ML19256A670

LER 78-114/03L-1 on 781110:borated Water Storage Tank Low Level Trip Setpoint Was Out of Tolerance (at 59.25 in H2O) on Safety Features Actuation Sys Channel 2.Caused by Instrument Drift of Bistable

ML19256A670
Person / Time
Site:	Davis Besse
Issue date:	12/07/1978
From:	Kovach S TOLEDO EDISON CO.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
Shared Package
ML19256A669	List: ML19256A668 ML19256A670
References
LER-78-114-03L, LER-78-114-3L, NUDOCS 7901090181
Download: ML19256A670 (1)

Text

U. S. NUCLE AR REGULATORY COMMISSION RC F ORM 366 '

(7 71) ' LICENSEE EVENT REPORT (PLE ASE PRINT OR TYPE ALL REQUIRED INFORMATION)

CONTROL BLOCK: l I

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i 8 9 lOlHlDlBlSl1l@l0l0l- 0{ LICE".SE 14  :$

0 Nl hvaEH P l F I -l Ol h 3 l@l 4 l ll 1l llSi1l@l 26 LICENSE TYPE JO ul dd

.LICEN5EE CODti C ON' T o i 3ajo RE 9 T,lL)@l0l5l DOCsET 0l -l 0l 3 l 4 6ol 6 63l@lEVENT 1 lOATE 1 l l l 0 l 7 l 8REaORT 14 75 )@l1 DATE l 280l 0 l 7 l 7 l 7 6 60 61 NUV3ER EVENT DESCRIPTION AND during PROB ABLE CONSEQUENCES the performance h of surveillance testing, it was dis- 1 o 2 l At 1130 hours0.0131 days <br />0.314 hours <br />0.00187 weeks <br />4.29965e-4 months <br /> on 11/10/78 the Borated Water Storage Tank (BUST) low level trip setpoint was out of [

I o l a l l covered that I

4 tolerance (at 59.25 inches H 0) 2 on Safety Features Actuation System (SFAS) Channel 2.

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C BWST level instrument strings shall be l a s l Technical Specification 3.3.2.1 states that The 1 o 6 l operable in Modes 1, 2, and 3 with trip setpoint 249.5 and $55.0 inches H30.

strings were operable during the period that I o 7 1 other three BWST low level instrument 1

(NP-33-78-133) o a I the setpoint for Channel 2 was out of tolerance. 80 COYP. VA LV E 7 8 9 CAUSE CAUSE SUBCODE SUBCODE SYSTENt COYPONENiCODE CCOE CODE SUSCODE R lU h Wh yh ll oE 8 I Il B}h Uh l El@ lI lN l S lT OCCURRENCE 9 10 11 12 13 Id 19 REPORT 20 REVISION SEQUENTI AL CODE TYPE N O.

LER RO EVENT YEAR REPORT NO.

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24 26 21 28 29 JO 31 32

_ 21 22 S PFLIE AtA trA T RER HOURS 22 SB iT D FO s 8.

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44 47 I33E [gl34Z lg l32Z g lJoZl@ 3e 40 41 4 CAUSE DESCR6PTION AND CORRECTIVE ACTIONS h l i o l The apparent cause of this occurrence is attributed to instrument drif t of the bi-

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li li j l stable. At 1145 hours0.0133 days <br />0.318 hours <br />0.00189 weeks <br />4.356725e-4 months <br /> en 11/10/78. Instrument and Control technicians reset the The monthly surveillance test effec- J SFAS Channel 2 BWST low level trip setpoint.

, 7 l I

l,l3)l tively spots any such instrument drif t on this setnoint.

1 80 1 4 l 7 8 9 DISCoV ERY DESCRIPTION ISCO RY OTHER STATUS STA S DO..E R ST 5031.01 l i 5 l ElQ l q '4l 9l@l NA l l B l@l Surveillance Test ACTIVITY C T E *.T LOCATION OF RELEASE AMOUNT OF ACTIVITY l, RELEASED OF RE LE ASE NA l l NA 80 l1 l68 l9 6 @ l Z l@1 7

10 1 44 45 PE RSGN'.EL E x PCCU A ES '

Nu'*9 E R TYPE C E SC PIP TION l 80 i 7 1 Di el 01@LzJ@l N^

PE RSON",E L INJ IES NuvaEs cESCR PnONh I NA 80 lil-1 1 01 01 0 @ l 7 8 9 11 12 LOSS Or en DAvscE to F4Citirv g m"@

( 09 7S0109Q3/

, s gg;mE"ON NRC USE ONLY 7 8 9 10 *

'WO T Y c DE4:a> DO*. I IIIIlllllIlI]} c3 2 o e;cg-)hlNA l l ca 69

, a 3 6 punyg419-259-5000. Ext. 230 2,

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