05000333/LER-2013-003, Regarding Unfused DC Ammeter Circuits Result in Unanalyzed Condition
| ML13360A260 | |
| Person / Time | |
|---|---|
| Site: | FitzPatrick  |
| Issue date: | 12/26/2013 |
| From: | Coyle L Entergy Nuclear Northeast, Entergy Nuclear Operations |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| JAFP-13-0158 LER 13-003-00 | |
| Download: ML13360A260 (4) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 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)(i) 10 CFR 50.73(a)(2)(ii)(A), Seriously Degraded 10 CFR 50.73(a)(2)(ii)(B), Unanalyzed Condition 10 CFR 50.73(a)(2)(iii) 10 CFR 50.73(a)(2)(iv)(A), System Actuation 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)(v), Loss of Safety Function 10 CFR 50.73(a)(2)(vii), Common Cause Inoperability 10 CFR 50.73(a)(2)(viii)(A) 10 CFR 50.73(a)(2)(viii)(B) 10 CFR 50.73(a)(2)(ix)(A) 10 CFR 50.73(a)(2)(x) |
| 3332013003R00 - NRC Website | |
text
~Entergy JAFP-13-0158 December 26, 2013 United States Nuclear Regulatory Commission Attn: Document Control Desk Washington, D.C. 20555-0001 Entergy Nuclear Northeast Entergy Nuclear Operations, Inc.
James A. Fitzpatrick NPP P.O. Box 11 0 Lycoming, NY 13093 Tel 315-349-6024 Fax 315-349-6480 Lawrence M. Coyle Site Vice President - JAF
Subject:
LER: 2013-003, Unfused DC Ammeter Circuits Result in Unanalyzed Condition
Dear Sir or Madam:
James A. FitzPatrick Nuclear Power Plant Docket No. 50-333 License No. DPR-59 This report is submitted in accordance with 10 CFR 50. 73(a)(2)(ii)(B), as a condition that resulted in the plant being in an unanalyzed condition that significantly degraded plant safety.
There are no commitments contained in this report.
Questions concerning this report may be addressed to Mr. Chris M. Adner, Manager, Regulatory Assurance at (315) 349-6766.
el:~a Lawrence M. Coyle Site Vice President LMC/CMA/ds Enclosure(s): JAF LER 2013-003, Unfused DC Ammeter Circuits Result in Unanalyzed Condition cc:
USNRC, Region 1 USNRC, Project Directorate USNRC, Resident Inspector INPO Records Center (ICES)
NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION (10-2010)
LICENSEE EVENT REPORT (LER)
APPROVED BY OMB: NO. 3150-0104 EXPIRES: 10/31/2013 Estimated burden per response to comply with this mandatory collection request: 80 hours9.259259e-4 days <br />0.0222 hours <br />1.322751e-4 weeks <br />3.044e-5 months <br />. Reported lessons learned are incorporated into the licensing process and fed back to industry. Send comments regarding burden estimate to the Records and FOIA/Privacy Service Branch (T-5 F53), U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001, or by internet e-mail to infocollects.resource@nrc.gov, and to the Desk Officer, Office of Information and Regulatory Affairs, NEOB-10202, (3150-0104), Office of Management and Budget, Washington, DC 20503. If a means used to impose an information collection does not display a currently valid OMB control number, the NRC may not conduct or sponsor, and a person is not required to respond to, the information collection.
- 1. FACILITY NAME James A. FitzPatrick Nuclear Power Plant
- 2. DOCKET NUMBER 05000333
- 3. PAGE 1 OF 3
- 4. TITLE Unfused DC Ammeter Circuits Result in Unanalyzed Condition
- 5. EVENT DATE
- 6. LER NUMBER
- 7. REPORT DATE
- 8. OTHER FACILITIES INVOLVED MONTH DAY YEAR YEAR SEQUENTIAL NUMBER REV NO MONTH DAY YEAR FACILITY NAME N/A DOCKET NUMBER N/A 10 31 13 2013 - 003 -
00 12 26 13 FACILITY NAME N/A DOCKET NUMBER N/A
- 9. OPERATING MODE 1
- 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check all that apply) 20.2201(b) 20.2201(d) 20.2203(a)(1) 20.2203(a)(2)(i) 20.2203(a)(2)(ii) 20.2203(a)(2)(iii) 20.2203(a)(2)(iv) 20.2203(a)(2)(v) 20.2203(a)(2)(vi) 20.2203(a)(3)(i) 20.2203(a)(3)(ii) 20.2203(a)(4) 50.36(c)(1)(i)(A) 50.36(c)(1)(ii)(A) 50.36(c)(2) 50.46(a)(3)(ii) 50.73(a)(2)(i)(A) 50.73(a)(2)(i)(B) 50.73(a)(2)(i)(C) 50.73(a)(2)(ii)(A)
X 50.73(a)(2)(ii)(B) 50.73(a)(2)(iii) 50.73(a)(2)(iv)(A) 50.73(a)(2)(v)(A) 50.73(a)(2)(v)(B) 50.73(a)(2)(v)(C) 50.73(a)(2)(v)(D) 50.73(a)(2)(vii) 50.73(a)(2)(viii)(A) 50.73(a)(2)(viii)(B) 50.73(a)(2)(ix)(A) 50.73(a)(2)(x) 73.71(a)(4) 73.71(a)(5)
OTHER Specify in Abstract below or in
=
Background===
Preceding events Unit: 1 Event Date: 10/31/2013 Event Time: 17:22 EST Mode: 1 Mode Name: Power Operation Reactor Power: 100 percent
EVENT DESCRIPTION
During James A. Fitzpatricks (JAF) review of OE INPO ICES-305419, JAF identified a similar condition. The stations review determined that the plant wiring design for the station batteries (71SB-1 and 71SB-2) [EIIS Identifier: BTRY] ammeter [II] circuits contains a shunt in the current flow from each direct current (DC) battery, with leads to an ammeter in the main control room (MCR). The small difference in voltage between the two taps on the shunt is enough to deflect the ammeter in the MCR when current flows from the battery through the shunt. The ammeter wiring attached to the shunt does not have fuses, and if one of the ammeter wires shorts to ground during a fire, at the same time another DC wire from the opposite polarity on the same battery also shorts to ground during the fire, a ground loop through the unfused ammeter cable could occur. With enough current going through the cable, the potential exists that the overloaded ammeter wiring could damage other wiring in direct physical contact with the cable resulting in a loss of the associated safe shutdown function/capability or a secondary fire in another fire area.
This event was reported to the NRC (ENS 49491) on October 31, 2013 per 10 CFR 50.72(b)(3)(ii)(B). The required actions of the Technical Requirement Manual for fire barrier penetrations were implemented. This report is being submitted in accordance with 10 CFR 50.73(a)(2)(ii)(B), a condition that resulted in the plant being in an unanalyzed condition that significantly degraded plant safety.
EVENT ANALYSIS & CAUSE The premise for this event to occur requires two concurrent extremely low resistance (hard) grounds (i.e., one on the positive side of the battery through the ammeter circuit wiring routed to the control room and one on the negative side of the battery through a second ground on the same battery system). The ammeter circuit only contains one pole of the battery and the event requires an unrelated circuit (of opposite polarity) shorting to ground. Furthermore, this circuit must contain an overcurrent protective device not adequately rated for the ammeter wiring. The DC distribution system is floating with no established ground other than the high resistance ground provided through the ground detector [GDET]. It is designed in this manner to allow the system to withstand one hard ground (zero resistance) with no adverse effect on the operation of any equipment fed from the DC system. Since this is a very low probability event, it was likely not considered during the development of the original Appendix R analysis and related Institute of Electrical and Electronics Engineers (IEEE) standards.
EXTENT OF CONDITION An extent of condition review determined that this issue applies to Divisions 1 and 2 ammeter circuit wiring. The areas with the deficient fire barriers are the DC Switchgear Room 1A and 1B, Cable Spreading Room, Relay Room and Control Room.
FAILED COMPONENT IDENTIFICATION:
None U.S. NUCLEAR REGULATORY COMMISSION (10-2010)
LICENSEE EVENT REPORT (LER)
CONTINUATION SHEET
- 1. FACILITY NAME
- 2. DOCKET
- 6. LER NUMBER
- 3. PAGE James A. FitzPatrick Nuclear Power Plant 05000333 YEAR SEQUENTIAL NUMBER REV N0.
3 OF 3 2013 -
003
00 CORRECTIVE ACTIONS
Completed Actions The required actions of the Technical Requirement Manual for fire barrier penetrations were implemented. The Operability of fire detectors on both sides of the subject penetrations was verified.
Open Actions The condition is being tracked by the corrective action process; an analysis is underway to determine the appropriate resolution.
SAFETY SIGNIFICANCE
Nuclear Safety There were no actual consequences for this event. The potential consequences of this event are that the overloaded ammeter wiring could damage other wiring in direct physical contact with the cable resulting in a loss of the associated safe shutdown function/capability or a secondary fire in another fire area.
Radiological Safety No radiological impact or dose associated with this condition.
Industrial Safety No safety events or abnormal increases to personnel risk.
SIMILAR EVENTS
A review was performed and it was determined that there are no similar historical cases at JAF.
REFERENCES October 31, 2013 - CR-JAF-2013-05546