05000335/LER-2016-003, Regarding Generator Lockout Relay Actuation During Power Ascension Results in Reactor Trip
| ML16302A061 | |
| Person / Time | |
|---|---|
| Site: | Saint Lucie  |
| Issue date: | 10/20/2016 |
| From: | Costanzo C Florida Power & Light Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| L-2016-189 LER 16-003-00 | |
| Download: ML16302A061 (4) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(ii)(A), Seriously Degraded 10 CFR 50.73(a)(2) 10 CFR 50.73(a)(2)(ii)(B), Unanalyzed Condition 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)(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) |
| 3352016003R00 - NRC Website | |
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,..... October 20, 201_6
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U.S. Nuclear Regulatory Commission Attn: Document Control Desk W?shington, D.C. 20555
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Re: St. Lucie Unit 1 Docket No. 50-335
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Reportable Event: 2016-003-00 Date of Event: August 21, 2016
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L-2016-189 10 CFR 50.73 Generator Lockout Relay Actuation During Power Ascension Results in Reactor Trip The attached Licensee Event Report 2016-003-00 is being submitted pursuant to the requirements of 10 CFR 50. 73 to provide notification of the subject event.
Christopher R. Costanzo Site Vice President St. Lucie Plant CRC/rcs Attachment cc:
NRG Region II Administrator St. Lucie Plant NRC Senior Resident Inspector Florida Power & Light Company 6501 S. Ocean Drive, Jensen Beach, FL 34957
NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 10/31/2018 (06-2016)
, the NRC may not conduct or sponsor, and a person is not required to respond to, the infonmation collection.
,3. PAGE St. Lucie Unit 1 05000335 1OF3
- 4. TITLE Generator Lockout Relay Actuation During Power Ascension Results in Reactor Trip
- 5. EVENT DATE
- 6. LER NUMBER
- 7. REPORT DATE
- 8. OTHER FACILITIES INVOLVED MONTH DAY YEAR YEAR I SEQUENTIAL I REV MONTH DAY FACILITY NAME DOCKET NUMBER NUMBER NO.
YEAR NA 08 21 2016 2016 003 00 10 20 2016 FACILITY NAME DOCKET NUMBER NA
- 9. OPERATING MODE 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR§: (Check all that apply}
D 20.2201 (b}
D 20.2203(a)(3)(i)
D 50.73(a)(2)(ii)(A)
D 50.73(a)(2)(viii}(A) 1 D 20.2201 (ct>
D 20.2203(a)(3)(ii)
D 50.73(a)(2)(ii)(B)
D 50.73(a)(2)(viii}(B)
D 20.2203(a)(1>
D 20.2203(a)(4)
D so.13(a)(2)(iii)
D 50.73(a)(2)(ix)(A)
D 20.2203(a)(2)(i)
D 50.36(c)(1)(i)(A)
~ 50.73(a)(2)(iv)(A)
D 50.73(a)(2)(x)
D 20.2203(a)(2)(ii)
D 50.36(c)(1)(ii)(A)
D
- 50. 73(a)(2)(v)(A)
D 13.11(a)(4)
- 10. POWER LEVEL D 20.2203(a)(2)(iii)
D so.36(c><2>
D 50.73(a)(2)(v)(B)
D 13.11<a>
38%
D 20.2203(a)(2)(iv)
D so.46(a)(3)(ii)
D 50.73(a)(2)(v)(C)
D 13.11(a)(1)
D 20.2203(a)(2)(v)
D 50.73(a)(2)(i)(A)
D 50.73(a)(2)(v)(D)
D 13.11(a)(2)(i)
D 20.2203(a)(2)(vi)
D 50.73(a)(2)(i)(B)
D 50.73(a)(2)(vii)
D 13.11(a)(2)(ii)
D 50.73(a)(2)(i)(C)
D OTHER Specify in Abstract below or in Prior to this event, Operators were performing normal power ascension evolutions following a maintenance outage. The Unit 1 main generator was manually synchronized to the electrical grid.
Previous synchronizations since the 2013 modification had been performed using the automatic synchronization feature, which was not affected by the missing wire. Following the manual synchronization on August 21, 2016, the lockout relay circuit did not reset as designed but remained armed with a trip setpoint of 8000 amps through the main generator.
This licensee event report is being reported in accordance with 10 CFR 50.73(a)(2)(iv)(A) as "Any event or condition that resulted in manual or automatic actuation of any of the systems listed in paragraph (a)(2)(iv)(B)." This event included automatic actuations of the reactor protection system and the 1A and 1 B emergency diesel generators, and manual actuation of the auxiliary feedwater system.
Safety Significance
This condition was mitigated by the automatic system actuations and concurrent Operator actions.
The Conditional Core Damage Probability (CCDP) and Conditional Large Early Release Probability (CLERP) values were evaluated for the stated event and were found to be below the thresholds of 1.0E-6 and 1.0E-7 for CCDP and CLERP, respectively. Therefore, it is concluded that the risk impact of the stated event is not risk-significant.
The health and safety of the public were n.ot affected by this event.
Corrective Actions to Prevent Recurrence
- 1. The removed wire for the lock out relay circuit was reinstalled.
- 2. Implemented procedure guidance to verify the inadvertent energization relay is reset prior to exceeding 8000 amps when synchronizing to the grid manually.
Failed Component 86/INAD/1790 Main Generator Inadvertent Energization Lockout Relay Manufacturer General Electric Model: 12HEAG1B237X16 Previous Occurrence No previous similar LERs.
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