05000272/LER-2012-004, Regarding Loss of Circulating Water and Manual Reactor Trip Due to Hurricane Sandy
| ML13002A004 | |
| Person / Time | |
|---|---|
| Site: | Salem  |
| Issue date: | 12/26/2012 |
| From: | Fricker C Public Service Enterprise Group |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| LR-N12-0361 LER 12-004-00 | |
| Download: ML13002A004 (6) | |
| 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 |
| 2722012004R00 - NRC Website | |
text
PSEG Nuclear LLC P.O. Box 236, Hancocks Bridge, NJ 08038-0236 0 PSEG Nuclear LLC DEC 2 62012 LR-N12-0361 10CFR 50.73 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 LER 272/2012-004 Salem Nuclear Generating Station Unit 1 Facility Operating License No. DPR-70 NRC Docket No. 50-272
SUBJECT:
Loss of Circulating Water and Manual Reactor Trip Due to Hurricane Sandy The Licensee Event Report, "Loss of Circulating Water and Manual Reactor Trip Due to Hurricane Sandy," is being submitted pursuant to the requirements of the Code of Federal Regulations, 10CFR 50.73(a)(2)(iv)(A) for Reactor Protection System, Auxiliary Feedwater and Main Steam Isolation Valve actuations.
The attached LER contains no commitments. Should you have any questions or comments regarding the submittal, please contact David Lafleur of Salem Regulatory Assurance at 856-339-1754.
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Site Vice President - Salem Attachments (1)
Document Control Desk Page 2 LR-N12-0361 cc Mr. W. Dean, Administrator - Region 1, NRC Mr. John Hughey, Licensing Project Manager -Salem, NRC Ms. E. Bonney, USNRC Senior Resident Inspector, Salem (X24)
Mr. P. McKenna, USNRC Resident Inspector, Salem Mr. P. Mulligan, Manager IV, NJBNE Mr. T. Joyce, President and Chief Nuclear Officer - Nuclear Mr. T. Cachaza, Salem Commitment Tracking Coordinator Mr. L. Marabella, Corporate Commitment Tracking Coordinator Mr. D. Lafleur, Salem Regulatory Assurance Page 2 of 2
NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 10/31/2013 (10-2010)
, the NRC may not conduct or sponsor, and a person is not required to respond to, the information collection.
- 3. PAGE Salem Generating Station - Unit 1 05000272 1
of 4
- 4. TITLE Loss of Circulating Water and Manual Reactor Trip Due to Hurricane Sandy
- 5. EVENT DATE
- 6. LER NUMBER
- 7. REPORT DATE
- 8. OTHER FACILITIES INVOLVED MONTH DAY YEAR YEAR SEQUENTIAL REVN FACILITY NAME DOCKET NUMBER MOTH.
A YAR YER NUMBER NO.
MONTH DAY YEAR IDOCKET NUMBER 10 30 2012 2012 0 0 4_01_12 26 2012
- 9. OPERATING MODE
- 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR§: (Check all that apply)
El 20.2201(b)
El 20.2203(a)(3)(i)
El 50.73(a)(2)(i)(C)
[I 50.73(a)(2)(vii)
El 20.2201(d)
El 20.2203(a)(3)(ii)
El 50.73(a)(2)(ii)(A)
[I 50.73(a)(2)(viii)(A)
El 20.2203(a)(1)
[I 20.2203(a)(4)
El 50.73(a)(2)(ii)(B)
El 50.73(a)(2)(viii)(B)
[I 20.2203(a)(2)(i)
El 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)
Cl 50.36(c)(1)(ii)(A)
ED 50.73(a)(2)(iv)(A)
El 50.73(a)(2)(x)
E] 20.2203(a)(2)(iii)
El 50.36(c)(2)
E] 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) 100%
[E 20.2203(a)(2)(v)
El 50.73(a)(2)(i)(A)
El 50.73(a)(2)(v)(C)
El OTHER El 20.2203(a)(2)(vi)
[E 50.73(a)(2)(i)(B)
El 50.73(a)(2)(v)(D)
Specify in Abstract below or in tripping of a CWP when its CW Traveling Screen differential pressure is greater than 8 feet. At 0049 hours5.671296e-4 days <br />0.0136 hours <br />8.101852e-5 weeks <br />1.86445e-5 months <br /> on October 30, 2012, the 13B CWP was tripped due to a report of a high differential pressure across the 13B CW Traveling Screen. At 0102 hours0.00118 days <br />0.0283 hours <br />1.686508e-4 weeks <br />3.8811e-5 months <br />, the 11 B CWP was manually tripped due to its CW Traveling Screen being reported as having high differential pressure and not turning. At 0103 hours0.00119 days <br />0.0286 hours <br />1.703042e-4 weeks <br />3.91915e-5 months <br />, the 11 A CWP was manually tripped due to a report that its CW Traveling Screen had a high differential pressure and had also stopped.
At 0104 hours0.0012 days <br />0.0289 hours <br />1.719577e-4 weeks <br />3.9572e-5 months <br />, a turbine load reduction to 80% power was commenced to maintain condenser backpressure within limits in accordance with the Circulating Water Malfunction procedure.
At 0109 hours0.00126 days <br />0.0303 hours <br />1.802249e-4 weeks <br />4.14745e-5 months <br />, the 12A CWP was manually tripped due to a high CW Traveling Screen differential pressure and operators performed a manual trip of the reactor in accordance with plant operating procedures due to the loss of four CWPs with power above 10%. An automatic actuation of Auxiliary Feedwater occurred as expected due to low Steam Generator water levels induced by the unit transient.
Operators entered Emergency Operating Procedure 1-EOP-TRIP-1, Reactor Trip or Safety Injection. At 0111 hours0.00128 days <br />0.0308 hours <br />1.835317e-4 weeks <br />4.22355e-5 months <br />, Operations transitioned to 1-EOP-TRIP-2, Reactor Trip Response.
At 0113 hours0.00131 days <br />0.0314 hours <br />1.868386e-4 weeks <br />4.29965e-5 months <br />, the 12B CWP tripped due to motor overcurrent. At 0118 hours0.00137 days <br />0.0328 hours <br />1.951058e-4 weeks <br />4.4899e-5 months <br />, the remainingl3A CWP was manually tripped due to a high CW Traveling Screen differential pressure.
At 0141 hours0.00163 days <br />0.0392 hours <br />2.331349e-4 weeks <br />5.36505e-5 months <br />, operators transitioned from emergency operating procedures to normal operating procedures maintaining Hot Standby, Mode 3 conditions.
At 0513 hours0.00594 days <br />0.143 hours <br />8.482143e-4 weeks <br />1.951965e-4 months <br /> operators manually initiated a Main Steam Line Isolation due to a loss of condenser cooling and indications of high condenser backpressure.
The maximum recorded river level was 97.2 feet between 0120 and 0135 hours0.00156 days <br />0.0375 hours <br />2.232143e-4 weeks <br />5.13675e-5 months <br />. The maximum recorded sustained wind speed throughout the storm was approximately 55 miles an hour.
CAUSE OF OCCURRENCE The cause of the loss of all six CWPs was due to heavy river detritus loading on the CW Traveling Screens due to wind, wave and current effects of Hurricane Sandy.
Heavy detritus loading caused high differential screen pressures requiring manual trips of operating CWPs. Buildup of detritus on the CW Traveling Screens caused shear pin breakage and repositioning of screen hubs on rotating shafts causing stopping and in some cases subsequent overload trips. One CWP experienced an instantaneous overcurrent trip due to cavitation as a result of low bay level.
PREVIOUS SIMILAR OCCURRENCES A review of LERs at Salem Station dating back to 2009 identified two other manual reactor trips in
response to degraded Circulating Water system conditions. LER 311/2010-001, "Manual Reactor Trip Due to Degraded Condenser Heat Removal" reported a manual trip of Salem Unit 2 on January 3, 2010, due to heavy ice loading on CW Traveling Screens. LER 272/2011-003, "Manual Reactor Trip Due to Degraded Condenser Heat Removal" reported a manual reactor trip of Salem Unit 1 on April 21, 2011, due to abnormally high amounts of river detritus entrainment on the CW Traveling Screens.
SAFETY CONSEQUENCES AND IMPLICATIONS
There were no safety consequences associated with the manual reactor trip. Operators appropriately responded to the loss of CWPs and degradation of condenser pressure by manually tripping the reactor.
All safety systems operated as required. Automatic Auxiliary Feedwater actuation occurred as expected for this transient. Manual Main Steamline Isolation was performed in response to indications of high condenser backpressure.
The maximum recorded river level and wind speed during the event did not meet the criteria for Emergency Action Level reporting, Technical Specification or administrative required shutdown actions.
A review of this event determined that a Safety System Functional Failure (SSFF) as defined in Nuclear Energy Institute (NEI) 99-02 did not occur.
CORRECTIVE ACTIONS
- 1. The CW Intake Structure, CW Traveling Screens and CWPs were inspected for damage. Divers inspected Circulating Water Bays, Traveling Screens and affected CWPs. All intake debris was removed. Traveling Screens and affected CWPs were repaired.
- 2. The CW system was placed back in service and Unit 1 was returned to service on November 2, 2012 at 2115 hours0.0245 days <br />0.588 hours <br />0.0035 weeks <br />8.047575e-4 months <br />.
- 3. A root cause analysis is in progress to assess the design of the CW systems ability to withstand severe weather and to develop operating strategies for the future.
COMMITMENTS
No commitments are made in this LER.