05000373/LER-2012-001, Secondary Containment Inoperable Due to Interlock Doors Open
| ML12340A440 | |
| Person / Time | |
|---|---|
| Site: | LaSalle  |
| Issue date: | 11/09/2012 |
| From: | Vinyard H Exelon Generation Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| RA12-055 LER 12-001-00 | |
| Download: ML12340A440 (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 |
| 3732012001R00 - NRC Website | |
text
LaSalle Station 2601 North 21st Road ExeLon Generation, Marseilles, IL 61341 815 415 2000 Telephone www.exeloncorp.com 10 CFR 50.73 RA12-055 November 9, 2012 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 LaSalle County Station, Units 1 and 2 Facility Operating License Nos. NPF-1 1 and NPF-1 8 NRC Docket Nos. 50-373 and 50-374
Subject:
Licensee Event Report 2012-001-00 Secondary Containment Inoperable Due to Interlock Doors Open In accordance with 10 CFR 50.73(a)(2)(v)(C) and (D), Exelon Generation Company (EGC), LLC, is submitting Licensee Event Report Number 2012-001-00 for LaSalle Units 1 and 2.
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.
Respectfully, 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: 10/31/2013 10-2010)
, the NRC may sfor each b'ock) not conduct or sponsor, and a person is not required to respond to, the digits/characters finformation collection.
- 3. PAGE LaSalle County Station, Unit 1 05000373 1 OF 3
- 4. TITLE Secondary Containment Inoperable Due to Interlock Doors Open
- 5. EVENT DATE
- 6. LER NUMBER
- 7. REPORT DATE
- 8. OTHER FACILITIES INVOLVED FACILITY NAME DOCKET NUMBER MONTH DAY YEAR YEAR SUE REV MONTH DAY YEAR LaSalle County Station, Unit 2 05000374 MONH DY YAR EAR NUMBER NO.
FACILITY NAME DOCKET NUMBER 09 18 2012 2012 001 00 11 09 2012 N/A N/A OPERATING MODE
- 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check all that apply)
El 20.2201(b)
El 20.2203(a)(3)(i)
[I 50.73(a)(2)(i)(C)
El 50.73(a)(2)(vii) 1 El 20.2201(d)
Cl 20.2203(a)(3)(ii)
Cl 50.73(a)(2)(ii)(A)
El 50.73(a)(2)(viii)(A)
El 20.2203(a)(1)
El 20.2203(a)(4)
Cl 50.73(a)(2)(ii)(B)
El 50.73(a)(2)(viii)(B)
El 20.2203(a)(2)(i)
El 50.36(c)(1)(i)(A)
[E 50.73(a)(2)(iii)
El 50.73(a)(2)(ix)(A)
- 10. POWER LEVEL El 20.2203(a)(2)(ii)
El 50.36(c)(1)(ii)(A)
[E 50.73(a)(2)(iv)(A)
El 50.73(a)(2)(x)
El 20.2203(a)(2)(iii)
[E 50.36(c)(2) 0l 50.73(a)(2)(v)(A)
El 73.71(a)(4) 100 El 20.2203(a)(2)(iv)
El 50.46(a)(3)(ii)
El 50.73(a)(2)(v)(B)
El 73.71(a)(5)
El 20.2203(a)(2)(v)
El 50.73(a)(2)(i)(A) 0 50.73(a)(2)(v)(C)
El OTHER El 20.2203(a)(2)(vi)
El 50.73(a)(2)(i)(B) 0 50.73(a)(2)(v)(D)
Specify in Abstract below or in
D. SAFETY ANALYSIS
The safety significance of this event was minimal. The Reactor Building-to-outside differential pressure remained negative throughout the period that the Secondary Containment was inoperable. The Secondary Containment was inoperable for a brief period (i.e. approximately 10 seconds), TS 3.6.4.1 entered and exited at 0115 CDT, which was significantly less than the four-hour Completion Time to restore the secondary containment to operable status allowed by TS 3.6.4.1 Required Action A.1
E. CORRECTIVE ACTIONS
" The interlock door limit switch has been replaced
" The solenoid mounting bracket was removed, tightened, and re-installed.
F. PREVIOUS OCCURRENCES
LER 2011-003-00 On March 2, 2011, Unit 1 was in Mode 1 at 100% power and Unit 2 was in Mode 5 in a refueling outage, with fuel moves in progress. At 0928 hours0.0107 days <br />0.258 hours <br />0.00153 weeks <br />3.53104e-4 months <br /> CST, the Unit 1 Reactor Operator reported that the control room indication for secondary containment [NG] vacuum was 0.17 inch of vacuum water gauge.
The cause of the event could not be determined; however, it is suspected that both Unit 2 steam tunnel airlock doors were simultaneously opened and held open to transport material during outage demobilization activities.
G. COMPONENT FAILURE DATA
Locknetics/SDC style lock