ML18037A072

Provides EDG Annual Rept for 1990,per Tech Spec 6.9.1.4 & 4.8.1.1.3 of App a

ML18037A072
Person / Time
Site:	San Onofre
Issue date:	02/25/1991
From:	Nandy F SOUTHERN CALIFORNIA EDISON CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
NUDOCS 9103010220
Download: ML18037A072 (16)

Text

ACCELERATED DISTRIBUTION DEMONSTRATION SYSTEM REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)

ACCESSION NBR:9103010220 DOC.DATE: 91/02/25 NOTARIZED: NO FACIL:50-361 San Onofre Nuclear Station, Unit 2, Southern Californ 50-362 San Onofre Nuclear Station, Unit 3, Southern Californ AUTH.NAME AUTHOR AFFILIATXON NANDY,F.R.

Southern California Edison Co.

RECIP.NAME RECIPIENT AFFXLIATION Document Control Branch (Document Control Desk)

SUBZECT: Provides EDG annual rept for 1990,per Tech Spec 6.9.1.4 4.8.1.1.3 of App A,respectively.

DISTRIBUTION CODE:

A001D COPIES RECEIVED:LTR L ENCL t

SIZE:

TXTLE: OR Submittal:

General Distribution NOTES:

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05000361 05000362 D

RECIPIENT ID CODE/NAME PD5 LA KOKAJKO,L.

INTERNAL: ACRS NRR/DET/ESGB NRR/DST 8E2 NRR/DST/SICB 7E NUDOCS-ABSTRACT OGC/HDS3 RES/DSIR/EIB EXTERNAL: NRC PDR COPIES LTTR ENCL 1

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2 6

6 1

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1 1

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1 RECIPIENT ID CODE/NAME PD5 PD NRR/DET/ECMB 9H NRR/DOEA/OTSB11 NRR/DST/SELB 8D NRR/DST/SRXB 8E OC/LFMB R

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D NOTE TO ALL"RIDS" RECIPIENTS:

PLEASE HELP US TO REDUCE KVASTE! CONTACT THE DOCUMENT CONTROL DESK, ROOM Pl-37 (EXT. 20079) TO ELIMINATEYOUR NAME FROM DISTRIBUTION LISTS FOR DOCUMENTS YOU DON'T NEED!

TOTAL NUMBER OF COPIES REQUIRED:

LTTR 24 ENCL 22 D

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Southern California Edison Company 23 PARKER STREET IRVINE, CALIFORNIA92718 F. R. NANDY MANAGER.NUCLEAR LICENSING February 25, 1991 TCLGPHONG (714) 454 4504 U. S. Nuclear Regulatory Commission Document Control Desk Washington, D. C.

20555

Subject:

Docket Nos.30-361 and 50-362 Diesel Generator Annual Report - 1990 San Onofre Nuclear Generating Station, Units 2 and 3 The purpose of this letter is to provide the Emergency Diesel Generator Annual Report for 1990 as required by Technical Specifications 6.9.1.4 and 4.8.1.1.3 of Appendix A, Technical Specifications to Facility Licences NPF-10 and NPF-15 for San Onofre Nuclear Generating Station, Units 2 and 3, respectively.

There were four valid test failures and two non-valid test failures during 1990.

Ifyou require any additional information, please',let me know.

F Very truly yours, Enclosures cc:

J. B. Martin (Regional Administrator, NRC Region V)

C. W. Caldwell (NRC Senior Resident Inspector, Units 1, 2 and 3)

Institute of Nuclear Power Operations (INPO)

ACi>0XOZZO VZOZZ>

PDR ADQCK OS000361 R

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Emergency Diesel Generator Report Southern California Edison Company San Onofre Nuclear Generating Station Units 2 and 3, Docket Nos. 50-361 and 50-362 Event Date: January 12, 1990 The following information is provided in accordance with Technical Specification Surveillance Requirement 4.8.1.1.3 and Regulatory Position C.3.b of Regulatory Guide (RG) 1.108 as revised by Generic Letter (GL) 84-15.

RG 1.108 requested the following seven items for each valid or invalid test failure:

1.

This failure involved a valid test of the San Onofre Unit 2 Emergency Diesel Generator (EDG) 2G002.

This was the first failure in the last 20 valid tests and the first failure in the last 100 valid tests of 2G002.

(Reported as requested in GL 84-15.)

3.

A post-maintenance operability test of 2G002 was terminated due to no indication of either field voltage or current with automatic voltage regulator (AVR) "B" selected.

Operability was verified with AVR "A" selected.

4.

Inspection revealed two burned fuses for AVR "B". The fuses were replaced and the EDG was tested satisfactorily with AVR "B" selected.

5.

This event occurred during a period of inoperability previously scheduled for maintenance activities.

6.

The surveillance test interval remained at 31 days.

7.

The surveillance test interval was in accordance with the schedule of Technical Specification Table 4.8-1.

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Emergency Diesel Generator Report Southern California Edison Company San Onofre Nuclear Generating Station Units 2 and 3, Docket Nos. 50-361 and 50-362 Event Date: January 25, 1990.

The following information is provided in accordance with Technical Specification Surveillance Requirement 4.8.1.1.3 and Regulatory Position C.3.b of Regulatory Guide (RG) 1.108 as revised by Generic Letter (GL) 84-15.

RG 1.108 requested the following seven items for each valid or invalid test failure:

1.

This failure involved a valid test of the San Onofre Unit 2 Emergency Diesel Generator (EDG) 2G003.

2.

This was the first failure in the last 20 valid tests and the second failure in the last 100 valid tests of 2G003.

(Reported as requested in GL 84-15.)

3.

During post maintenance testing, EDG 2G003 tripped on loss-of-excitation under full-load conditions.

Investigation revealed that the loss-of-excitation was due to loose automatic voltage regulator fuse clips.

The automatic voltage regulator fuse clips were cleaned and tightened to provide positive contact and 2G003 was successfully retested for operability.

Future plant equipment operator training willinclude proper fuse manipulations to prevent recurrence, 5.

This failure occurred during a period of inoperability previously scheduled for maintenance activities.

6.

The surveillance test interval remained at 31 days.

7.

The surveillance test interval was in accordance with the schedule of Technical Specification Table 4.8-1.

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Emergency Diesel Generator Report Southern California Edison Company San Onofre Nuclear Generating Station Units 2 and 3, Docket Nos. 50-361 and 50-362 Event Date: August 2, 1990.

The following information is provided in accordance with Technical Specification Surveillance Requirement 4.8.1.1.3 and Regulatory Position C.3.b of Regulatory Guide (RG) 1.108 as revised by Generic Letter (GL) 84-15.

RG 1.108 requested the following seven items for each valid or invalid test failure:

1.

This failure involved a valid test of the San Onofre Unit 3 Emergency Diesel Generator (EDG) 3G002, 2.

3.

This was the first failure in the last 20 valid tests and the second failure in the last 100 valid tests of 3G002.

(Reported as requested in GL 84-15.)

During post maintenance testing, EDG 3G002 tripped at 57 minutes into a one-hour operability test.

Investigation revealed that an open circuit could be created across the primary fuse holder when the fuse was moved in it's holder.

The loose fuse clips combined with normal operating vibration caused erratic operation of the automatic voltage regulator resulting in the "high stator overtemperature" alarm.

The automatic voltage regulator fuse clips were cleaned and tightened to provide positive contact and 3G002 was successfully retested for operability.

Future plant equipment operator training willinclude proper fuse manipulations as was initiated in response to the failure of January 25, 1990.

5.

This failure occurred during a period of inoperability previously scheduled for maintenance activities, 6.

The surveillance test interval remained at 31 days.

7.

The surveillance test interval was in accordance with the schedule of Technical Specification Table 4.8-1.

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Emergency Diesel Generator Report Southern California Edison Company San Onofre Nuclear Generating Station Units 2 and 3, Docket Nos. 50-361 and 50-362 Event Date: August 3, 1990 The following information is provided in accordance with Technical Specification Surveillance Requirement 4.8.1.1.3 and Regulatory Position C.3.b of Regulatory Guide (RG) 1.108 as revised by Generic Letter (GL) 84-15.

RG 1.108 requested the following seven items for each valid or invalid test failure:

This failure involved a valid test of the San Onofre Unit 3 Emergency Diesel Generator (EDG) 3G002.

2.

This was the second failure in the last 20 valid tests and the third failure in the last 100 valid tests of 3G002.

(Reported as requested in GL 84-15.)

3.

During a post-maintenance operability test of EDG 3G002, one of the two 50%

capacity emergency supply fans did not operate.

These fans are required for cooling the room during EDG operation.

The fans were not operable through manual or automatic control and the thermal overloads were found tripped.

The thermal overloads were replaced with qualified in kind parts and tested by manually starting the fan three times.

A one-hour test run of the fan (3MA275) was performed on the third start.

5.

This event occurred during a period of inoperability previously scheduled for maintenance activities.

6.

The surveillance test interval was reduced &om 31 to 7 days.

7.

The surveillance test interval was in accordance with the schedule of Technical Specification Table 4.8-1.

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Emergency Diesel Generator Report Southern California Edison Company San Onofre Nuclear Generating Station Units 2 and 3, Docket Nos. 50-361 and 50-362 Event Date: September 6, 1990 The following information is provided in accordance with Technical Specification Surveillance Requirement 4.8.1.1.3 and Regulatory Position C.3.b of Regulatory Guide (RG) 1.108 as revised by Generic Letter 84-15.

RG 1:108 requested the following seven items for each valid or invalid test failure:

1.

This failure involved an invalid test of the San Onofre Unit 2 Emergency Diesel Generator (EDG) 2G003.

2.

This event was not considered a valid test of 2G003.

3.

During a post-maintenance operability test, EDG 2G003 tripped on high coolant temperature.

The high coolant temperature was a result of the radiator fan power supply breakers being opened without either proper documentation or procedural direction.

4 The radiator fan breakers were closed and EDG 2G003 retested satisfactorily.

A revision to the procedure willindicate that the radiator fan breakers should be tagged opened when the DC control power is tagged opened.

The responsible individuals were counseled on the requirements for manipulating safety related equipment.

An Operating Division Experience Report (2-90-22) has been prepared in response to this event.

5.

This failure occurred during a period of inoperability previously scheduled for maintenance activities.

6.

The surveillance test interval remained at 31 days.

7.

The surveillance test interval was in accordance with the schedule of Technical Specification Table 4.8-1.

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L Emergency Diesel'enerator Report Southern California Edison Company San Onofre Nuclear Generating Station Units 2 and 3, Docket Nos. 50-361 and 50-362 Event Date: September 21, 1990 The following information is provided in accordance with Technical Specification Surveillance Requirement 4.8.1.1.3 and Regulatory Position C.3.b of Regulatory Guide (RG) 1.108 as revised by Generic Letter 84-15.

RG 1.108 requested the following seven items for each valid or invalid test failure:

1.

This failure involved an invalid test of the San Onofre Unit 2 Emergency Diesel Generator (EDG) 2G002.

2.

This event was not considered a valid test of 2G002.

3.

During post-maintenance functional testing, EDG 2G002 failed to develop either voltage or frequency and was manually shut down in response to the "breaker open" and "undervoltage/underfrequency" alarms.

Another test attempt was made after switching from automatic voltage regulator (AVR) "B" to AVR "A".

This second test resulted in an EDG trip on an over-excitation alarm.

Investigation of the failure revealed that the line pot fuses were not installed when the EDG was being returned to service.

This failure was a direct consequence of operator error.

4 A human performance event evaluation was initiated (HPES90-021) and appropriate disciplinary action was taken.

5.

This failure occurred during a period of inoperability previously scheduled for maintenance activities.

6.

The surveillance test interval remained at 31 days.

7.

The surveillance test interval was in accordance with the schedule of Technical Specification Table 4.8-1.

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