05000461/LER-2012-002, Regarding Division 1 Emergency Diesel Generator Supply Air Damper Failure
| ML12341A232 | |
| Person / Time | |
|---|---|
| Site: | Clinton  |
| Issue date: | 11/27/2012 |
| From: | Noll W Exelon Generation Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| U-604101 LER 12-002-00 | |
| Download: ML12341A232 (4) | |
| 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 |
| 4612012002R00 - NRC Website | |
text
-7Exelon Generation Clinton Power Station 8401 Power Road Clinton, IL 61727 U-6041 01 10 CFR 50.73 November 27, 2012 SRRS 5A.108 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D. C. 20555-0001 Clinton Power Station, Unit 1 Facility Operating License No. NPF-62 NRC Docket No. 50-461
Subject:
Licensee Event Report 2012-002-00 Enclosed is Licensee Event Report (LER) No. 2012-002-00: Condition Prohibited by Technical Specifications Due to Ventilation Damper Coupling Disconnected. This report is being submitted in accordance with the requirements of 10 CFR 50.73.
There are no regulatory commitments contained in this report.
Should you have any questions concerning this report, please contact Ms. Kathy Ann Baker, Regulatory Assurance Manager, at (217)-937-2800.
Respectf ully, William G. Noll Site Vice President Clinton Power Station EET/blf
Enclosures:
Licensee Event Report 2012-002-00 cc:
Regional Administrator - NRC Region III NRC Senior Resident Inspector - Clinton Power Station Office of Nuclear Facility Safety - IEMA Division of Nuclear Safety
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 block) not conduct or sponsor, and a person is not required to respond to, the digits/characters finformation collection.
I3. PAGE Clinton Power Station, Unit 1 05000461 1 OF 3
- 4. TITLE Division 1 Emergency Diesel Generator Supply Air Damper Failure
- 5. EVENT DATE
- 6. LER NUMBER
- 7. REPORT DATE
- 8. OTHER FACILITIES INVOLVED MYI SEQUENTIAL II RFACILITY NAME DOCKET NUMBER MONTH DAY YEAR YEAR E NUMBER NO.
NMONTH DAY YEAR 05000 OR IS IFACILITY NAME DOCKET NUMBER 03 01 2012 2012 002 -
00 11 27 2012 05000
- 9. OPERATING MODE
- 11. THIS REPORT is SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check all that apply)
E] 20.2201(b)
El 20.2203(a)(3)(i)
F] 50.73(a)(2)(i)(C)
El 50.73(a)(2)(vii)
El 20.2201(d)
E3 20.2203(a)(3)(ii)
El 50.73(a)(2)(ii)(A)
El 50.73(a)(2)(viii)(A)
[I 20.2203(a)(1)
El 20.2203(a)(4)
[I 50.73(a)(2)(ii)(B)
[I 50.73(a)(2)(viii)(B)
[I 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)
EQ 50.73(a)(2)(iv)(A)
El 50.73(a)(2)(x)
El 20.2203(a)(2)(iii) 0l 50.36(c)(2)
El 50.73(a)(2)(v)(A)
[E 73.71(a)(4) 097 El 20.2203(a)(2)(iv)
El 50.46(a)(3)(ii) 0 50.73(a)(2)(v)(B)
El 73.71(a)(5)
El 20.2203(a)(2)(v)
El 50.73(a)(2)(i)(A)
[3 50.73(a)(2)(v)(C)
[E OTHER E] 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
C. CAUSE OF EVENT
Hydramotor 1TZVD001A (model NH91), which controls the 1VD01YA damper, was last replaced per Work Order (WO) 1220488 on September 29, 2010. At the time of replacement the workers did not identify either deficiencies or discrepant conditions on the old hydramotor coupling or on the as-left coupling installation (i.e., loose lock nut or stripped threads).
The Apparent Cause Evaluation performed on the event determined the cause was failure to ensure the lock nut on the coupling was sufficiently tightened during the previous hydramotor replacement because of a lack of quantitative procedural guidance.
D. SAFETY CONSEQUENCES
There were no actual nuclear, radiological or industrial safety significant consequences related to this event. This event resulted in the loss of EDG Room Ventilation, due to the 1VD01YA damper hydramotor 1TZVD001A coupling becoming disconnected, which resulted in the supply air damper remaining in the closed position. Engineering has determined that an Operator would have a sufficient amount of time, approximately 109 minutes, to perform simple actions to restore a ventilation flow path before high temperatures would be expected that could exceed the room maximum design temperature.
This event was determined to be of very low safety significance during a detailed quantitative Significance Determination Process review since the delta core damage frequency and delta large early release frequency were both determined to be negligible based upon crediting operator recovery actions to restore EDG room ventilation.
E. CORRECTIVE ACTIONS
CPS Procedure 8452.04, "AH91/NH91 Hydramotor Actuator Maintenance", has been revised to include supervisory oversight on the assembly of the lock nut and coupling and allow the use of an engineered adhesive (i.e., Loctite) for coupling lock nuts.
F. PREVIOUS OCCURRENCES
A review for previous occurrences did not identify similar events at CPS.
G. COMPONENT FAILURE DATA
Manufacturer Nomenclature Manufacturer Model Number Pacific Air Products Hydramotor SL-100-5600 NR FORCM 366A (10-2010)