ML20247E158
| ML20247E158 | |
| Person / Time | |
|---|---|
| Site: | Callaway  |
| Issue date: | 07/19/1989 |
| From: | Blosser J UNION ELECTRIC CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| 89-08, 89-8, ULNRC-2040, NUDOCS 8907260099 | |
| Download: ML20247E158 (4) | |
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NION ECTRICI
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'iB p-Canaway Rant
{l' July 19, 1989 U. S. Nuclear Regulatory Commission Document Control Desk Washington, DC 20555 h
ULNRC-2040 Gentlemen:
DOCKET NUMBER 50-483 CALLAWAY PIJNT UNIT 1 L
FACILITY OPERATING LICENSE NPF-30 i
SPECIAL REPORT 89-08 INVALID FAILURE CF DIESEL GENERATOR 'B' DUE TO OPERATOR FAILING TO KEEP PUSHBUTTONS DEPRESSED LONG ENOUGH TO GENERATE START SIGNAL This Special Report is being submitted pursuant to Technical Specification (T/S) 4.8.1.1.3 concerning the invalid failure of Diesel Generator.(D/G) 'B' due to an operator failing to keep undervoltage pushbuttons depressed long enough to generate a D/G start signal..
d. _C J. D. Blosser Manager, Callaway Plant
-r' b m W TPS/MKD: jew cc: Distribution attached 4
8907260099 890719 gg44 PDR-ADOCK 05000483
'S PDC-
. Mailing Address' P.O. Box 620, FuMon, MO 65251
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cc distribution for ULNRC-2040 Mr.~A. Bert Davis Mr. Thomas Alexion (2 copies) f Regional Administrator Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission F. S. Nuclear Regulatory Commission Region III Eail Stop 13-E-21 799 Roosevelt Road Washington, D.C.
20555 Glen Ellyn, IL 60137 American Nuclear Insurers Mr. O. Maynard c/o Dottie Sherman, Library Wolf Creek Nuclear Operating Corp.
The Exchange Suite 245 P. O.
ox 411 270 Farmington Avenue Burlington, KS 66839 Farmington, CT 06032 Mr. Merlin Williams Manager, Electric Department Supt. of Regulatory Quality &
Missouri Public Service Commission Administrative Services P. O. Box 360 Wolf Creek Nuclear Operating Corp.
Jefferson City, MO 65102 P. O. Box 411 Burlington, KS 66839 Records Center Institute of Nuclear Power Operations Mr. R. W. DeFayette Suite 1500 Chief, Project Section 3A 1100 Circle 75 Parkway U.S. Nuclear Regulatory Commission Atlanta, GA 30339 Region III 799 Roosevelt Road NRC Resident Inspector Glen Ellyn, IL 60137
'D. F. Schnell (400)
G. L. Randolph R. P. Wendiing (470)
J. V. Laut A. C. Passwater/D. E. Shafer/D. J. Walker (470)
G. A. Hughes Z170.05 (QA Record)
Z40SR (Z170.09 Commercial Record)
M. S. Evans M. E. Taylor H. Wuertenbaccher, Jr. (100)
S. L. Auston (470)(NSRB)
S..J. Bellers/D. R. Oelrichs E210.01 Z40ULNRC A160.761 N. Date (Sandra Auston) (470)
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SPECIAL REPORT 89-08 INVALID FAILURE OF DIESEL GENERATOR 'B' DUE TO OPERATOR FAILING TO KEEP PUSHBUTTONS DEPRESSED LONG ENOUGH TO GENERATE START SIGNAL on 4/3/89, at 1212 CST, emergency diesel generator (D/G) 'B' failed to start during. performance of a surveillance test procedure due to operator error. This operator error is attributable to a procedural inadequacy. This was an invalid failure which is reported per Technical Specification (T/S) 4.8.1.1.3.
Procedure ISP-SA-2413B, " Diesel Generator and Segeencer Testing (Train B)", step 7.3, " Blackout with Safety Injection Signal" initiates a shed signal to the safety related bus NB02 incoming feeder breakers, using a 2/4' undervoltage (UV) channels tripped. Each of the four UV signals originatire at the NB02 switchgear is processed by the Load Shedding and Emergency. Load Sequencing (LSELS) logic circuitry which has time delays of 0.5 and 1.2 seconds.
Per the test procedure, a licensed opere, tor announced "UV initiated" as he pressed two of the UV pushbuttons at the NB02 switchgear. Immediately, the operator at the Solid State Protection System initiated a Safety Injection, at which time the operator at NB02 heard breakers cycling and thought the bus had shed its loads. A review of strip chart recordings indicated that the two UV pushbuttons at NB02 were only maintained for 0.5 seconds. This was long enough for one of the channels to time out, producing i
a 1/4 UV signal on the LSELS logic. The other UV channel did not time out before the UV pushbuttons were released and, therefore, the 2/4 UV shed sigunl was not initiated from LSELS to shed the incoming breakers. As a result, the D/G did not receive a start signal.
Proper operation of the two UV pushbuttons was verified by pressing and observing each to produce a 1/4 UV condition at LSELS. ISP-SA-2413B, step 7.3 was re-performed. Because the procedure step did not specify that the pushbutton must be held for a given length of time, this contributed to the operator error. Procedures ISP-SA-2413B and ISP-SA-2413A have been revised to caution the 1.2 second time delay.
The D/G 'B' availability to perform its safety function was not affected by this event. Since the failure is directly attributable to operator error, this was an invalid failure and the surveillance test interval of T/S Table 4.8-1 is not affected. This position is consistent with Regulatory Guide 1.108.C.2.e(2).
A starting history of D/G
'B' as of this report date is summarized as follows:
No. of No. of failures No. of failures Valid Tests During Valid Tests During Invalid Tests 75 0
3#
- Reference Special Reports 85-05, 89-01 Page 1 of 2
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SPECIAL REPORT 69-08 INVALID FAILURE OF DIESEL GENERATOR 'B' DUE TO OPERATOR FAILING TO KEEP PUSHBUTTONS
. DEPRESSED LONG ENOUGH TO GENERATE START SIGNAL Surveillance tests are currently performed at least once per 31 days for D/G 'B'.
This is in conformance with the schedule in T/S Table 4.8-1 which requires a test interval of not more than 31 days if the number of failures in the last 20 valid tests is one or less or the number of failurer in the last 100 vclid testi, is four or less.
Submittal of this report was delayed due to an earlier utility interpretation that since the D/G start signal was never initiated, the operator error was not reportable as a D/G failure. Based on conversations with the Office of Nuclear Reactor Regulation, this interpretation has been expanded to include attempts to start the D/G whether or not the signal is generated.
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