05000395/LER-2008-001, Regarding Manual Reactor Trip Due to Low Steam Generator Level Caused by Feedwater Flow Control Valve Malfunction
| ML080810445 | |
| Person / Time | |
|---|---|
| Site: | Summer  (NPF-012) |
| Issue date: | 03/20/2008 |
| From: | Archie J South Carolina Electric & Gas Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| LER 08-001-00 | |
| Download: ML080810445 (4) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(iv), System Actuation 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 |
| 3952008001R00 - NRC Website | |
text
A SCANA COMPANY Jeffrey B. Archie Vice President, Nuclear Operations 803.345.4214 March 20, 2008 Document Control Desk U. S. Nuclear Regulatory Commission Washington, DC 20555
Dear Sir / Madam:
Subject:
VIRGIL C. SUMMER NUCLEAR STATION (VCSNS)
DOCKET NO. 50-395 OPERATING LICENSE NO. NPF-12 LICENSEE EVENT REPORT (LER 2008-001-00)
MANUAL REACTOR TRIP DUE TO LOW STEAM GENERATOR LEVEL CAUSED BY FEEDWATER FLOW CONTROL VALVE MALFUNCTION Attached is Licensee Event Report (LER) No. 2008-001-00, for the Virgil C. Summer Nuclear Station (VCSNS). The report describes the sequence of actions that led to a manual reactor trip due to low steam generator level resulting from the malfunction of a feedwater flow control valve. This report is submitted in accordance with 1 OCFR50.73(a)(2)(iv).
Should you have any questions, please call Mr. Bruce Thompson at (803) 931-5042.
JT/JBA/dr Attachment c:
K. B. Marsh S. A. Byrne N. S. Carns J. H. Hamilton R. J. White V. M. McCree R. E. Martin NRC Resident Inspector M. N. Browne K. M. Sutton D. L. Abstance P. Ledbetter EPIX Coordinator INPO Records Center J&H Marsh & McLennan NSRC RTS (C-08-00292)
File (818.07)
DMS (RC-08-0042)
SCE&G I Virgil C. Summer Nuclear Station - P. 0. Box 88 -Jenkinsville, South Carolina 29065.T (803) 345.5209. www.sceg.com
NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 08/31/2010 (9-2007)
, the NRC may (See reverse for required number of not conduct or sponsor, and a person is not required to respond to, the diqits/characters for each block) information collection.
- 3. PAGE Virgil C. Summer Nuclear Station 05000 395 1
OF 3
- 4. TITLE Manual Reactor Trip Due to Low Steam Generator Level Caused by Feedwater Flow Control Valve Malfunction
- 5. EVENT DATE
- 6. LER NUMBER
- 7. REPORT DATE
- 8. OTHER FACILITIES INVOLVED MONTH DAY YEAR YEAR SEQUENTIAL REV MONTH DAY YEAR FACILITY NAME DOCKET NUMBER MOT DY YER YER NUMBER NO.
05000 0 FACILITY NAME DOCKET NUMBER 01 24 2008 2008 1
0 03 20 2008 05000
- 9. OPERATING MODE
- 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check all that apply)
Mode 1 5 20.2201(b) 5 20.2203(a)(3)(i)
C] 50.73(a)(2)(i)(C)
C] 50.73(a)(2)(vii) 5 20.2201(d) 5 20.2203(a)(3)(ii)
[J 50.73(a)(2)(ii)(A) 5 50.73(a)(2)(viii)(A) 5 20.2203(a)(1) 5 20.2203(a)(4) 5 50.73(a)(2)(ii)(B) 5 50.73(a)(2)(viii)(B)
[]
20.2203(a)(2)(i) 5 50.36(c)(1)(i)(A) 5 50.73(a)(2)(iii) 5 50.73(a)(2)(ix)(A)
- 10. POWER LEVEL E] 20.2203(a)(2)(ii) 5 50.36(c)(1)(ii)(A) 50.73(a)(2)(iv)(A) 5 50.73(a)(2)(x)
[
20.2203(a)(2)(iii) 5 50.36(c)(2) 5 50.73(a)(2)(v)(A) 5 73.71(a)(4) 100%
5 20.2203(a)(2)(iv) 5 50.46(a)(3)(ii) 5 50.73(a)(2)(v)(B) 5] 73.71(a)(5) 5 20.2203(a)(2)(v) 5] 50.73(a)(2)(i)(A) 5 50.73(a)(2)(v)(C) 5 OTHER i]
20.2203(a)(2)(vi)
[] 50.73(a)(2)(i)(B)
[
50.73(a)(2)(v)(D)
Specify in Abstract below or in
CAUSE OF EVENT
Initial malfunction of IFV00498 is attributed to accumulation of brass particulate in the valve positioner created by degradation of a brass pilot valve in the air supply line. A Root Cause Analysis (RCA 08-00292) is currently in progress to identify the primary cause and determine corrective actions to preclude recurrence. SCE&G will submit a supplemental report upon completion of the Root Cause Analysis and approval by the VCSNS Corrective Action Review Board. This supplemental report is projected to be submitted by August 1, 2008.
ANALYSIS OF EVENT
Flow Control Valve IFV00498 is a design backup to the associated Feedwater Isolation Valve (FWIV). The condition of IFV00498 did not affect the ability of the FWIV to perform its function. Only the flow control function of IFV00498 was impacted by this condition. However, the capability of the valve to close on an isolation signal and meet its safety function was not impacted.
CORRECTIVE ACTIONS
A Failure Modes Analysis team assembled immediately after the event directed additional maintenance on Feedwater Flow Control Valves (A) IFV00496 and (B) IFV00497 to address extent of condition of the valve positioners. No brass particulate was found on either the A or B valve positioners.
Further corrective actions to prevent recurrence will be investigated by the Root Cause Analysis Team.
PRIOR OCCURRENCES There have been two other instances of Feedwater Flow Control Valve malfunctions in the past. A similar event occurred on March 30, 2004 and was reported by Licensee Event Report (LER) 2004-001-00. Valve positioners on all three feedwater flow control valves were replaced. An engineering evaluation was initiated to address resolution of pilot valve performance issues.
VCSNS subsequently experienced degraded response of IFV00498 while shutting down the reactor on December 4, 2004. All three valve positioners were replaced on January 28, 2005.PRINTEO ON RECYCLED PAPERPRINTED ON RECYC'LFn PAPER