ML19343A229

LER 80-035/03L-0:on 800814,during Containment Spray Sys Automatic Actuation Test,High Drywell Pressure Switches IP-15A & IP-15D Tripped at Higher than Specified Setpoint of 2 Psig.Caused by Instrument Repeatability

ML19343A229
Person / Time
Site:	Oyster Creek
Issue date:	09/10/1980
From:	Ross D JERSEY CENTRAL POWER & LIGHT CO.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML19343A228	List: ML19343A227 ML19343A229
References
LER-80-035-03L, LER-80-35-3L, NUDOCS 8009160474
Download: ML19343A229 (3)

Text

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NRC FORM 366 U. S. NUCLEAR REGULATORY COMMISSION (7-77)

LICENSEE EVENT REPORT CONTROL BLOCK. l l I l l l (PLE ASE PRINT OR TYPE ALL REQUIRED INFORMATION) l 0 l 11 l N ILICENSEE J l 0 lCCCE C l P l141 l@l 0 l 0 l -l 0 uCENSE l 010 Nuv8ER l0l0l I O l 0 j@l 4 l 1 l 1 l 1 l 1 Ihl_ I l@

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[*% l 60L l@l 015 lOOCK 61 0 lET0NUVSER l 0 l 2 ] l6al 969hl 01811 EVENT DATEl 4 ! 8 l 0 hl 01 74 75 REPORT oOATE I l l 0 l80 A l 0 lh EVENT DESCRIPTION AND PROBABLE CONSEOUENCES h 10!21 l on Aucust 14 1980. while performine the " Containment Sorav Sys tem Auto- I l o 13 l l matic Actuation Test", high drvwell pressure switches IP-15A and IP-15D l l o 141 I tripped et a value greater than that specified in T.S. Table 3.1.1. Item I Io Isl l E.1. The as-found trio coint for IP-15A was 2.04 psig and that for IP- 1 I O 16 I I ISD was 2.15 osin. The desired setooint is 2.00 osie maximum. The  !

lO I7I I safety sienificance is considered minimal since the switches would have l 1 o Ie l I actuated but at a pressure slightiv higher than that specified. 80 I

7 8 9 SYSTEM CAUSE CAUSE COMP. VA LV E CODE CODE SUSCCDE COMPONE N T CODE SUSCODE SUSCODE 10191 7 8 l Sl Blh l Xlh l Z lh l Il Nl Sl Tl Rl Ulh l Sl@ l Zlh 9 10 11 12 13 18 19 2Q SEQUENTI AL OCCURRENCE REPORT REVISION EV ENT YE AR R EPORT NO. CODE TYPE N O.

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44 47 33 CAUSE DESCRIPTION AND CORRECTIVE ACTIONS Iiloll The cause of the event is attributed to ins trument repeatabilitv. 1 Ii Ii l l Pressure switch IP-15A was adjusted to trip within the Technical Soeci- l l, i7l [ fication limit. Due to difficulties encountered in getting pressure l l i l 31 l switch IP-15D to repeat following adjustment, the high alarm switch l Ii64l l assembiv was replaced and a satisfactorv tes t was performed. I 80 7 8 9 ST ,S 5 POWER OTHER STATUS SCO RV O'SCOVERY OESCRIPTION li l5 l l lh l0l9l5l@l NA l l B l@l Surveillance Test l ACTIVITY CO TENT RELEASEO OF RELEASE AMOUNT OF ACTIVITY LOCATION OF RELEASE NA l NA l l1 l68 l9 l Zl@

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IS$v E DESCRrPTION 12 )9 ol Whl Weekly News Release l ll lllllllll!l}

7 3 to 68 69 80 5 Donald A. Ross 201-455-8784 {

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4 Jersey Central Power & Ught Company

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.k--k. ,z.-! Mac: son Av9nue at Punch Bowl Road i Mornstown, New Jersey 07950 (201)455-8200 OYSTER CREEK NUCLEAR GENERATING STATION Forked River, New Jersey 08731 Licensee Event Report Reportable Occurrence No. 50-219/ 80-35/ 3L Report Date Sep tember 10, 1980 Occurrence Date Augus t 14, 1980 Identification of Occurrence Containment Spray System high drywell pressure switches IP-15A and IP-15D tripped at a value greater than that specified in the Technical Specifications Table 3.1.1, item E.1.

This event is considered to be a reportable occurrence as defined in the Techni-cal Specifications, paragraph 6.9.2.b. (1) .

Conditions Prior to Occurrence The plant was operating at steady s tate power.

Plant parameters at the time of occurrence were:

Power: Core, 1833 MRt Electrical, 585 MWe 4 gpm Flow: Recirculation, 15.3 x 10 Feedwater, 6.6 x 106 lb/hr Description of Occurrence On Thursday, August 14, 1980, while performing the " Containment Spray System Automatic Actuation Tes t", the IP-15A and IP-15D trip points were found to be less conservative than those specified in the Technical Specifications. S u r-veillance testing on the High Drywell pressure switches for the Containment Spray Sys tem revealed the following data:

Pressure Switch Designation Desi red Setpoir.t As Found As Left IP-15A ;E 2 psig 2.04 1.96 IP-15B  ;[ 2 psig 1.98 1.98 IP-15C j[ 2 psig 2.00 1.99 IP-15D  ;[ 2 psig 2.15 1.98 Jersey Centrat Power & Lght Comcany is a Member of tre General Pubhc Uttt:es System L

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Reportable Occurrence No. 50-219/ 80-35/ 3L Page 2 Sep tember 10, 1980 Apparent Cause of Occurrence The cause of the occurrence was attributed to instrument repea tability. The high alarm switch setpoints are set at 2.0 + 0.1 psig and the long term repeatability of the instruments is approximately 2-3% (.2 .3 psig) of full range. Therefo re, although the instruments will be operating within design accuracy, the techni-cal specification limit of 2.0 psig can be exceeded during surveillance testing.

Analysis of Occurrence The Containment Spray System consists of two independent cooling loops, each capable of removing fission product decay heat from the primary containment after a postulated loss of cooling accident. The containment spray system auto-matically initiates upon receipt of two high drywell pressure and two reactor low-low water level signals in either of two trip systems.

The safety significance of this event is considered minimal since the high dry-well pressure switches would have actuated but at a slightly higher pressure than the required setpoint. This function would have been delayed by only a small fraction of a second (approximately 0.1 seconds from the start of the design basis loss of coolant accident) . Since the reactor low-low water level setpoint is not expected to be re' ached until approximately 4 seconds from the start of the design basis accident, the delay in actuating the high drywell pressure switches would have had no effect on initiating the containment spray system.

Corrective Action Pressure switch IP-15A was adjus ted to trip withd 1 the Technical Specification limit of < 2 psig. Due to difficulties encounte.ed in getting pressure switch IP-15D to repeat following adjustment the high alarm switch assembly was re- -

l placed and tested satisfactorily.

Failure Data Manufacturer - ITT Barton Model - 228A Indicating Pressure Switch Range: 0-10 psig

.