05000416/LER-2013-001, Regarding Reactor Protection System Actuation Due to a Main Turbine Generator Trip
| ML13064A371 | |
| Person / Time | |
|---|---|
| Site: | Grand Gulf  (NPF-029) |
| Issue date: | 03/04/2013 |
| From: | Perino C Entergy Operations |
| To: | Office of Nuclear Reactor Regulation, Document Control Desk |
| References | |
| GNRO-2013/00005 LER 13-001-00 | |
| Download: ML13064A371 (7) | |
| 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 |
| 4162013001R00 - NRC Website | |
text
- =:="Entergy GNRO-2013/00005 March 4,2013 u.s. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555-0001 Entergy Operations, Inc.
P. O. Box 756 Port Gibson, MS 39150 Christina L. Perino Director, Nuclear Safety Assurance Grand Gulf Nuclear Station Tel. (601) 437-6299
SUBJECT:
Dear Sir or Madam:
Licensee Event Report 2013-001-00 Reactor Protection System Actuation Due to a Main Turbine Generator Trip Grand Gulf Nuclear Station, Unit 1 Docket No. 50-416 License No. NPF-29 Attached is Licensee Event Report 2013-001-00, which is a final report. This report is submitted in accordance with Title 10 Code of Federal Regulations 50.73(a)(2)(iv)(A).
This letter contains no new commitments. If you have any questions or require additional information, please contact Christina L. Perino at (601) 437-6299.
Sincerely,
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{7UA f e..l. ~~.;.o CLP/ras Attachment Licensee Event Report (LER) 2013-001-00 cc:
(see next page)
GNRO-2013/00005 Page 2 of2 cc:
u. S. Nuclear Regulatory Commission ATTN: Mr. Elmo E. Collins, Jr.
Regional Administrator, Region IV 1600 East Lamar Boulevard Arlington, TX 76011-4511 U. S. Nuclear Regulatory Commission ATTN: Mr. Alan Wang, NRRlDORL Mail Stop OWFN/8 B1 11555 Rockville Pike Rockville, MD 20852-2378 NRC Senior Resident Inspector Grand Gulf Nuclear Station Port Gibson, MS 39150
Attachment to GNRO-2013/00005 Licensee Event Report (LER) 2013-001-00
NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 10/31/2013 (10-2010) digits/characters for each block) the NRC may not conduct or sponsor, and a person is not required to respond to, the information collection.
- 13. PAGE Grand Gulf Nuclear Station, Unit 1 05000416 10F4 4.11TLE Reactor Protection System Actuation Due to a Main Turbine Generator Trip
- 5. EVENT DATE
- 6. LER NUMBER
- 7. REPORT DATE
- 8. OTHER FACILlllES INVOLVED YEAR I SEQUENTIAL I REV MONTH FACILITY NAME N/A MONTH DAY YEAR NUMBER NO.
DAY YEAR N/A 01 04 2013 2013-001-00 03 05 2013 N/A N/A
- 9. OPERAllNG MODE
- 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check all that apply) o 20.2201 (b) o 20.2203(a)(3)(i) o 50.73(a)(2)(i)(C) o 50.73(a)(2)(vii) 1 o 20.2201 (d) o 20.2203(a)(3)(ii) o 50.73(a)(2)(ii)(A) o 50.73(a)(2)(viii)(A) o 20.2203(a)(1) o 20.2203(a)(4) o 50.73(a)(2)(ii)(B) o 50.73(a)(2)(viii)(B) o 20.2203(a)(2)(i) o 50.36(c)(1 )(i)(A) o 50.73(a)(2)(iii) o 50.73(a)(2)(ix)(A)
- 10. POWER LEVEL o 20.2203(a)(2)(ii) o 50.36(c)(1)(ii)(A) 18150.73(a)(2)(iv)(A) o 50.73(a)(2)(x) o 20.2203(a)(2)(iii) o 50.36(c)(2) o 50.73(a)(2)(v)(A) o 73.71 (a)(4) 94 o 20.2203(a)(2)(iv) o 50.46(a)(3)(ii) o 50.73(a)(2)(v)(B) o 73.71 (a)(5) o 20.2203(a)(2)(v) o 50.73(a)(2)(i)(A) o 50.73(a)(2)(v)(C) o OTHER o 20.2203(a)(2)(vi) o 50.73(a)(2)(i)(B) o 50.73(a)(2)(v)(D)
Specify in Abstract below or in
E. CORRECTIVE ACTIONS
- 2. DOCKET
- 6. LER NUMBER
- 3. PAGE 30F4 Removal and/or thread cutting of the micarta plate bolts to ensure minimum cold clearance of 0.5 inch between the CT and the micarta plate bolts was completed on January 6, 2013.
For each main generator CT, the Post Maintenance Test special requirement planning notes will be revised to ensure that 0.5 inch cold clearance is maintained between the micarta plate bolts and the main generator CTs.
Plant personnel will perform boroscopic inspection of CTs and add work instruction steps that include Entergy hold points to ensure adequate cold clearance of 0.5 inch is maintained between the micarta plate bolts and the main generator CTs.
Applicable drawings will be revised to incorporate a minimum cold clearance of 0.5 inch to be maintained between the CT and micarta plate bolts.
F. SAFETY ASSESSMENT
The event posed no threat to public health and safety as the RPS performed as designed. All safety systems responded as designed. The breaker thermal for the 1N21 F01 OB start-up outlet valve was reset and returned to service and did not prevent Operations from controlling the reactor water level.
Immediate actions performed by the Operations staff were adequate and appropriate in placing and maintaining the reactor in a safe shutdown condition.
Nuclear safety was not significantly compromised because safety related equipment necessary to safely shutdown the unit performed its safety function.
During the event, no Technical Specification defined Safety Limits were challenged.
Radiological Safety was not affected since there was no radiological release to the public during the event.
Response of the crew did not challenge established industrial safety protocol or requirements. There was no impact to the safety of the public, industrial safety or radiological safety as a result of this event.
- 2. DOCKET
- 6. LER NUMBER
- 3. PAGE 40F4
G. ADDITIONAL INFORMATION
The cause was the same as the December 29, 2012, SCRAM, which is addressed in LER-2012-008-00 and CR-GGN-2012-13290. The instruments installed following the December 29, 2012, SCRAM enabled the determination of the cause of both SCRAMs.
CR-GGN-2008-01476 documents a CT-related SCRAM but was not caused by CT grounding. The CT that caused both the December 29, 2012, SCRAM and the January 4, 2013, SCRAM was installed between February and April 2012.
The cause of start-up outlet valve 1N21 F01 08 not opening was determined to be a thermal overload breaker trip. The breaker thermal was reset and the valve was returned to service. CR-GGN-2012-13297 documents this issue and the corrective actions that will be taken as part of a work order during the next refueling outage.