ML20114C519

Special Rept 92-03:on 920705,electromatic Relief Valve C Inadvertently Opened While Testing Pressure Switch of Valve A.Caused by Personnel Error.Training Session Will Be Held & Engineering Work Request Submitted Re Switch Terminal Point

ML20114C519
Person / Time
Site:	Oyster Creek
Issue date:	08/26/1992
From:	J. J. Barton GENERAL PUBLIC UTILITIES CORP.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
92-03, 92-3, C321-92-2233, NUDOCS 9209020253
Download: ML20114C519 (4)

Text

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..t GPU Nuclear Corporation 5 ..S Muclear  :::en:r3ee Fo.ked Rwer, New Jerse) 08731-0388 609 971-4000 Wnter's Direct Dial Nurnber:

CS21-92-2233

, August 26, 1992 U.S. Nuclear Regulatory Commission i Attention: Document Control Desk Washington, D.C. 20555 Gentlemen:

Subject:

Oyster Creek Nuclear Generating Station Docket No. 50-219

, Special Report No. 92-03 Enclosed is Special Report No. 92-03 which is submitted in accordance with Technical Specification 6.9.3.1.

If you should have any questions or require further information, please contact Brenda DeMerchant, OC Licensing Engineer at (609) 4- 971-4642.

Very truly yours, _

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John J. Barton ice President & Director l Oyster Creek 1

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l JJE/BDEM:jc cc: ' Administrator, Region 1 Senior NRC Resident Inspector Oyster Creek NRC Project Manager i

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SPECIAL REPORT NO, 92-03 OCCURRENCE QI7El 7/5/92 IDENTIf1 CATION OF_ OCCURRENCE:

During performance of.the Electromatic Reli?f Valve pressure switch test and calibration, the 'C'-Electromatic .telief Valve (EMRV) was inadvertently opened. This-occurred when the instrument and control (I&C) technicians, after testing the pressure switch for the 'A' EMRV, requested:that the_ control room-turn off the control-station for~the 'B' EMRV so that it could be tested. The I&C technicians-then mistakanly tested the pressure switch for the 'C' EMRV, which.

caused the ' C' EMRV to-lift.

The five Electromatic Re.ief Valves (EMRVs) at Oyster Creek provide the automatic depressurization function for the Emergency Core

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Cooling System (ECCS). The Automatic Depressurization System (ADS) is provided to depressurize the reactor to ensure that the core spray system will be effective for breaks which are too small to result in-significant depressurization, but which exceed the capacity of-available high pressure injection paths'. The-ADS function of the-EMRVs'is not affected by the-pressure switches. The EMRVs also provide a high pressuce relief function for tne reactor pressure vessel. The EMRVs discharge to the torus to depressurize the reactor to approximately 50.psig.

D_pSCRIPTION OF OCCUJLILENCE:

During the 1600 to 2400 shift _ on July 5, 1992, two' instrument and ,

control technicians were scheduled to perform the EMRV pressure switch test and calibration surveillance. .After a review of the surveillance, the Group Shift Supervisor (GSS) gave the I&C technicians permission to perform the. surveillance at 1730 hours0.02 days <br />0.481 hours <br />0.00286 weeks <br />6.58265e-4 months <br />.

The I&C technicians want to inntrument rack RK01, which is located on the 67' platform elevation, accessed from the reactor building 75' alevation. After requesting the control. room operators place the control switch for the 'A' EMRV in the off position, they performed a calibration on the pressure switch for the 'A' EMRV.- Control-room.

operators then placed the control switch for the 'A' EMRV in_

Jautomatic.

. . s 1 4 Speci$1 Report 92-03 i Page 2 While still at instrument rack RKJ1, the I&C technicians requested that the control attch for the 'B' EMRV be placed in the off position per step o.3.1 of the surveillance in order to test the pressure switch for the 'B' EMRV. This instrument is located on the reactor building 51' elevation (west) and is so stated in section 6.3 of the procedure. However, the I&C technicians.instead went to the pressure switch for the 'C' EMRV on instrument rack RK02, which is located on the reactor building 51' alevation (east) and proceeded.to perform a calibration of the pressure switch for the ' C' EMRV instead of the pressure switch for the 'B' EMRV. Prior to performing the calibration, the I&C technicians did not verify that they were at the proper pressure switch.

The technicians then performed step 5.3.2 of the procedure which is to insure that the control switch is turned off by verifying no voltage is present at the contacts of the switch. The technicians believed they were on the proper-switch when the voltmeter indicated 6.2 mvdc vice the 120 yde expected, had the switch been energized.

The location to check for voltage (connectors L1 and L2) was in a tight corner of the sensor box, It is thought that the meter may not have been making proper contact. The technicians then closed-the switch isolation valve without using-the surveillance procedure; therefore, they did not verify that they were closing the correct valve (step 6.3.3). Step 6.3.4-requires the test connection valve V-130-164 to be opened. However, the pressure switch for the 'C' EMRV does not have a test connection valve.

l The technicians proceeded to increase pressure to test the switch, when the pressure reached approximately 1070 psig, the 'C' EMRV lifted. The control room operator turned the control station switch to off, (per procedure), which closed the 'C' EMRV. The I&C technicians were-instructed to return the_ pressure: switch to service. <

ROOT CAUdE DETERMINATION This. incident is classified as persconel error. Had the technicians

-perf ormed their duties in accordance with accepted craft-practices and expected expertise, including self checking and using the procedure "in hand" the technicians would have caught their mistake a '

minimum of four. times, as follows:

1) 'Section 6.3 of the procedure, stated the pressure switch for the

'B' EMRV was located on the Reactor building S1' elevation, west.--However, the technicians went to1the-east' area of the L

reactor building.

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Special Report 92-03 Page 3

2) After arriving at the pressure switch, the technicians did not verify that they were actually at the proper switch by verifying the calibration sticker or the label.

3) Step 6.3.3 of the procedure, stated that valve V-130-159 be unlocked and closed. Instead the technicians unlocked and closed valve V-130-117.

4) Step 6.3.4 of the procedure, stated that test connection valve V-130-164 be opened. The pressure switch for the 'C' EMRV does not have a test connection valve.

IMMEDIATE CORRECTIVE ACTION:

The 'C' EMRV was closed when the control room opera'.or turned the control station switch to off.

LONG TERM CORRECTIVE ACTION:

The I&C technicians involved in this incident will be given a requalification program that will include a training session on self-checking as well as requalifying on their 'A' core OJT surveillance, and other surveillances as assigned by the I&C superintendent. The I&C technicians involved in the incident will conduct a training session on ways to avoid a reoccurrence of this type of mistake.

The scheduled completion date for this program is November 1,-1992.

The I&C technicians will not be allowed to work on safety related systems until they'have been requalified by I&C supervision.

In addition, an Engineering Work Request will be submitted to investigate the feasibility of mo ing the switch terminal points to-an area which would allow for easier access in testing.

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