ML18095A423
ML18095A423 | |
Person / Time | |
---|---|
Site: | Salem ![]() |
Issue date: | 08/15/1990 |
From: | Miller L Public Service Enterprise Group |
To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
References | |
90-9, NUDOCS 9008210167 | |
Download: ML18095A423 (4) | |
Text
Public Service Electric and Gas Company P.O. Box 236 Hancocks Bridge, New Jersey 08038 Salem Generating Station U. S. Nuclear Regulatory Commission Document Control Desk Washington, DC 20555
Dear Sir:
SALEM GENERATING STATION LICENSE NO. DPR-75 DOCKET NO. 50-311 UNIT NO. 2 SPECIAL REPORT 90-9 August 15, 1990 This Special R.eport *addresses the circumstances surrounding* th*e 2A Diesel Generator valid failure occurring on July 22, 1990.
This report is being*submitted pursuant to the requirements of Technical Specification Surveillance 4.8.1.1.4.
MJP:pc Distribution 9008210167 900815 PDR ADOCK 05000311 S
PDC The Energy People Sincerely yours, ti/'~~
L. K. Miller
~CA./
General Manager -
Salem Operations x_E 2-z.
95-2189 (10M~ (2!89
SPECIAL REPORT NUMBER 90-*
PLANT IDENTIFICATION:
Salem Generating Station - Unit 2 Public Service Electric & Gas Company Hancock's Bridge, New Jersey 08038 IDENTIFICATION OF OCCURRENCE:
2A Diesel Generator valid failure due to equipment failure Event Date{s):
7/22/90 Report Date:
8/15/90 This report was initiated by Incident Report No.90-509.
This spe~ial report describes a valid test failure in~olving 2A Diesel Generator (D/G) occurring on July 22, 1990.
This report is submitted for informational purposes in accordance ~ith Technical Specification Surveillance Requirement 4.8.1.1.4 and contains the information required by Regulatory Guide 1.108, Revision 1, August 1977, Regulatory Position C.3.b.
Surveillance Requirement 4.8.1.1.4 states:
All diesel generator failures, valid or non-valid, shall be reported to the Commission pursuant to Specification 6.9.1.
CONDITIONS PRIOR TO OCCURRENCE:
Mode 4 (Hot Shutdown)
DESCRIPTION OF OCCURRENCE:
On July 22, 1990 at 0121 hours0.0014 days <br />0.0336 hours <br />2.000661e-4 weeks <br />4.60405e-5 months <br />, the 2A D/G was declared inoperable.
It had failed to achieve rated load (2600 kW) within 60 seconds during a one _(1) hour surveillance test.
It had taken approximately 67 seconds.
Subsequently, the 2A D/G was declared inoperable and Technical Specification 3.8.1.lb Action Statement "a was entered.
The surveillance was being performed in accordance with Surveillance Procedure SP(O) 4.8.1.1.2, "Electrical Power Systems -
Emergency Diesels".
Technical Specification 3.8.1.1 states:
"As a minimum, the following A.C. electrical power sources shall be OPERABLE:
- a.
Two physically independent circuits between the off~i~e transmission network and the onsite Class lE distribution system (vital bus system) and
- b.
Three separate and independent diesel generators with:
Technical Specification 3.8.1.1 Action Statement a states:
"With either an offsite circuit or diesel generator of the above
UNIT 2 SPECIAL REPORT 90-*
- DESCRIPTION OF OCCURRENCE:
(cont'd}
required A.C. electrical power sources inoperable, demonstrate the OPERABILITY of the remaining A.C. sources by performing Surveillance Requirements 4.8.1.1.1.a and 4.8.1.1.2.a.2 within one hour and at least once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> thereafter; restore at least two offsite circuits and three diesel generators to OPERABLE status within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> or be in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN within the following 30 hour3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />s~"
. APPARENT CAUSE OF OCCURRENCE:
The cause of the 2A DIG valid test failure has been attributed to equipment failure.
Upon investigation, it was identified that the electro-hydraulic actuator had failed by restricting engine throttle position.
ANALYSIS OF OCCURRENCE:
The 2A DIG's failure, to achieve rated load within 60 seconds during surveillance testing, constitutes a valid test failure as described in Regulatory Guide 1.108.
This was the fifth DIG failure in the last 100 starts for all three (3) DIG's.
The other failures included:
a valid failure of 2C DIG, occurring on January 9, 1990, (reference Special Report 311/90~1) due to the failure of its Woodward Governor; a valid failure of 2B DIG, occurring on May 2, 1990 (reference Special Report 311190-5), due to the failure of the.
turbocharger to allow full loading of the DIG; and valid failures on May 18, 1990 and May 21, 1990 (reference Specdal Report 311190-6),
jacket water leaks had developed on the 2A and 2B DIG jacket water vent piping during twenty-four (24) hour loaded survetllance runs.
With one diesel inoperable, the remaining diesels.are capable of providing power to the minimum safeguards equipment required for analyzed accident and transient conditions.
During this event*, 2B DIG and 2C DIG remained operable; therefore, this event did: not impact the health and safety of the general public~
CORRECTIVE ACTION:
The electro-hydraulic governor actuator was replaced.
The new actuator and associated controls were calibrated and a D/G operability run was successfully completed.
Subsequently, Technical Specification 3.8.1.1 Action "a" was exited at 2150 hours0.0249 days <br />0.597 hours <br />0.00355 weeks <br />8.18075e-4 months <br /> on July 24, 1990.
The electro-hydraulic actuator is being sent out for failure analysis.
This is the third electro-hydraulic governor actuator that has required replacement; reference Special Reports 311188-4, "2A D/G Valid Failure" and 311190-1, "2C D/G Valid Failure".
Since this is an abnormal failure rate, system engineering is reviewing these failures.
Based upon the results of the failure analysis of this and the other two actuators, appropriate corrective actions will be
7
~~~~-SPECIAL REPORT 90-99
- CORRECTIVE ACTION:
(cont'd) implemented.
The surveillance frequency remains at once every three {3) days due to the number of failures in the last 100 starts, as required by Technical Specification 3.8.1.1.
FAILURE DATA:
Woodward Governor Actuator Model EGB-lOC MJP:pc SORC Mtg.90-107
!//#~.
General Manager -~°'-'
Salem Operations