05000328/LER-2006-001, Re Reactor Trip Resulting from Actuation of the Main Generator Neutral Overvoltage Relay
| ML061460142 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 05/22/2006 |
| From: | Pace P Tennessee Valley Authority |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| LER 06-001-00 | |
| Download: ML061460142 (6) | |
| 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) 10 CFR 50.73(a)(2)(iv)(A), System Actuation 10 CFR 50.73(a)(2)(v), Loss of Safety Function |
| 3282006001R00 - NRC Website | |
text
Tennessee Valley Authority, Post Office Box 2000, Soddy-Daisy, Tennessee 37384-2000 May 22, 2006 U.S. Nuclear Regulatory Commission 10 CFR 50.73 ATTN:
Document Control Desk Washington, D.C. 20555-0001 Gentlemen:
TENNESSEE VALLEY AUTHORITY -
SEQUOYAH NUCLEAR PLANT (SQN)
UNIT 2 -
DOCKET NO. 50-328 -
FACILITY OPERATING LICENSE DPR LICENSEE EVENT REPORT (LER) 50-328/2006-001-00 The enclosed LER provides details concerning an automatic turbine and reactor trip resulting from actuation of the main generator neutral overvoltage relay.
This report is being submitted in accordance with 10 CFR 50.73(a)(2)(iv) as an event that resulted in the automatic actuation of engineered safety features, including the reactor protection system.
Sincerely P. L. Pace Manager, Site Licensing and Industry Affairs Enclosure cc (Enclosure):
INPO Records Center Institute of Nuclear Power Operations 700 Galleria Parkway, SE, Suite 100 Atlanta, Georgia 30339-5957 PNnted on recycled papw
I NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 06/30/2007 (6-2004)
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LICENSEE EVENT REPORT (LER)
U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001, or by internet e-mail to infocollectsEnrc.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 (See reverse for required number of impose an information collection does not display a currently valid OMB sfor each block) control number, the NRC may not conduct or sponsor, and a person is not digits/characters frequired to respond to, the information collection.
- 1. FACILITY NAME DOCKETNUMBER PAGE Sequoyah Nuclear Plant (SQN) Unit 2 05000328 1 OF 5
- 4. TITLE Reactor Trip Resulting F1rom Actuation Of The Main Generator Neutral Overvoltage Relay
- 5. EVENT DATE
- 6. LER NUMBER
- 7. REPORT DATE
- 8. OTHER FACILITIES INVOLVED SEUETALRE ACLrrY NAME DOCKETrNUMBER MONTH DAY YEAR YEAR SEQUMENTR MONTH DAY YEAR F
05000 FACLnY NAME DOCKEThNUMBER 03 22 2006 2006 -
001 00 05 22 2006 05000 9.OPEATING plODE
).THISREPORTISS OF10CFR§: (Checkathatapply) 0 20.2201(b) 0 20.2203(a)(3Xi) 0 50.73(a)(2)(i)(C) 0 50.73(a)(2)(vii) 1 20.2201(d) a 20.2203(a)(3Xii) 0 50.73(aX2)ii)(A) 0 50.73(a)(2)(vii)xA) 020.003(a)1) 0 20.2203(aX4) 0 50.73(aX2)(iiXB) 0 50.73(a)(2)(viiiXB) 020.2203(aX2Xi) 03 50.36(cX1)()(A) 0 50.73(aX2)(iii)
El 50.73(aX2)(ixXA)
- 10. POWER LEVEL 0
20.2203(a)(2)(ii) 0 50.36(c)(1)(ii)XA) 0 50.73(a)(2)(iv)(A) 3 50.73(a)(2Xx) o 20.2203(aX2)(iii) 0 50.36(c)(2) 0 50.73(a)(2Xv)(A) 0 73.71 (a)(4) 100 E 20.2203(aX2Xiv) 0 50.46(aX3)(ii) 0 50.73(aX2)(v)(B) 0 73.71(a)(5) o0 20.2203(aX2)(v) 0 50.73(a)(2X)(XA) 0 50.73(aX2Xv)(C) 0 OTHER 0
20.2203(aX2)(vi) 0 50.73(a)(2)(iXB) 0 50.73(a)(2)(vXD)
Specify in Abstract below or in (ff more space is required, use additional copies of (If more space is required, use additional copies of NRC Form 366A)
B. Corrective Actions to Prevent Recurrence:
The bus duct was modified to no longer require the gasket. The gasket was removed from Unit 1 bus ducts and will be removed from the bus ducts on Unit 2 during the upcoming refueling outage.
VIl.
ADDITIONAL INFORMATION
A.
Failed Components:
The gasket material part number 868A8151H36 was manufactured by Westinghouse.
B. Previous LERs on Similar Events:
A review of previous reportable events identified a similar event that resulted in a reactor trip that was initiated from a loose gasket causing a short. LER 50-328 / 95002 addressed a reactor trip that resulted from a neoprene gasket coming loose and causing a phase-to-ground fault. The gasket was replaced and sealed with sealant to secure the gasket in place and an independent means (tie-wraps) were added to support the gasket. Additional corrective actions included inspection of the other Unit 2 transformers and revising a PM to periodically inspect gaskets and bus alignments at the transformer doghouses and rework or replace as required.
C.
Additional Information
None.
D. Safety System Functional Failure:
This event did not result in a safety system functional failure in accordance with 10 CFR 50.73(a)(2)(v).
E. Loss of Normal Heat Removal Consideration:
This condition did not result in a loss of normal heat removal.
Vil.
COMMITMENTS
None.