ML19254F906

LER 79-046/03L-0:on 791011,noted That Sequence of Manual Switching of Primary Coolant Low Level Dew Point Moisture Monitors Can Result in Degraded Mode of Limiting Conditions for Operation.Sys Operating Procedure Revised

ML19254F906
Person / Time
Site:	Fort Saint Vrain
Issue date:	11/09/1979
From:	Gahm J PUBLIC SERVICE CO. OF COLORADO
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
Shared Package
ML19254F895	List: ML19254F894 ML19254F906
References
LER-79-046-03L, LER-79-46-3L, NUDOCS 7911190386
Download: ML19254F906 (1)

Text

NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION nm LICENSEE EVENT REPORT CONTROL BLOCK: l l l l l l l (PLEASE PRINT OR TYPE ALL REQUIRED INFORMATION) 1 6 MlC 7 8 9 l6lF l S l V I 1 l@l L CENSEE CODE 14 0 l 0 l - l 0 lLICENSE 15 0 l 0NUMBER l 0 l 0 l- l 0 l 025l@l26 4 l1LICENSE l 1 l:TYPEl 0JOl@l57 CAT l l@

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EVENT DESCRIPTION AND PROBABLE CONSEQUENCES h O 2 lOn October 11, 1979, it was determined that due to procedural inadequacies, a parti- l 0 3 l cular sequence of manual switching of the primary coolant low level dew point moisture l o 4 l monitors could have resulted in a degraded mode of LCO 4.4.1. This is reportable per l o s i Fort St. Vrain Technical Specification AC 7.5.2(b)3. l 0 6 l l 0l7 l l 0 8 l 7 8 9 80 SYSTEM CAUSE CAUSE COMP. VALVE CODE CODE SUSCODE COMPONENT CODE SUSCODE SU8 CODE l0 7

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,,, SEQUENTI AL OCCURRENCE REPORT REVISION LER RO EVENTYEAR REPORT NO. CODE TYPE N O.

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44 47 CAUSE DESCRIPTION AND CORRECTIVE ACTIONS h i o l An approved field change notice (FCN 3738B) made the automatic trip on moisture l i i l monitor system failure a manual action and revised the logic to allow individual [

, 7 l moisture monitors to be tripped (rather than disabling by pairs) . However, if the

, 3 l correct switching sequence was not followed it was possible to lock out a moisture l 3 4 l monitor inadvertently. The system oeprating procedure was revised to prevent this  ;

7 8 p 9f m occurring. No further corr ivgggign is anticipated or required. 80 STATUS  % POWER OTHER STATUS DISCOVERY DISCOVERY CESCRIPTION 1 5 l El@ l 0 l 6 0 l@l N/A l Al@l Instrument Personnel Observation ACTIVITY CO TENT RELEASED OF RELEASE AMOUNT OF ACTIVITY LOCATION OF RELEASE 1 6

[_Z) h @l N/A l l N/A l 7 8 9 10 11 44 45 80 PERSONNEL EXPOSURES NUMBER TYPE CESCRIPTION 1 7 10]0l0l@lZl@lN/A l PERSONNEL INJURIES NUMBER DESCRIPTION 1 a l0l0l0l@lN/A _ . l LOSS OF OR O AGE TO FACILITY Q TYPE DESCRIPTION  %/

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