05000285/LER-2007-003, Calhoun Regarding Inoperability of a Diesel Generator with Inoperable Containment Spray Pump from the Opposite Bus
| ML071140029 | |
| Person / Time | |
|---|---|
| Site: | Fort Calhoun  |
| Issue date: | 04/17/2007 |
| From: | Reinhart J Omaha Public Power District |
| To: | Document Control Desk, Plant Licensing Branch III-2 |
| References | |
| LIC-07-0027 LER 07-003-00 | |
| Download: ML071140029 (4) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 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 |
| 2852007003R00 - NRC Website | |
text
mmmm Omaha Public Power Distict 444 South 16th Street Mall Omaha NE 68102-2247 LIC-07-0027 April 17, 2007 U. S. Nuclear Regulatory Commission Attn: Document Control Desk Mail Station P1-137 Washington, DC 20555
Reference:
Subject:
Docket No. 50-285 Licensee Event Report 2007-003 Revision 0 for the Fort Calhoun Station Please find attached Licensee Event Report 2007-003, Revision 0, dated April 17, 2007. This report is being submitted pursuant to 10 CFR 50.73(a)(2)(i)(B) and 10 CFR 50.73(a)(2)(v)(D).
..If you should have any questions, please contact me. The attached LER commits to the following:
Procedural guidance for post maintenance testing will be reviewed and enhanced to improve the quality of post maintenance tests. This will ensure that no additional problems have been created by the work activity. The procedures will be revised by May 15, 2007. In addition, training will be provided to personnel specifying post maintenance tests as well as personnel reviewing post maintenance test requirements. This training will be completed by July 11, 2007.
ý Jt Director Fort Calhoun Station JA-Rdk' t
Attachment:-
c:
.B. S. Mallett, NRC Regional Administrator, Region IV A. B. Wang, NRC Project Manager J. D. Hanna, NRC Senior Resident Inspector INPO Records Center Employment with Equal Opportunity
NRC FORM 366 U.S. NUCLEAR REGULATORY COMn APPROVED BY OMB: NO. 3150-0104 EXPIRES: 06/30/2007 (6-2004)
Estimated burden per response to comply with this mandatory collection request: 50 hours5.787037e-4 days <br />0.0139 hours <br />8.267196e-5 weeks <br />1.9025e-5 months <br />.
Reported lessons learned are incorporated into the licensing process and fed back to industry.
Send comments regarding burden estimate to the Records and FOIA/Privacy Service Branch (T-5 F52), U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001, or by intemet e-mail LICENSEE EVENT REPORT (LER) to infocollects@nrc.gov, and to the Desk Officer, Office of Information and RegulatoryAffairs, NEOB-1 0202, (3150-0104), Office of Management and Budget, Washington, DC 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 (See reverse for required number of information collection.
digits/characters for each block)
- 3. PAGE Fort Calhoun Station 05000285 1 OF 3
- 4. TITLE Inoperability of a Diesel Generator with Inoperable Containment Spray Pump from the Opposite Bus
- 5. EVENT DATE
- 6. LER NUMBER
- 7. REPORT DATE
- 8. OTHER FACILITIES INVOLVED MONTH DAY YEAR YEAR SEQUENTIAL REV MONTH DAY YEAR NUMBER NUMBER NO.
05000 FACILITY NAME DOCKET NUMBER 02 16 2007 2007
- - 003 -
00 04 17 2007 05000
- 9. OPERATING
- 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR§: (Check all that apply)
MODE D[ 20.2201(b)
(I 20.2203(a)(3)(i)
El 50.73(a)(2)(i)(C)
[I 50.73(a)(2)(vii)
El 20.2201(d)
El 20.2203(a)(3)(ii)
[] 50.73(a)(2)(ii)(A)
El 50.73(a)(2)(viii)(A) 1 El 20.2203(a)(1)
El 20.2203(a)(4) 0l 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)
[I 50.73(a)(2)(ix)(A)
- 10. POWER LEVEL El 20.2203(a)(2)(ii)
[I 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)
El 50.36(c)(2)
El 50.73(a)(2)(v)(A)
El 73.71(a)(4)
E] 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)
El 50.73(a)(2)(v)(C)
El OTHER El 20.2203(a)(2)(vi)
[
50.73(a)(2)(i)(B)
[
50.73(a)(2)(v)(D)
.* Specify in Abstract below' or in (if more space is required, use additional copies of NRC Form 366A) (17)
The auxiliary contacts were replaced with new contacts from the warehouse. The GE 2CR contactor was tested 12 times by energizing the main contactor coil using an external power supply. Resistance readings were taken on the contacts during the testing to ensure good contact. The diesel was started and flashed twice to ensure proper operation of the field flashing circuit. The monthly performance of the DG-1 surveillance test was completed satisfactorily on Saturday, February 17, 2007.
The root cause for this event was determined to be inadequate testing of the auxiliary contacts conducted during post maintenance testing (PMT) on February 14, 2007. Specifically, this involved failure to verify that the normally closed auxiliary contacts returned to the closed state following the surveillance test of the diesel.
The field flash circuitry is common to both emergency DG-1 and DG-2. During follow up to the DG-1 failure, the identical GE 2CR relay auxiliary contacts in DG-2 were replaced and successfully tested.
In addition, auxiliary contacts are utilized on other relays in the plant. Routine surveillance testing of associated equipment provides assurance that the safety function will be met, as evidenced by identification of misoperation of the contacts associated with DG-1 on February 16, 2007. However, actions are planned to address weaknesses in post maintenance testing practices as a result of this event.
CORRECTIVE ACTIONS
As previously indicated, the auxiliary contacts associated with DG-1 and DG-2 were replaced with new contacts.
Procedural guidance for post maintenance testing will be reviewed and enhanced to improve the quality of post maintenance tests to ensure no additional problems have been created by the work activity. The procedure changes will be completed by May 15, 2007.
Training will be provided on this event and on changes to procedural guidance. The training will be provided to personnel who specify post maintenance tests as well as personnel reviewing PMT requirements. This training will be completed by July 11, 2007.
SAFETY SIGNIFICANCE
At the time of discovery, both trains of the containment spray system were available from its normal power supply to provide cooling to the containment should it be required.
The amount of time that the VA-3B containment cooling fan was inoperable was a short, approximately 2.5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> to perform surveillance testing. The amount of time required to restore the system to operability when being tested is short. Although the system was inoperable due to the surveillance testing, it was quickly restorable if needed. The probability of an accident occurring during.the time of inoperability is very low. The DG-1 was inoperable for approximately 3 days.
Due to the short amount of time of inoperability of VA-3B, the ability to quickly restore VA-3B, and the low probability of an accident during that time, there was very small impact on the health and safety of the public.
SAFETY SYSTEM FUNCTIONAL FAILURE This event does result in a safety system functional failure in accordance with NEI-99-02.
PREVIOUS SIMILAR EVENTS
There have not been any other instances of a similar nature resulting in the diesels not being able to field flash due to post maintenance testing at FCS in the last three years.
L.
NRCL FURM 366A (1-20uu)