RBG-30243, Responds to NRC Bulletin 88-007,Suppl 1, Power Oscillations in Bwrs. All Appropriate Operating Procedures Revised & Currently Implemented

Responds to NRC Bulletin 88-007,Suppl 1, Power Oscillations in Bwrs. All Appropriate Operating Procedures Revised & Currently Implemented

ML20235Y526
Person / Time
Site:	River Bend
Issue date:	03/03/1989
From:	Booker J GULF STATES UTILITIES CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
IEB-88-007, IEB-88-7, RBG-30243, NUDOCS 8903140272
Download: ML20235Y526 (4)

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. GULF - STATES UTILITIES ' COMPANY pj! IltVER HEND STATION POST OFFtCF BOX 22D - ST. FRANCISVILLE. LOUI54ANA 70776 :

i .l . AREA CODE LO4 636 6094 346-86$1

-March 3, 1989 RBG'- 30243 . .

. File Nos. G9.5, G9.33.1

-U. S. Nuclear Regulatory Commission J Document. Control-Desk .

Washington, D.C. 20555

+

• Gentlemen

River Bend Station - Unit 1 Docket No. 50-458

, NRC Bulletin 88-07 Supplement 1 This letter provides; Gulf. States Utilities Company's (GSU) response to NRC Bulletin 88-07, Supplement.1, " Power Oscillations in Boiling Water Reactors (BWRs)."'

' Bulletin 88-07, Supplement 1, contained:the following action items:

1): Implement the General Electric' interim stability' recommendations as outlined in the bulletin supplement. A manual: scram'. should be initiated under all operating conditions when two recirculation pumps' trip (or "no pumps operating").in the RUN mode.

a)- Intentional operation shall not be allowed in Region A or Region i of the power ' flow map provided in the bulletin supplement and guidance provided by the Boiling Water Reactor Owners Group (BWROG). (NOTE: This is as in'.erpreted in the BWROG letter to the NRC dated January 26 1989 from D. N. Grace to A. Thadani.)

b). If Region A is unintentionally entered:

' Plant operators shall manually scram the reactor to exit the region.

c).IfRegionBisunintentionallyentered:

L Plant operators shall take immediate action to exit the region, p' Immediate action consists of:

L Insertion of a predefined set of control rods which will most effectively reduce core thermal power.

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L NRC March 3, 1989 Increasing recirculation pump speed or recirculation flow if one or more pumps are in operation. Starting a recirculation pump or shifting from low to high speed to exit this region is NOT an appropriate action.

d. Intentional operation in Region C shall be allowed only for control rod withdrawals during startup requiring PCIOMR. This region should be avoided for control rod sequence exchanges, surveillance testing and reactor shutdowns.

During control rod withdrawal, flux monitoring should be conducted in accordance with SIL 380, Revision 1.

e. If at any time during operation in Region A, B or C, core thermal hydraulic instability occurs, the plant operator shall manually scram the reactor.

Evidence of thermal hydraulic instability consists of APRM peak to peak oscillations of greater than 10% or periodic LPRM up::cale or downscale alarms in addition to the guidance provided in SIL 380, Revision 1.

2) For new fuel designs, the stability boundaries should be reevaluated and justified based on any applicable operating experience, calculated changes in core decay ratio using NRC approved methodology, and/or corc decay ratio measurements. There should be a high degree of assurance that instabilities will not occur under any circumstances of operation in Region C.

3) Although the GE interim recommendations state that intentional operation in Region B is not permitted and operation in Region C is permitted only for purposes of fuel conditioning during rod withdrawal startup operations, intentional entry into Region B or C is also allowable in situations where rod insertion or a flow increase is required by procedures to exit Regions A and B after unintentional entry. Licensees should ensure that the procedures and training employed for implementation of these recommendations avoid any similar ambiguity which could lead to operator confusion.

This letter is confirmation that all these action items have been completed and implemented at River Bend Station. All appropriate operating procedures have been revised and are currently implemented. The concerns of action item I were resolved by revision of Abnormal Operating Procedure, A0P-0024, " Decrease in Recirculation System Flow Rate" and a Standing Order (S0-67) to the plant staff which prohibits intentional operations in regions A, B, or C. With regard to action item 2, River Bend fuel is designed and analyzed in accordance with NRC approved acceptance criteria and methodology prior to each reload. Therefore, GSU considers this item

i NRC March 3,1989 addressed within the present program. Action item 3 was considered in revision of the above stated procedures and the training associated with each revision.

If you have any questions or require additional information, please contact Mr. L. L. Dietricn of my staff at 409/839-3011.

Sincerely,

,[ "

J. E. Booker Manager-River Bend Oversight River Bend Nuclear Group cc: U. S. Naclear Regulatory Commission Region IV 611 Ryan Plaza Drive Suite 1000 Arlington, TX 76011 NRC Senior Resident Inspector P. O. Box 1051 St. Francisville, LA 70775 I

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• UNITED STATES OF AMERICA

-NUCLEAR REGULATORY COMMISSION p.

STATE OF LOUISIANA )

PARISH OF WEST FELICIANA )

Docket'No.'50-458 In the Matter of )

GULF STATES-UTILITIES COMPANY )

(River Bend Station -' Unit 1)

' AFFIDAVIT J. E. Booker, being duly sworn, states that he is Manager-River- Bend Oversight for Gulf States Utilities Company; that he is authorized on the part of said company.to sign and file with the Nuclear Regulatory Commission the documents attached hereto; that .he has read all of the statements contained in such documents attached thereto and made a part thereof; and that all such statements made and matters set forth therein are true and correct to the best of

'his knowledge, information and belief.

//.[. 9

d. E. Booker Subscribed and sworn to before me, a Notary Public in and for the State and Parish above named, this .3#d day of 7h a ALL , 1979 . My Commission expires with Life.

NAJlll.tL-Notary Public in and for

, .k West Feliciana Parish, Louisiana

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