05000311/LER-2012-002, Regarding Auxiliary Feedwater Flow Control Valve Failed Open with Zero Demand
| ML12251A003 | |
| Person / Time | |
|---|---|
| Site: | Salem  |
| Issue date: | 09/04/2012 |
| From: | Fricker C Public Service Enterprise Group |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| LR-N12-0233 LER 12-002-00 | |
| Download: ML12251A003 (6) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 10 CFR 50.73(a)(2)(v), Loss of Safety Function 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 |
| 3112012002R00 - NRC Website | |
text
PSEG Nuclear LLC P.O. Box 236, Hancocks Bridge, NJ 08038-0236
% PSEG Nuclear LLC SEP 0 4 2012 LR-N12-0233 10CFR 50.73 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 LER 311/2012-002 Salem Nuclear Generating Station Unit 2 Facility Operating License No. DPR-75 NRC Docket No. 50-311
SUBJECT:
Auxiliary Feedwater Flow Control Valve Failed Open with Zero Demand The Licensee Event Report, "Auxiliary Feedwater Flow Control Valve Failed Open on Demand," is being submitted pursuant to the requirements of the Code of Federal Regulations, 10 CFR 50.73(a)(2)(i)(B), "Any operation or condition which was prohibited by Technical Specifications" and 10 CFR 50.73(a)(2)(v)(D), "Any event or condition that could have prevented the fulfillment of the safety function of structures or systems that are needed to mitigate the consequences of an accident."
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.
- Since,
'rlI dcker Site Vice. President - Salem, Attachments (1)
Document Control Desk Page 2 LR-N 12-0233 SEP 0 4 201?
cc Mr. W. Dean, Administrator - Region 1, NRC Mr. John Hughey, Licensing Project Manager-Salem, NRC Mr. D. Schroeder, USNRC Senior Resident Inspector, Salem (X24)
Mr. P. Mulligan, ManagerIV, 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 APPROVEDBY OMB: NO. 3150-0104 EXPIRES: 10/31/2013
'110-2010)
, 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 2 05000311 1 of 4
- 4. TITLE Auxiliary Feedwater Flow Control Valve Failed Open with Zero Demand
- 5. EVENT DATE
- 6. LER NUMBER
- 7. REPORT DATE
- 8. OTHER FACILITIES INVOLVED MONTH DAY YEAR YEAR SEQUENTIAL REV MONTH D
FACILITY NAME DOCKET NUMBER NUMBER NO.
MONT___
AYYEAR I
0DOCKET NUMBER 07 05 2012 2012 0 0
2 0
09 04 2012
- 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)
[I 50.73(a)(2)(vii) 1E 20.2201(d)
[I 20.2203(a)(3)(ii)
[] 50.73(a)(2)(ii)(A)
E3 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)
E] 20.2203(a)(2)(i)
El 50.36(c)(1)(i)(A)
[E 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)
[E 50.73(a)(2)(iv)(A)
[I 50.73(a)(2)(x)
[I 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)
El 50.46(a)(3)(ii)
El 50.73(a)(2)(v)(B)
El 73.71(a)(5) 100%
[1 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) 0 50.73(a)(2)(i)(B)
Z 50.73(a)(2)(v)(D)
Specify in Abstract below or in misposition of an air supply valve to the 23AF21 electro-pneumatic converter. The valve was returned to its normally open position. Valve 23AF21 was retested successfully and the unit exited TS 3.6.3 at 1220 hours0.0141 days <br />0.339 hours <br />0.00202 weeks <br />4.6421e-4 months <br />. A successful retest of the 21 AFW Pump was performed and the 21 AFW Pump was declared operable. TS 3.7.1.2 was exited at 1349 hours0.0156 days <br />0.375 hours <br />0.00223 weeks <br />5.132945e-4 months <br />.
An 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> report to the NRC was made at 1745 hours0.0202 days <br />0.485 hours <br />0.00289 weeks <br />6.639725e-4 months <br /> under 10 CFR 50.72(b)(3)(v)(D), "Any event or condition that at the time of discovery could have prevented the fulfillment of the safety function of structures or systems needed to mitigate the consequences of an accident."
CAUSE OF OCCURRENCE Troubleshooting identified the cause of the failure to be the misposition of air supply valve 2FA3957 IV to the 23AF21 electro-pneumatic converter. The air supply valve was in the closed position instead of its normal open position. Valve 2FA3957 IV is located in local AFW system air control panel 205-2. The 23AF21 valve is an air to close actuating valve and a loss of air to the flow control valve electro-pneumatic converter caused 23AF21 to fully open on the start of the 21 AFW Pump.
A review of work history in the area which might have affected the 23AF21 air supply valve could not identify the cause of the mispositioned valve. The likely cause of this event was inadvertent valve manipulation of 2FA3957 IV sometime between the time of discovery and the previously performed AFW surveillance test on April 5, 2012. A causal evaluation of this event is in progress.
PREVIOUS OCCURRENCES
A review of LERs for Salem Units 1 and 2 for the previous three years did not identify any similar events.
SAFETY CONSEQUENCES AND IMPLICATIONS
This event did not adversely affect the ability of the AFW system to deliver AFW flow to the SGs. The 21 AFW Pump was capable of performing its design function of providing AFW flow to the 23 and 24 SGs.
This event is reported under 10 CFR 50.73(a)(2)(i)(B), "Any operation or condition which was prohibited by the plant's Technical Specifications." The mispositioning of the air supply valve to 23AF21 may have placed the 21 AFW Pump in an inoperable status as early as the last in-service test of the 21 AFW Pump which occurred on April 5, 2012 (91 days). This would have made the AFW Pump inoperable for a period greater than the AFW TS 3.7.1.2 Allowed Outage Time of 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> for single pump inoperability. Further investigation of maintenance and testing history indicated that the 23 AFW Pump was also inoperable due to scheduled maintenance for approximately 29 hours3.356481e-4 days <br />0.00806 hours <br />4.794974e-5 weeks <br />1.10345e-5 months <br /> during this period. This could have created a
condition in which two AFW Pumps were inoperable for a time exceeding the 6 hour6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> AFW TS 3.7.1.2 Allowed Outage Time for two pump inoperability. The Containment Isolation function of 23AF21 would also have been inoperable during this 91, day period exceeding the Containment Isolation Valve TS 3.6.3 isolation requirement of 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />.
This event is also reported under 50.73(a)(2)(v)(D), "Any event or condition that could have prevented the fulfillment of the safety function of structures or systems that are needed to mitigate the consequences of an accident." The Salem Updated Final Safety Analysis Report (UFSAR) assumptions for a postulated Steamline Break and Main Feedline Break allow only 10 minutes for operators to perform necessary actions to terminate AFW flow to a faulted SG. In the case of a steamline or main feedline break, blow down of the affected SG could cause a Lo-Lo SG Level AFW Pump auto-start actuation signal to lock-in preventing the stopping of the AFW Pump from the control room panel and continue to feed the SG. Emergency Operating Procedures provide continuous action steps for isolating a faulted SG. A failed open 23AF21 which could not be closed from the control room would need to be l0caliy closed, isolated, or it's associated 21 AFW Pump breaker would need to be tripped. Subsequent steaming through the SG fault greater than the 10 minute time could result in higher containment design pressure and temperature.
A review of this event determined that a Safety System Functional Failure as defined in Nuclear Energy Institute (NEI) 99-02 did occur.
CORRECTIVE ACTIONS
- 1. An extent of condition component lineup verification was performed on both Salem Units 1 and 2 for the AFW system air control panels. No other issues were identified.
- 2. A causal evaluation is in progress to determine root causes and any further corrective actions.
COMMITMENTS
No commitments are made in this LER
- NRC FORM 366A (10-2010)