not susceptible to high cycle thermal loads of the type that produced thermal fatigue cracks in the plants mentioned in NRC Bulletin 88-08.
This position can be verified with an appropriate temporary monitoring program on one unit.
Hr.
R. A. Kadlec AEP-92-003 January 6,
1992 It is judged that monitoring, along with a detailed investigation into the potential for a cycling mechanism in the spray line, would result in the conclusion that the spray lines structural integrity would not be violated even if a cyclic leak occurred in the auxiliary spray valve.
.It is therefore our recommendation that the Donald C.
Cook units consider a
'rogram of temporary monitoring on one unit along with an investigation into the thermal hydraulic and structural response characteristics of their spray lines to determine the susceptibility of said.lines to fatigue initiated cracks induced by cyclic thermal stratification loads.
If you have any questions please contact E. L. Cranford (412) 256-6486.
Very truly yours, N. Steinmetz, Project Hanager Central Area Domestic Customer Projects Department cc:
T..-"S..datyan'-Sharma.:-'~
g L!