ML20155G172

Responds to Generic Ltr 88-03 Re Generic Safety Issue 93 Concerning Disabling of Auxiliary Feedwater Pumps by Steam Binding Caused by Backleakage of Main Feedwater Past Check Valves.Procedures in Place or Being Developed at Each Plant

ML20155G172
Person / Time
Site:	Byron, Braidwood, Zion, 05000000
Issue date:	06/03/1988
From:	Morgan W COMMONWEALTH EDISON CO.
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
REF-GTECI-093, REF-GTECI-NI, TASK-093, TASK-93, TASK-OR GL-88-03, GL-88-3, IEB-85-001, IEB-85-1, NUDOCS 8806170186
Download: ML20155G172 (4)

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i' D Commorr;;ealth Edison

'; ) On2 First National Plaza Chicago. Illinois s.--

~/ Address Reply to: Post Office Box 767

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Q Chicago, Illinois 60690 0767 June 3, 1988 U.S. Nuclear Regulatory Commission Docu Control Desk Washi. D.C. 20555

Subject:

Zion Station Units 1 and 2 Byron Station Units 1 and 2 Braidwood Station Units 1 and 2 Response To Generic Letter 88-03 NRC Docket Nos. 50-295/304, 50-454/455 and 50-456/457

Reference:

(a) NRC Generic Letter 88-03 dated February 17, 1988.

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Dear Sir:

The abeve referenced letter was issued to inform licensees of the NRC's resolution of the subject safety issue. Additionally, addressees were requested to provide a letter of confirmation to the NRC indicating that the procedures discussed in the referenced letter are in place and will be maintained.

Commonwealth Edison has completed its review pursuant to the request outlined in Generic Letter 88-03 for Zion, Byron and Braidwood Stations. This information is attached in enclosure 1.

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8806170186 880603 PDR ADOCK 05000295

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P DCD L - - - - - - - -

To the best of my knowledge and belief, the statements contained above are true and correct. In some respect these statements are not based ]

I on my personal knowledge, but obtained information furnished by other commonwealth Edison employees, contractor employees, and consultants. Such  !

information has been reviewed in accordance with company practice, and I l believe it to be reliable.

Please address any questions that you or your staff may have concerning this response to this office.

l Respectfully, b

W.E. Morgan

!;uclear Licensing Administrator rf Attachments i

cc: A.B. Davis Resident Inspectors - Z/By/Bw Subsc befor bedandSwQ3nto e this % day of . klf , 1988

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A40 NotaryPublic[]

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ATTACHMENT 1 Generic Safety Issue 93 concerns the potential for disabling auxiliary feedwater (AFW) pumps by steam binding that is caused by backleakage of main feedwater (MFW) past the checx valves between the APW and mfd systems. NRC I.E. Bulletin 85-01 requesced licensees to implement procedures for monitoring AFW piping temperatures for backleakage indications, and procedures for pump operabili y restoration if steam binding were to occur.

Generic Letter 88-03 resolsas the issue by requesting licensees to permanently maintain the pracadures developed for I.E. Bulletin 85-01.

Zion Station i

2. As required in the Generi-. Letter it has been verified that the i condition is checked for on a shiftly basis. Additionally, procedures i are in place for recognizing steam binding and for restoring the system to operable status, should steam binding occur.

3. The pump casing temperatures are verified to be at ambient conditions on a shiftly basis per the Auxiliary Building Operator's Log, PT-0 Appendix X page 8. If casing temperatures are greater than ambient (potential I steam binding) the Shift Engineer is immediately notified. To restore I the pump to service and rescat the leaking check valve the pump casing is first vented and then the pump is run per pT-7.

Byron Station l

Byron Station's response to I.E. Bulletin 85-01 (Byron Letter 86-0105) reported the revision of an existing procedure and the development of a new procedure. "383 Elevation HX Aisle, AF Readiness Unit 1" round sheet (BOP 199-A40) was revised to include a check of AFW piping temperature at the AF005 valves on a once per shift basis. "Auxiliary Feedwater Check Valve Leakage Unit 1" abnormal operating procedure (IBOA SEC-12) was developed to direct actions for operability restoration of a steam bound AFW pump.

Subsequent to the dissemination of the Station's response to I.B. Bulletin 85-01, the following actions have been taken:

1) "383 Elevation HX Aisle, AF Readiness Unit 2" round sheet (BOP 199-A61) has been implemented to address Unit 2 operation.

2) "Auxiliary Feedwater Check Valve Leakage Unit 2" abnormal operating l procedure (2 BOA SEC-7) has been implemented to address Unit 2 operation.

3) IBOA SEC-12) has been revised to clarify required actions and redesignated as IBOA SEC-7 The portions of BOP 199-A40 and BOP 199-A61 addressing I.E. Bulletin 85-01 j actions are designated as commitment related, as are the entire 1 BOA SEC-7 '

and 2 BOA SEC-7 procedures. Therefore, I.E. Bulletin 85-01 actions are considered to be permanently implemented at Byron Units 1 and 2, and the requirements of Generic Letter 88-03 are satisfied.

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Braiduood station ,

The following procedures are in place and will be maintained:

a. Per Braidwood Operating Procedures BwOP 199-A72 (Unit 1) and BwOP 199-A88 (Unit 2), shiftly temper ture chects of the APW piping are performed at the AF005 pump discharge valves.

b. Braidwood Operating Abnormal Procedure 1/2BwOA SEC -7, Auxiliary Feedwater Check Valve Leakage, provides actions required to prevent steam binding of AFW pumps and potential waterhammer of APW piping due .

to check valve leakage.

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