05000339/LER-2007-004, Automatic Reactor Trip Due to Loss of Coolant Flow with Power Greater than 30 Percent
| ML080630505 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 02/20/2008 |
| From: | Stoddard D Virginia Electric & Power Co (VEPCO) |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| 07-0843 LER 07-004-00 | |
| Download: ML080630505 (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 |
| 3392007004R00 - NRC Website | |
text
VIRGINIA EILECTRIC AND POWER COMPANY 100CFR5O.73 RLICHMOND, VIRGINIA 23261 Virginia Electric and Power Company North Anna Power Station P. 0. Box 402 Mineral, Virginia 23117 February 20, 2008 U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, D. C. 20555-0001 Serial No.:
NAPS:
Docket No.:
License No.:
07-0843 MPW 50-339 NPF-7
Dear Sirs:
Pursuant to 10CFR5O.73, Virginia Electric and Power Company hereby submits the following Licensee Event Report applicable to North Anna Power Station Unit 2.
Report No. 50-339/2007-004-00 This report has been reviewed by the Facility Safety Review Committee and will be forwarded to the Management Safety Review Committee for its review.
Sincerely, Daniel 0. Stoddard, P.E.
Site Vice President North Anna Power Station Enclosure Commitments contained in this letter: None cc:
United States Nuclear Regulatory Commission Region 11 Sam Nunn Atlanta Federal Center 61 Forsyth Street, SW, Suite 23T85 Atlanta, Georgia 30303-8931 NRC Senior Resident Inspector North Anna Power Station
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NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSIO APPROVED BY OMB NO. 3150-0104 EXPIRES: 8/31/2010 (9-2007)
, the NRC may dgt/hrcesfor each block) not conduct or sponsor, and a person is not required to respond to, the digis/caracersinformation collection.
- 3. PAGE NORTH ANNA POWER STATION, UNIT 2 105000 339 1 OF 4
- 4. TITLE Automatic Reactor Trip Due to Loss of Coolant Flow With Power Greater Than 30 Percent
- 5. EVENT DATE
- 6. LER NUMBER J 7. REPORT DATE
- 8. OTHER FACILITIES INVOLVED MONTH DAY YEAR YEAR SEQUENTIAL REV MONTH DAY YEAR FACILITY NAME DOCUMENT NUMBER
_______NUMBER NO.
I
______________05000 12 25 2007 2007
-- 004 --
00 02 20 2008 FACILITY NAME DOCUMENT NUMBER
_____ I______
______________________05000
- 9. OPERATING MODE
- 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check all/that apply)
Li 20.2201(b)
E]
20.2203(a)(3)(i)
Li50.73(a)(2)(i)(C)
Li 50.73(a)(2)(vii)
El20.2201 (d)
[3 20.2203(a)(3)(ii)
Li50.73(a)(2)(ii)(A)
LI50.73(a)(2)(viii)(A) 1[I20.2203(a)(1)
LI20.2203(a)(4)
LII 50.73(a)(2)(ii)(B)
E]50.73(a)(2)(viii)(B) i20.2203(a)(2)(i)
Li50.36(c)(1)(i)(A)
[] 50.73(a)(2)(iii)
E] 50.73(a)(2)(ix)(A)
- 10. POWER LEVEL [I20.2203(a)(2)(ii)
Li50.36(c)(1)(ii)(A) lE]
50.73(a)(2)(iv)(A)
[1 50.73(a)(2)(x)
Li1 20.2203(a)(2)(iii)
Li50.36(c)(2)
Li50.73(a)(2)(v)(A) 73.71 (a)(4)
Li20.2203(a)(2)(iv)
[] 50.46(a)(3)(ii)
Li50.73(a)(2)(v)(B)
Li7171(a)(5)
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[]50.73(a)(2)(i)(A)
Li-50.73(a)(2)(v)(C)
Li OTHER 100%
E] 20.2203(a)(2)(vi)
Li50.73(a)(2)(i)(B)
F[i 50.73(a)(2)(v)(D)
VOLUNTARY LER
- 12. LICENSEE CONTACT FOR THIS LER FACILITY NAME TELEPHONE NUMBER (Include Area Code)
F. Miaden, Director Station Safety and Licensing (540) 894-2108CAUSE ISYSTEM COMPONENT MANU-REPORTABLE ICAUSE SYSTEM OPNN MANU
RC P
W120 Y
- 14. SUPPLEMENTAL REPORT EXPECTED
- 15. EXPECTED MONTH DAY YEAR L~
ES(f e, oplt 1.EXETE UBISINDATE)
LiNO SUBMISSION 05 30 I08
_____es opet 5
XPCE UBISO DATE'_
ABSTRACT (Limit to 1400 spaces, i.e., approximately 15 single-spaced typewritten lines)
On December 25, 2007 at 2110 hours0.0244 days <br />0.586 hours <br />0.00349 weeks <br />8.02855e-4 months <br />, with Unit 2 in Model1 at 100% power, an-automatic reactor trip occurred. The automatic reactor trip was a result of a loss of coolant flow with power greater than 30 percent. The loss of coolant flow was the result of the B Reactor Coolant Pump (RCP) motor trip. A review of the event determined that the breaker supplying the B RCP motor opened due to a response by the neutral over current protection relay. Post-event testing of the B RCP motor trip identified a "B" phase to ground fault. The cause of this event will be determined following the motor failure analysis being performed by an offsite vendor. This event is reportable pursuant to 10 CFR 50.73(a)(2)(iv)(A) for an event that resulted in the automatic actuation of the Reactor Protection System and Engineered Safety Features Actuation Systems. All Engineered Safety Feature equipment responded as designed with the exception of the steam driven auxiliary feedwater pump which tripped due to actuation of the over-speed trip valve and was manually reset and subsequently placed in service. The health and safety of the public were not affected at any time during the event.
NRC FORM 366 (9-2007)
PRINTED ON RECYCLED PAPER
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(If more space is required, use additional copies of (If more space is required, use additional copies of (If more space is required, use additional copies of NRC Form 366A) (17) 6.0 ACTIONS TO PREVENT RECURRENCE Following the completion of the B RCP motor failure analysis corrective actions will be implemented to prevent recurrence.
Maintenance procedures for the steam driven auxiliary feedwater pump have been revised to ensure adequate trip valve linkage and emergency trip mechanism engagement meets the manufacturer recommended tolerances.
7.0
SIMILAR EVENTS
There have been no similar events where the reactor tripped on a loss of coolant flow with power greater than 30 percent as a result of an RCP motor trip.
8.0
ADDITIONAL INFORMATION
At the time of this event, North Anna Unit 1 was operating at 100 percent power and was not affected by this event.
Component information:
Description
Reactor Coolant Pump Motor Manufacturer:
Westinghouse Model No.:
CS Serial No.:
1 S81 P777NRC ORM 66A(9-207)PRINTED ON RECYCLED PAPER