05000410/LER-2014-001, Regarding Emergency Diesel Generator Actuation Due to Loss of Offsite Power Source Line 5
| ML14121A076 | |
| Person / Time | |
|---|---|
| Site: | Nine Mile Point  |
| Issue date: | 04/17/2014 |
| From: | John Stanley Exelon Generation Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| LER 14-001-00 | |
| Download: ML14121A076 (7) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(iv)(A), 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)(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 10 CFR 50.73(a)(2)(iv)(B), System Actuation |
| 4102014001R00 - NRC Website | |
text
.S Exelon Generation.
Jim Stanley Plant Manager - Nine Mile Point P.O. Box 63 Lycoming, NY 13093 315 349 5205 Office www.exeloncorp.com James.stanley@exeloncorp.com April 17, 2014 U.S. Nuclear Regulatory Commission Washington, DC 20555-0001 ATTENTION: Document Control Desk
SUBJECT:
Nine Mile Point Nuclear Station, Unit 2 Renewed Facility Operating License No. NPF-69 Docket No. 50-410 Licensee Event Report 2014-001, Emergency Diesel Generator Actuation Due to Loss of Offsite Power Source Line 5 In accordance with 10 CFR 50.73(a)(2)(iv)(A), please find attached Licensee Event Report 2014-001, Emergency Diesel Generator Automatic Actuation Due to Loss of Offsite Power Source Line 5.
There are no regulatory commitments in this submittal.
Should you have questions regarding the information in this submittal, please contact Everett (Chip)
Perkins, Director Licensing, at (315) 349-5219.
Sincerely, JJS/KP
Attachment:
Licensee Event Report 2014-001, Emergency Diesel Generator Actuation Due to Loss of Offsite Power Source Line 5 cc:
NRC Project Manager NRC Resident Inspector NRC Regional Administrator
- - 7_1ý'-) /-)
ATTACHMENT LICENSEE EVENT REPORT 2014-001 EMERGENCY DIESEL GENERATOR ACTUATION DUE TO LOSS OF OFFSITE POWER SOURCE LINE 5 Nine Mile Point Nuclear Station, LLC April 17, 2014
NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 0113112017 (02-2014)
Estimated burden per response to comply with this mandatory collection request: 80 hours9.259259e-4 days <br />0.0222 hours <br />1.322751e-4 weeks <br />3.044e-5 months <br />.
Reported lessons learned are incorporated into the licensing process and fed back to industry.
Send comments regarding burden estimate to the FOIA, Privacy and Information Collections Branch (T-5 F53), U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001, or by LICENSEE EVENT REPORT LE )
intemet e-mail to lnfocoflects.Resource@nrc.gov, and to the Desk Officer, Office of Information and (See Page 2 for required number of Regulatory Affairs, NEOB-10202, (3150-0104), Office of Management and Budget, Washington, DC 20503. If a means used to impose an information collection does not display a currently valid OMB digits/characters for each block) control number, the NRC may not conduct or sponsor, and a person is not required to respond to, the information collection.
- 3. PAGE Nine Mile Point Unit 2 05000410 1 OF 5
- 4. TITLE Emergency Diesel Generator Actuation Due to Loss of Offsite Power Source Line 5
- 5. EVENT DATE
- 6. LER NUMBER
- 7. REPORT DATE
- 8. OTHER FACILITIES INVOLVED MONTH DAY YEAR YEAR SEQUENTIAL REV MONTH DAY YEAR N
/A N/A NUMBER NO.
N/A N/A FACILITY NAME DOCKET NUMBER 2
16 2014 2014-001 00 4
17 2014 N/A N/A
- 9. OPERATING MODE
- 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check all that apply)
E-20.2201(b)
El 20.2203(a)(3)(i)
El 50.73(a)(2)(i)(C)
El 50.73(a)(2)(vii)
El 20.2201(d)
El 20.2203(a)(3)(ii)
El 50.73(a)(2)(ii)(A)
El 50.73(a)(2)(viii)(A)
El 20.2203(a)(1)
El 20.2203(a)(4)
El 50.73(a)(2)(ii)(B)
El 50.73(a)(2)(viii)(B)
El 20.2203(a)(2)(i)
[I 50.36(c)(1)(i)(A)
El 50.73(a)(2)(iii)
El 50.73(a)(2)(ix)(A)
- 10. POWER LEVEL El 20.2203(a)(2)(ii)
El 50.36(c)(1)(ii)(A) 0 50.73(a)(2)(iv)(A)
El 50.73(a)(2)(x)
El 20.2203(a)(2)(iii)
El 50.36(c)(2)
El 50.73(a)(2)(v)(A)
El 73.71(a)(4)
El 20.2203(a)(2)(iv)
[I 50.46(a)(3)(ii)
El 50.73(a)(2)(v)(B)
El 73.71 (a)(5)
El 20.2203(a)(2)(v)
El 50.73(a)(2)(i)(A)
El 50.73(a)(2)(v)(C)
El OTHER E
20.2203(a)(2)(vi)
E 50.73(a)(2)(i)(B) 50.73(a)(2)(v)(D) specnAbtrac below or in
- 12. LICENSEE CONTACT FOR THIS LER LIE*ENSE Peris D
o c
Everett Perkins, Director, Licensing ITLEPHOI-'N NUMUBE (Include Area Uode)
(315) 349-5219
CAUSE
SYSTEM COMPONE B
FK XCT
- 14. SUPPLEMENTAL REPORT EXPECTED SYES (If yes, complete 15. EXPECTED SUBMISSION DATE)
[]NO I
ABSTRACT (Limit to 1400 spaces, i.e., approximately 15 single-spaced typewritten lines)
On February 16, 2014 at 1216, Nine Mile Point Unit 2 (NMP2) was operating at 100 percent power when an automatic actuation of the Division I and III Emergency Diesel Generators (EDG) occurred due to a loss of a 115kV off-site power source (Line 5) owned by National Grid. Automatic actuation of the EDGs is reportable under 10 CFR 50.72(b)(3)(iv)(A) and 10 CFR 50.73(a)(2)(iv)(A). The cause of the loss of Line 5 is due to a faulted current transformer associated with 345kV Breaker R210 owned by National Grid, the transmission owner. The faulted transformer caused a voltage transient for both station service and offsite power loads. This resulted in the loss of;
- 1) the service water radiation monitor and radwaste/reactor building vent gaseous effluent monitoring systems 2) the
'C' and 'D' Reactor Water Cleanup (WCS) filter strings, and 3) spent fuel pool cooling. The voltage transient also caused Feed Water level control valve actuator controls to lock up and go to manual operation. The corrective action planned includes working with the transmission line owner, National Grid, to complete a causal analysis for the failure of the current transformer then implement corrective actions. NMP I LER 2008-001 and NMP2 LER 2012-004 are similar LERs submitted previously which involve the actuation of the EDGs due to a loss of Power Line 5.
NRC FORM 366 (02-2014)
I. DESCRIPTION OF EVENT
A. PRE-EVENT PLANT CONDITIONS:
Prior to the event, Nine Mile Point Unit 2 (NMP2) was operating at rated reactor power.
B. EVENT:
On February 16, 2014, at 1216, Offsite Power Line 5 was lost due to a fault and fire on a National Grid Current Transformer (CT) related to Breaker R210. This occurrence resulted in the actuation of the Division I and Division III EDGs, 2EGS*EG 1 and 2EGS*EG2. In response, Operations personnel entered the action statements for TS 3.8.1, Condition A, for Line 5 inoperability.
The fault resulted in a voltage transient for both station service and offsite power loads. It caused Feed Water level control valves (2FWS-LV IOA and 2FWS-LV lOB) actuator controls to lock up and go into manual operation. It resulted in the loss of 'C' and 'D' Reactor Water Cleanup (WCS) filter strings. The fault of Breaker R210 also resulted in the loss of Service Water Radwaste Monitor 2SWP*RE 146A and Radwaste/Reactor Building Vent Gaseous Effluent Monitoring Systems and a loss of spent fuel pool cooling.
Immediate actions in plant procedure N2-SOP-3, Loss of AC Power, were taken to stabilize the plant.
Actions were taken in N2-SOP-38, Loss of Spent Fuel Pool Cooling, to start the Division II Spent Fuel Pool Cooling and Cleanup pump in cooling only mode. Operations personnel took further action per N2-SOP-6, Feed Water Failures, and restored control to automatic with a slight rise in reactor water level.
Review of feed water level control drawings and condition reports validated that a momentary loss of control voltage or a large dip can cause the controls for these valves to lock up. Compensatory measures were also established for Service Water Radiation Monitor, 2SWP*RE146A and the Radwaste/Reactor Building Vent Gaseous Effluent Monitoring Systems in accordance with plant procedures and the Offsite Dose Calculation Manual.
The loss of Power Line 5 event which resulted in the EDG actuation has been entered into the corrective action program as CR-2014-001352.
Nine Mile Point Unit I (NMP1) was unaffected by the condition associated with the loss of Power Line 5.
C. INOPERABLE STRUCTURES, COMPONENTS, OR SYSTEMS THAT CONTRIBUTED TO THE EVENT:
The fault and fire on a National Grid CT related to Breaker R210 resulted in the loss of power to Power Line 5 and resulted in the automatic actuation of the EDGs.
D. DATES AND APPROXIMATE TIMES OF MAJOR OCCURRENCES
The dates, times and major occurrences for this event are as follows:
February 16 February 17 1216 1216 1216 1216 1235 1253 1327 1430 1450 0240 1449 1628 Received multiple annunciations due to loss of Line 5 Division I and Division III EDGs energized Entered TS 3.8.1 Entered N2-SOP-3 and 6 Operator dispatched to Scriba switchyard due to report of smoke N2-SOP-38 is entered N2-SOP-6 is exited N2-SOP-38 is exited Service Water Radiation Monitor restored Radwaste/Reactor Building Vent Gaseous Monitoring restored N2-SOP-3 is exited Line 5 restored to OPERABLE
E. OTHER SYSTEMS OR SECONDARY FUNCTIONS AFFECTED
No other systems or secondary functions were affected beyond systems discussed in Section I.B.
F. METHOD OF DISCOVERY
Operations received multiple annunciations in the Control Room due to a loss of Power Line 5. A plant operator was dispatched to investigate report of smoke coming from the Scriba switchyard.
The investigation confirmed that a current transformer related to Breaker R210 had failed and was on fire.
G. MAJOR OPERATOR ACTION:
Operations personnel made entries into the Action Statements for TS 3.8.1, Condition A, for Line 5 inoperability. Operations personnel also entered procedures N2-SOP-3, N2-SOP-6, N2-SOP-38 and took compensatory measures as required by station procedures and the Offsite Dose Calculation Manual (ODCM).
H. SAFETY SYSTEM RESPONSES:
Following the loss of Power Line 5, Division I and Division III EDGs were automatically actuated.
II. CAUSE OF EVENT
The loss of offsite Power Line 5 was due to a fault and fire on a National Grid CT associated with Breaker R210. Nine Mile Point is working with National Grid to determine the cause of the CT failure and an action associated with CR-2014-001352 has been created to obtain results of the causal analysis.
III. ANALYSIS OF THE EVENT
This event is reportable in accordance with 10 CFR 50.72(b)(3)(iv)(A), and 10 CFR 50.73(a)(2)(iv)(A).The event caused a valid actuation of the Division I and Division III EDGs, a safety system named in 10 CFR 50.73(a)(2)(iv)(B). The actuation was not part of a preplanned sequence during testing or reactor operation.
The onsite emergency (safety-related) AC power system includes the standby diesel generators that feed the safety-related loads in case of a loss of offsite power (LOOP). The onsite emergency AC power system is divided into three physically separate and electrically independent divisions, any two out of three divisions being capable of bringing the plant to safe shutdown in case of a loss-of-coolant accident (LOCA) or any other Design Basis Accident (DBA). The emergency AC power system is normally energized from offsite power sources. In case of a LOOP, this system is energized by the standby diesel generators. When the loss of Line 5 occurred, the diesel generators actuated automatically, as designed, to energize the safety-related loads. NMP2 was operating at steady-state 100 percent power prior to, during, and following the event.
There were no actual nuclear safety consequences associated with this event.
Based on the above discussion, it is concluded that the safety significance of this event is low and the event did not pose a threat to the health and safety of the public or plant personnel.
This event does not affect the NRC Regulatory Oversight Process Indicators.
IV. CORRECTIVE ACTIONS
A. ACTION TAKEN TO RETURN AFFECTED SYSTEMS TO PRE-EVENT NORMAL STATUS:
Operations personnel took action per N2-SOP-3, N2-SOP-6 and N2-SOP-38 to restore the plant to pre-event conditions.
B. ACTION TAKEN OR PLANNED TO PREVENT RECURRENCE:
Nation Grid is performing a casual analysis. NMP will work with the Transmission Owner in the completion of the causal analysis to determine the cause of R210 CT failure and then implement the
corrective actions
The scheduled revision to this LER will document the results of the causal analysis including corrective actions.
M1ISSION
V. ADDITIONAL INFORMATION
A. FAILED COMPONENTS:
There were no other failed components that contributed to this event.
B. PREVIOUS LERs ON SIMILAR EVENTS:
NMP2 LER 2012-005 reported that on October 29, 2012 at 21:00, NMP2 was operating at 100 percent power when an automatic actuation of the Division I EDG occurred due to the loss of a 15 kV off-site power source (Line 5) due to remnant winds of Hurricane Sandy.
NMP 1 LER 2008-001 reported that emergency diesel generators actuated when the plant experienced a loss of offsite power. A power line shared with the James A. FitzPatrick was lost.
C. THE ENERGY INDUSTRY IDENTIFICATION SYSTEM (EIIS) COMPONENT FUNCTION IDENTIFIER AND SYSTEM NAME OF EACH COMPONENT OR SYSTEM REFERRED TO IN THIS LER:
IEEE 803 FUNCTION IDENTIFIER IEEE 805 SYSTEM IDENTIFICATION COMPONENT Current Transformer Emergency Diesel Generator Spent Fuel Pool Cooling Pump Service Water Radiation Monitor Reactor Water Cleanup Filter D. SPECIAL COMMENTS:
None XCT DG P