05000348/LER-2006-002, Regarding Main Steam Isolation Valve Failure to Close
| ML061570034 | |
| Person / Time | |
|---|---|
| Site: | Farley  |
| Issue date: | 06/05/2006 |
| From: | Sumner H Southern Nuclear Operating Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| FOIA/PA-2008-0016, NL-06-1175 LER 06-002-00 | |
| Download: ML061570034 (4) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 10 CFR 50.73(a)(2)(ii)(A), Seriously Degraded 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) 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 |
| 3482006002R00 - NRC Website | |
text
H. 1. Sumner, Jr.
Vice President Southern Nuclear Operating Company, Inc.
40 lnverness Center Parkway Post Off ice Box 1295 Birmingham, Alabama 35201 Tel 205,992,7279 Fax 205.992.0341 June 5, 2006 Docket No.: 50-348 SOUTHERN A COMPANY Energy to Serve Your World SH NL 1 175 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D. C. 20555-000 1 Joseph M. Farley Nuclear Plant - Unit 1 Licensee Event Report 2006-002-00 Main Steam Isolation Valve Failure to Close Ladies and Gentlemen:
Joseph M. Farley Nuclear Plant - Licensee Event Report (LER) No. 2006-002-00 is being submitted in accordance with 10 CFR 50.73(a)(2)(i)(B).
This letter contains no NRC commitments. If you have any questions, please advise.
Sincerely, o?h S-H. L. Sumner, Jr.
HLSICHMlsdl Enclosure: Licensee Event Report 2006-002 Unit 1 cc:
Southern Nuclear Operating Comuanv Mr. J. T. Gasser, Executive Vice President Mr. J. R. Johnson, General Manager -Plant Farley RTYPE: CFA04.054; LC# 14442 U. S. Nuclear Rewlatorv Commission Dr. W. D. Travers, Regional Administrator Mr. R. E. Martin, NRR Project Manager - Farley Mr. C. A. Patterson, Senior Resident Inspector - Farley
)NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION I APPROVED BY OMB: NO. 3150-0104 EXPIRES: 0613012007 (6-2004)
LICENSEE EVENT REPORT (LER)
(See reverse for required number of digitslcharacters for each block)
- 1. FACILITY NAME J. R. Johnson - Nuclear Plant General Manager 1334-899-5 156
, the NRC may not conduct or sponsor, and a person 1s not requlred to respond to, the information collection.
- 2. DOCKET NUMBER
- 13. PAGE Joseph M. Farley Nuclear Plant - Unit 1 I
05000348 I
1 OF 3
- 1. TITLE Main Steam Isolation Valve Failure to Close I CAUSE MANU-SYSTEM COMPONENT FACTURER 1
I
- 8. OTHER FACILITIES INVOLVED TO EPlX 111
- 9. OPERATING MODE 3
- 10. POWER LEVEL 0
FACILITY NAME FACILITY NAME
- 7. REPORT DATE
- 5. EVENT DATE
CAUSE
- 11. THIS REPORT IS SUBMllTED PURSUANT TO THE REQUIREMENTS OF 10 CFRS: (Check all that apply)
[7 20.2201(b)
[7 20.2203(a)(3)(i) 50.73(@(2)(i)(C)
[7 50,73(a)(2)(vii)
[7 20.2201(d)
[7 20.2203(a)(3)(ii) 50.73(a)(2)(ii)(A)
[7 50,73(a)(2)(viii)(A) 20.2203(a)(l)
[7 20.2203(a)(4) 50.73(a)(2)(ii)(B)
[7 50.73(a)(2)(viii)(B) 20.2203(a)(2)(i) 50.36(c)(l )(i)(A)
[7 50.73(a)(2)(iii) 50.73(a)(2)(ix)(A) 20.2203(a)(2Xii) 50.36(~)(1 )(ii)(A) 50.73(a)(2)(iv)(A) 50.73(a)(2)(~)
[7 20.2203(a)(2)(iii) 50.36(c)(2) 50.73(a)(2)(v)(A)
[7 73.71 (a)(4) 20.2203(a)(2)(iv) 50.46(a)(3)(ii) 50.73(a)(2)(v)(B)
[7 73.71(a)(5) 20.2203(a)(2)(v) 50.73(a)(2)(i)(A) 50.73(a)(2)(v)(C)
OTHER [7 20.2203(a)(2)(vi) 50.73(a)(2Xi)(B) 50.73(a)(2)(v)(D)
Specify in Abstract below or in =
(If more space is required, use additional copies of (If more space is required, use additional copies of NRC Form 366A) (17)
The upstream valves were not affected by this event. Therefore, at least one train of Main Steam Line Isolation remained operable throughout this event. This event does not represent a Safety System Functional Failure.
Following cooldown, all three MSIV's stroked fully open and closed from the Main Control Room. All tests were conducted on the downstream valves without assistance of steam flow. It is the engineering judgment of the plant and the valve manufacturer that even though there may have been some binding in the full open position, had the valves been called upon to close under accident conditions with choke flow, they would have closed in the event of a steamline break downstream of the MSIV's.
The Unit 2 valves are operable at this time. The downstream Unit 2 MSIV's (farthest from containment) were inspected during the last Unit 2 outage, including penetrant testing. No cracks were identified in the shafts. The MSIV's were reassembled and satisfactorily tested and additionally were stroked in Hot Standby conditions. All of the Unit 2 MSIV's were partial stroke tested on April 24, 2006 and all stroked satisfactorily. In the event that a closure of the valves was necessary, movement into the steam flowpath would provide additional motive force to close the valves to assist the mechanical closure mechanisms.
Corrective Action
The Maintenance procedure for MSIV overhaul will be revised by August 1,2006. The Operations MSIV cold shutdown surveillance test procedure (STP) has been revised.
The quarterly partial stroke test procedure has been re-established for Units 1 and 2. The test cylinder used at Farley Nuclear Plant during partial stroke testing does not allow the disc to enter the flow stream, and therefore does not present the risks associated with partial stroke testing that the industry is currently experiencing.
All load-bearing components in contact with the shaft have been replaced on Unit 1 downstream valves including new shafts with radius design keyways.
Preventive maintenance (PM) for replacement of the shafts and load-bearing components in contact with the shafts will be established on Unit 1 and Unit 2 by August 1,2006 Both upstream and downstream Unit 1 valves have been successfUlly tested at cold and hot shutdown conditions.
An engineering review to consider possible design changes to reduce the severity of the service conditions in the downstream valves will be completed by March 15, 2007.
Additional Information
The following LER's have been submitted in the past two years on Technical Specification violations:
LER 2005-001 -00 Unit 1 Technical Specification 3.3.2.C Violation due to Solid State Protection System Card Failure Troubleshooting LER 2005-002-00 Unit 1 Technical Specification 3.8.1 Violation due to 1F Bus Synchroscope Failure I
NRC FORM 366 (7-2001)