05000237/LER-2007-001, Regarding Unit 2s Standby Liquid Control System Tank Inoperable Due to a Small Linear Crack
| ML070860201 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 03/19/2007 |
| From: | Bost D Exelon Generation Co, Exelon Nuclear |
| To: | Document Control Desk, NRC/NRR/ADRO |
| References | |
| SVPLTR # 07-0016 LER 07-001-00 | |
| Download: ML070860201 (5) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 10 CFR 50.73(a)(2)(vii), Common Cause Inoperability 10 CFR 50.73(a)(2)(i) 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 |
| 2372007001R00 - NRC Website | |
text
Exeln,.
Exelon Generation Company, LLC wwwexeloncorp.com Nuclear Dresden Nuclear Power Station 6500 North Dresden Road Morris, IL 60450-9765 10 CFR 50.73 SVPLTR # 07-0016 March 19, 2007 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Dresden Nuclear Power Station, Unit 2 Renewed Facility Operating License No. DPR-19 NRC Docket No. 50-237
Subject:
Licensee Event Report 237/2007-001-00, "Unit 2 Standby Liquid Control System Tank Inoperable Due To A Small Linear Crack" Enclosed is Licensee Event Report 237/2007-001 -00, "Unit 2 Standby Liquid Control System Tank Inoperable Due To A Small Linear Crack," for Dresden Nuclear Power Station, Unit 2.
This event is being reported in accordance with 10 CFR 50.73(a)(2)(i)(B), "Any operation or condition which was prohibited by the plant's Technical Specifications," and 10 CFR 50.73(a)(2)(vii)(D), "Any event where a single cause or condition caused at least one independent train or channel to become inoperable in multiple systems or two independent trains or channels to become inoperable in a single system designed to mitigate the consequences of an accident."
Should you have any questions concerning this report, please contact Mr. James Ellis, Regulatory Assurance Manager, at (815) 416-2800.
Respectfully, Danny G. Bost Site Vice President Dresden Nuclear Power Station Enclosure cc:
Regional Administrator - NRC Region III NRC Senior Resident Inspector - Dresden Nuclear Power Station
NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 06/30/2007 (6-2004)
, the NRC may not conduct or sponsor, and a person is not required to respond to, the digits/characters for each block) r...nfi nlprtn
- 3. PAGE Dresden Nuclear Power Station, Unit 2 05000237 1 OF 4
- 4. TITLE Unit 2 Standby Liquid Control System Tank Inoperable Due To A Small Linear Crack
- 5. EVENT DATE
- 6. LER NUMBER
- 7. REPORT DATE
- 8. OTHER FACILITIES INVOLVED SEQUENTIAL REV FACILITY NAME DOCKET NUMBER MONTH DAY YEAR YEAR NUMBER NO.
MONTH DAY YEAR N/A N/A FACILITY NAME DOCKET NUMBER 01 18 2007 2007
- - 001
- - 00 03 19 2007 N/A N/A
- 9. OPERATING MODE
- 11. THIS REPORT IS SUBMI'TED PURSUANT TO THE REQUIREMENTS OF 10 CFR§: (Check all that apply)
[_i 20.2201(b)
El. 20.2203(a)(3)(i)
[] 50.73(a)(2)(i)(C)
[D 50.73(a)(2)(vii)
E] 20.2201(d)
El 20.2203(a)(3)(ii)
El 50.73(a)(2)(ii)(A)
El 50.73(a)(2)(viii)(A)
El 20.2203(a)(1)
El 20.2203(a)(4)
El 50.73(a)(2)(ii)(B)
El 50.73(a)(2)(viii)(B) 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)
- 10. POWER LEVEL El 20.2203(a)(2)(ii)
El 50.36(c)(1)(ii)(A)
[I 50.73(a)(2)(iv)(A)
El 50.73(a)(2)(x)
Ej 20.2203(a)(2)(iii)
[E 50.36(c)(2)
El 50.73(a)(2)(v)(A)
El 73.71(a)(4)
El 20.2203(a)(2)(iv)
El 50.46(a)(3)(ii)
El 50.73(a)(2)(v)(B)
El 73.71 (a)(5) 100 El 20.2203(a)(2)(v)
El 50.73(a)(2)(i)(A)
[E 50.73(a)(2)(v)(C) 0l OTHER El 20.2203(a)(2)(vi) 0 50.73(a)(2)(i)(B)
El 50.73(a)(2)(v)(D)
Specify in Abstract below or in (If more space is required, use additional copies of (If more space is required, use additional copies of NRC Form 366A) (17)
E.
Corrective Actions
The SLC Tank was repaired by encapsulating the cracked component. The system was restored to operable status on January 20, 2007 at 0015 hours1.736111e-4 days <br />0.00417 hours <br />2.480159e-5 weeks <br />5.7075e-6 months <br /> (CST) within the time allowed by the NOED.
The written NOED request was submitted to the NRC on January 22, 2007, consistent with the guidelines provided in Regulatory Issue Summary 2005-01 and NRC Inspection Manual Part 9900.
The cracked component will be removed from SLC Tank during the next Unit 2 refueling outage currently scheduled for October 2007. The cracked component will be sent to a vendor's lab for evaluation.
A Supplemental Licensee Event Reports (LER) will be submitted on or before March 20, 2008 containing the information obtained from the additional evaluation performed at the vendor's lab.
An inspection of the Unit 3 SLC Tank identified no observable leakage from the tank.
F.
Previous Occurrences
A review of DNPS Licensee Event Reports (LERs) for the last three years did not identified any LERs associated with through-wall leakage of the SLC Tank.
G.
Component Failure Data
NA