05000272/LER-2010-001, Regarding Automatic Start of the 1C Emergency Diesel Generator (EDG)
| ML101740077 | |
| Person / Time | |
|---|---|
| Site: | Salem  |
| Issue date: | 06/14/2010 |
| From: | Fricker C Public Service Enterprise Group |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| LR-N 10-0208 LER 10-001-00 | |
| Download: ML101740077 (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 |
| 2722010001R00 - NRC Website | |
text
PSEG Nuclear LLC P.O. Box 236, Hancocks Bridge, New Jersey 08038-0236 0 PSEG ON 1-4 2010, Nuclear LLC 10CFR50.73 LR-N 10-0208 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington DC 20555-001 LER 272/2010-001 Salem Nuclear Generating Station Unit 1 Facility Operating License No. DPR-70 NRC Docket No. 50-272
SUBJECT:
Automatic Start of the 1 C Emergency Diesel Generator (EDG)
This Licensee Event Report, "Automatic Start of the 1 C Emergency Diesel Generator (EDG)," is being submitted pursuant to the requirements of the Code of Federal Regulations 10 CFR 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)."
The attached LER contains no commitments. Should you have any questions or comments regarding this submittal, please contact Mr. Brian Thomas at 856-339-2022.
- Sin~cer, arl dicker Site Vice President - Salem Attachments (1) 95-2168 REV. 7/99
Document Control Desk Page 2 JUN 142O3*
LR-N10-0208 cc Mr. S. Collins, Administrator, Region I, NRC Mr. R. Ennis, Licensing Project Manager - Salem, NRC Mr. D. Schroeder, USNRC Senior Resident Inspector, Salem (X24)
Mr. P. Mulligan, Manager IV, NJBNE L. Marabella, Corporate Commitment Tracking Coordinator H. Berrick, Salem Commitment Tracking Coordinator
NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO.'3150-0104 EXPIRES: 08/31/2010 (9-2007)
, 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 Automatic Start of the 1C Emergency Diesel Generator (EDG)
- 5. EVENT DATE
- 6. LER NUMBER _
- 7. REPORT DATE
- 8. OTHER FACILITIES INVOLVED MONTH DAY YEAR YEAR SEQUENTIAL REV MONTH DAY YEAR
.FACILITY NAME DOCKET NUMBER NUMBER NO.
DOCKET NUMBER 04 16 2010201000 1 0 06 14 2010
- 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) 6 El 20.2201(d)
El 20.2203(a)(3)(ii)
El 50.73(a)(2)(ii)(A)
[1 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)
_ 20.2203(a)(2)(i)
El 50.36(c)(1)(i)(A)
[1 50.73(a)(2)(iii)
El 50.73(a)(2)(ix)(A)
- 10. POWER LEVEL C 20.2203(a)(2)(ii)
El 50.36(c)(1)(ii)(A)
[
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)
El 50.46(a)(3)(ii)
El 50.73(a)(2)(v)(B)
El 73.71(a)(5) 0 El 20.2203(a)(2)(v)
[I 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 DESCRIPTION OF OCCURRENCE (cont'd)
Troubleshooting determined that the breaker auxiliary position switch (52STA switch) for the 13CSD breaker, the offsite power infeed from the 13 Station Power Transformer (SPT) to the 1C 4160 volt vital bus, was bound and the contacts associated with the breaker's closed position were still made up when the 13CSD breaker was actually open. In order for the alternate 14CSD infeed breaker from the 14 SPT to close, the 13CSD breaker needs to indicate open. This led to the failure of the bus to transfer and loss of power resulting in the start of the 1C EDG. The failure of the 13CSD breaker 52STA switch to indicate open also prevented the 1C EDG output breaker from closing as designed. Following replacement of the 13CSD breaker 52STA switch, the breaker plunger gap check was performed during breaker rack-in. The gap was determined to be unsatisfactory and was properly adjusted per procedure SC.MD-PR.4KV-0002.
On April 17, 2010, at 0032 hours3.703704e-4 days <br />0.00889 hours <br />5.291005e-5 weeks <br />1.2176e-5 months <br />, the 1C 4160 volt vital bus was energized from the 14SPT through the 14CSD breaker and TSAS 3.1.2.1 was exited. At 0113 hours0.00131 days <br />0.0314 hours <br />1.868386e-4 weeks <br />4.29965e-5 months <br />, the 1C 4160 volt vital bus automatic transfer test was completed satisfactorily and abnormal procedure Sl.OP-AB.4KV-0003 was exited. Operators then performed a loaded run of the 1C EDG to verify proper operation following the repairs to the 13CSD breaker. At 0500 hours0.00579 days <br />0.139 hours <br />8.267196e-4 weeks <br />1.9025e-4 months <br />, the 1C EDG was declared operable. At 0729 hours0.00844 days <br />0.203 hours <br />0.00121 weeks <br />2.773845e-4 months <br />, TSAS 3.7.10 was exited with 2 chillers restored to operable.
This report is made in accordance with 10CFR50.73 (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)."
CAUSE OF OCCURRENCE The unexpected start of the 1C EDG was the result of the failure of the 13CSD 52STA switch. The failure of the 52STA switch was the result of binding caused by misadjustment of the gap between the breaker and the 52STA switch assembly. The misadjustment was the result of unclear procedural guidance for measuring the breaker plunger gap.
PREVIOUS OCCURRENCES
A review of LERs for Salem Units 1 and 2 for the past 3 years did not identify any prior similar occurrences of an EDG start as a result of improper breaker switch adjustment.
SAFETY CONSEQUENCES AND IMPLICATIONS
There were no safety consequences associated with this event. Salem Unit 1 was in Mode 6 with fuel movement in progress. The loss of the 1C 4160 volt vital bus did not impact shutdown cooling and spent fuel pool cooling was not lost. Movement of irradiated fuel was suspended. The deficient breaker condition was detected during restoration of the equipment to service following maintenance that introduced the deficient condition and did not exist during the operating cycle.
A review of this event determined that a Safety System Functional Failure (SSFF) as defined in NEI 99-02, Regulatory Assessment Performance Indicator Guidelines, did not occur since the ability to remove residual heat and mitigate the consequences of an accident were maintained.
CORRECTIVE ACTIONS
- 1. The damaged 52STA switch was replaced and the breaker plunger gap was verified in the 13CSD breaker.
- 2. An inspection was performed on the 14CSD breaker (the alternate infeed for the 1C bus) and verified there was no binding on the 52STA switch.
- 3. A visual inspection of the 52STA switches and plunger gaps was performed for the 1 B, 2A, 2B and 2C 4160 volt vital bus infeed breakers and EDG breakers. The 1A 4160 volt vital bus infeed breakers were determined to be functioning properly following replacement of the 13ASD breaker by successful performance of the vital bus transfer procedure.
- 4. Operations procedure SC.OP-SO.4KV-0001, "4KV Breaker Operation," was revised to include guidance on verifying the position of the 52STA switch rod.
- 5. Maintenance procedure SC.MD-PR.4KV-0002 will be revised to validate the 52STA switch rod position.
COMMITMENTS
No commitments are made in this LER.