ML20086P830

Special Rept 91-006:on 911121,operators Depressed Test Button to Energize Relay K615 But EDG a Would Not Start. Caused by Incomplete Description of Initial Conditions in Surveillance Procedure.Statement Added to Procedure

ML20086P830
Person / Time
Site:	Wolf Creek
Issue date:	12/20/1991
From:	Bailey J WOLF CREEK NUCLEAR OPERATING CORP.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
91-006, 91-6, NO-91-0356, NO-91-356, NUDOCS 9112270210
Download: ML20086P830 (3)

Text

t h W@ NUCLEAR LF CREEK OPERATING C John A. Dailey vice President Operations December 20,1991 NO 91-0356 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Mail Station Pl-137 Washington, D. C. 20555

Subject:

Docket No. 50-482: Special Report 91-006 The attached Special Report is being submitted in accordance with Technical Specification 4.8.1.1.3 and 6.9.2 concerning an invalid failure of Emergency Diesel Generator "A'.

Very truly yours, O t[t John A. Baildy (

Vice President 1 Operations JAB /aem Attachment cc A. T. Howell (NRC), w/a R. D. Martin (NRC), w/a G. A. Pick (NRC), w/a W. D. Reckley (NRC), w/a n -!

l b"}0 g I

'., ; 2. 2 i [ ) { i -i;.._ 'O Box 411/ Burlington. KS 66839 > Phone-(316) 364-8831

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An Equal Opportunny Employer M F HC VET

.t Attadunant to 10 91-0356 lbge 1 of 2 SPICIAI, RF30fP 91-006 Invalid Pailum of ihnnyvxy Diem 1 Grsnrntor *A" mis report describes an invalid failure of DIergency Diesel Generator (EDG)

"A" which occurred on Ibvember 21, 1991. his report is being subnitted in accordance with 'Ibchnical Specifications 4.8.1.1.3 and 6.9.2.

Dimqy_rTCN OF WFNIS On Ibvember 21, 1991, with the plant in Mode 5, Cold Shutdoan, survoillance procedure STS IC-615A was being perfonied. his pmcedum pertonus a functional test of Train A Safety Injection slave mlay K615, as Itquimd by

'Ibchnical Specification 4.3.2.1, Table 4.3-2(1b) . Upon energization of the relay frun the Safeguards Test Cabinet, several pieces of equipient are actuated, including EDG "A". At 0027 hours3.125e-4 days <br />0.0075 hours <br />4.464286e-5 weeks <br />1.02735e-5 months <br /> an operator depressed the test button to energize relay K615. Operators noted that EDG "A" didn't start.

We test button was depressed a second tine at 0031 hours3.587963e-4 days <br />0.00861 hours <br />5.125661e-5 weeks <br />1.17955e-5 months <br /> in an attempt to detennine the cause of the problem. A technician detennined that no relays had energized as would nontally be expected. Shortly afterward operators realized that both trains of the Solid State Protection System (SSPS) were placed in test for Mode 5. SSPS Train "A" would need to be in nornal in order for the relays to actuate. Operators returned the SSPS Train "A" to normal in accordance with procedures and successfully perfonted STS IC-615A. 'Ihis resulted in a start of EDG "A" at 0059 hours6.828704e-4 days <br />0.0164 hours <br />9.755291e-5 weeks <br />2.24495e-5 months <br />.

HOCTP CAIEE AND (IERICPIVE JCPIONS We root cause of this event was an incmplete description of initial conditions in STS IC-615A for testing in lede 5. 'Ihis surveillance procedure is required to be performed quarterly for Modes 1, 2, 3 and 4. It was being performed in Mode 5 to alloa for its empletion prior to entering Mode 4. In order to perfonn this procedure, the SSPS must be in nornal. Ibwver, in Mcxie 5, the SSPS is in test in order to prevent an inadvertent safety injection during shutdown. Since STS IC-615A is typically performed in Modes 1, 2, 3, or 4, this procedure did not include a requirment to ensure the SSPS is in normal prior to the performance of the test. In order to provent similar events fran occurring, a statement has been added to S'IS IC-615A and B to require verification that the train's general warning annunciator is clear prior to irrformance of the test. h is will ensure the SSPS is in normal when conducting the test.

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a-Attadunmt to No 91-0356 Rxp 2 of 2 FAUlllE CJgi,IFICATICN 1his invalid failure was the msult of procedure error concerning test equipment not used in the mergency operating node. Therefore, this event is not considered a valid test or failure in accordance with paragraph C.2.e.(2) of Regulatory Guide 1.108. EDG "A" had been declared inoperable prior to this test; therefore, this event had no affect on the availability of the EDG.

'1his invalid failure does not affect the current surveillance test interval of 31 days as required in Table 4.8-1 of ibchnical Specification 3.8.1.1.

Uhrough tknunber 21, 1991, there have been 3 valid failures of EDG "A" in the last 100 valid tests. Frm the tinn of the last valid failure of ECG "A" on Decmter 10, 1987, EDG "A" has undergone 72 sucmssful valid tests. Too last invalid failuru ot' ElXi **A' occurred on March 4,1991 (Special Report 91 002) .

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