ML20154L500

Forwards Response to Generic Ltr 88-03, Resolution of Generic Safety Issue 93,Steam Binding of Auxiliary Feedwater Pumps. Three Check Valves in Series Between Main Feedwater Lines & Awf Pumps Designated to Prevent Reverse Flow

ML20154L500
Person / Time
Site:	Wolf Creek
Issue date:	05/24/1988
From:	Withers B WOLF CREEK NUCLEAR OPERATING CORP.
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, WM-88-0146, WM-88-146, NUDOCS 8805310325
Download: ML20154L500 (4)

Text

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t W$LF CREEK NUCLEAR OPERATING CORPORATION Bart D. Withers President and CNef Executive Omcor May 24, 1988 WM 88-0146 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D. C. 20555 Subj ec t : Docket No. 50-482 : Response to Generic Letter 88-03 Gentlemen:

The purpose of this letter is to transmit a response to Generic Letter 88-03, "Resolution of Generic Safety Issue 93, Steam Binding of Auxiliary Feedwater Pumps" pursuant to 10 CFR 50.54( f) . The generic letter w . issued to (1) inform licensee's of the Staff's resolution of generic safety issue 93, and (2) request licensee's to continue to implement, as a minimum, the monitoring and corrective procedures previously identified for interim cesolution of this issue in IE Bulletin 85-01, "Steam Binding of Auxiliary Feedwater Pumps".

If you have any questions concerning this matter, please contact me or Mr. O. L. Maynard of my staf f.

Very truly yours, Bart D. Withers President and Chief Executive Officer BDW/jad

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Attachment cc: B. L. Bartlett (NRC), w/a D. D. Chamberlain (NRC)

R. D. Martin (NRC), w/a P. W. O' Connor ( NRC) , w/a (2) .0 8805310325 880524 PDR P

ADOCK 05000482 DCD RO. Box 411/ Buriington, KS 66839 / Phone: (316) 364-8831 An Equal Opporturwy Employer h4 F tCVET

_ _ _ _ _ _ _ _ _ _ __________ ________ _____..___ __ _ _ _ _ _ _ ._ l

STATE OP KANSAS )

) SS COUNTY OP COPPEY )

Bart D. Withers, of lawful age, being first duly sworn upon oath says that he is President and Chief Executive Officer of Wolf Creek Nuclear Operating Corporation; that he has read the foregoing document and knows the content thereof; that he has executed that same for and on behalf of said Corporation with full power and authority to do so; and that the facts therein stated are true and correct to the best of his knowledge, information and belief.

By Bart D. Withers q)

President and Chief Executive Officer SU3 SCRIBED and sworn to before me this 8 Y day of h) 9 , 1988.

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Notary Public mf s ~.

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• Attachment to WM 88-0146 Page 1 of 2 RESPONSE TO GENERIC LETTER 88-03_

Generic Letter 88-03, "Resolution of Generic Safety Issue 93, Steam Binding of. Auxiliary Feedwater Pumps", was issued on February 17, 1988. This generic letter-was issued to:

(1) in fo rm licensee's of the NRC's resolution of Generic Safety Issue 93, and (2) request that licensee's continue to implement, as a. minimum, .the monitoring and corrective procedures previously identified for interim resolution of this issue in IE Bulletin 85-01, "Steam Binding of Auxiliary Feedwater Pumps".

To reduce the probability of AFW pump failure as a consequence of steam binding if backleakage does occur, IE Bulletin 85-01 requested.that certain licensee's and construction permit holders imp'ement procedures both for monitoring the AFW piping temperatures tor indication of possible backleakage and -for restoring the pumps to operable status if steam binding were to occur. IE Bulletin 85-01 recommended that procedural controls remain in effect until (1) the completion of hardware modifications to substantially reduce the liklihood of steam binding, or (2) it was L

superseded' by action implemented as a result of' resolution of . Generic Issue 93._ Generic Letter 85-05 resolves Generic Issue 93-by perpetuating the recommendations of IE Bulletin 85-01. In particular, the generic letter stated that all addresses should:

(1) Maintain procedures to monitor fluid conditions within the AFW system each shift during times when-the system is required to be operable. This monitoring should ensure that fluid temperature at the AFW pump discharge is maintained at about ambient levels.

(2) Maintain procedures for recognizing steam binding and for restoring the AFW system to operable status, should steam binding occur.

On February 11, 1986, the response to Bulletin 85-01 was submitted for Wolf Creek Generating Station (WCGS) . This response identified procedures which are being used to monitor fluid conditions within the Auxiliary Feedwater

( AFW) System. In addition, procedures are in place to recognize steam

!. binding and restore the AFW pumps to an operable status.

At WCGS, temperature elements are provided at the top of the feedwater lines between the pump discharge check valves and pump discharge flanges which indicate the temperature on the Balance of Plant computer. Procedure STS CR-001, Revision 3, requires temperature readings be taken once per shif t to monitor fluid conditions while in modes 1, 2, and 3.

a. ,

g Attachment to WM 88-0146

' Page 2 of 2-Procedures were also developed for recognizing steam b'inding a n'd for restoring the AFW system to operable status should' steam binding occur.

Procedure ' STS _ CR-001 . recognizes the possibility of - steam. binding by monitoring fluid. temperature. .

If the temperature approaches 200 F

. procedure OFN 00-026, Rev iis on 0, is implemented. OFN 00-026 was developed to provide . actions to be followed upon identification of possible steam binding of any AFW pump.

In addition to the above mentioned administrative controls, the following design features at WCGS will minimize problems due to steam binding of 'AFW pumps:

(1) There are three check valves .in series between the main feedwater lines and the AFW pumps that are designated to prevent reverse flow to the AFW pumps.

I (2) The piping is not insulated from the AFW check valve at the. main-feedwater line to the pump discharge flange. The exposed line should help condense any steam formed in the pipe.

(3) The steam driven AFW pump minimum flow line tap is on the-top of a line located 16" from the discharge flange. The minimum flow lines on the motor driven AFW pumps are 45 degrees from vertical and 30" from the pump' discharge flanges. These locations will' help vent the steam to the condensate storage tank, should back' leakage occur.

The combination of design . features and administrative controls mentioned above reduces the probability for steam binding of AFW p umps to an Should steam binding . occur adequate procedures are in

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acceptable level.

place to recognize the situation and restore the AFW pumps to an operable status. These procedures have been in place since 1985 and' will be maintained at WCGS.

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