ML19263C900

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LER 78-027/03X-3 on 790214:four Helium Circulator Seal Malfunction Differential Pressure Switches Would Not Trip or Tripped Outside Limiting Conditions for Operation.Caused by Dirt Accumulation in Switches.Settings Checked Monthly
ML19263C900
Person / Time
Site: Fort Saint Vrain Xcel Energy icon.png
Issue date: 03/05/1979
From: Gahm J
PUBLIC SERVICE CO. OF COLORADO
To:
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
Shared Package
ML19263C893 List:
References
LER-78-027-03X, LER-78-27-3X, NUDOCS 7903120320
Download: ML19263C900 (5)
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REPORT DATE: March 5,1979 REPORTABLE OCCURRENCE 78-27 ISSUE 3 OCCURRENCE DATE: Feb ruary 14, 1979 Page 1 o f 5 FORT ST. VRAIN NUCLEAR GENERATING STATION PUBLIC SERVICE COMPANY OF COLORADO P. O. BOX 361 PLATTEVILLE, COLORADO 80651 REPORT NO. 50-267/ 78-27/03-X-3 Supplemental Report - Additional Information IDENTIFICATION OF OCCURRENCE:

During performance of the monthly check of the helium circulator seal malfunc-tion pressure differential switches, it was discovered that four of twelve switches either would not trip or tripped outside the limits specified in LCO 4.4.1, Table 4.4-3.

This is reportable per Fort St. Vrain Technical Specification AC 7.5.2(b)1 and AC 7.5.2 (b)2. ,

This report is submitted as a supplement to Reportable Occurrence Report No.

50-267/78-27/03-L-0, Preliminary, to provide additional information on the problems experienced with the helium circulator seal malfunction switches.

EVENT DES CRIPTION:

While the reactor was in a shutdown condition, instrument personnel performed the circulator seal malfunction (buffer-mid-buffer) switch operability check.

The switches were calibrated and tested under Surveillance Test SR 5.4.1.3.6.c-R. Due to the problems cited in Reportable Occurrence Report No. 50-267/78-27, Preliminary, a check of buffer-mid-buffer switch trip settings on a monthly basis has been undertaken as an interim measure to test operability.

The trip settings for twelve switches are listed in Tables 1, 2, 3, and 4.

CAUSE DES CRIPTION:

Dirt buildup and accumulation in the electrical switches prevented them from making proper contact.

CORRECTIVE ACTION: _

The electrical switches on PIDS-21152, PDIS-21153, and PDIS-21158 were replaced with approved spares. All switches were recalibrated.

790syg9$p

REPORTABLE OCCURRENCE 78-27 .

ISSUE 3 Page 2 of 5 CORRECTIVE ACTION (continued): l switches, Due to the continuing problems being experienceddwith on a the electrica monthly basis.

the interim check of the trip settings is being conducte differential i d During the scheduled refueling outage, three i tion. The(3) re-of the pres evaluation to determine what can be done to correct this s tua sults will be reported in a future supplemental report.

REPORTABLE OCCURRENCE 78-27 ISSUE 3 Page 3 of 5 TABLE 1 - CIRCULATOR 1A AS LEFr PDIS AS FOUND Inc.

+74 Inchaa We'jr Inc. +80 Inches Water 21149 Dec. -6 Inches Water Dec. ~5 Inches Water Inc.

+75 Inches Water Inc. +75 Inches Water 21151 Dac. -6 Inches Water Dec. -10 Inches Water

+76 Inches Water Would Not Trip Inc.__

21153 Inc. (IX3')3 Dec. -6 Inches Water i Dec. (2) -12 Inches Water TABLE 2 - CIRCULATOR 1B AS LEFT PDIS AS FOUND Inc.

+75 Inches Water Inc. +78 Inches Water 21155 Dec. -6 Inches Water _

Dec. -6 Inches Water Inc. +75 Inches Water Inc. +80 Inches I' ster 21157 Dec. -6 Inches Water Dec. -9 Inches Water Inc. +74 Inches Water Inc. +79 Inches Water 21159 _

Dec. l -6 Inches Water __

l Dec. -9 Inches Water trip.

@ "Jenotes switch (es) which would not

@ Denotes switch (es) out of tolerance.

@ Denotes switch (es) which were replaced.

REPORTABLE OCCURRENCE 78-27 ISSUE 3 Page 4 of 5 TABLE 3 - CIRCULATOR 1C PDIS AS EDUND AS LEFT 21150 Inc. +78 Inches W.cer Inc. +76 Inches Water Dec. -8 Inches Water Dec. -6 Inches Water 21152 Inc. (I)(3) Would Not Trip Inc. +75 Inches Water Dec. O Inches Water Dec. -6 Inches Water 21154 Inc. +78 Inches Water Inc. +76 Inches Water Dec. -5 Inches Water Dec. -6 Inches Water TABLE 4 - CIRCULATOR 1D P DIS AS FOUND AS LEFT 21156 Inc. @ Erratic Inc. +76 Inches Water Dec. -7 Inches Water Dec. -6 Inches Water 21158 Inc. @(I) Would Not Trip Inc. +75 Inches Water Dec. (I)(5) Would Not Trip Dec. -6 Inches Water 21160 Inc. +75 Inches Water Inc. +75 Inches Water Dec. -9 Inches Water Dec. -6 Inches Water

@ Denotes switch (es) which would not trip.

@ Denotes switch (es) out of tolerance.

@ Denotes switch (es) which were replaced.

REPORTABLE OCCURRENCE 78-27 ISSUE 3 Page 5 of 5 Prepared by: f /  % De Mich el J. Ferris Techn cal Services ngineer Reviewed by: ,

J W . Gatim echnical Services Supervisor Reviewed by: v

  • Frank M. Mathie Operations Manager Approved by: Mm 7d/ , . . 4 Don Warembourg /

Manager, Nuclear Production

NRC FORM 366

  • U. S. NUCLEAR REGULATOR TMMISSION (7 77)
  • LICENSEE EVENT REPORT CONTROL BLOCK: l 1

l l l l l lh 6

(PLEASE PRINT OR TYPE ALL REQUIRED INFORMATION) 0 1 l Cl 0 F SlVl1l@l0l0 -l0 0 0l0l0 -

0 l 025l@l264 l 1LICENSE 1l2 0 @l$7 CAT l

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i 8 9 LICENSEE CODE 14 15 LICENSE NUMBER TYPE JO CON'T 7

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OuRCE 60 L @ 61 0 l 5 l DOCK 0 l 0 l 0 l 2 l 6 l 687 @l69 0 l 2EVENT ET NUV8ER l 1OlATE4 l 7 ] 9 l@]74 75 0 lREPORT 3 l 0DATEI S l 7 80 9!@

EVENT DESCRIPTION AND PRO 8ABLE CONSEQUENCES h o 2 During tes ting it was discovered that four of twelve helium circulate r seal mal- l o a i function differential pressure switches either would not trip or tripped outside the l o 4 limits of LCO 4.4.1, Table 4.4-3. Reportable per Technical Specifications AC l o 3 l 7.5. 2(b)1 and AC 7. 5. 2(b)2. No effect on public health or safety. Redundant systen l 0 6 l not available for one of the circulators but was available for the other three o 7 l circulators. Similar occurrence Reportable Occurcer. :e Report No. 77-47. l I

o a l 80 7 8 9 CE CODE SU8C E COMPONENT CODE SU 8 CO D'E SU CE O 9 lc In lh l_Ejh W h lI lN l S lT 9 10 12 13 R l U lh 18 19 Sl@ lZ l@ 20 7 8 11 SEQU ENTf AL OCCURRENCE REPORT REVISION EVENT YEAR R EPORT NO. CODE TYPE NO.

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44 47 CAUSE DESCRIPTION AND CORRECTIVE ACTIONS i o l ITT Barton Model 289 pressure dif ferential switches failed to activate at trip point l li li l due to dirt accumulation in switches. Trip settings being checked on a monthly i Problem under investigation. l 1 7 Qasis.

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7 8 9

'*'2N75 ST spowER OTHER STATUS h '

eiSEONRv' oiSCOveRY oESCRiPriON @

i 5 l El@ l 0 l 0 0 l@l N/A l lClgl Operability Test l ACTIVITY CO TENT RELE ASED OF PELEASE AMCUNT OF ACTIVITY LOCATION OF RELEASE N/A 7

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@l 11 N/A 44 l l 45 80 l

PERSONNEL EXPOSURES ,

NUV8ER TYPE DESCRIPTION i 7

] 0 l 0 l0 l@l Z l@l N/A l

,tRSONNe'L ,mVIES NUMBER CESCRIPTION i s 10 l010j@l N/A 80 l

7 8 9 11 12 LOSS OF CR OAMAGE To FACILITY Q TYPE C E 5CRIPTION v i 9 N/A 3 9 l Z l@l10 80 F

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ISSUEU@DE l CRIPTION N/A l lllllllllllljj 1112J 68 69 80 &

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