ML20249B392
| ML20249B392 | |
| Person / Time | |
|---|---|
| Site: | Limerick  |
| Issue date: | 06/15/1998 |
| From: | Geoffrey Edwards PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| IEB-96-003, IEB-96-3, NUDOCS 9806230019 | |
| Download: ML20249B392 (3) | |
Text
Station Support Department
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NRCB No. 96-03 10CFR50.54(f)
PECO NUCLEAR r><co emerov cemnemv 965 Chestertirook Boulevard A Unit of PECO Energy wavne. Fw 19087-set June 15,1998 l
Docket No. 50-352 License No. NPF-39 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555
Subject:
Limerick Generating Station, Unit 1 Supplemental Response to NRC Bulletin 96-03, " Potential Plugging of Emergency Core Cooling Suction Strainers by Debris in Boiling Water Reactors"
Dear Sir / Madam:
On May 6,1996, the NRC issued Bulletin 96-03, " Potential Plugging of Emergency Core Cooling Suction Strainers by Debris in Boiling Water Reactors," requesting that addressees implement appropriate procedural measures and plant modifications to minimize the potential for clogging of Emergency Core Cooling System (ECCS) suppression pool suction strainers by debris generated during a Loss-of-Coolant-Accident (LOCA).Bulletin 96-03 also required that all addressees submit written reports discussing the specific actions that will be taken, and when the actions have been completed.
By letter dated November 1,1996, PECO Energy responded to Bulletin 96-03 for Limerick Generating Station (LGS), Units 1 and 2. In our response, we discussed specific details regarding the plant modifications and associated actions that would be implemented at LGS in response to this Bulletin.
Subsequently, by letter dated October 6,1997, PECO Energy submitted a license amendment request to support implementation of the plant modification to install the replacement strainers on pump suction lines for the Residual Heat Removal (RHR) and Core Spray (CS) systems at LGS, Units 1 and 2. We requested the license amendment, since a 10CFR50.59 Review prepared in support of the modification concluded that an unreviewed safety question (USQ) was involved. Specifically, the USO pertained to the sizing methodology used to design the replacement strainers. The NRC approved our request and issued the associated license amendment (i.e., Facility Operating License No. NPF-39, Appendix C, Amendment No.128) as documented in a letter dated May 14,1998.
Bulletin 96-03 also required that within 30 days of completion of all requested actions, a written report be submitted confirming completion and summarizing the actions taken. Accordingly, this letter serves to notify the NRC that PECO Energy has completed the installation of new large-capacity, passive strainers on the Residual Heat Removal (RHR) and Core Spray (CS) system pump suction lines at LGS, Unit 1. This modification work was performed during the last Unit 1
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9806230019 980615 PDR ADOCK 05000352 f( b;
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Juns 15,1998 Page 2 refueli,ng outage (1R07) which was completed en May 18,1998. The new strainers have been j
sized to provide adequate surface area to ensure operability of the ECCS pumps, and therefore, I
will assure that the ECCS can perform its intended safety function and minimize the need for l
operator action to mitigate the consequences of a LOCA. The size and shape of the new strainers will preclude a loss of net positive suction head (NPSH) for the ECCS pumps due to debris accumulation on the strainers following e LOCA.
As previously discussed in our letter dated November 1,1996, and reiterated in supplemental correspondence conceming Bulletin 96-03, new strainers were not installed on the Unit i High Pressure Coolant injection (HPCl) system pump suction line, since the HPCI system does not function to provide long-term cooling capability following a LOCA. In addition, the primary source for suction supply for HPCI is the Condensate Storage Tank (CST) and not the Suppression Pool.
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Furthermore, as documented in our letter datod April 3,1997, PECO Energy discussed the interim j
monitoring program that was developed and implemented to ensure ECCS operability pending installation of the replacement strainers. We also discussed our intentions with regard to discontinuing some aspects of the monitoring program following installation of the new strainers.
Specifically, the following portions of the program will be discontinued for Unit 1 only:
Sampling of water and sludge material for the presence of fiber.
Measurement and trending of ECCS pump differential pressure (dP) data. This also includes the measurement and trending of Reactor Core isolation Cooling (RCIC) system pump dP data as previously committed in our letter dated October 6,1995.
PECO Energy has completed the requested actions associated with Bulletin 96-03 for LGS, Unit
- 1. We do not believe that any additional actions are necessary at this time, and that we have achieved long-term resolution of the Bulletin. We will continue to implement our Foreign Material Exclusion (FME) program controls and will conduct the required Suppression Pool and strainer inspections as specified in the Unit i license condition. Suppression pool and strainer cleaning j
will be performed as previously committed. Therefore, we are requesting closure of Bulletin 96-03 i
I for LGS, Unit 1. This letter is being submitted under affirmation, and the required affidavit is enclosed.
If you have any questions or require additional information, please do not hesitate to contact us.
Very truly yours, 4
Garrett D. Edwards Director - Licensing cc:
H. J. Miller, Administrator. USNRC, Region 1 A. L. Burritt, USNRC Senior Resident inspector, LGS 1
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COMMONWEALTH OF PENNSYLVANIA ss.
COUNTY OF PHILADELPHIA J. B. Cotton, being first duly sworn, deposes and says:
That he is Vice President of PECO Energy Company; that he has read the foregoing response documenting the completion of the actions associated with Bulletin 96-03," Potential Plugging of Emergency Core Cooling Suction Strainers by Debris in Boiling Water Reactors," for Limerick Generating Station, Unit 1, and knows the contents thereof; and that the statements and matters set forth therein are true and correct to the best of his knowledge, information, and belief.
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Vice President Subscribed and swom to before me this /d day of 1998.
Notary Pu c NOTARIAL SEAL CAPOL A. WALTON Notary Putes Cityof PhHadelphia. Pbda.Cour.sy Mw t' ";; ion Expires May 28, M u___________.________
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