ML20155A150

Special Rept 86-01:on 860306,during Surveillance Testing, Emergency Diesel Generator a Intentionally Secured W/O Loading to at Least 50% of Continuous Rating.Caused by Failure of Load Sequencer.Test Completed on 860307

ML20155A150
Person / Time
Site:	Callaway
Issue date:	03/31/1986
From:	Randolph G UNION ELECTRIC CO.
To:	James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
References
86-01, 86-1, ULNRC-1280, NUDOCS 8604080243
Download: ML20155A150 (5)

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March 31,1986 Mr. James G. Keppler

. Regional Administrator Office of Inspection & Enforcement U.S. Nuclear Regulatory Commission Region III 799 Roosevelt Road Glen Ellyn IL 60137 ULNRC-1280

Dear Mr. Keppler:

DOCKET NUMBER 50-483 ,

CALLAWAY PLANT UNIT 1 '

FACILITYOPERATINGLICENSENPF-30}-

SPECIAL REPORT 86-01 ,

DIESEL GENERATOR FAILURE DURING AN INVALID TEST The enclosed Special Report is submitted pursuant to Technical Specification 4.8.1.1.3 and 6.9.2 concerning a diesel generator failure during an invalid test.

l k wt G. L. Randolph I

Manager, Callaway Plant e #' -

hl713 d-DEY/TPS/;WK/drs Enclosure cc Distribution attached I

8604000243 060331 1 PDR ADOCK 05000403 S PDR g2W l

i Mading Address:PO. Box 620 FultortMO65251 l

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cc distribution for ULNRC-1280 Mr. Paul O'Connor Manager, Electric Department Office of Nuclear Reactor Regulation Missouri Public Service Commission U.S. Nuclear Regulatory Commission P. O. Box 360 Mail Stop P-316 Jefferson City, MO 65102 7920 Norfolk Avenue Bethesda, MD 20014 Mr. O. Maynard Kansas Gas and Electric Company P. O. Box 208 American Nuclear Insurers Wichita, KS 62701 c/o Dottie Sherman, Library The Exchange Suite 245 Mr. Nicholas A. Petrick 270 Farmington Avenue Executive Director, SNUPPS Farmington, CT 06032 5 Choke Cherry Road Rockville, MD 20850 Mr. J. H. Smith Bechtel Power Corporation Records Center SNUPPS Project Institute of Nuclear Power Operations 15740 Shady Grove Road Suite 1500 Gaithersburg, MD 20877-1454 1100 Circle 75 Parkway Atlanta, CA 30339 NRC Resident Inspector D. F. Schnell (400)

R. J. Schukai (470)

S. E. Miltenberger J. F. McLaughlin J. E. Davis (240LER)

(Z40LER) (w/c)

D. W. Capone /R. P. Wendling (470)

F. D. Field (470)

A. P. Neuhalfen A. C. Passwater/D. E. Shafer/D. J. Walker (470)

G. A. Hughes 240.03 (QA Record)

J. M. Price D. E. Young M. E. Taylor H. Wuertenbaecher, Jr. (100)

S. L. Auston (470)(NSRB)

J. D. Schnack

. GLR Chrono 3456-0021.6 3456-0260 Z40ULNRC G56.37 N. Date (Sandra Auston) (470)

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SPECIAL REPORT 86-01 DIESEL GENERATOR FAILURE DURING AN INVALID TEST Surveillance Procedure ISP-SA-2413A, Diesel Generator and Sequencer Testing (Train A), was in progress on 3/6/86 to satisfy various 18 month Technical Specification (T/S) surveillance requirements. The plant had entered Mode 5, Cold Shutdown, on 3/4/86. During performance of the

"'A' Train Blackout Without SIS (Safety Injection Signal)" portion of ISP-SA-2413A, the 'A' emergency diesel generator (D/G) was intentionally secured without loading to at least 50% of continuous rating. The D/G was secured to investigate a failure of the load sequencer to properly sequence the required emergency loads onto the 4.16 kV safety-related bus (NB01) energized by 'A' D/G.

Since the successful D/G start was terminated intentionally without loading to at least 50% of continuous rating, it is not considered a valid test or failure in accordance with Regulatory Position C.2.e(4) of Regulatory Guide 1.108, Revision 1. August 1977. The D/G testing frequency established by T/S Table 4.8-1 is therefore not affected by this incident and this Special Report is being submitted as required for all D/G failures, valid or nonvalid, per T/S 4.8.1.1.3. It is noted that the D/G could have been manually loaded and a valid test completed had the operators not intentionally secured the D/G for troubleshooting of the load sequencer.

Starts of the D/G's have been tracked since the completion of Preoperational Testing on 5/11/84. The starting history of the D/G's as of the date of this report is summarized as follows:

Number of Number of Number of Failures During Failures During i- D/G Valid Tests Valid Tests Invalid Tests A 31 1* Si B 27 0 15

• Reference Special Report 84-02.

1. Reference Special Reports 85-01, 85-02, 85-07, and 86-01.

5 Reference Special Report 85-05.  ;

The following is a summary of the events applicable to this incident.

- The "'A' Train Blackout Without S1S" portion of ISP-SA-2413A began at approximately 2018 on 3/6/86.

- Loads shed off bus NB01 as required when the test signal (blackout without SIS) was initiated.

'A' D/G successfully started and attained the required voltage and frequency.

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s o' SPECIAL REPORT 86-01 Page 2

'A' D/G output breaker closed.

- Only 'A' Centrifugal Charging Pump and 'A' Component Cooling Water Pump sequenced onto bus NB01 and were powered by the 'A' D/G.

- Testing activities were halted and troubleshooting initiated.

- Troubleshooting of the 'A' D/G output breaker identified that the plunger bolt (which actuates certain stationary contacts when the breaker closes) was out of adjustment.

Consequently, the stationary contacts did not initiate a signal to the load sequencer that the breaker was closed.

The condition also prevented synchronizing of the D/G with offsite power by not allowing a synchronizing check relay to pick up.

- Temporary adjustments were made such that the synchronizing check relay picked up. The D/G was paralleled with offsite power and the loads were transferred off the D/G. The D/G output breaker was opened, and the D/G secured and declared inoperable at approximately 2350 on 3/6/86.

The plunger bolt was found to be out of adjustnent by approximately 3/32 of an inch. It was adjusted within tolerance per Electrical Preventive Maintenance Procedure MPE-ZZ-QS005, Cleaning, Inspection, and Lubrication of 13.8 kV and 4.16 kV Breakers, at 0210 on 3/7/86.

- The "'A' Train Blackout Without SIS" portion of ISP-SA-2413A was again commenced at approximately 2040 on 3/7/86 and completed satisfactorily.

'A' D/G was declared operable at 2222 on 3/7/86.

! Verification of proper adjustment of the plunger bolt for 'A' D/G output breaker was last performed on 5/20/85 during an 18 month preventive maintenance inspection. The cause of the plunger bolt being out of adjustment is unknown. This type of problem has not been a frequently experienced occurrence associated with the D/G output breakers; however, due to the significance of the plunger bolt / stationary contacts function, a preventive maintenance inspection for proper adjustment of the plunger bolt will be evaluated for increased periodicity for 'A' and 'B' D/G output breakers.

This incident occurred while the plant was in Mode 5. In this mode, T/S 3.8.1.2 requires only one diesel generator to be operable.

'B' D/G was operable while 'A' D/G was out of service for testing and

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SPECIAL REPORT 86-01 Page 3 inoperable due to the output breaker plunger bolt. Performance of ISP-SA-2413B, Diesel Generator and Sequencer Testing (Train B), began following completion of ISP-SA-2413A. On 3/10/86 the load sequencer for for 'B' train functioned satisfactorily when the breaker closed during the "'B' Train Blackout Without SIS" portion of ISP-SA-2413B.

Surveillance tests are currently performed at least once per 31 days for each D/C. This is in conformance with tha schedule of Regulatory Position C.2.d of Regulatory Guide 1.108. Revision 1 August 1977, and Technical Specification Table 4.8-1 which require the test interval.to be not more than 31 days if the number of failures in the last 100 valid tests is one or zero.

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