RBG-37103, Special Rept:On 920522,determined That Control Panel 1ERS-NBI102 (Voltage Regulator/Timing Oscillator Board) Could Not Be Adjusted to within Specified Tolerances.Cause Not Determined.Supplemental Rept to Be Submitted by 920803

Special Rept:On 920522,determined That Control Panel 1ERS-NBI102 (Voltage Regulator/Timing Oscillator Board) Could Not Be Adjusted to within Specified Tolerances.Cause Not Determined.Supplemental Rept to Be Submitted by 920803

ML20101M720
Person / Time
Site:	River Bend
Issue date:	07/01/1992
From:	Odell W GULF STATES UTILITIES CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
RBG-37103, NUDOCS 9207090018
Download: ML20101M720 (2)

Text

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GULF STATEL UTILITIES COMPANY We'[r, St ND $14 HON PO$T Of hcl BD12M 51 i AANCtSVhlt LOultLANA 4??b .

amt a copt pad ()$ toga 346 80$1 July 1,1992 '

RBG- 37103 File Nos. G9.5, G9.23.1.3 i U.S. Nuclear Regulatory Commission Document Control Desk  !

Washington, D.C. 20555 Gentlemen:

River Bend Station - Unit 1 {

Docket No. 50-458 Enclosed is Gulf States Utilities Company's Special Report concerning an inoperative seismic instrument at River Bend Station (RBS). This report is submitted pursuant to RBS Technical Specification 3.3.7.2 and 6.9.2. -

Sincerely,

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W.H. Odell Manager -_ Oversight .

b River Bend Nuclear Group- l 1 DG/ /I'C MPD/kvm cc: U.S. Nuclear Regulatory Commission 611 Ryan Plaza Drive, Suite 400 Arlington, TX 76011 NRC Resident Inspector P.O. Box 1051 tl St. Francisville, LA 70775 INPO Records Center 1100 Circle Parkway.

Atlanta, GA 30339-3064 :

[ $diu i Mr. C. R. Oberg Public Utility Commissioner of Texas -

7800 Shoal Creek Blvd.', Suite 400 North ff.;i Austin, TX 78757 - -

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p 9207090018 920701-P DR -- ADOCK O$000458 - I' '

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IbEODUCTION On May 22,1992 during periormance of surveillance test procedure (STP)-557-4213 (an 18 month mnnel calibration for scismic instruments), it was determined that control panel 1ERS-NBD02 (voltage regulator / timing oscillator (VR/TO) board) could not be adjused to within the tolerances specified. Tne estrument was declared inoperable and the action statement of Te % Spe:20 cation (" >> 3.3.7.2 was entered. This permits 30 days for restoration, oihe.wi.,c a Spec w ' wt is required within the following 10 days. The instrument was tutel four days fu cing expiration of the 30 day time limit. Therefore, this Special Report a submitted pursuant to TS 3.3.7.2 and TS o.9.2.

" J' . _ATIf F 'tN" ':ORRECTIVE ACTION ,

STP-5',; d ir . channel calibrations on several seismic instruments, incluc cg tic ontrol pamM . as required by Technical Specifiutions 4.3.7.2.1,4.3.7.2.',

+- ables 4.3.7.0 t', J.

STP-557sf ?l2 was he' .forined on May 22,1992 when the positive and negative voltages >

en the VR/TO boat x :nd out of tole ance at +4.5 Vdc and -4.1 Vdc. The desired vo;tage inputs are +8 s c _d -R Vdc with a tolcrance af i .01 Vdc in each case. The procedure was contiracd to .. e adjustment section when an attempt was made to adjust the voltage values to wEtin the specified tolerances. This had no effect on the as-found voltages.

Since the STP s ..d not he continued, maintenance work order request (MWOR) 152922 ws.s v ;iden to troubleshcot and rework IERS-NBIl02. The VR/TO board was replaced per the g MWOR job plan. Tne STP was satisfactory completed on June 25,1992.

GSU cantinues to investigate the survellance test failure. A suppleinental report will be su' d by Aur,ust 3,1992 to 7tovide the cause of failure, n

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