ML20106D469
| ML20106D469 | |
| Person / Time | |
|---|---|
| Site: | Limerick  |
| Issue date: | 10/05/1992 |
| From: | Beck G PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| GL-89-13, NUDOCS 9210130005 | |
| Download: ML20106D469 (2) | |
Text
.
PIIILADELPillA ELECTRIC COMi%NY NUCLEAR GROUP HEADQUARTERS 955-65 CHESTERBROOK BLVD.
WAYNE, PA 19087-5691 October 5, 1992 (215) 6404x10 Docket No. 50-353 License No. NPF-85 NUCLEAR SERVICl3 del %KrMENT U.
S.
Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555
Subject:
Lirnerick Generating Station, Unit 2 Follow-Up Written Request for a Temporary Walver of Compliance by the Office of Nuclear Reactor Regulation - Additional Information Gentlemen:
Our let.ter dated October 2, 1932 provided our written foisow-up of our verbal request for a tempora ry waiver of complianc.e made, and approved by the NRC, on October 1, 1992.
That request for a temporary waiver of compliance for Limerick Generuting Station (LGS), Unit 2, involved a temporary change of the acceptance criterion of 10,000 gpm through the Residual Heat Removal (RHR) heat exchanger specified in Technical Specifications (TS)
Surveillance Requirement (SR) 4.6.3.2.b.
The alternate acceptance criterion proposed was a RHR pump flow of 10,000 qpm through the flow path for the Suppression Pool Cooling (SPC) mode of the RHR system, including leakage through the.RHR heat exchanger bypass valve.
This alternate acceptance criterion had previously been submitted to the NRC as a TS change request in our letter dated August 11, 1992.
As a result of discussions with J.
Shea, NRC, on October 2,
1992, this letter provides additional information concerning the determination of the minimum RHR flow through the heat exchanger to support our request for e temporary waiver of compliance.
Heat transf er testing of the RHR heat exchangers is performed as a result of implementation of tne commitments made in our letter dated January 29, 1992, responding to NRC Generic Letter 89-13, " Service Water System Problems Affecting Safety - Related Equipment."
This testing demonstrates that the derign heat removal requirements for the RHR heat exchangers are met by conducting an integrated performance test of the RilR and RHR Service Water (RHRSW) systems.
Results from previous performance of these tests have shown that the required heat transfer can be accomplished with less than a total RHR pump flow of 10,000 gpm passing through the RHR heat exchanger when the RHR systen is operated in *he SPC moda.
Calculations have shown that a RHR system flow rate of approximately 7,500 gpre is needed to pass through the RHR heat exchanger 9210130005 921005 HI
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U.S.
Nuclear Regalatory Commission October 5, 1992 Document Control Desk Page 2 i
to remove the desitin heat load, assuming the design maximurn value for T.he heat exchanger rouling factors, a nominal number of plugged tubes, and the maximum RilRSW inlet teaperature.
The raost recent heat transfer test of the Unit 2
'B' RHR heat exchanger was performed on October 2, 1992, and showed that the actunl fouling f actors were significantly less than the design maximum values.
Also, no Unit 2 RHR heat exchanger tubes are plugged.
Furthermore, with the onset of Fall, the RHRSW temperature is and will continue to be less than the maximum value used in c.his heat transfer calculation.
If you have any questions or rcquire additional information, please contact us.
Very truly yours, f f}l
,6#4/
G. JI Beck, Manager Licensing Section cc:
T.
T.
Martin, Administrator, Region I, USNRC T.
J.
Kenny, USNRC Senior Resident Inspector, LGS 1
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