05000458/LER-2005-002, Unit 1 Re Unplanned Automatic Actuation of Standby Service Water Due to Procedure Error
| ML052410141 | |
| Person / Time | |
|---|---|
| Site: | River Bend  |
| Issue date: | 08/23/2005 |
| From: | Lorfing D Entergy Operations |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| G9.25.1.3, G9.5, RBF1-05-0137, RBG-46472 LER 05-002-00 | |
| Download: ML052410141 (5) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(i) 10 CFR 50.73(a)(2)(vii), Common Cause Inoperability 10 CFR 50.73(a)(2)(ii)(A), Seriously Degraded 10 CFR 50.73(a)(2)(viii)(A) 10 CFR 50.73(a)(2)(ii)(B), Unanalyzed Condition 10 CFR 50.73(a)(2)(viii)(B) 10 CFR 50.73(a)(2)(iii) 10 CFR 50.73(a)(2)(ix)(A) 10 CFR 50.73(a)(2)(iv)(A), System Actuation 10 CFR 50.73(a)(2)(x) 10 CFR 50.73(a)(2)(v)(A), Loss of Safety Function - Shutdown the Reactor 10 CFR 50.73(a)(2)(v)(B), Loss of Safety Function - Remove Residual Heat 10 CFR 50.73(a)(2)(i)(A), Completion of TS Shutdown 10 CFR 50.73(a)(2)(v), Loss of Safety Function 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications |
| 4582005002R00 - NRC Website | |
text
En tergy Entergy Operations, Inc.
River Bend Station 5485 U.S. Highway 61 N St. Francisville, LA 70775 Tel 225381 4157 Fax 225 635 5068 dlorfin~entergy.com David N. Lorfing Manager-Licensing August 23, 2005 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555
Subject:
Licensee Event Report 50-458 / 05-002-00 River Bend Station - Unit 1 Docket No. 50-458 License No. NPF-47 File Nos.
G9.5, G9.25.1.3 RBG-46472 RBF1-05-0137 Ladies and Gentlemen:
In accordance with 10CFR50.73, enclosed is the subject Licensee Event Report.
This document contains no commitments.
Sincerely, David N. Lorfing Manager - Licensing DNL/dhw Enclosure
Licensee Event Report 50-458 / 05-002-00 August 23, 2005 RBG-46472 RBF1 0137 Page 2 of 2 cc:
U. S. Nuclear Regulatory Commission Region IV 611 Ryan Plaza Drive, Suite 400 Arlington, TX 76011 NRC Sr. Resident Inspector P. 0. Box 1050 St. Francisville, LA 70775 INPO Records Center E-Mail Mr. Jim Calloway Public Utility Commission of Texas 1701 N. Congress Ave.
Austin, TX 78711-3326 Mr. Ronnie Wascom Louisiana Department of Environmental Quality Office of Environmental Compliance P.O. Box 4312 Baton Rouge, LA 70821-4312
NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 06/30/2007 (6-2004)
, the NRC may digits/characters for each block) not conduct or sponsor. and a person Is not required to respond to, the Information collection.
- 3. PAGE River Bend Station, Unit 1 05000 458 1 of 3
- 4. TITLE Unplanned Automatic Actuation of Standby Service Water Due to Procedure Error
- 5. EVENT DATE
- 6. LER NUMBER
- 7. REPORT DATE
- 8. OTHER FACILITIES INVOLVED FACILITY NAME DOKTNUMBER MONTH DAY YEAR YEAR SEQUENTIAL REV MONTH DAY YEAR NUMBER NO.
50 FACILITY NAME IDOCKET NUMBER 06 24 2005 2005 - 002 -
00 08 23 2005 105000
- 9. OPERATING MODE II. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR§: (Check all that apply) o 20.2201(b) 0 20.2203(a)(3)(i)
El 50.73(a)(2)(i)(C)
E 50.73(a)(2)(vii) 4 0 20.2201(d)
E 20.2203(a)(3)(ii)
D 50.73(a)(2)(ii)(A) 0 50.73(a)(2)(viii)(A) o 20.2203(a)(1)
E 20.2203(a)(4)
E 50.73(a)(2)(ii)(B)
El 50.73(a)(2)(viii)(B) o 20.2203(a)(2)(i)
D 50.36(c)(1)(i)(A)
D 50.73(a)(2)(iii)
[I 50.73(a)(2)(ix)(A)
- 10. POWER LEVEL 0 20.2203(a)(2)(ii) 0l 50.36(c)(1)(ii)(A) 0D 50.73(a)(2)(iv)(A)
El 50.73(a)(2)(x)
E3 20.2203(a)(2)(iii) 0 50.36(c)(2)
El 50.73(a)(2)(v)(A)
E 73.71(a)(4)
E 20.2203(a)(2)(iv)
El 50.46(a)(3)(ii) al 50.73(a)(2)(v)(B)
El 73.71 (a)(5) 0 E 20.2203(a)(2)(v)
D 50.73(a)(2)(i)(A)
D 50.73(a)(2)(v)(C) 0 OTHER El 20.2203(a)(2)(vi) 0 50.73(a)(2)(i)(B) 0 50-73(a)(2)(v)(D)
Specify In Abstract below or In NRC Form 366A
- 12. LICENSEE CONTACT FOR THIS LER FACILITY NAME TELEPHONE NUMBER (incude Area Code)
David N. Lorfing, Manager - Licensing (acting) 225-381-4157CAUSE SYSTEM l COMPONENT MANU-REPORTABLE
CAUSE
SYSTEM COMPONENT MANU L
REPORTABLE FACTURER TO EPIX FACTURER TO EPIX
- 14. SUPPLEMENTAL REPORT EXPECTED
- 15. EXPECTED MONTH DAY YEAR SUBMISSION E YES (If yes, complete 15. EXPECTED SUBMISSION DATE) 0 NO DATE ABSTRACT (Limit to 1400 spaces, i.e., approximately 15 single-spaced typewritten lines)
On June 24, 2005, at approximately 1:13 a.m. CDT, an unplanned automatic start of a Division 2 standby service water pump occurred. The plant was in cold shutdown at the time. This event Is being reported in accordance with 10CFR5073(a)(2)(iv) as a condition that resulted in the automatic initiation of an emergency service water system. The Division 2 subsystem was being aligned to support diagnostic testing of a motor-operated valve in the system. The other Division 2 pump had already been started in accordance with the system operating procedure, and the subsequent steps directed the operator to open the inlet valve to the standby cooling tower. At this point, the pressure in the normal service water supply header decreased momentarily below the trip setpoint of the Division 2 automatic start circuitry. The second Division 2 pump started as designed. The causal analysis determined that the system operating procedure was inadequate for the alignment being performed, as it did not preserve sufficient margin in the normal service water supply pressure to avoid actuation of the low pressure trip units that start the standby system.
The system operating procedure has been changed to correct this deficiency. No loads being supplied by service water were adversely affected by the actuation of the second Division 2 standby service water pump. Thus, this event was of minimal safety significance.
NRC FORM 366(6-2004)
PRINTED ON RECYCLED PAPER NRC FORM 366 (6-2004)
PRINTED ON RECYCLED PAPERU.S. NUCLEAR REGULATORY COMMISSION (1-2001)'
LICENSEE EVENT REPORT (LER)
FAILURE CONTINUATION
- 1. FACILITY NAME
- 2. DOCKET
- 6. LER NUMBER
- 3. PAGE lSEQUENTIAL lREVISION YEAR NUMBER lNUMBER River Bend Station Unit 1 05000-458 2005 002 00 2
OF 3
REPORTED CONDITION On June 24, 2005, at approximately 1:13 a.m. CDT, an unplanned automatic start of the "D" standby service water (SSW) pump (**P**) occurred. The plant was in cold shutdown at the time. This event is being reported in accordance with 10CFR5073(a)(2)(iv) as a condition that resulted in the automatic initiation of an emergency service water system.
The SSW system consists of two pumps in each of two independent subsystems. The "B" and "D" pumps supply the Division 2 subsystem. The Division 2 subsystem was being realigned to support diagnostic testing of a motor-operated valve (**ISV**) in the system. The "B" pump had already been started in accordance with the system operating procedure, and the subsequent steps directed the operator to open the inlet valve to the standby cooling tower. At this point, the pressure in the normal service water (NSW) supply header decreased momentarily below the trip setpoint of the Division 2 automatic start circuitry. The "D" pump started as designed. Normal service water flow in the plant was not interrupted.
IMMEDIATE ACTIONS and CAUSAL ANALYSIS The Division 2 standby service water subsystem was operating normally following the automatic actuation of the "D" pump. This alignment was subsequently maintained to allow the scheduled testing of the motor operated valve.
The causal analysis determined that the system operating procedure was inadequate for the realignment being performed, as it did not preserve sufficient margin in normal service water supply pressure to avoid actuation of the low pressure trip units that start the SSW system. In the operation being conducted, the system was momentarily in a configuration in which the operating pumps were not supplying adequate flow for the loads that were in service, resulting in a drop in supply header pressure.
This event is similar to an event that occurred in April 1999, in which the system was being restored to normal alignment following surveillance testing. The procedure steps put the system in such an alignment that allowed a momentary drop in header pressure.
The corrective action for that event included the revision of numerous surveillance test procedures, but did not include the system operating procedure. It could not be determined why that omission occurred.
CORRECTIVE ACTIONS TO PREVENT RECURRENCE An engineering evaluation of the standby service water system was performed to develop a number of potential changes for the system operating procedure. The optimum solution was selected, involving a change in the alignment of the supply to the reactor plantU.S. NUCLEAR REGULATORY COMMISSION (l20CV)
LICENSEE EVENT REPORT (LER)
FAILURE CONTINUATION
- 1. FACILITY NAME
- 2. DOCKET
- 6. LER NUMBER
- 3. PAGE YEAR SEQUENTIAL l REVISION YNUMBER I NUMBER River Bend Station Unit 1 05000-458 2005 002 00 3
OF 3
component cooling water (CCP) heat exchangers. The CCP system heat exchangers are the major load on the system in its normal alignment. The system operating procedure has been revised to implement this change.
A separate broad-scope review of the normal and standby service water systems is being conducted to identify commonality between equipment, procedural, organizational, and programmatic issues associated with automatic actuations of the SSW system over the last 15 years. This review will examine all actuations regardless of cause, with the purpose of developing comprehensive corrective actions to prevent a recurrence of these types of events. The results of that review will be documented in the station corrective action program.
PREVIOUS EVENTS EVALUATION This event is similar to an event that occurred in April 1999, in which the system was being restored to normal alignment following surveillance testing. The procedure steps put the system in such an alignment that allowed a momentary drop in header pressure.
The corrective action for that event included the revision of numerous surveillance test procedures, but did not include the system operating procedure. It could not be determined why that omission occurred.
SAFETY ANALYSIS
No loads being supplied by service water were adversely affected by the actuation of the "D" standby service water pump, and the plant was in cold shutdown at the time. Thus, this event was of minimal safety significance.
(NOTE: Energy Industry Component Identification codes are annotated as (**XX**).)