05000483/LER-2004-001, Regarding Manual Initiation of Essential Service Water System Due to Loss of Normal Service Water System
| ML040150569 | |
| Person / Time | |
|---|---|
| Site: | Callaway  |
| Issue date: | 01/08/2004 |
| From: | Witt W AmerenUE |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| ULNRC04935 LER 04-001-00 | |
| Download: ML040150569 (7) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(iv), System Actuation |
| 4832004001R00 - NRC Website | |
text
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. I AmerenUE Callaway Plant PO Box 620 Fulton, M1O 65251 January 8, 2004 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Mail Stop P1-137 Washington, DC 20555-0001 WAmeren UE ULNRC04935 Ladies and Gentlemen:
DOCKET NUMBER 50-483 CALLAWAY PLANT UNIT 1 UNION ELECTRIC CO.
FACILITY OPERATING LICENSE NPF-30 LICENSEE EVENT REPORT 2004-001-00 Manual initiation of Essential Service Watcr svstem due to loss of normal Service Watcr system The enclosed licensee event report is submitted in accordance with I OCFR50.73(a)(2)(iv), to report the manual actuation of the emergency service water system which does not normally operate and serves Callaway as an ultimate heat sink system and backup emergency feedwater system.
Hw Warren A. Witt Manager, Callaway Plant WAW/ewh Enclosure r,
' :'j, e? a subsidiary of Ameren Corporation
ULNRC04935 January 8, 2004 Page 2 Mr. Bruce S. Mallett Regional Administrator U.S. Nuclear Regulatory Commission Region IV 611 Ryan Plaza Drive, Suite 400 Arlington, TX 76011-4005 Senior Resident Inspector Callaway Resident Office U.S. Nuclear Regulatory Commission 8201 NRC Road Steedman, MO 65077 Mr. Jack N. Donohew (2 copies)
Licensing Project Manager, Callaway Plant Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission Mail Stop 7E1 Washington, DC 20555-2738 Manager, Electric Department Missouri Public Service Commission PO Box 360 Jefferson City, MO 65102 Records Center Institute of Nuclear Power Operations 700 Galleria Parkway Atlanta, GA 30339
Abstract
On 11/12/03 while restoring the Circulating and Service Water pump house electrical bus lineups to a normal configuration, two out of three electrical buses were de-energized resulting in a loss of the service water system and necessitating manual actuation of the Essential Service Water (ESW) system. The loss of service water coupled with a reduction in circulating water system capacity required Control Room Operators to manually reduce Main Generator electrical loading to prevent a loss of condenser vacuum and automatic main turbine runback.
After operator actions restored service water system operation, power stabilized at approximately 70 percent. An Event Review Team concluded the cause of the event was failure to follow an approved plant procedure. The Licensed Operator selected position 2201-2202 versus the proper position of 2201-2102, which is located on a different selector switch. A contributing cause was the fact the two bus transfer selector switches have identical name plate labels.
Once the cause of the event was understood, power was increased to 100 percent and normal operation resumed.
Corrective actions include revising the Main Control Board name plate labels for the bus transfer selector switches and revising plant procedures to reflect the new labels.
NRC FORM 366(7-2001)
(If more space is required, use additional copies of NRC Form 366.A) (17)
I.
DESCRIPTION OF THE REPORTABLE EVENT
A. REPORTABLE EVENT CLASSIFICATION This actuation of ESW is reportable per 10CFR50.73(a)(2)(iv) as a manual actuation of emergency service water systems that do not normally run and that serve as ultimate heat sinks. The ESW system also serves as a backup source of auxiliary feedwater to the steam generators and this actuation is reportable per 1 OCFR50.73(a)(2)(iv) as a manual actuation of a PWR emergency feedwater system.
B. PLANT OPERATING CONDITIONS PRIOR TO THE EVENT Callaway Plant was in Mode 1 at 100 percent power.
C. STATUS OF STRUCTURES, SYSTEMS OR COMPONENTS THAT WERE INOPERABLE AT THE START OF THE EVENT AND THAT CONTRIBUTED TO THE EVENT Circulating and Service Water pump house electrical bus PB122 was cross tied with electrical bus PB121.
D. NARRATIVE SUMMARY OF THE EVENT, INCLUDING DATES AND APPROXIMATE TIMES On 11/12/03 while restoring the Circulating and Service Water pump house electrical bus lineups to a normal configuration, two out of three electrical buses were de-energized resulting in a loss of the service water system and necessitating manual actuation of the Essential Service Water (ESW) system.
Initial electrical bus configurations consisted of:
electrical bus PB121 being supplied by its normal transformer source XPB121 via closed breaker
- PB12101, electrical bus PB122 normal feeder breaker PB12201 being open and the bus instead being energized by being cross tied with bus PB121 through closed cross tie breaker PB 12102, electrical bus PB123 being supplied by its normal transformer source XPB123 via closed breaker
- PB12301, cross tie breaker PB12202 between bus PB122 and PB123 was open.
Initial circulating water and service water pump electrical lineups consisted of:
circulating water pump PDA2101A being supplied from PB121, circulating water pump PDA2101 B being out of service for maintenance, circulating water pump PDA2101C being supplied from PB123, service water pump PEA2101A being supplied from bus PB121, service water pump PEA2101 B being supplied from bus PB122, service water pump PEA2101C, normally supplied from bus PB123, was secured but available for service.
After being instructed to restore electrical bus PB122 to a normal lineup, a licensed operator prepared to perform a fast bus transfer" where the normal feeder breaker PB12201 is closed and crosstie breaker PB12102 is opened simultaneously using bus paralleling circuitry, thus accomplishing a "bumpless" power supply transfer and no loss of power to downstream electrical loads. Using plant procedure OTN-PB-00001 titled NON-CLASS IE 4.16KV ELECTRICAL SYSTEM, the licensed operator designated to perform the switching operation read the appropriate procedure step, but grasped the incorrect
'CLOSED BUS TRANSFER SELECTOR SWITCH' and placed it in position "2201-2202". Instead of aligning the electrical circuitry to monitor for a parallel operation between cross tie breaker PB1 2102 and (if more space is required, use additional copies of (If more space is required, use additional copies of (If more space is required, use additional copies of NRC Form 366A) (17)
VI.
ADDITIONAL INFORMATION
The system and component codes listed below are from the IEEE Standard 805-1984 and IEEE Standard 803A-1984 respectively.
System:
N/A Component:
N/A This section is not applicable because this event was not the result of a component failure.