05000373/LER-2014-002, County Station, Regarding Unit 1 Division 3 Ventilation Failure
| ML14143A134 | |
| Person / Time | |
|---|---|
| Site: | LaSalle  |
| Issue date: | 05/23/2014 |
| From: | Vinyard H Exelon Generation Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| RA 14-027 LER 14-002-00 | |
| Download: ML14143A134 (4) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(v), Loss of Safety Function 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)(i)(B), Prohibited by Technical Specifications |
| 3732014002R00 - NRC Website | |
text
10 CFR 50.73 RA14-027 May 23, 2014 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 LaSalle County Station, Unit 1 Facility Operating License No. NPF-1 1 NRC Docket No. 50-373
Subject:
Licensee Event Report 2014-002-00 Unit 1 Division 3 Ventilation Failure In accordance with 10 CFR 50.73(a)(2)(v)(D), Exelon Generation Company (EGC), LLC, is submitting Licensee Event Report Number 2014 -002-00 for LaSalle County Station Unit 1.
There are no regulatory commitments in this letter. Should you have any questions concerning this report, please contact Mr. Guy V. Ford, Regulatory Assurance Manager, at (815) 415-2800.
Harold T. Vinyard Plant Manager LaSalle County Station
Enclosure:
Licensee Event Report cc:
Regional Administrator - NRC Region III NRC Senior Resident Inspector - LaSalle County Station
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 f 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 digits/characters for each block) 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.
- 3. PAGE LaSalle County Station Unit 1 05000373 1
OF 3
- 4. TITLE Unit 1 Division 3 Ventilation Failure
- 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 03 29 2014 2014 -
002 00 05 23 2014 FACILITY NAME N/A DOCKET NUMBER N/A
- 9. OPERATING MODE
- 11. THIS REPORT IS SU BMITTED PURSUANT TO T HE REQUIREMENTS OF 10 CFR §: (Check all that apply) q 20.2201(b) q 20.2203(a)(3)(i) q 50.73(a)(2)(i)(C) q 50.73(a)(2)(vii) q 20.2201(d) q 20.2203(a)(3)(ii) q 50.73(a)(2)(ii)(A) q 50.73(a)(2)(viii)(A) 1 q 20.2203(a)(1) q 20.2203(a)(4) q 50.73(a)(2)(ii)(B) q 50.73(a)(2)(viii)(B) q 20.2203(a)(2)(i) q 50.36(c)(1)(i)(A) q 50.73(a)(2)(iii) q 50.73(a)(2)(ix)(A)
- 10. POWER LEVEL q 20.2203(a)(2)(ii) q 50.36(c)(1)(ii)(A) q 50.73(a)(2)(iv)(A) q 50.73(a)(2)(x) q 20.2203(a)(2)(iii) q 50.36(c)(2) q 50.73(a)(2)(v)(A) q 73.71(a)(4) q 20.2203(a)(2)(iv) q 50.46(a)(3)(ii) q 50.73(a)(2)(v)(B) q 73.71(a)(5) 100 q 20.2203(a)(2)(v) q 50.73(a)(2)(i)(A) q 50.73(a)(2)(v)(C) q OTHER q 20.2203(a)(2)(vi) q 50.73(a)(2)(i)(B) 50 73(a)(2)(v)(D)
Specify in Abstract below or in
LaSalle County Station Unit 1 is a General Electric Company Boiling Water Reactor with 3546 Megawatts Rated Core Thermal Power.
A.
CONDITION PRIOR TO EVENT
Unit(s): 1 Event Date: March 29, 2014 Event Time: 1620 CDT Reactor Mode(s): 1 Mode(s) Name: Power Operation Power Level: 100%
B.
DESCRIPTION OF EVENT
On March 29, 2014, Unit 1 was in Mode 1 at 100% power. At 1620 hours0.0188 days <br />0.45 hours <br />0.00268 weeks <br />6.1641e-4 months <br /> CDT, the Division 3 Core Standby Cooling System (CSCS) Pump Room, Switchgear Room, and Battery Room Ventilation system [VF] failed in such a manner that heat could not be removed from the rooms. Due to the lack of ventilation in the Division 3 Switchgear Room, the High Pressure Core Spray (HPCS) [BG] system was declared inoperable and Condition B of Technical Specification (TS) 3.5.1 was entered.
TS 3.5.1 Required Action (RA) B.1, which verifies by administrative means, that Reactor Core Isolation Cooling (RCIC) [BN] is operable, was immediately entered and completed. TS 3.5.1 RA B.2 was entered to restore the HPCS system to an operable status within 14 days.
HPCS was restored to an available status at 1745 CDT on March 29, 2014 by manually wiring the 1 VD1 8Y, Division 3 CSCS Ventilation Recirculation Damper, open.
The cause of the event was failure of the hydramotor pump bearing for the 1 VD1 9Y, Division 3 CSCS Ventilation Return Fan Outlet Damper. The loss of hydraulic pressure in the hydramotor resulted in the 1 VD19Y damper failing in the closed position.
The corrective action for the event was the replacement of the hydramotor for the 1 VD1 9Y damper.
Hydramotor replacement and testing was completed and HPCS restored to operable at 1615 CDT on March 30, 2014.
This occurrence is reportable under 10 CFR 50.73(a)(2)(v)(D) as an event or condition that could have prevented the fulfillment of the safety function of the structures or systems that are needed to mitigate the consequences of an accident. An ENS report was made to the NRC (EN 49973) at 2349 ET on March 29, 2014, pursuant to 10 CFR 50.72(b)(3)(v)(D).
This event constitutes a safety system functional failure for Unit 1.
C.
CAUSE OF EVENT
Troubleshooting found that the hydramotor hydraulic pump bearing failed resulting in a loss of hydraulic pressure. The 1 VD1 9Y damper is designed to fail closed on a loss of hydraulic pressure to protect room components from freezing during winter months.
The corrective action completed was replacement of the 1 VD1 9Y hydramotor.
D.
SAFETY ANALYSIS
The safety significance of this event was minimal. The HPCS system was unavailable and inoperable for a short period of time (unavailable for 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> 25 minutes and inoperable for 23 hours2.662037e-4 days <br />0.00639 hours <br />3.80291e-5 weeks <br />8.7515e-6 months <br /> and 55 minutes). During this period of time all other Emergency Core Cooling Systems were operable.
E.
CORRECTIVE ACTIONS
The 1 VD1 9Y hydramotor was replaced and tested satisfactorily.
F.
PREVIOUS OCCURRENCES
A search of LaSalle LERs over the last 10 years did not identify any LERs initiated as a result of a failed hydramotor.
In 2012 LaSalle performed a Common Cause Analysis (CCA) for switchgear room cooling failures that included hydramotor equipment issues. The CCA documented 6 hydramotor equipment issues from 2008 to 2012. There were 3 issues in 2008, two in 2010, and one in 2012. None of the six hydramotor equipment issues recorded in the CCA resulted in an LER and none had the same failure mode as the 1 VD1 9Y.
Improved hydramotor performance has been seen at LaSalle by replacing the hydramotors on a six year preventative maintenance schedule with vendor (AREVA) refurbished hydramotors.
G. COMPONENT FAILURE DATA
Automatic Switch Company (ASCO)/Model AH91 Hydramotor