05000298/LER-2013-001, Regarding Unfused Direct Current Ammeter Circuits Result in Unanalyzed Condition
| ML13361A084 | |
| Person / Time | |
|---|---|
| Site: | Cooper  |
| Issue date: | 12/20/2013 |
| From: | Limpias O Nebraska Public Power District (NPPD) |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| NLS2013101 LER 13-001-00 | |
| Download: ML13361A084 (4) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 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)(iv)(A), System Actuation 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 |
| 2982013001R00 - NRC Website | |
text
H Nebraska Public Power District Always there when you need us NLS2013 101 December 20, 2013 U.S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, D.C. 20555-0001
Subject:
Licensee Event Report No. 2013-001-00 Cooper Nuclear Station, Docket No. 50-298, DPR-46
Dear Sir or Madam:
The purpose of this correspondence is to forward Licensee Event Report 2013-001-00.
There are no new commitments contained in this letter.
Sinc rel V
Os a A. Limpias Vice President Nuclear-Chief Nuclear Officer hJo Attachment: Licensee Event Report 2013-001-00 cc:
Regional Administrator w/attachment USNRC - Region IV Cooper Project Manager w/attachment USNRC - NRR Project Directorate IV-l Senior Resident Inspector w/attachment USNRC - CNS SRAB Administrator w/attachment NPG Distribution w/attachment INPO Records Center w/attachment via ICES entry SORC Chairman w/attachment CNS Records w/attachment STATION NE 68321-0098 Fax: (402) 825-5211 or t o COOPER NUCLEAR P.O. Box 98 / Brownville, Telephone: (402) 825-3811 /
w'w.nppd.co
NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB NO. 3150-0104 EXPIRES 10/31/2013 (10-2010)
Estimated burden per response to comply with this mandatory information collection request: 80 hrs. Reported lessons learned are incorporated into the licensing process and fed back to industry.
Send comments regarding burden estimate to the FOIA/Privacy Service Branch (T-5 F53), U.S. Nuclear Regulatory Commission, LICENSEE EVENT REPORT (LER)
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, (See reverse for required number of (3150-0104), Office of Management and Budget, Washington, DC 20503. If a means digits/characters for each block) 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.
- 3. PAGE Cooper Nuclear Station 05000298 1 of 3
- 4. TITLE Unfused Direct Current Ammeter Circuits Result in Unanalyzed Condition
- 5. EVENT DATE
- 6. LER NUMBER
- 7. REPORT DATE
- 8. OTHER FACILITIES INVOLVED FACILITY NAME DOCKET NUMBER MONTH; DAY YEAR YEAR SEQUENTIAL REV MONTH DAY YEAR NUMBER NO.
i05000 ii ii FACILITY NAME DOCKET NUMBER 10 30 2013 2013
- - 001 -
00 12 20 2013 A5LYM
- 9. OPERATING MODE
- 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR 6: (Check all that aoolv)
[1] 20.2201(b)
El 20.2203(a)(3)(i)
El 50.73(a)(2)(i)(C)
El 50.73(a)(2)(vii)
El 20.2201(d)
EL 20.2203(a)(3)(ii)
[L 50.73(a)(2)(ii)(A)
El 50.73(a)(2)(viii)(A)
Li 20.2203(a)(1)
Ei 20.2203(a)(4)
ED 50.73(a)(2)(ii)(B)
EL 50.73(a)(2)(viii)(B)
Li 20.2203(a)(2)(i)
El 50.36(c)(1)(i)(A)
EL 50.73(a)(2)(iii)
El 50.73(a)(2)(ix)(A)
El 20.2203(a)(2)(ii)
El 50.36(c)(1)(ii)(A)
El 50.73(a)(2)(iv)(A)
[I 50.73(a)(2)(x)
- 10. POWER LEVEL [L
20.2203(a)(2)(iii)
El 50.36(c)(2)
[: 50.73(a)(2)(v)(A)
Li 73.71(a)(4) 100 Li 20.2203(a)(2)(iv)
EL 50.46(a)(3)(ii)
El 50.73(a)(2)(v)(B)
Li 73.71(a)(5)
Li 20.2203(a)(2)(v)
Li 50.73(a)(2)(i)(A)
E] 50.73(a)(2)(v)(C)
El OTHER Li 20.2203(a)(2)(vi)
Li 50.73(a)(2)(i)(B)
Li 50.73(a)(2)(v)(D)
Specify in Abstract below or in
SAFETY SIGNIFICANCE
This event is reportable in accordance with 10 CFR 50.73(a)(2)(ii)(B) as a condition that resulted in the nuclear power plant being in an unanalyzed condition that significantly degraded plant safety in that the self-heating on the overloaded ammeter wiring could cause damage to adjacent cables/equipment that may be required for safe shutdown following a fire in the Control Room or Cable Spreading Room.
There were no actual consequences to report as this identifies an unanalyzed condition with no occurrence of an event. An extent of condition review determined that this issue applies to the 125 and 250 VDC ammeter circuit wiring.
CAUSE
The cause of the unfused ammeter circuits is that the original design criteria had not factored in the potential of the multiple shorts to ground failure mode and therefore, did not require overcurrent protection for remote shunt fed ammeter circuits.
CORRECTIVE ACTION
Compensatory fire watch measures have been implemented until an analysis is performed demonstrating that remote circuits can meet fire protection requirements without fuses. If an analysis cannot demonstrate meeting fire protection requirements with the existing circuit design, then a modification to correct the remote ammeter circuits will be implemented.
PREVIOUS EVENTS On July 13, 2010, during the review of the Safe Shutdown Analysis Report, station personnel discovered that although the plant credits Containment Overpressure (COP), the Appendix R analysis did not ensure COP is maintained. The cause of the event was approval oversight did not detect that unanalyzed Appendix R issues were being deferred and not promptly addressed.
The event was reported under Licensee Event Report 2010-002-00, Appendix R Containment Overpressure Credit, dated September 7, 2010.