05000267/LER-1982-018, Forwards LER 82-018/03L-0.Detailed Event Analysis Encl

Forwards LER 82-018/03L-0.Detailed Event Analysis Encl

ML20053E869
Person / Time
Site:	Fort Saint Vrain
Issue date:	05/28/1982
From:	Warembourg D PUBLIC SERVICE CO. OF COLORADO
To:	Jay Collins NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
Shared Package
ML20053E870	List: 05000267/LER-1982-018, Forwards LER 82-018/03L-0.Detailed Event Analysis Encl 05000267/LER-1982-018-03, /03L-0:on 820501,essential 480-volt Buses Tie Breaker Would Not Close During Surveillance Test Simulating Loss of Outside Power & Turbine Trip.Caused by Breaker Spring Charging Motor Switch in Off Position
References
P-82170, NUDOCS 8206100163
Download: ML20053E869 (6)

LER-1982-018, Forwards LER 82-018/03L-0.Detailed Event Analysis Encl

Event date:
Report date:
2671982018R00 - NRC Website

text

..

r public servlee rompany of ochmde 16805 Road 19 1/2, Platteville, Colorado 80651-9298 I

l May 28, 1982 Fort St. Vrain Unit No. 1 P-82170

\\

\\

\\

'\\'

\\

7 7 --,

,{y \\

?'_

Mr. John T. Collins, Regional Administrator bi Region IV

_ D' '

2 Nuclear Regulatory Commission 611 Ryan Plaza Drive Suite 1000 Arlington, Texas 76011

Reference:

Facility Operatirg License No. DPR-34 Docket No. 50-267

Dear Mr. Collins:

Enclosed please find a copy of Reportable Occurrence Report No. 50-267/82-018, Final, submitted per the requirements of Technical Specification AC 7.5.2(b)2.

Also, please find enclosed one copy of the Licensee Event Report for Reportable Occurrence Report No. 50-267/82-018.

Very truly yours, h Wwd Don Warembourg Manager, Nuclear Production DW/cis Enclosure cc:

Director, MIPC e2 8206100163 820528 gDRADOCK 05000267 PDR

w REPORTABLE OCCURRTNG DISTRIBUTION Number of Copies De p a r t men t o f Ene r gy - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

1 (P I4tter)

San ~Fr'ancisco Operations Of fice Atta : California Patent Group 1333 Broadway Oakland, California 94612 De p a r tme n t o f En e rgy - - - - - - - - - - - - - - - - - - - - - - - - - - -

1 (P Letter)

Mr. Glen A. Newby, Chief RTR Branch Division of Nuclear Power Development Mail Station B-107 Washin gton, D.C.

20545 De p a r t me n t o f En e r gy - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

1 (P Letter)

Attn: Project Manager 110 Wes t A S t ree t, Suite 460 San Diego, California 92101 Original of P Intter)

!!r. John T. Collins, Regicnal Administrator Region IV j

Nuclear Regulatory Commission 611 Ryan Plaza Drive Suite 1000 Arlington, Texas 76011 Mr. George Kuzmvez - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

1 (P Letter)

Nuclear Regulatory Commission 7920 Norfolk Avenue Bethesda, Maryland 20034 Di r e c t o r - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

1 (P Letter)

Of fice of hanagenent Information and Program Control Nuclear Regulatory Commission Washington, D. C.

20555 Re c o rds Ce n t e r - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

1 (P Letter)

Institute of Nuclear Power Operations 1820 Water Place Atlanta, Georgia 30339 Mr. Richard Phelps FSV, CA Site Rep re sentative - - - - - - - - - - - - - - - -

1 (P Letter)

General Atomic Co@any 16864 Weld County Road 191/2 Platteville, Colorado 80651 1 (P Letter)

NRC Resident Site Inspector

'S

REPORT DATE:

May 28, 1982 REPORTABLE OCCURRENCE SC-0:2 ISSUE O OCCURRENCE DATE:

May 1, 1982 Page 1 of 4 FORT ST. VRAIN NUCLEAR GENERATING STATION

- ~

PUBLIC SERVICE COMPANY OF COLORADO 16805 WELD COUNTY ROAD 19 1/2 PLATTEVILLE, COLORADO 80651-9298 REPORT NO. 50-267/82-018/03-L-0 Final IDENTIFICATION OF OCCURRENCE:

During performance of a Surveillance Test, simulating a " loss of outside power and turbine trip," the tie breaker between 480 volt essential buses 2 and 3 failed to close.

This is a degraded mode of LCO 4.6.1(d)3 and is reportable per Fort St.

Vrain Technical Specification AC 7.5.2(b)2.

EVENT

DESCRIPTION

A',

1200 hours0.0139 days <br />0.333 hours <br />0.00198 weeks <br />4.566e-4 months <br />, May 1, 1982, with the reactor shutdown, Operations personnel were performing a Surveillance Test, SR 5.6.lb-SA, " Loss of Outside Power and Turbine Trip," to verify the operability of the auxiliary electrical system prior to start up and rise-to power.

A design function of the system is that in the event the plant should experience a loss of power from the simultareous loss of all transmission lines and the tripping of the turbine generator, the two standby generators, K-9201 and K-9202, will automatically start. The first n7rmally functioning u.11 t will be selected to pick up the programmed load on its respective 480 volt load center and also the 480 volt bus 2.

The second unit will carry the one remaining essential 480 volt load center and programmed loads.

Referring to Figure 1, one section of the tes required inhibiting the start f standby generator set 1A (K-9201)

, so that se IB (K-9202) 2 ould reach normal operating con itions first Timer, T2, 4 s arted, allowing standby generator IB loc -out

relay, 86 IB, 5 to

energize, followed by control

relay, C

204 6 The control relay caused bus 3 breaker, 252DG1B, to ose and should have caused bus 2 and 3 tie breaker, 2

T32, 8 to close.

However, the bus 2 and 3 tie breaker failed l

to close automatically, so a Control Room operator attempted to manually close it by operating HS-9237, 9

but the tie breaker still would not close.

Since standby generator IB lockout relay, 286G18, h been energized first, standby generator IA lockout relay, l

286GIA, 10 was inhibited from e argizing, and thereby prevented bus 1 to tie breaker, 252BT12, 11 from automatically closing, even t

h it could have been manually closed by operating HS-9235 The operator halted the Surveillance Test at this

REPORTABLE CCCURRENCE E2-018

~

ISSUE 0 Page 2 of 4

~~

point in order to ascertain, the cause of the failure and correct the problem.

At 1400 hours0.0162 days <br />0.389 hours <br />0.00231 weeks <br />5.327e-4 months <br /> on May 1, 1982, the plant electric 6' foreman troubleshooting the failure, found the problem, corrected it, and the Surveillance Test was rerun without any problems.

Operability of the bus 2 a'nd 3 tie. breaker was last verified during performance of the Surveillance Test, SR 5.6.lb-SA, completed on December 3, 1981.

Since the reactor had been operated at power since the last verification of operability, it must be assumed that operation was in a degraded mode of Fort St.

Vrain Technical Specification LCO 4.6.1(d)3 and is reportable per AC 7.5.2(b)2.

CAUSE

DESCRIPTION:

The 480 volt bus 2 and 3 tie breaker spring charging motor ON-0FF switch was found in the OFF position.

This preve-ted the breaker springs from being charged and thereby, prevented the breaker points from closing.

The reason for the switch being in the OFF position is unknown.

CORRECTIVE ACTION:

The 480 volt bus 2 and 3 tie breaker DN-OFF switch for the spring charging motor was placed in the ON position.

The Surveillance Test was rerun, demonstrating operability of the 480 volt bus 2 and 3 tie breaker.

No further corrective action is anticipated or required.

l l

REPORTTE'.E OCC ; T:CE S2-0l?

ISSUE 0 Page 3 of 4 FIGUkE 1 12 9

HS-9235 HS-9237 O

i i

(480 V. Switchg ar 1) ( 252BT12 l

(480 V.

l 252BT32 ) (480 V. Switchgear 3)

Switch-3 4 A

) gear 2)(

p sg 4

J L

_____________l_____

t T

I E

I

( 252DGlA k ay CR-9204 ----4------

( 252DGlB )

TR-9271 l q t te a t Gene r-ine Engine Gene r-EnSA ine EnfB l

1A ator 1B Engine ator K-9203-lA K-9204 '

l K-9205-1B K-9206-X K-9201 X

X K-9202 X

I 5

i i

I I

I I

I 1r y

i I

I I

I CR-9201 t- - - + 286G1B +-l CR-9202 l

I I

I I

1 I

I I

I l

1 I

lf I

I 10 l

i I

lf "AND" Gate I

I I

I I

I"AND" Gate -

Normal Oper-L _ >A

--I 4.-__w286GlA + __ j L+

g-s Normal Oper-ating Conditions' l

N ating Condi-tions I

i l

4 i

i I

l i

l I

b---->

Timer Timer

• --- o I

Tl T2 g

i A

(

l i

_p_____J I

i L.___----_.------_--__a

REPORTABLE 0:CURRENCE 82-02e ISSUE O Page 4 of 4

\\

Prepared By:

Paul A. Tramp f

Technical Services Technician J

Reviewed By:

/g

,fd Charles Fuller Technical Services Engineering Supervisor 7

l Reviewed By:

'), /

Edwin/0' HiTi~

Station Manager Approved By:

W Don Warembourg

/

Manager, Nuclear Production i