05000244/LER-2014-002, Regarding Unanalyzed Condition Due to Postulated Hot Short Fire Event Involving DC Control Circuits Affecting Multiple Fire Areas
| ML14134A011 | |
| Person / Time | |
|---|---|
| Site: | Ginna  |
| Issue date: | 05/08/2014 |
| From: | Philippon M Exelon Generation Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| NUREG-1022 LER 14-002-00 | |
| Download: ML14134A011 (5) | |
| 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 |
| 2442014002R00 - NRC Website | |
text
Mike Philippon Plant Manager IR.E.
Ginna Nuclear Power Plant
'1503 Lake Rd.
Exelon Generation Ontario. NY14519 585 7715205 Office 315 236 6278 Mobile www.exeloncorp.com michel.philippon@exeloncorp.com May 8, 2014 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 R.E. Ginna Nuclear Power Plant Facility Operating License No. DPR-18 NRC Docket No. 05000244
SUBJECT:
LER 2014-002, Unanalyzed Condition Due to Postulated Hot Short Fire Event Involving DC Control Circuits Affecting Multiple Fire Areas The attached Licensee Event Report (LER) 2014-002 is submitted under the provisions of NUREG-1022, Event Reporting Guidelines. There are no new commitments contained in this submittal.
Should you have any questions regarding this submittal, please contact Thomas Harding at 585-771-5219.
Sincerely, Mike Philippon Plant Manager R.E. Ginna Nuclear Power Plant MP/KC
Attachment:
LER 2014-002 cc:
NRC Regional Administrator, Region I NRC Project Manager, Ginna NRC Resident Inspector, Ginna W L0 R L
-/00-8&1
Attachment LER 2014-002
NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 01/31/2017 (02-2014)
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 FOIA, Privacy and Information Collections LICENSEE EVENT REPORT (LER)
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 (See Page 2 for required number of 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 digits/characters for each block) control number, the NRC may not conduct or sponsor, and a person is not required to respond to, the information collection.
- 3. PAGE R.E. Ginna Nuclear Power Plant 05000244 1 OF
- 4. TITLE Unanalyzed condition due to postulated hot short fire event involving DC control circuits affecting multiple fire areas
- 5. EVENT DATE
- 6. LER NUMBER
- 7. REPORT DATE
- 8. OTHER FACILITIES INVOLVED MONTH DAY SEQUENTIAL REV FACILITY NAME DOCKET NUMBER YEAR NUMBER NO.
MONTH DAY YEAR 05000 FACILITY NAME DOCKET NUMBER 03 13 2014 2014 -
002
- - 00 05 08 2014 05000
- 9. OPERATING MODE
- 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check all that apply) 20.2201(b)
[I 20.2203(a)(3)(i)
[]
50.73(a)(2)(i)(C)
El 50.73(a)(2)(vii)
D 20.2201(d)
El 20.2203(a)(3)(ii)
[I 50.73(a)(2)(ii)(A)
[: 50.73(a)(2)(viii)(A)
D 20.2203(a)(1)
[]
20.2203(a)(4)
Z 50.73(a)(2)(ii)(B)
F] 50.73(a)(2)(viii)(B)
_ 20.2203(a)(2)(i)
Ej 50.36(c)(1)(i)(A)
D1 50.73(a)(2)(iii)
D 50.73(a)(2)(ix)(A)
- 10. POWER LEVEL LI 20.2203(a)(2)(ii)
L] 50.36(c)(1)(ii)(A)
[]
50.73(a)(2)(iv)(A)
[
50.73(a)(2)(x)
LI 20.2203(a)(2)(iii)
D 50.36(c)(2)
El 50.73(a)(2)(v)(A)
D 73.71(a)(4) 10 20.2203(a)(2)(iv)
[_ 50.46(a)(3)(ii)
Ej 50.73(a)(2)(v)(B)
LI 73.71(a)(5) 1 % 20.2203(a)(2)(v)
LI 50.73(a)(2)(i)(A)
LI 50.73(a)(2)(v)(C)
L] 50.73(a)(2)(i)(B)
El 50.73(a)(2)(v)(D)
Specity in Abstract below or in
_____________________________________________________________________________NRC___FoNRCForm66A
- 12. LICENSEE CONTACT FOR THIS LER LICENSEE CONTACT TELEPHONE NUMBER (Include Area Code)
Thomas Harding, Director-Licensing [585-771-5219MANU-REPORTABLE MANU-REPORTABLE
CAUSE
SYSTEM COMPONENT FACTURERI
CAUSE
SYSTEM COMPONENT FACTURER TO EPIX
- 14. SUPPLEMENTAL REPORT EXPECTED
- 15. EXPECTED MONTH DAY YEAR SUBMISSION U YES (Ifyes, complete 15. EXPECTED SUBMISSION DATE)
[]
NO DATE ABSTRACT (Limit to 1400 spaces, i.e., approximately 15 single-spaced typewritten lines)
On March 13, 2014 during an industry Operating Experience review, a postulated Appendix R fire scenario was identified that could potentially impact several fire areas and potentially affect safe shutdown equipment. The postulated scenario could allow fire spread via unprotected DC control circuit for non-safety related circulating water pump discharge motor operated valves (MOV). The affected wiring is routed through the screenhouse, "B" Emergency Diesel Generator room, turbine building, air handling room, relay room, and control room.
Compensatory actions taken include hourly fire tours in the potentially impacted areas.
Corrective action to install fuses to protect the circuits for the Circulating Water Pump Discharge MOVs was completed.
NRC FORM 366 (02-2014)
YJRC =
1. DESCRIPTION OF EVENT
A. PRE-EVENT CONDITIONS At the time of discovery, the plant was in Mode 1 at approximately 100% power.
B. EVENT DESCRIPTION
On March 13, 2014, during a review of industry Operating Experience (OE), Ginna identified that there were unprotected DC control circuits for Non Safety Related DC motors which are routed from the turbine building to other separate fire areas. Fuses used to protect the motor power conductors appear to be inadequate to protect the control conductors. It is postulated that under fire safe shutdown conditions, a fire in one area can cause short circuits potentially resulting in secondary fires or cable failures in other fire areas where the cables are routed. The secondary fires or cable failures are outside the assumptions of the 10 CFR 50 Appendix R Safe Shutdown Analysis.
C. DATES AND TIMES OF OCCURENCES 1967 03/13/2014 04/11/2014 Original Construction Review of Industry Operating Experience identifying postulated Hot Short Condition Fuses installed in Circulating Water Pump Discharge MOV control circuits
D. METHOD OF DISCOVERY
Review of systems and drawings based upon industry operating experience.
E. MAJOR OPERATOR ACTION Established compensatory actions consisting of hourly fire tours of the affected areas.
F. SAFETY SYSTEM RESPONSE None required.
2. CAUSE OF EVENT
The cause of this condition is that the Original Design did not meet current fire protection standards.
This is a latent design issue that has been present since plant construction (in the late 1960s). A postulated fire-induced circuit failure that causes the condition requires two opposite polarity conductors to short to each other.
Contributing to this, the design analysis for this non-safety related electrical panel only evaluated protection for the power cables connected to the fuses, and not the control circuits for the motors.
3. ANALYSIS OF EVENT
This event is reportable under 10CFR50.73(a)(2)(ii)(B) for the concern is it could be possible for a fire in one fire area to damage this circuit and cause a short circuit that would overheat the cables before the fuses would provide protection. This short circuit could possibly result in secondary fires or cable damage in other fire areas where the cables are routed. The Ginna Fire Protection Plan does not analyze for simultaneous fires in two or more fire protection areas. If the situation were to occur, the plant would be in an unanalyzed condition, with the potential to impact equipment credited for safe shutdown.
This condition was entered into the corrective action program under CR-2014-001346.
All DC motor circuits were reviewed for the potential vulnerability. DC Motor control circuits were reviewed to determine if the conductors are adequately protected and validate they do not have to potential to propagate a fire.
4. CORRECTIVE ACTIONS
Fuses have been installed to protect the control circuits for the Circulating Water Pump Discharge MOVs.
The design analysis will be revised to reflect the new configuration.
5. ADDITIONAL INFORMATION
A. FAILED COMPONETS None.
B. PREVIOUS LERs ON SIMILAR EVENTS LER 2011-001 Unanalyzed Condition due to Postulated Fire Causing a Station Blackout LER-2013-003 Unanalyzed Condition for Potential Floodwater Intrusion into Vital Battery Rooms