05000280/LER-2075-021, Re 6% Low Reading of T Protection Channel 1

Re 6% Low Reading of T Protection Channel 1

ML19105A197
Person / Time
Site:	Surry
Issue date:	01/09/1976
From:	Stallings C Virginia Electric & Power Co (VEPCO)
To:	Moseley N NRC/RGN-II
References
Serial No. 851 LER 1975-021-00
Download: ML19105A197 (3)

LER-2075-021, Re 6% Low Reading of T Protection Channel 1

Event date:
Report date:
2802075021R00 - NRC Website

text

e VIRGINIA ELEOTRIO.A.ND POWER COMP.A 1**, I I\\

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I RIOHMOND, VIRGINIA 23261 January 9,.1976 Mr. Norman C. Moseley, Director Office of Inspection and Enforcement Serial No. 851 PO&M/ ALH: clw United States Nuclear Regulatory Commission Region II - Suite 818 Docket No. 50-281 230 Peachtree Street, Northwest Atlanta, Georgia 30303

Dear Mr. Moseley:

License No. DPR-37 Pursuant to Surry Power Station Technical Specification 6.6.B.l, the Virginia Electric and Power Company hereby submits forty (40) copies of Abnormal Occurrence Report No. AO-S2-75~21.

The substance of this report has been reviewed by the Station Nuclear Safety and Operating Committee and will be placed on the agenda for the next meeting of the System Nuclear Safety and Operating Committee.

Enclosures 40 copies of AO-S2-75-21 cc:

Mr. Robert W. Reid Very truly yours,

'Z{}. Jin_ 01Mu-~,r:v C.. M. Stallings Vice President-Power Supply and Production Operations 349

REPORT AO-S2-75-21

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8 9 CATEGORY REPORT TYPE 6

LICENSE NUMBER I o I o 1-1 o Io Io I o I o 1-1° IO I 15 25 REPORT SOURCE DOCKET NUMBER LCEN3E TYPE ti_ I 1 I 1 l__ij_Q_J 26 30 EVENT DATE Lo ! l I 31 32

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59 60 61 68 B9 74 75 60

EVENT DESCRIPTION

lsi:@. !During normal operation, it was noted that f:IT protection channel 11 1" was reading 6 per !

7 8 9 80 [o]3] lcent low.

Channel 11 111 f:IT protection was placed in the 11 tripped 11 mode.

The other 6.T I

7 89

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@El jprotection channels were*operable.

A similar event occurred on October 3, 1975 and i~J 7

B 9 BJ [6"@1 I described in report AO-S2-7 5-17.

This occurrence is a violation of Technical I

7 89

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[Q}ID !Specification 2.*3.

(AO-S2-75-21)

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7 8 9 SYSTEM CODE

~ W..AJ 7

B 9 10

CAUSE

CODE l!U 11 CAUSE DESCF!IPTION COMPONENT CODE

!r jN Is I TjR ju I 12 17 PRIME COMPONENT SUPPLIER lB_J 43 COMPONENT MANUFACTURER IRl3!7iOJ 44 47 VIOLATION L1J 48

@:Ifil !An investigation revealed that a crack in a steam generator blowdown pipe allowed 7

8 9 [ofgl I steam to impinge upon the 11A1 1 loop TH RTD, causing it to erroneously read low.

The 80

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7 8 9

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Lolunic 7

8 9 ao characteristics of the installed spare RTD were also incorrect because (con 1 t) J 8Q FACiUIY METHOD OF STATUS

% POWER OTHER STATUS DISCOVERY DISCOVERY DESCRIPTION

((i]

~ lo I 6j sJ IN/A

~

N/A

• 7 8 9

10 12 13 44 45 46 BO FOFlM OF ACTIVITY CONTENT N/A rn RELEASED OF RELEASE AMOUNT Of ACTIVITY lLl WL N/A LOCATION OF RELEASE 7

8 9

10 11 44 45 80 PERSONNEL EXPOSURES NUMBER TYPE

DESCRIPTION

[2El I o I oJ o I liJ N/A 7

8 9 11 12 13 80 PERS"ONNEL INJURIES NUMBER

DESCRIPTION

EEi I O I 010 J L N/ A 7

8 9 11 12 *---------------------------------------B_JO OFFSITE CONSEQUENCES rn LN/A 7

89 -------------*----------------

_J BCJ LOSS OR DAMAGE TD FACILITY TYPE

DESCRIPTION

.[i)) ~

N/A 7

8 9 10 80 PUBLICITY [ill] LN/A 7

8 9 --------------

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£.,Q ADDITIONAL FACTORS [i]~I I The health and safety of the* general public were not affected because the other t,,,o 7

8 9 80

!Jii! L<:Eerable protection channels would have tripped the. unit if necessary.

7 89

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8-0 N.A.ME:

T. L. Bauconi ------------

PHONE: (804) 357-3184 GPO 681 * ~67

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e CAU~TIESCRIPTION (con' t) of the steam leak.

After the leak was stopped, the RTD's returned to normal as they dried.

The normal RTD was returned to service.

The same model RTD's are in use in both units.

Any long term corrective action will be described in subsequent update reports to AO-Sl-75-19, previous report date October 2, 1975.

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