05000440/LER-2002-002, Re Failure of the High Pressure Core Spray Pump to Start
| ML023650501 | |
| Person / Time | |
|---|---|
| Site: | Perry  |
| Issue date: | 12/23/2002 |
| From: | Kanda W FirstEnergy Nuclear Operating Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| PY-CEI/NRR-2676L LER 02-002-00 | |
| Download: ML023650501 (5) | |
| Event date: | |
|---|---|
| Report date: | |
| 4402002002R00 - NRC Website | |
text
FENOC fltEhey Micear Operating Conpany Perry Nuclear Power Plant 10 Center Road Perry Ohio 44081 111r Fx R. Eanda 440-280-5579 Vice President -Nuclear Fax: 440-280-8029 December 23, 2002 PY-CEIINRR-2676L United States Nuclear Regulatory Commission Document Control Desk Washington, D.C. 20555 Perry Nuclear Power Plant Docket No. 50-440 LER 2002-002-00 Ladies and Gentlemen:
Enclosed is Licensee Event Report (LER) 2002-002, Failure of the High Pressure Core Spray Pump to Start. This event is being reported in accordance with 10CFR50.73(a)(2Xv)(D), as an event or condition that could have prevented the fulfillment of the safety function of structures or systems that are needed to mitigate the consequences of an accident. There are no regulatory commitments contained in this letter.
Any actions discussed in this document that represent intended or planned actions, are described for the NRC's information, and are not regulatory commitments.
If you have questions or require additional information, please contact Mr. Vernon K. Higaki, Manager -
Regulatory Affairs, at (440)-280-5294.
Yor Williarh R. Kanda Enclosure: LER 2002-002 cc:
NRC Project Manager NRC Resident Inspector NRC Region HII
- -A-
Abstract
On October 23, 2002, at 111 3, the High Pressure Core Spray (HPCS) pump failed to start during routine testing of the HPCS Room Cooler at the Perry Nuclear Power Plant (PNPP). At the time of the failure, the HPCS system was inoperable for the conduct of the testing and required Technical Specification actions had already been completed.
The root cause of the failure was determined to be mechanical wear of the pump motor breaker cell switch operating linkage.
Contributing to the failure was misalignment of this linkage related to a previous breaker replacement, and inadequate visual inspection of the cell switch contact alignment due to inadequate procedural detail. Following adjustment of the cell switch linkage and verification of proper operation, HPCS was returned to operable status at 1529 on October 24, 2002.
Adequate redundant Emergency Core Cooling Systems remained available during the unavailability of HPCS, but HPCS is significant from a risk perspective. Therefore, this event is considered to have had moderate safety significance.
This event was reported to the NRC via the Emergency Notification System on October 23, 2002, at 1216, (ENF#39311) in accordance with IOCFR50.72(b)(3)(v)(D) as a condition that could have prevented the fulfillment of a safety function needed to mitigate the consequences of an accident.
NRC FORM 368 (7-21)
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V) CORRECTIVE ACTIONS The cell switch linkage for the HPCS pump breaker was adjusted to obtain proper alignment. Proper cell switch/linkage operation was verified, both visually and electrically, during breaker racking evolutions. Proper operation of the system, as a whole, was confirmed on October 23, 2002, at 1848, when the HPCS pump was started in accordance with the system operating instruction.
The system was declared operable at 1529, October 24, 2002.
No obvious deficiencies were identified during a visual inspection of the safety-related and non-safety related 5kV switchgear.
However, work orders have been generated to make adjustments as appropriate to assure proper alignment of the cell switch/linkage is maintained. A verification check of these cell switch contacts using test equipment has been completed for the safety-related switchgear which confirmed the results of the visual inspection.
Other corrective actions identified by the investigation and captured in the corrective action program include:
Revision of the electrical maintenance procedure to provide additional criteria for the inspection of cell switch contacts and evaluation of the need to provide training on the changes to the maintenance/inspection procedure. These corrective actions are intended to ensure that cell switch contacts are properly engaged following maintenance activities, which verifies the operating linkage is properly adjusted for possible misalignment or wear.
Evaluation of revising the system operating instruction to include a visual check of the switch contact position when performing breaker racking evolutions and evaluation of the need to provide training for the instruction changes. These corrective actions are intended to ensure that cell switch contacts are properly engaged following routine activities to monitor for potential wear of the operating linkage.
This event has been documented in the PNPP corrective action program. The corrective actions will be tracked and implemented in accordance with the processes and requirements of the corrective action program.
VI) PREVIOUS SIMILAR EVENTS A search of Licensee Event Reports (LER) over the past 3 years from the Perry plant found that no similar events had been reported.
A review of the PNPP Corrective Action Program identified three similar events. In June 2001 (CR 01-2441), a Reactor Feed Booster Pump failed to start, and the investigation found the breaker cell switch was not making good contact on the contact points.
This was corrected by adjusting the switch linkage. A corrective action for that event provided awareness training for electrical maintenance personnel. This corrective action by itself was not sufficient to prevent the current event. In March 2001 (CR 01-1347), a breaker cell switch did not change position and was found to be dirty. While similar, the corrective action for that event would not have been expected to prevent the current event. In 1998 (Potential Issue Form 98-125), following routine breaker maintenance, the HPCS pump failed to start for retest. The investigation of that event determined no cause and documented no evidence of the pump's failure to start as being associated with cell switch misalignment.
COMMITMENTS
No regulatory commitments were identified in this report Energy Industry Identification System (EUS) Codes are identified in the text by square brackets [XX].