05000272/LER-2012-001, Regarding Single Train Actuation of Safety Injection Due to Failure of Solid State Protection System
| ML121840084 | |
| Person / Time | |
|---|---|
| Site: | Salem  (DPR-070) |
| Issue date: | 06/27/2012 |
| From: | Fricker C Public Service Enterprise Group |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| LR-N12-0154 LER 12-001-00 | |
| Download: ML121840084 (7) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(iv)(A), System Actuation 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 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 |
| 2722012001R00 - NRC Website | |
text
PSEG Nuclear LLC P-0. Box 236, Hancocks Bridge, NJ 08038-0236 0 PSEG Nuclear LLC J
S27N
,2 012 LR-N12-0154 10CFR 50.73 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 LER 272/2012-001 Salem Nuclear Generating Station Unit 1 Facility Operating License No. DPR-70 NRC Docket No. 50-272
SUBJECT:
Single Train Actuation of Safety Injection Due to Failure of Solid State Protection System The Licensee Event Report, "Single Train Actuation of Safety Injection Due to Failure of Solid State Protection System," is being submitted pursuant to the requirements of the Code of Federal Regulations, 10CFR 50.73(a)(2)(iv)(A), "Any event or condition that resulted in manual or automatic actuation of any of the systems listed in paragraph (a)(2)(iv)(B)..." and under 10 CFR50.73(a)(2)(i)(B) for conditions which were prohibited by the plant's Technical Specifications.
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.
Sincere Carl iricker Site Vice President - Salem Attachments (1)
L-.J u
Document Control Desk Page 2 LR-N 12-0154 JUN 2 7 2012 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, 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 5
- 4. TITLE Single Train Actuation of Safety Injection Due to Failure of Solid State Protection System
- 5. EVENT DATE
- 6. LER NUMBER__
- 7. REPORT DATE
- 8. OTHER FACILITIES INVOLVED MONTH DAY YEAR YEAR SEQUENTIAL REV MONTH DAY YEAR FAITYNMDOKTUBE NUMBER NO.
DOCKET NUMBER 04 30 201220120 0
1 0 06 27 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)
El 50.73(a)(2)(vii) 10 20.2201(d)
[3 20.2203(a)(3)(ii)
El 50.73(a)(2)(ii)(A) 0l 50.73(a)(2)(viii)(A)
El 20.2203(a)(1)
El 20.2203(a)(4)
El 50.73(a)(2)(ii)(B)
[I 50.73(a)(2)(viii)(B)
El 20.2203(a)(2)(i)
[I 50.36(c)(1)(i)(A)
[I 50.73(a)(2)(iii)
El 50.73(a)(2)(ix)(A)
- 10. POWER LEVEL E] 20.2203(a)(2)(ii)
E] 50.36(c)(1)(ii)(A)
ED 50.73(a)(2)(iv)(A)
[I 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)
El 50.46(a)(3)(ii)
El 50.73(a)(2)(v)(B)
El 73.71(a)(5) 100%
El 20.2203(a)(2)(v)
[3 50.73(a)(2)(i)(A)
[3 50.73(a)(2)(v)(C)
El OTHER El 20.2203(a)(2)(vi) 0 50.73(a)(2)(i)(B)
El 50.73(a)(2)(v)(D)
Specify in Abstract below or in Following the trip, control room personnel notified Fire Protection of fire alarms in the following areas:
11, 13 and 14 Reactor Coolant Pumps (RCPs) {AC/PFR}, South Containment Penetration, Generator Seal Oil Unit {TI}, and Turbine Generator {TB}. At 1018 hrs. an Unusual Event (UE) was declared due to having non-validated fire alarms in the Protected Area of the plant for greater than 15 minutes. The UE was terminated at 1249 hrs. when all fire alarms were determined to be invalid.
Troubleshooting of the Train A SSPS was commenced. At 1428 hrs. Operations exited TS 3.0.3 by removing SSPS Train A from service and resetting SSPS Train B SI and declaring SSPS Train B Operable.
With Unit 1 in Mode 3 and Train A of SSPS still inoperable, several Technical Specification (TS) Action Statements applied to limit plant operation. As delineated in TS Table 3.3-3, Engineered Safety System Actuation Instrumentation, shift management acknowledged entry into Functional Unit 1. b., Safety Injection, Turbine Trip and Feedwater Isolation automatic actuation logic. The applicable Action Statement 13 allows the plant 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> to restore Operability or be in Mode 3 within the next 6 hrs. and in Mode 5 within the following 30 hrs. Shift management did not recognize additional requirements under TS Table 3.3-3, Functional Units 4 and 8, Steam Line Isolation and Auxiliary Feedwater (AFW), which required entry into the more restrictive Action Statement 20. Action Statement 20 allows 6 hrs. to restore operability or be in Mode 3 within the next 6 hrs. and in Mode 4 within the following 6 hrs.
Compliance with Action Statement 20 would have required that the unit enter Mode 4 by 0228 hrs. on May 1.
On May 1, at 0802 hrs., shift personnel recognized the TS Mode compliance error and declared entry into TS Table 3.3-3, Action Statement 20. Unit 1 commenced a cooldown entering Mode 4 at 1739 hrs.
and Mode 5 at 2129 hrs.
CAUSE OF OCCURRENCE The SI actuation was caused by a failure of SSPS Train A logic. Troubleshooting and testing did not identify a definitive cause for the failure as the inadvertent SI signal could not be replicated. Potential causes were evaluated using a Failure Mode Cause Tree analysis. All major fault trees were investigated and possible causes were refuted or repaired. Potential signals that could cause the trip signal to be generated were confirmed absent and relays used as part of the 1 PT505 functional test were exercised with no voltage perturbations or abnormal results received. All circuit cards in question were replaced. Additionally, all new style SSPS circuit cards were removed and replaced with the old style circuit cards in both SSPS trains. Note that five new style SSPS circuit cards were installed in SSPS Trains A and B in previous refueling outages. The five new style circuit cards consisted of three Safeguard Driver cards, 1 UV Driver card and 1 Tester card.U.S. NUCLEAR REGULATORY COMMISSION (10-2010)
LICENSEE EVENT REPORT (LER)
- 1. FACILITY NAME
- 2. DOCKET
- 6. LER NUMBER
- 3. PAGE SEQUENTIAL REVISION Salem Generating Station Unit 1 05000272 YEAR NUMBER NUMBER 1 2012
- - 0 0 1-00 4 of 5 High noise on the A407 Universal Logic card and an intermittent E-1 Error LED on the Undervoltage Driver card were noted. The apparent cause of the inadvertent SI was identified as induced noise on the SSPS 15 volt logic circuit. A review of applicable Operating Experience revealed that newer model SSPS driver cards may be sensitive to signal noise.
The apparent cause of the failure to identify all applicable TS and Mode change requirements was due to inadequate procedural adherence. The applicable entries into TS Action Statements were identified in the I&C procedure used for blocking the SSPS Train A system logic but were not briefed to the Control Room Supervisor and were not tracked. The Reactor Operator working with I&C did not enter the LCOs called for in the procedure at the time since TS 3.0.3 was more limiting and was in effect. No follow-up to apply these TS requirements occurred once Train B was reset and the I&C procedure LCO entries were effectively in use.
PREVIOUS OCCURRENCES
Salem Unit 2 LER 2007-003-001 reported a reactor trip on low-low level in a Steam Generator (SG)
{SG} due to a spurious Feedwater isolation signal. The Feedwater isolation was generated by a faulty SSPS output driver card. The failed circuit card was due to a defective solder joint.
Salem Unit 1 LER 272/2010-004 reported a failure to recognize TS 3.0.4.b requirements for a risk assessment based on a Chiller being inoperable. The failure was due to inattention to detail when reviewing procedural controls for movement of irradiated fuel to a Dry Cask Storage Facility.
SAFETY CONSEQUENCES AND IMPLICATIONS
The health and safety of the public was not impacted by this event. Spurious actuation of SI while at power is a Condition 2 Event analyzed in section 15.2.14 of the plant UFSAR. All equipment responded as required and described for a spurious SI actuation in the safety analysis. Spurious Safety Injection with or without an immediate Reactor Trip presents no hazard to the integrity of the RCS, no cladding damage, no release of fission products and thus no safety hazard.
SSPS is comprised of two fully redundant trains that ensure its required safety function is met if one train is inoperable or malfunctions. Though the allowable time for the plant to be in Mode 3 was exceeded under TS Action Statement 20, Train B SSPS was Operable and capable of performing its intended SI actuation function. Both the Main Steam Isolation Valves (MSIVs) {SB/ISV} and the AFW system were Operable and capable of performing their design functions of steam line isolation and providing feedwater flow to the Steam Generators (SG) {SJ} when actuated on an SSPS generated signal. The MSIVs and the AFW system were also capable of manual control after the Train B SI signal was reset.
A review of this event determined that a Safety System Functional Failure (SSFF) as defined in NEI 99-02, Regulatory Assessment Performance Indicator Guideline, did not occur.U.S. NUCLEAR REGULATORY COMMISSION (10-2010)
LICENSEE EVENT REPORT (LER)
- 1. FACILITY NAME
- 2. DOCKET
- 6. LER NUMBER
- 3. PAGE SEQUENTIAL REVISION Salem Generating Station Unit 1 05000272 YUMBER 2012
- - 0 0 1-00 of 5
CORRECTIVE ACTIONS
- 1. The four universal logic circuit cards which potentially could have caused the SI/Reactor Trip were replaced.
- 2. The five new style SSPS circuit cards were replaced on both SSPS trains for Salem Unit 1. New style SSPS circuit cards had not been installed in Unit 2 and thus did not need card replacement.
- 3. The A407 Universal Logic card was replaced and the induced noise on the SSPS 15 volt logic system was verified to be corrected.
- 4. The applicable SSPS cards will be sent to Westinghouse for additional testing.
- 5. A stand alone Shift Technical Advisor was assigned throughout the forced outage to monitor and ensure that proper control room crew oversight and back-up was provided for identification of TS compliance issues.
- 6. An evaluation is in progress to determine lessons learned and to identify follow-up actions for the failure to identify all applicable TS Action Statements when exiting TS 3.0.3.
COMMITMENTS
No commitments are made in this LER.