ML19309C982

LER 80-026/03L-0:on 800307,during Steady State Operation, Drifting Low Power Range Monitor Caused Process Computer to Indicate Operation in Excess of Thermal Limits.Caused by Drifting Low Power Range Monitor 44-37C,due to Age

ML19309C982
Person / Time
Site:	FitzPatrick
Issue date:	04/03/1980
From:	W. Verne Childs POWER AUTHORITY OF THE STATE OF NEW YORK (NEW YORK
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML19309C979	List: ML19309C977 ML19309C982
References
LER-80-026-03L, LER-80-26-3L, NUDOCS 8004090440
Download: ML19309C982 (2)

Text

NMcTORM M U. S. NUCLEAR REGULATORY COMMISSION 9* (7-7/l + LICENSEE EVENT REPORT CONTROL BLOCK. l l l l l lh (PLEASE PRINT OR TYPE ALL REQUIRED INFORMATIONI l0 li] lN lY IJ l A lF l1 l@l 0 l0 l- l0 10 !0 l0I-l0l0l0l@lhlIl111lIl@l

• 'l 'J LICENSEE Colt 14 l5 tiCE!,L E *. ;'/e E H h .6 UCE NSE T YPE JO l

'a i 'Af U l@

CON'T 10121 ."g 3 l L J@l 0 15 l 0 l 0 l0 13 l 3 13 l@l 013 l 0171810 l@l O ! 4101 31 81 OCJ l@ 15

1. 4 kJ 61 DOCK E T NLYdE H M CJ EVENT OATE 14 REPOHT D A T E EVENT DESCPIPTION AND PDOHABLE CONSEQUENCES h to121 Lourino normal steady state operation, a drifting LPRfi caused the process l

[ o 13 l l computer to indicate operation in excess of the thermal limits of T.S. 3.1.B. ]

I o I 4 I l No hazard existed. See attachment for details. ]

• Io Iul i I lo lo l l I lo 11! I I 10181 1 I

? H 9 du SY ST E U CAUSE CAUSE CO*39 VALVE CObf COUi SUHCUUE COM9Cf.EN T CODE SUBCODE SUBCOLE lo19]

/ 8 l llE l@ W@ l F l@ l1IJ lN l 5 lT lR lU l@ lE l@ ]@

') 1(i it il 1 -i l 'a 20 SE QUE N TI A L OCCU R N f.r.CE RErOni R E V15;C N u a un E V 5. *. T Y E A H HEPOHTt.O COCE TYPE NC O .ylr; 18!0I l-l 1012 l 6]

24 pl [0 l3 l

?J l Ll 3')

[_j l0 l

_lt // 23 .b 27 28 31 32 ACTf"'N IU TtM8F EFFECT SHUIDG..N ATT ACM.* E N T NPRD 4 PRIVE COMP. CO*.'PO *M N T T4Ar* A(. f iGN ON PL AN T ML TedOD HOUHS SUaYtTTED FORM ms SUPPLI E R MANLFAC RED LxJ81 ^ lO JJ 4 LZJ@

3's LzJ@

Jn l

3/

i I .

40 I LYjg 41 l H lg 42 l N lg 43 l G l0 l 44 l0 ;

47 CAUCE DESCHIPTION AND COHHECTIVE ACTIONS h ii 1 ; I l Dri f tinq of LPRti 44-37C due to age. Bypassed drifting LPRM. Al1 LPRM j li lij i strings will be replaced during Spring 1980 Outage. No additional action l

, l,l 1 [ required. See attachment for details. I i 1 l I t i l 41 1 I i u 2 w F AE1'.t Y v .

METHODOk ST A t u'2  % PGAf ti OTHE R ',T A T US OgSCOt[qy DISCOV6 HY DE5CHtritON  %'

1  %

b @ l0l9l2l@l " "

NA l lA l g Operator Observation

• s *> a l

A2nm,rv COL.o -

n,u A En Or iu u A a EOC A T,0N O, nEtm @

AccoNT Or ACnv,Tv @ l li lo l L1J @ UGI F 6 ) 10 33 Na 44 I

4 <,

Fm gg i

Pt FP,0NNt L f 4 61 N 14 3 [ S NLYHER T v r'r Os scH!P iloy M i i loI0l0_j@lZl@l NA J

> 1 o 2 i, o o o etHsow t <N;umcs NtNHIH DrSC*npiiON -

Ii11IeIolOl@l

, 8 s is i2 NA l

LQZ Of Of 4 OAY%E TO F ACILITY TYPE DE SQliP f u';N 7

8 l_Z_j@l

'J 10 NA 3 0 0 4090 Nd I ge 1% CHIP TION

l > l ol LdUE 10@l NA l llllllllll ll l 7 41 9 t,8 69 8@

NAVE Or PHEPARER W. Verne Chiids pn oy g . 315-34?-3840 4

.s POWER AUTHORITY 0F THE STATE OF NEW YORK JAMES A. FITZPATRICK NUCLEAR POWER PLANT 00CKET NO.50-333 ATTACHMENT TO LER 80- 026/03L-0 Page 1 of 1 During normal operation, a routine process computer printout of reactor thermal limits indicated that the Minimum Critical Power Ratio (MCPR) was in excess of the limits of Technical Specification Paragraph 3.1.B. MCPR values are displayed by the process computer in terms of the ratio of the most limiting MCPR value present in the core to the Technical Specification MCPR limit. Thus, when MCPR for any fuel type is at the limit the computer displays a value of 1.000 meaning at least one (1) core location is at the Technical Specification limit. In the case of the computer printout of concern, a value of 1.007 was displayed.

No recent power, recirculation flow or control rod position changes had been made. Evaluation of LPRM data indicated that LPRM 44-37C had drifted. This drifting caused the plant process computer to indicate MCPR value in excess of the Technical Specification limits.

The LPRM was bypassed and another printout of core thermal limits was obtained revealing a MCPR value of 0.970 compared to a limit of equal to or less than 1.000. Replacement of the LPRM detectors is scheduled for the 1980 Refueling Outage. This action will remove LPRM 44-37C and a number of other detectors which have failed due to normal age and use. The event did not represent a significant hazard to the public health and safety.

l 9