ML20196E585
| ML20196E585 | |
| Person / Time | |
|---|---|
| Site: | Byron, Braidwood  |
| Issue date: | 11/24/1998 |
| From: | Krich R COMMONWEALTH EDISON CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| GL-98-02, GL-98-2, NUDOCS 9812040052 | |
| Download: ML20196E585 (4) | |
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Commonwealth Edison Company 1400 Opus Place Downers Grove, IL 60515-5701 November 24,1998 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington D. C. 20555-0001 Braidwood Statum, Units 1 and 2 Facility Operating License Nos. NPF-72 and NPF-77 NRC Docket Nos. STN 50-456 and STN 50-457 Byron Station, Units 1 and 2 1
Facility Operating License Nos. NPF-37 and NPF-86 NRC Docket Nos. STN 50-454 and STN 50-455 hhjart Response to NRC Generic Letter 98-02, " Loss of Reactor Coolant inventory ano' Associated Potential for Loss of Emergency Mitigation Functions While in a Shutdown Condition" On May 28,1998, the Nuclear Regulatory Commission (NRC) issued Genenc Letter (GL) 98-02, " Loss of Reactor Coolant inventory and Associated Potential for Loss of Emergency Miti9ation Functions While in a Shutdown Condition." NRC GL 98-02 requests us to perform an assessment of the susceptibility of the residual heat removal (RHR) system and emergency core cooling system (ECCS) to common-cause failure as a result of reactor coolant system (RCS) draindown whilt in a hot shutdown condition.
If the assessment reveals that a susceptibility to common-cause failure does exist, the results of the assessment are required to be submitted in writing, in accordance with 10 CFR 50.54(f) and 10 CFR 50.4, within 180 days of the date of the GL (i.e., by November 24,1998). In this case, a description of the features of the 10 CFR 50, Appendix B, Quality Assurance Program that provide assurance that the safety-related functions of the RHR system and ECCS will not be adversely affected by activities conducted during hot shutdown is also requested to be prepared. NRC GL 98-02 does not require the description of these features to be submitted to the NRC. However, the description of these features and the results of the assessment must be kept in a retrievable licensee system that the NRC can verify on an as-needed basis or sample basis.
By this letter, Commonwealth Edison Company is providing the required 180-day response to NRC GL 98-02. Should you have any questions concoming this letter, f
please contact Mr. D. J. Chrzanowski at (630) 663-7205.
if Respectfully, o*\\
R.M.K' Vice President - Regulatory Services 9812040052 981124 P
PDR ADOCK 05000454, P
PDR g A Unicom Company
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November 24,1998 U. S. Nuclear Regulatory Commission Page 2 Attachments: Affidavit i
NRC Generic Letter 98-02 Response l
cc:
Regional Administrator-NRC Region 111 l
NRC Senior Resident inspector-Braidwood Station i
NRC Senior Resident inspector - Byron Station i
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STATE OF ILLINOIS
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COUNTY OF DUPAGE
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IN THE MATTER OF
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COMMONWEALTH EDISON (COMED) COMPANY
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Docket Numbers BRAIDWOOD STATION, UNITS 1 AND 2
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STN 50-456 and STN 50-457 AND
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BYRON STATION, UNITS 1 AND 2
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STN 50-454 and STN 50-455
SUBJECT:
Response to NRC Generic Letter 98-02 AFFIDAVIT l affirm that the content of this transmittal is true and correct to the best of my knowledge, information and belief.
R. M.Krich //
l Vice President - Regulatory Services Subscribed and swom to before me, a Notary Public in and For the State above named, this
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!! JEFFERY A BATARA h Notary Public l > GINANY MAME:. 9 FATE W m ; i j
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Attachment NRC Generic Letter (GL) 98-02 Response Braidwood Station, Units 1 and 2, and Byron Station, Units 1 and 2 in accordance with NRC GL 08-02, Braidwood Station and Byron Station personnel have reviewed the adequacy of existing configuration control, operating practices, and training for assuring that the safety function capability of the residual heat removal (RHR) system and the emergency core cooling system (ECCS) is maintained, based on the information from prior events and the potential for containment bypass. The following is the response to NRC GL 98-02 for Braidwood Statien, Units 1 and 2, and Byron Station, Units 1 and 2.
REQUEST 1:
Perform an assessment to determine if the emergency core cooling systems include certain design features, such as a common pump suction header, which can render the systems susceptible to common-cause failure as a result of events similar to the Wolf Creek RCS draindown event of September 17,1994.
RESPONSE
An assessment has been performed as requested by NRC GL 98-02. One design feature does exist that can render the Residual Heat Removal (RHR) system and the ECCS susceptible to a common cause failure, similar to the events at Wolf Creek. One common header (i.e., designated 1/2S101B-24") provides suction from the refueling water storage tank (RWST) to all ECCS pumps. Each pump has a suction line that taps off the common header. In addition, a normally isolated line from the discharge of the RHR pumps (i.e., designated 1/2Sl01 A/B-8") ties into the common header.
REQUEST 2:
If this susceptibility is found, prepare a description of the features of the Appendix B quality assurance program that provide assurance that the safety-related functions of the RHR system and ECCS will not be adversely affected by activities conducted at hot shutdown (such as occurred at Wolf Creek), with consideration of plant specific design attributes.
RESPONSE
The description of the features governed by 10 CFR 50, Appendix B, Quality Assurance Program that provide assurance that the safety-related functions of the RHR system and the ECCS will not be adversely affected by activities conducted at hot shutdown has been prepared. This description is available for NRC review and is maintained in retrievable file systems at Braidwood Station and Byron Station.
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