05000387/LER-2003-006, Re Automatic Scram and ECCS Injection Following C Reactor Feed Pump Turbine Trip
| ML033360617 | |
| Person / Time | |
|---|---|
| Site: | Susquehanna  |
| Issue date: | 11/19/2003 |
| From: | Richard Anderson Susquehanna |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| PLA-5692 LER 03-006-00 | |
| Download: ML033360617 (7) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(iv)(A), System Actuation |
| 3872003006R00 - NRC Website | |
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R. L. Anderson Vice President - Nuclear Operations PPL Susquehanna, LLC 769 Salem Boulevard Berwick, PA 18603 Tel. 570.542.3883 Fax 570.542-1504 rlanderson pplweb.com I
Td NOV 19 2003 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Mail Stop OP1-17 Washington, DC 20555 SUSQUEHANNA STEAM ELECTRIC STATION LICENSEE EVENT REPORT 50-387/2003-06-00 LICENSE NO. NPF-14 PLA-5692 Docket No. 50-387 Attached is Licensee Event Report 50-387/2003-006-00. This event was determined reportable per 10 CFR 50.73(a)(2)(iv)(A) in that the Unit 1 reactor automatically scrammed on low water level following a trip of the 'C' Reactor Feed Pump. The initiation of the automatic scram, subsequent injections of both the HPCI and RCIC systems, and the containment isolations resulting from the transient are considered unplanned actuations of systems that mitigate the consequences of significant events. All safety systems functioned as designed. There were no actual consequences to the health and safety of the public as a result of this event.
No new regulatory commitments have been created through issuance of this report.
Richard L. Anderson Vice President - Nuclear Operations Attachment
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Document Control Desk PLA-5692 cc: Mr. H. J. Miller Regional Administrator U.S. Nuclear Regulatory Commission 475 Allendale Road King of Prussia, PA 19406 Mr. S. L. Hansell Sr. Resident Inspector U.S. Nuclear Regulatory Commission P.O. Box 35 Berwick, PA 18603-0035 Mr. R. Osborne Allegheny Electric Cooperative P. 0. Box 1266 Harrisburg, PA 17108-1266 Mr. R. R. Janati Bureau of Radiation Protection Rachel Carson State Office Building P. 0. Box 8469 Harrisburg, PA 17105-8469
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Abstract
At 00:53 on September 24, 2003 with Unit 1 in Mode 1 at 100% power, an automatic reactor scram occurred in response to low reactor water level conditions. While performing required testing of the 'C' Reactor Feed Pump Turbine (RFPT), a control room operator incorrectly manipulated the 'C' RFPT lockout key switch instead of the Reset pushbutton thus causing the turbine to trip. Although the 'A' and 'B' Reactor Feed Pumps increased speed in an attempt to maintain reactor inventory levels, the reactor automatically scrammed when water level reached the Low-Level RPS initiation setpoint. HPCI and RCIC automatically initiated to assist the operating Feed Pumps with level restoration. Numerous Primary Containment Isolations occurred as designed during the transient. Susquehanna was designed to withstand a single RFPT trip without experiencing a Rx Low-Level Scram. This event suggests that previous changes made at Susquehanna have affected the plant's integrated response to the loss of a single RFPT and have cumulatively resulted in a reduction of the originally designed operating margin. The RFPT trip has been attributed to human performance error. Error prevention techniques will be reinforced to support desired human performance attributes. The scram that resulted following the human performance error has been attributed to the reduction in operating margin resulting from inadequate identification of operating margin requirements in plant change processes.
Corrective actions have been initiated to strengthen station operating margin controls within plant change processes. This event is reportable for Unit 1 as an unplanned actuation of systems that mitigate the consequences of significant events per 10 CFR 50.73(a)(2)(iv)(A). There were no actual adverse consequences to the fuel, any plant equipment, or to the health and safety of the public as a result of this event.
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ADDITIONAL INFORMATION
Failed Component Information:
Component - Unit I 'C' Reactor Feed Pump Turbine Model - DRV 631122913 Manufacturer - General Electric
Previous Similar Events
At Susquehanna, there is no history of scrams resulting from a loss of a single Reactor Feed Pump. In September 1999, loss of a single Reactor Feed Pump resulted in a Recirc #2 limiter runback. At that time, the remaining operational Feed Pumps restored water level to normal levels to avoid a low-water level scram.