05000348/LER-2015-001
| Joseph M. Farley Nuclear Plant, Unit 1 | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(iv)(A), System Actuation |
| 3482015001R00 - NRC Website | |
Reported lessons learned are incorporated into the licensing process and fed back to industry.
Send comments regarcing burden estimate to the FOIA, Pnvacy and Information Collections Branch (T-5 F53), U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001, or by intemet e-mail to Infocollects.Resource@nrc.gov, and to the Desk Officer, Office of Information and Regulatory Affairs, NEOB-10202, (3150.0104), Office of Management and Budget, Washington, DC 20503. If a means used to impose an information collection does not cisplay a currently valid OMB control number, the NRC may not conduct or sponsor, and a person is not required to respond to, the Information collection.
PLANT AND SYSTEM IDENTIFICATION
Westinghouse - Pressurized Water Reactor Energy Industry Identification Codes are identified in the text as [XX].
DESCRIPTION OF EVENT
On May 5, 2015, at 04:22 CDT, Farley Nuclear Plant (FNP) Unit 1 was in mode 2 and reactor power was approximately 1 percent. With the 1A Steam Generator Feedwater Pump (SGFP) in the tripped condition, an Auxiliary Feedwater (AFW) autostart signal was received due to manually tripping of the 1B SGFP. The trip of the second SGFP initiated the auto start signal for the Motor Driven Auxiliary Feedwater (MDAFW) pumps due to the auto start signal not being defeated. When the actuation signal was received, both the A and B MDAFW pumps were already in service supplying AFW to the steam generators (SG). The effects of this actuation were that the AFW Flow Control Valves were fully opened and the SG blowdown and SG blowdown sample valves were closed.
These actions occurred successfully and the auto start signal was reset.
Just prior to the event the 1B SGFP was rolling on boiler control and not providing feed flow. Due to a degrading condenser vacuum which had started at approximately the same time that the feed pump was started, the Shift Supervisor, after consultation with the Shift Manager and the Outage Control Center, gave specific direction to the Unit Operator to decrease the 1B SGFP speed to 2400 rpm and to then "trip" the SGFP, instead of securing it. A peer check was performed to "trip" the 1B SGFP; however the peer check operator had only overheard the reason for tripping the SGFP, assumed an abnormal operating mindset, and did not take the time to challenge the decision or method in which the pump was to be secured. The task performer did not challenge the directions from the Shift Supervisor because of familiarity with the task and because the terminology "trip the SGFP" was used in specific directions by the Shift Supervisor.
When the only running SGFP was secured all the automatic actuations occurred as expected. Steam generator blowdown was secured and the flow control valves went full open. Both motor driven auxiliary feed water pumps were already running. The operating crew reset the flow control valve main control board hand switches to gain control of AFW.
CAUSE OF EVENT
This was a human performance-related event. The cause was that the operating crew did not meet expectations for effective teamwork to ensure proper decision making. While responding to a degrading condenser vacuum, the operating crew made the decision to trip the 1B SGFP instead of securing it per the standard operating procedure, which would have been adequate for preventing the event.
Reported lessons learned are incorporated into the licensing process and fed back to industry.
Send comments regarding burden estimate to the FOIA, Privacy and Information Collections Branch (T-5 F53), U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001, or by Internet e-mail to Infocollects.Resource@nrc.gov, and to the Desk Officer, Office of Information and Regulatory Affairs, NEOB-10202, (3150-0104), Office of Management and Budget, Washington, DC 20503. If a means used to impose an information collection does not display a currently valid OMB control number, the NRC may not conduct or sponsor, and a person is not required to respond to, the information collection.
REPORTABILITY ANALYSIS AND SAFETY ASSESSMENT
This event is reportable in accordance with 10 CFR 50.73(a)(2)(iv)(A) as a condition that resulted in automatic actuation of the Auxiliary Feedwater System.
When the only running SGFP was secured all the automatic actuations occurred as expected. Steam generator blowdown was secured and the flow control valves went full open. Both motor driven auxiliary feed water pumps were already running. The operating crew reset the flow control valve main control board hand switches to gain control of AFW. There was no impact on Steam Generator water level.
CORRECTIVE ACTION
Corrective actions included individual remediation plans. Planned corrective actions include the installation of bump preventer covers with caution placards, and management intervention on teamwork and decision-making.
ADDITIONAL INFORMATION
Other system affected: No systems other than those mentioned in this report were affected by this event.
Commitment Information: This report does not create any licensing commitments Previous Similar Events: No similar previously reported events were identified