ML20245K751
| ML20245K751 | |
| Person / Time | |
|---|---|
| Site: | Limerick  |
| Issue date: | 05/02/1989 |
| From: | Clark R Office of Nuclear Reactor Regulation |
| To: | Hunger G PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC |
| Shared Package | |
| ML20245K753 | List: |
| References | |
| TAC-72729, NUDOCS 8905050163 | |
| Download: ML20245K751 (5) | |
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"g UNITED STATES NUCLEAR REGULATORY COMMISSION h
WASHINGTON, D. C. 20555 k..... p#
May 2, 1989 Docket No. 50-352 Mr. George A. Hunger, Jr.
Director-Licensing Philadelphia Electric Company 1
Correspondence Control Desk P. O. Box 7520 Philadelphia, Pennsylvania 19101
Dear Mr. Hunger:
SUBJECT:
INDICATION IN RECIRCULATION RISER N0ZZLE TO SAFE END WELD (TAC NO. 72729)
RE:
LIMERICK GENERATING STATION, UNIT 1
~
By letter dated April 3,1989 you submitted two reports related to the above subject. One of the reprrts sunnarized your evaluation of the indication and requested our approval for operation in Cycle 3 without repairs to the weld (e.g., weld overlay) but with installation of equipment to detect and monitor the crack growth rate and planned improvements in reactor water chemistry.
The second letter of the same date discusses the actions you wilr take to improve water chemistry. These actions include:
- 1) installation of continuous in-line analyzers to measure water chemistry parameters, 2) limiting chemical transients and 3) reducing copper concentrations in the feedwater. These actions are discussed in more detail in Section 10.4 of SSER 7 to NUREG-0991.
As discussed in the enclosed safety evaluation we have concluded that the N2H nozzle-to-safe end weld is acceptable for continued service during cycle 3 on the basis of the analyses you performed and the monitoring programs you proposed to implement. We concur with your analysis which estimates that growth of the existing flaw will be minimal with improved water chemistry and should not exceed the ASME Code Section XI allowable limit established by fracture mechanics analysis during one generating cycle. Based on experience at other BWRs, the CAVS method will provide verification that the fracture mechanics analysis is applicable to the reactor coolant environmental effects on crack growth rate. The extent of subsequent examinations per IWB 3122.4 or the corrective action you will take for ultimate disposition of the UT indication will be established prior to or during the third Unit I refueling outage.
We appreciate your installation of the experimental acoustic emission (AE) monitoring equipment developed under one of our research programs. We hope it will provide supplemental information on the flaw growth rate in the N2H nozzle. Until the perfonnance of the AE system is evaluated, it is not expected that the results can be used to quantify the extent of crack growth.
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' Mr. George A. Hunger, Jr. May 2, 1989 i
We understand there has been some problems obtaining a relic.ble signal when the recirculation pumps are operating. We would appreciate being kept j
informed of the comparative results from the CAVS and AE equipment.
Sincerely, h
o cha rk, Project Manager Pro ect Directorate I-2 Division of Reactor Projects I/II Office of Nuclear Reactor Regulation
Enclosure:
Safety Evaluation cc w/ enclosure:
See next page i
Mr. George A. Hunger, Jr. May 2, 1989 We understand there has been ;ome problems obtaining a reliable signal when the recirculation pumps are operating. We would appreciate being kept informed of the comparative results from the CAVS and AE equipment.
Sincerely, Original signed by Richard J. Clark Richard J. Clark, Project Manager Project Directorate I-2 Division of Reactor Projects I/II Office of Nuclear Reactor Regulation
Enclosure:
Safety Evaluation cc w/ enclosure:
See next page DISTRIBUTION w/ enclosure t' Docket 111e;c[j NRC PDR Local PDR PDI-2 Reading SVarga BBoger WButler M0'Brien i
RClark RMartin OGC EJordan BGrimes ACRS (10) i
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PDI-2/PM c
PDI-2/D WButler RClark:
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Mr. George A. Hunger, Jr.
Limerick Generating Station Philadelphia Electric Company Units 1 & 2 I
CC:
Troy B. Cenner, Jr., Esquire Mr. Ted Ullrich Conner and Wetterhahn Manager - Unit 2 Startrv i
1747 Pennsylvania Ave., N.W.
Limerick Generating Station
)
Washington, D. C.
20006 P. O. Box A Sanatoga, Pennsylvania 19464 Mr. Rod Krich S7-1 Philadelphia Electric Company Mr. John Doering 2301 Market Street Superintendent-Operations Philadelphia, Pennsylvania 19101 Limerick Generating Station P. O. Box A Mr. David Honan N2-1 Sanatoga, Pennsylvania 19464 Philadelphia Electric Company 2301 Market Street Thomas Gerusky, Director Philadelphia, Pennsylvania 19101 Bureau of Radiation Protection PA Dept. of Environmental Resources Mr. Graham M.'Leitch, Vice President P. O. Box 2063 Limerick Generating Station Harrisburg, Pennsylvania 17120 Post Office Box A Sanatoga, Pennsylvania 19464 Single Point of Contact P. O. Box 11880 Harrisburg, Pennsylvania 17108-1880 Mr. James Linville U.S. Nuclear Regulatory Comission Mr. Philip J. Duca Region I Superintendent-Technical i
475 Allendale Road Limerick Generating Station
'i King of Prussia, PA 19406 P. O. Box A Sanatoga, Pennsylvania 19464 Mr. Thomas Kenny Senior Resident Inspector l
US Nuclear Regulatory Comission l
P. O. Box 596 Pottstown, Pennsylvania 19464 Mr. Joseph W. Gallagher Vice President, Nuclear Services Philadelphia Electric Company 2301 Market Street Philadelphia, Pennsylvania 19101 Mr. John S. Kemper Senior Vice President-Nuclear Philadelphia Electric Company 2301 Market Street 1
Philadelphia, Pennsylvania 19101 1
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