05000339/LER-2005-001, Re Automatic Reactor Trip Due to Lightning Strike
| ML052780043 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 09/28/2005 |
| From: | Jennifer Davis Virginia Electric & Power Co (VEPCO) |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| 05-535 LER 05-001-00 | |
| Download: ML052780043 (5) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(ii)(B), Unanalyzed Condition 10 CFR 50.73(a)(2)(ix)(A) 10 CFR 50.73(a)(2)(iii) 10 CFR 50.73(a)(2)(x) 10 CFR 50.73(a)(2)(iv)(A), System Actuation 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)(v), Loss of Safety Function 10 CFR 50.73(a)(2)(i)(A), Completion of TS Shutdown 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 10 CFR 50.73(a)(2)(vii), Common Cause Inoperability 10 CFR 50.73(a)(2)(i) 10 CFR 50.73(a)(2)(viii)(A) 10 CFR 50.73(a)(2)(ii)(A), Seriously Degraded 10 CFR 50.73(a)(2)(viii)(B) |
| 3392005001R00 - NRC Website | |
text
1 OCFR50.73 Virginia Electric and Power Company North Anna Power Station P. 0. Box 402 Mineral, Virginia 23117 September 28, 2005 U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, D. C. 20555-0001 Serial No.:
NAPS:
Docket No.:
License No.:
05-535 MPW 50-339 NPF-7
Dear Sirs:
Pursuant to 10CFR50.73, Virginia Electric and Power Company hereby submits the following Licensee Event Report applicable to North Anna Power Station Unit 2.
Report No. 50-339/2005-001-00 This report has been reviewed by the Station Nuclear Safety and Operating Committee and will be forwarded to the Management Safety Review Committee for its review.
Sincerely, Davis, Site Vice President 1 Anna Power Station Enclosure Commitments contained in this letter: None cc: United States Nuclear Regulatory Commission Region II Sam Nunn Atlanta Federal Center 61 Forsyth Street, SW, Suite 23T85 Atlanta, Georgia 30303-8931 Mr. J. T. Reece NRC Senior Resident Inspector North Anna Power Station
NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB NO. 3150-0104 EXPIRES 6-30-2007 (6-2004)
Estimated burden per response to comply with this mandatory collection request: 50 hours5.787037e-4 days <br />0.0139 hours <br />8.267196e-5 weeks <br />1.9025e-5 months <br />. Reported lessons learned are incorporated into the licensing process and fed back to industry. Send comments regarding burden estimate to the Records and FOIAIPrivacy Service Branch (T-5 F52), U.S. Nuclear Re ulatory Commission, LICENEEC EVENIT REPORT (LER)Washington, DC 20555-0001, or by internet e-mail to infocolects@nrc.gov, and to LICENSEE EV N REPORT (LER_
_ w
_..the Desk Officer, Office of Information and Regulatory Affairs, NEOB-10202 (3150-(See reverse for required number of digits/characters for each block) 0066), Office of Management and Budget, Washington, DC 20503. II a means used to impose information collection does not display a currently valid OMB control number, the NRC may not conduct or sponsor, and a person is not required to respond to, the information collection.
- 3. PAGE NORTH ANNA POWER STATION, UNIT 2 05000 339 1 OF 4
- 4. TITLE Automatic Reactor Trip Due to Lightning Strike
- 5. EVENT DATE
- 6. LER NUMBER
- 7. REPORT DATE
- 8. OTHER FACILITIES INVOLVED MONTH DAY YEAR YEAR SEQUENTIAL REVISION MONTH DAY YEAR FACIL0TY NAME D500 NUMBER NO.
08 05 2005 2005
-- 001 --
00 09 28 2005 FACILITY NAME DOCUMENT NUMBER 05000
- 9.
- 1. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check all that apply)
OPERATING MODE 1
20.2201(b) 20.2203(a)(3)(ii) 50.73(a)(2)(ii)(B) 50.73(a)(2)(ix)(A)
- 10. POWER 20.2201 (d) 20.2203(a)(4) 50.73(a)(2)(iii) 50.73(a)(2)(x)
LEVEL 100%
20.2203(a)(1) 50.36(c)(1)(i)(A)
X 50.73(a)(2)(iv)(A) 73.71 (a)(4) 20.2203(a)(2)(i) 50.36(c)(1)(ii)(A) 50.73(a)(2)(v)(A) 73.71 (a)(5) 20.2203(a)(2)(ii) 50.36(c)(2) 50.73(a)(2)(v)(B)
OTHER 20.2203(a)(2)(iii) 50.46(a)(3)(ii) 50.73(a)(2)(v)(C) 20.2203(a)(2)(iv) 50.73(a)(2)(i)(A) 50.73(a)(2)(v)(D) 20.2203(a)(2)(v) 50.73(a)(2)(i)(B) 50.73(a)(2)(vii)
Specity in Abstract below or 20.2203(a)(2)(vi) 50.73(a)(2)(i)(C) 50.73(a)(2)(viii)(A) in NRC Forrn 366A 20.2203(a)(3)(i) 50.73(a)(2)(ii)(A) 50.73(a)(2)(viii)(B)
- 12. LICENSEE CONTACT FOR THIS LER FACILllY NAME TELEPHONE NUMBER (Include Area Code)
J. M. Davis, Site Vice President (540) 894-2101CAUSE SYSTEM COMPONENT MANUFACTURER REPORTABLE
CAUSE
SYSTEM COMPONENT MANUFACTURER REPORTABLE
_'TO EPIX I
TO EPIX
<==
I I_
I
- 14. SUPPLEMENTAL REPORT EXPECTED 15.EXPECTED MONTH DAY YEAR I
SUBMISSION l
l YES (If yes, complete 15. EXPECTED SUBMISSION DATE)
X NO lIDATESllN ABSTRACT (Umit to 1400 spaces, I.e., approximately 15 single-spaced typewritten lines)
On August 5, 2005, at 2227 hours0.0258 days <br />0.619 hours <br />0.00368 weeks <br />8.473735e-4 months <br />, North Anna Unit 2 experienced an automatic Reactor trip from 100 percent power during a severe thunderstorm. A lightning strike was the direct cause of this event. The lightning strike caused an Overtemperature Delta T (OTDT) Unit 2 Reactor Trip signal without an actual overtemperature condition. The control room team responded to the reactor trip in accordance with procedure 2-E-0, Reactor Trip or Safety injection. All Engineered Safety Feature equipment responded as designed. A non-emergency 4-hour report was made to the NRC Operations Center at 0020 hours2.314815e-4 days <br />0.00556 hours <br />3.306878e-5 weeks <br />7.61e-6 months <br /> on August 6, 2005, in accordance with 10 CFR 50.72 (b)(2)(iv)(B). An 8-hour report was also made in accordance with 10 CFR 50.72(b)(3)(iv)(A) due to actuation of the Auxiliary Feedwater System (AFW).
This event is reportable pursuant to 10 CFR 50.73 (a)(2)(iv)(A) for a condition that resulted in automatic actuation of the reactor protection system and the AFW system. This event posed no significant safety implications since the reactor protection systems functioned to trip the reactor safely. Therefore, the health and safety of the public were not affected by this event.
NRC FORM 366 (67-2004)
PRINTED ON RECYCLED PAPER (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 Installation of the spare RTD grounds should prevent instrumentation spikes causing the OTDT fluctuations.
7.0 SIMILAR EVENTS
LER Report No. 50-339/98-004-00, dated October 6, 1998, documents an automatic reactor trip due to a lightning strike. The initiating reactor trip signals were the same for both events.
8.0 ADDITIONAL INFORMATION
Unit 1 was not affected by this event.