ML19318D132

LER 80-023/03L-0:on 800526,during Surveillance Testing, Channel B of Rod Block Monitor Sys Determined to Be Out of Calibr.Caused by Misinterpertation of Tech Specs. Requalification Program Will Include Sys Review

ML19318D132
Person / Time
Site:	Pilgrim
Issue date:	06/26/1980
From:	Mcloughlin M BOSTON EDISON CO.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML19318D108	List: ML19318D107 ML19318D132
References
LER-80-023-03L, LER-80-23-3L, NUDOCS 8007070388
Download: ML19318D132 (2)

Text

___

(7 77)

LICENSEE EVENT REPORT O CONTROL BLOCK: l t

l l l l l lh 6

(PLEASE PRINT CR TYPE ALL RECulIED INFIRMATl!N)

' @ l 8Mf l A LICENSEE lPlP l S l 1 l@l0 l0 l- l0LICENSE 1.,

l0 l0NUMBER l0 l 0l -l 0l 0l@l264 l 1l 25 1l 1l LICENSE TYPE 1l@l Jo l

57 CAT 68 lg 7 CODE 14 CON'T lolil 7 8

[on*C[ 60 l L @l 61 0 l 5OOCKET l 0 NUMB l- l0ERl 2 l 968l 3 69@l 0lEVENT Sl DATE 21 6l 8l74Ol@l 75 0l6 l2 DATE REPORT l6 l8 l080l@

EVENT DESCRIPTION AND PROBABLE CONSEQUENCES h ITTTll On June 16 1980 a management review revealed that operation of the Rod Block l 10 l 3 l l Monitor between the period of April 23 to April 26, 1980 was contrary to PNPS l lTTTl l Technical Specifications. I IO15l l Refer to Attachment for details. I 10161l I ITTT1I i 10181 I l 80 7 8 9 OE CODE S 8C E COMPONENT CODE SUS O'E SU E 10191 'lR lB lh (A j@ Wh l T I Nl S l T l R l U l@ W@ y @ 20 7 8 9 to 11_ 12 13 18 19

_ SEQUENTI AL CCCURRENCE REPORT REVISION LE R EVENT YE AR REPORT NO. CODE TYPE N O.

@ ygg!RO a

l8101 l-l l 01213 l l_/_] l0 l3 l lt l l-l l0 l

,_21 22 23 24 26 27 28 29 30 31 32 AK N AC O ON PLANT ME HOURS SS I PO 8. SUPPLIE MANUFACTURER lE JJ l@ J @34 l33Z l@ l36Z l@ l 010 l 0 l 0 l 31 40 l y l@

41 lNl@

42 lNl@

43 lGl0lal0l@

44 47 CAUSE OESCRIPTION AND CORRECTIVE ACTIONS h II l 0 l l Refer to Att ichment l l

lt 11 J I i 2 I I I

LL.L.J l I

L'_L4J l 80 7 G 9

$A S  % POWER OTHER STATUS DIS O Y OISCOVERY DESCRIPTION y [C_J@ l 0 l 4 l 7 l@l N.A. l lBl@l** ROUTINE TESTING l A!riviTY cO# TENT rELE ASED OP RELEASE AMOUNT OF ACTIVITY LOCATION OF RELEASE i s Lz_J @ Lz.J@l N.A. l l N.A. l 7 8 9 10 11 44 45 80 PE950NNEL EXPOSURES NUMBER TYPE DESCRIPTION W l0l0l0l@lZl@l N.A.

l PERSONNE L iNau'JiES

~unER DESCRirTiO~@

l 7

> R 8 9 10 l010 l@l12 11 N.A.

80 LOSS OF OR DAMAGE TO FACILITY TYPE D E SCRIPTION 1 9 N.A.  !

7 8 9 10 80 2 0 ISSUElto @DE CRIPTION__manBS N.A. l IlllIIlllllll 7 8 9 $QU4V* ' 68 69 80 3 NAME OF PREPARER Mr. M. Thomas McLoughlin pggyg;617-746-7900 g

BOSTON EDISON COMPANY

. . PILGRIM NUCLEAR POWER STATION DOCKET WO. 50-293 Attachment to LER 80-023/03L-0

• Description On May 26, 1980 at approximately 1700 hours0.0197 days <br />0.472 hours <br />0.00281 weeks <br />6.4685e-4 months <br /> while conducting daily surveil-lance testing it was determined Channel B of the Rod Block Monitor (RBM) system was out of calibration. Coincident with this determination it was ob-

' served that Channel A of the RBM was bypassed. Channel A was removed from bypass routinely checked and found to be operating properly. Upon request from the Watch Engineer to verify proper RBM operation, I&C personnel immediately initiated a functional check of both channels. No problems with Channel 'A' were discovered. Channel 'B' was found to have a faulty Null Sequence card.

Review of the Channel 'B' problem indicated that it would not have prevented

. Channel B of the RBM from initiating a rod block if a local core power surge was experienced while control rods were being pulled.

An investigation revealed that Channel ' A' of the RBM was probably bypassed on May 23, 1980 at 1351 hours0.0156 days <br />0.375 hours <br />0.00223 weeks <br />5.140555e-4 months <br />. No apparent reason for this bypass could be de-termined. Additionally a priority 'B' Maintenance Request No. 80-3082 was issued on May 22, 1980 which indicated that RBM A & B were out of calibration.

Technical Specification Table 3.2.C Note 1 indicates that if the minimum number of operable instrument channels per trip system cannot be met for one of the two trip systems, this condition may exist for up to seven days provided that during that time the operable system is functionally tested immediately and daily thereafter. If this condition cannot be met for both trip systems, the systems shall be tripped. Contrary to note 1 no functional test was performed on Channel B of the RBM and the issuance of MR 80-3082 indicates it was not one hundred percent reliable.

Cause This occurrence appears to have resulted from failure to interpret the signi- ,

ficance of T.S. Table 3.2.C and the frequency of RBM rod block alarms.

Corrective Action The following corrective actions are being taken:

1. W.E. Instruction Log entry was originated to preclude a similar occurrence and inform the Watch Engineers prior to the formalization of action via a station pro'cedure.

2. The reactor operator requalification program will include a review of oper-ation and corrective action for the RBM system.

3. Volume VIII procedure is being written to assist the operators to initiate action if a RBM channel malfunctions.

, These measures are believed adequate to prevent occurrences of this type in the future. I e N -