05000373/LER-2009-002, Regarding Loss of Shutdown Cooling Due to Spurious Closure of the Shutdown Cooling Suction Isolation Valve
| ML092720861 | |
| Person / Time | |
|---|---|
| Site: | LaSalle  |
| Issue date: | 09/18/2009 |
| From: | Rhoades D Exelon Corp, Exelon Generation Co, Exelon Nuclear |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| LER 09-002-00 | |
| Download: ML092720861 (4) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(v)(B), Loss of Safety Function - Remove Residual Heat 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)(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 |
| 3732009002R00 - NRC Website | |
text
Exe In.
LaSalle Generating Station 26ol North 21st Road Marseilles, I L 61341-9757 www.exelonCOTP.COM Nuclear September 18, 2009 10 CFR 50.73 United States Nuclear Regulatory Commission Attention: Document Control Desk Washington, D.C. 20555 LaSalle County Station, Units 1 Facility Operating License No. NPF 11 NRC Docket No. 50-373
Subject:
Licensee Event Report In accordance with 10 CFR 50.73 (a)(2)(v)(B), Exelon Generation Company, (EGC), LLC, is submitting Licensee Event Report Number 09-002-00,
,Docket No. 050-373.
Should you have any questions concerning this letter, please contact.
Mr. Terrence W. Simpkin, Regulatory Assurance Manager, at (815) 415-2800.
Respectfully, David P. Rhoades Plant Manager LaSalle County Station
Attachment:
Licensee Event Report cc:
Regional Administrator - NRC Region Ill NRC Senior Resident Inspector - LaSalle County Station
NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 08/31/2010 (9-2007)
, the NRC may digits/characters for each block) not conduct or sponsor, and a person is not required to respond to, the information collection.
i3. PAGE LaSalle County Station Unit 1 05000373 1 OF 3
- 4. TITLE Loss of Shutdown Cooling Due to Spurious Closure of the Shutdown Cooling Suction Isolation Valve
- 5. EVENT DATE
- 6. LER NUMBER
- 7. REPORT DATE
- 8. OTHER FACILITIES INVOLVED I FAILIYNMOKTNME MONTH DAY YEAR YEAR SEQUENTIAL REV MONTH DAY YEAR FAILIYNMOKTNME NUMBER NO. I__________
0FACILITY NAME DOCKET NUMBER 07 20 2009 2009 002 00 09 18 2009
- 9. 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) 4E 20.2201(d)
El 20.2203(a)(3)(ii) 0l 50.73(a)(2)(ii)(A)
El 50.73(a)(2)(viii)(A)
El 20.2203(a)(1) 0l 20.2203(a)(4)
El 50.73(a)(2)(ii)(B)
El 50.73(a)(2)(viii)(B)
I] 20.2203(a)(2)(i)
C3 50.36(c)(1)(i)(A)
El 50.73(a)(2)(iii)
[I 50.73(a)(2)(ix)(A)
- 10. POWER LEVEL
-- 20.2203(a)(2)(ii)
[I 50.36(c)(1)(ii)(A)
El 50.73(a)(2)(iv)(A)
El 50.73(a)(2)(x)
El 20.2203(a)(2)(iii)
[I 50.36(c)(2)
El 50.73(a)(2)(v)(A)
El 73.71(a)(4) 000 El 20.2203(a)(2)(iv)
El 50.46(a)(3)(ii) 0 50.73(a)(2)(v)(B)
El 73.71(a)(5)
[E 20.2203(a)(2)(v)
[E 50.73(a)(2)(i)(A)
El 50.73(a)(2)(v)(C)
El OTHER El 20.2203(a)(2)(vi)
[E 50.73(a)(2)(i)(B)
El 50.73(a)(2)(v)(D)
Specify in Abstract below or in D.
SAFETY ANALYSIS
The safety consequences of this event were minimal. Shutdown cooling was restored within 12 minutes and reactor coolant temperature rose 12 degrees F. Both Reactor Recirculation (RR)[AD] pumps were running during the event, so forced coolant circulation was maintained.
The event was determined to be reportable in accordance with 10 CFR50.73(a)(2)(v)(B) as an event or condition that could have prevented the fulfillment of the safety function of systems needed to remove residual heat. This event is considered a Safety System Functional Failure.
E.
CORRECTIVE ACTIONS
Corrective Actions:
The 1 B21 H-K77 relay was replaced.
The remaining affected Agastat relays in the SDC isolation logic system were scheduled for replacement in upcoming division work windows.
Corrective Action to Prevent Recurrence:
A preventative maintenance activity will be created to periodically replace the affected relays.
A design change will be evaluated for defeating the shutdown cooling isolation logic when not required to be operable by the Technical Specifications.
F.
PREVIOUS OCCURENCES
A document search found that LaSalle has not experienced a loss of shutdown cooling due to a spurious closure of the shutdown cooling suction isolation valve within the past five (5) years.
G.
COMPONENT FAILURE DATA
Tyco Electronics - Agastat Model E7000 Series Time Day Relay