ML20198B850
| ML20198B850 | |
| Person / Time | |
|---|---|
| Site: | Peach Bottom  |
| Issue date: | 12/11/1998 |
| 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 9812210170 | |
| Download: ML20198B850 (4) | |
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~;P-PECO NUCLEAR na % vc - v Nudear Group Headquarters A,l) NIT Of P[CO EMRGY 96s Chesterbrook Boulevard Wayne, PA 19o87-5691 December 11,1998 Docket Nos. 50-277 50-278 License Nos. DPR-44 DPR-56 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555
Subject:
Peach Bottom Atomic Power Station, Units 2 and 3 Withdrawal of License Amendment Requests Conceming Bulletin 96-03," Potential Plugging of Emergency Core Cooling Suction Strainers by Debris in Boiling Water Reactors" and Request for NRCB 96-03 Closure
Dear Sir / Madam:
This letter is being submitted to withdraw the subject license amendment requests and also to request closure of NRC Bulletin 96-03," Potential Plugging of Emergency Core Cooling Suction Strainers by Debris in Boiling Water Reactors," for Peach Bottom Atomic Power Station (PBAPS),
Units 2 and 3.
License Amendment Withdrawal By letter dated May 5,1997, PECO Energy submitted a request for license amendments to Facility Operating License Nos. DPR-44 and DPR-56 for PBAPS, Units 2 and 3. PECO Energy submitted this request, in accordance with the requirements of 10CFR50.90 and 10CFR50.59(c),
in order to facilitate implementation of a plant modification at PBAPS to install new replacement Emergency Core Cooling System (ECCS) pump suction strainers. This plant modification was l
Installed in response to Bulletin 96-03.
In support of this plant modification, PECO Energy performed a 10CFR50.59 Review which concluded that certain design aspects of the modification constituted an Unreviewed Safety Question (USQ), and therefore, a license amendment was required as stipulated in 10CFR50.59(c). Specifically, the USQ pertained to the design assumptions used for determining the amount of debris that would be expected to be generated under Loss of Coolant Accident (LOCA) conditions and the amount of material that would be transported to the suppression pool 1
9812210170 981211 7
001-I PDR ADOCK 05000277
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Dec:mber 11,1998 l
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Pag 3 2 (i.e., torus). The methodology used for sizing the new replacement strainers was consistent with the guidance provided in the Boiling Water Reactor Owners' Group (BWROG) draft Utility Resolution Guideline (URG) (i.e., Topical Report NEDO-32686, " Utility Resolution Guidance for ECCS Suction Strainer Blockage *) which was submitted to the NRC for review and approval by the BWROG.
Subsequently, the NRC appreved the BWROG URG as documented in its supporting Safety Evaluation Report (SER), dats : August 20,1998, and issued by letter dated September 3,1998.
In general, the NRC concluded that the URG provides good guidance on how to evaluate the potential strainer clogging issue on a plant-specific basis, and provides acceptable methods for sizing of the strainers. The NRC also indicated that the principal strength of the URG is that it reviews important considerations that licensees should be aware of in estimating the quantity of debris generated and transported from the drywell to suppression pool and then to the strainers, as well as the head loss resulting from the debris bed buildup.
PECO Energy has reviewed the approved URG and supporting NRC SER and concluded that the methodology used in support of the strainer modification work at PBAPS is consistent and conservative with respect to the analysis contained in the URG document approved by the NRC.
Therefore, PECO Energy is requesting that the license amendment requests submitted by letter dated May 5,1997, for PBAPS, Units 2 and 3, be withdrawn.
Bulletin 96-03 Closure As documented in our letter dated April 3,1997, PECO Energy discussed the interim monitoring program that was developed and implemented to ensure ECCS operability pending installatien 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. Since PECO Energy has installed the new strainers and completed the requested actions associated with NRCB 96-03 for PBAPS, Units 2 and 3, as documented in our letter dated November 25,1998, the following portions of the interim monitoring program will be discontinued at PBAPS:
Sampling of water and sludge material for the presence of fiber.
Measurement and trending of ECCS pump differential pressure (dP) data.
However, inspections of the suppression chambers and new strainers will continue. As a result of suppression chamber inspections and cleaning activities at PBAPS during previous refueling outages, PECO Energy has obtained baseline data regarding suppression chamber cleanliness and sludge accumulation rates. Ifit is determined that the amount of sludge material found does not exceed the design basis assumptions for the strainers (i.e.,100 lbs/ year), suppression chamber inspections will be performed every other refueling outage for each unit at PBAPS. The suppression chamber inspection and cleaning frequencies will be included as part of the Inservice inspection (ISI) Program requirements at PBAPS. Any changes in the inspection frequency will be appropriately evaluated to ensure there is no adverse impact on plant operations. This is consistent with what was previously communicated in our letter dated April 3,1997.
Therefore, based upon completion of suction strainer installation and establishment of controls to ensure appropriate periodic monitoring of suppression chamber cleanliness and cleaning (as necessary), PECO Energy requests closure of Bulletin 96-03 for PBAPS, Units 2 and 3.
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Page 3 This request 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, l
- h4hd Garrett D. Edwards Director-Licensing Enclosure
- cc:
' H. J. Miller, Administrator, USNRC, Region I (w/ enclosure)
A. C. McMurtray, USNRC Senior Resident inspector, PBAPS (w/ enclosure) l l
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COMMONWEALTH OF PENNSYLVANIA ss.
COUNTY OF CHESTER J. J. Hagan, being first duly swom, deposes and says:
That he is Vice President of PECO Energy Company; that he has read the foregoing request to 1) withdraw the license amendment requests for Peach Bottom Atomic Power Station (PBAPS), Units 2 and 3, concerning Bulletin 96-03 regarding debris generation methodology, and 2) request closure of Bulletin 96-03 for PBAPS, 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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Subscribed and swom to before me this //
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NOTARIAL SEAL l
CAROL A. WALTON. Notary Pubec Cny of Philadelphia, Phila. County i
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