ML18038B444

LER 95-003-00:on 950901,DGs Auto Start Occurred Due to Personnel Error During Performance of Common Accident Signal Logic Surveillance.Secured DGs & EECW Pump & Counseled Electricians to Further Emphasize Need to Be More Cautious

ML18038B444
Person / Time
Site:	Browns Ferry
Issue date:	09/26/1995
From:	Hsieh C TENNESSEE VALLEY AUTHORITY
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML18038B443	List: ML18038B442 ML18038B444
References
LER-95-003-03, LER-95-3-3, NUDOCS 9510030325
Download: ML18038B444 (10)

Text

NRC FORM 366 U.S. NUCLEAR REGULATORY C(NHIISSION ,APPROVED BY (NB NO. 3150-0104 (5 92) EXPIRES 5/31/95 ESTIMATED BURDEN PER RESPONSE TO 'COHPLY MITH THIS INFORHATIOH COLLECTIOH REQUEST: 50.0 HRS.

LICENSEE EVENT REPORT (LER) FORWARD COHMENTS REGARDING BURDEN ESTIMATE TO THE INFORHATIOH'ND RECORDS HANAGEHENT BRANCH (HHBB 7714), U.S. NUCLEAR REGULATORY COMMISSION, (See reverse for required number of digits/characters for each block) NASHINGTON, DC 20555-0001 AND TO THE PAPERNORK REDUCTION PROJECT (3140.0104), OFFICE OF MANAGEHEHT AND BUDGET NASHINGTOH DC 20503.

FACILITY NAHE (1) DOCKET M(ABER (2) PAGE (3)

Browns Ferry Nuclear Plant (BFN) Unit 3 05000296 1OF5 TITLE (4) DIESEL GENERATORS AUTO START DUE TO PERSONNEL ERROR DURING PERFORMANCE OF COMMON ACCIDENT SIGNAL LOGIC SURVEILLANCE EVENT DATE 5 LED HNIBER 6 REPORT DATE 7 OTHER FACILITIES INVOLVED 8 SEQUENT IAL REVISION FACILITY NAME DOCKET NUMBER HON'IH DAY YEAR MONTH DAY YEAR NA NUHBER HUHBER 09 01 95 95 003 00 09 '6 95 FACILITY NAHE NA DOCKET NUHBER OPERATING THIS REPORT IS SUBHITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR  : Check one or mor e 11 IHX)E (9)

N 20.402(b) 20.405(c) X, 50.73(a)(2)(iv) 73.71(b)

POMER 20.405(a)(1)(i) 50.36(c)(1) 50.73(s)(2)(v) 73.71(c)

LEVEL (10) 000 20.405(a)(1)(ii) 50.36(c)(2) 50.?3(s)(2)(vii) OTHER 20.405(a)(1)(iii) 50.73(a)(2)(i) 50.73(s)(2)(viii)(A) (Specify in 20.405(s)(1)(iv) 50.73(s)(2)(ii) 50.73(s)(2)(viii)(B) Abstract below snd in Text, 20.405(a)(1)(v) 50.73(a)(2)(iii) 50.73(a)(2)(x) NRC Form 366A LICENSEE CONTACT FOR THIS LED 12 HAHE TELEPHONE HUHBER (Include Area Code)

Clare S. Hsieh, Compliance Li.censing Engineer (205)729-2635 C(NIPLETE ONE LINE FOR EACH C(SIPOHENT FAILURE DESCRIBED IN THIS REPORT 13 SYS REPORTABLE REPORTABLE CAUSE COMPONENT CAUSE SYSTEM COHPOHEHT MANUFACTURER TEM TO HPRDS SUPPLEMENTAL REPORT EXPECTED 14 EXPECTED HONTH DAY YEAR SUBlllSS I ON YES (If yes, complete EXPECTED SUBMISSIOH DATE).

X, NO DATE (15)

ABSTRACT (Limit to 1400 spaces, i.e., approximately 15 single-spaced typewritten lines) (16)

On September 1, 1995, at 1834 hours0.0212 days <br />0.509 hours <br />0.00303 weeks <br />6.97837e-4 months <br />, all four Unit 3 diesel generators (DGs) inadvertently auto started during the performance of common accident signal logic testing. At 1835 hours0.0212 days <br />0.51 hours <br />0.00303 weeks <br />6.982175e-4 months <br />, Emergency Equipment Cooling Water (EECW) pump A3 started as expected to provide cooling water to the DGs. During this testing, electricians placed. a boot on a relay to inhibit a pre-accident signal to the Unit 3 DGs. While placing the boot, the electricians made up the relay contacts to start the DGs. This event was caused by personnel error.

Contributing to the event was the difficulty in performing this task. Corrective actions involved securing the DGs and the EECW',pump, and counseling the electricians to further emphasize the need to be more cautious when working on energized equipment. TVA is also.

reviewing the present methodology of placing a boot on energized relay contacts to determine if other methods can be used during testing. At the time of this event, Unit 3 was defueled and in a long-term outage. Unit 2 was operating at 100 percent power, and Unit 1 was shutdown and defueled. This report is submitted in accordance with 10 CFR 50.73 (a)(2)(iv) as a condition that resulted in automatic actuation of an engineered safety feature.

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95i0030325

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950926 PDR ADO(.K 05000296 S PDR

ii NRC FORM 366A U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY Q(B NO. 3150-0104 (5-92) EXP I RES 5/31/95 ESTIMATED BURDEN PER RESPONSE TO COMPLY WITH THIS INFORMATION COLLECTION REQUEST: 50.0 HRS. FORWARD COMMENTS REGARDING BURDEN 'ESTIMATE TO THE INFORHATION AND RECORDS MANAGEMENT BRANCH (MNBB 7714), U.ST NUCLEAR REGULATORY COMMISSION, LICENSEE EVENT REPORT 'WASHINGTON, DC 20555.0001, AND TO THE PAPERWORK REDUCTION TEXT CONTINUATION PROJECT (3150-0104), OFFICE OF HANAGEHENI'ND BUDGET, WASHINGTON, DC 20503 FACILITY NAME '(1) DOCKET HINIBER (2) LED HIRIBER (6) PAGE (3)

YEAR SEQUENTIAL REVISION NUMBER NUMBER Browns Ferry Unit 3 05000296, '95 003 00 2 of 5 TEXT If more s ce is r uired use additional co ies of NRC Form 366A (17)

I ~ PLANT CONDITIONS

'Unit 3 and Unit 1 were shutdown, and defueled. Unit 2,was operating at 3291 megawatts thermal (approximately 100 percent power).

DESCRIPTION OF EVENT A~ Event At 1834 hours0.0212 days <br />0.509 hours <br />0.00303 weeks <br />6.97837e-4 months <br /> on September 1, 1995, all four Unit 3 diesel generators (DGs) [EK] inadvertently auto started during the performance of Common Accident Signal (CAS) logic surveillance instruction (SI) 1/2-81-4.9.A.3.a. At 1835 hours0.0212 days <br />0.51 hours <br />0.00303 weeks <br />6.982175e-4 months <br />, Emergency Equipment Cooling Water (EECW) [BI) pump A3 started as expected to provide cooling water to the Unit 3 DGs.

At the time of the event, electricians (utility, nonlicensed) were conducting tests on the Division I CAS logic and were placing a boot on a Unit 3 pre-accident signal'elay [RLY). The boot was being placed on the contacts of relay 14A-K35A (General Electric (GE) type HGA located in, Panel 3-9-32 in the Auxiliary Instrument Room) to inhibit a pre-accident signal to the Unit 3 DGs.

When the Unit 3 DGs auto started, the Shift Operations Supervisor (SOS) [utility, licensed) notified the personnel in the Auxiliary Instrument Room to stop activities associated with the surveillance on the CAS logic. At 1901 hours0.022 days <br />0.528 hours <br />0.00314 weeks <br />7.233305e-4 months <br />, the DGs were stopped and at 1907 hours0.0221 days <br />0.53 hours <br />0.00315 weeks <br />7.256135e-4 months <br /> EECW pump A3 was stopped. The DGs were returned to standby readiness at 1914 hours0.0222 days <br />0.532 hours <br />0.00316 weeks <br />7.28277e-4 months <br />.

This event is reportable in accordance with 10 CFR 50.73 (a)(2)(iv) as an event or condition that resulted in an automatic actuation of an Engineered Safety Feature (ESF).

B. Ino erable Structures Com onents or S stems that Contributed to the Event:

None.

C. Dates and A roximate Times of Ma'or Occurrences:

September 1, 1995 at 0813 hours0.00941 days <br />0.226 hours <br />0.00134 weeks <br />3.093465e-4 months <br /> CAS SI began

i+i NRC FORH 366A U.S. NUCLEAR REGULATORY CQOIISSION APPROVED BY (N(B NO. 3150-0104 (5-92) EXPIRES 5/31/95 ESTIHATED BURDEN PER RESPONSE TO COHPLY NITH THIS INFORHATION COLLECT'ION 'REDUEST: 50.0 HRS. FORNARD COHHENTS REGARDING BURDEN ESTIHATE TO THE INFORHATION AND RECORDS HANAGEHENT BRANCH (HNBB 7714), U.S. 'NUCLEAR REGULATORY COHHISSION, LICENSEE EVENT REPORT NASHINGTON, 'DC 20555.0001, AND TO THE PAPERLlORK REDUCTION TEXT CONTINUATION PROJECT (3150-0104), OFFICE OF HANAGEHENT AND BUDGETS NASHINGTON, DC 20503 FACILITY NAHE (1) DOCKET NINIBER (2) 'LED NUHBER (6) PAGE (3)

TEAR SEQUENtIAL REVISION NUHBER NUHBER Browns Ferry Unit 3 05000296 95 003 00 3 of 5 TEXT tf more s ce is r ired use additional co ies of NRC Form 366A (17) at 1834 hours0.0212 days <br />0.509 hours <br />0.00303 weeks <br />6.97837e-4 months <br /> Unit 3 DGs auto started at 1835 hours0.0212 days <br />0.51 hours <br />0.00303 weeks <br />6.982175e-4 months <br /> EECW pump A3 started at 1901 hours0.022 days <br />0.528 hours <br />0.00314 weeks <br />7.233305e-4 months <br /> Unit 3 DGs stopped at 1907 hours0.0221 days <br />0.53 hours <br />0.00315 weeks <br />7.256135e-4 months <br /> EECW pump A3 stopped at 1914 hours0.0222 days <br />0.532 hours <br />0.00316 weeks <br />7.28277e-4 months <br /> Unit 3 DGs returned to standby readiness at 2035 hours0.0236 days <br />0.565 hours <br />0.00336 weeks <br />7.743175e-4 months <br /> TVA provided a 10 CFR 50.72(b)(2)(ii) notification to NRC Operations Center D~ Other S stems or Seconda Functions Affected:

None.

Method of Discover This condition was discovered when the Unit Operator

[utility, licensed) and the Assistant Shift Operations Supervisor [utility, licensed] in the control room received alarms (ALM] and indications that the Unit 3 DGs (3A, 3B, 3C, and 3D) had auto started.

F.. 0 erator Actions:

The operators observed the alarms in the control room. The SOS immediately notified personnel in the Auxiliary Instrument Room to stop activities associated. with the CAS logic surveillance.

G, Safet S stem Res onses!

The safety systems responded as designed for this type of event.

III'AUSE OF THE EVENT A. Immediate Cause:

The immediate cause of this event was an inadvertent closure of relay 14A-K35A contacts which resulted in the auto start of the Unit 3 DGs.

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NRC FORM'366A U.S. NUCLEAR REGULATORY C(NIIISSION APPROVED BY MS NO. 3150-0104 (5-92) EXPIRES 5/31/95 ESTIMATED BURDEN PER RESPONSE TO COMPLY WITH THIS INFORMATIOH COLLECTION REOUEST: 50.0 HRS. FORWARD COMMENTS REGARDING BURDEN ESTIMATE TO THE INFORMATION AND RECORDS MANAGEMENT'RANCH (MNBB 7714), U.S. NUCLEAR REGULATORY COMMISSION, LICENSEE EVENT REPORT WASHINGTON, DC 20555-0001, AND TO THE PAPERWORK REDUCTION TEXT CONTINUATION PROJECT (3150.0104), OFFICE OF MANAGEMENT AHO .BUDGETS WASHINGTON, DC 20503 FACILITY NAME (1) DOCKET NUMBER (2) LED MIN(GER (6) PAGE (3)

TEAR 003'EVISION SEOUENTIAL NUMBER NUMBER Browns Ferry Unit 3 05000296 95 00 5 of 5 TEXT If more s ace is r uired use additional co ies of NRC Form 3 66A (17)

TVA has revised the SI to eliminate the need to boot the HGA relay contacts. TVA is also reviewing the present methodology of placing .a boot on energized relay contacts for GE HGA relays to determine if other methods can be used during testing.'I

~ ADDITIONAL INFORMATION A~ Failed Com onents:

None.

B~ Previous LERs on Similar Events:

There have 'been several LERs written to document unplanned DG autostarts. Five of these LERs (i.e., 296/87004, 259/89014, 259/91004, 296/94001, and 296/95002) occurred as a result of miscellaneous personnel errors, but none of them involved booting relay contacts. Accordingly, the corrective actions for these LERs would not have precluded this event (LER 296/95003).

In one LER (296/91003), the individual did not properly install an inhibiting boot during the performance of an SI. Corrective actions included training maintenance personnel on the proper installation of boots. LER 296/91003 is similar to this LER 296/95003; however, the corrective actions in LER 296/91003 would not have precluded LER 296/95003 since the boot was properly installed on the relay contacts in LER 296/95003.

VII ~ COMMITMENTS None.

Energy Industry Identification System (EIIS) system and component codes are identified in the text with brackets (e.g., [XX].

This action is not a regulatory commitment.

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