05000346/LER-2012-001, For Davis-Besse Regarding Direct Current Source for Diesel Generator Transferred to Inoperable Source During Fuel Movement
| ML12208A111 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 07/23/2012 |
| From: | Allen B FirstEnergy Nuclear Operating Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| L-12-239 LER 12-001-00 | |
| Download: ML12208A111 (6) | |
| 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 |
| 3462012001R00 - NRC Website | |
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5501 North State Route 2 FirstEnergy Nuclear Operating Company Oak Harbor, Ohio 43449 Bany S. Allen 419-321-7676 Vice President - Nuclear Fax: 419-321-7582 July 23, 2012 L-1 2-239 10 CFR 50.73 ATTN: Document Control Desk United States Nuclear Regulatory Commission Washington, D.C. 20555-0001
SUBJECT:
Davis-Besse Nuclear Power Station Docket Number 50-346, License Number NPF-3 Licensee Event Report 2012-001 Enclosed is Licensee Event Report (LER) 2012-001, "Direct Current Source for Diesel Generator Transferred to Inoperable Source During Fuel Movement." This LER is being reported in accordance with 10 CFR 50.73(a)(2)(i)(B) and 10 CFR 50.73(a)(2)(v)(D).
There are no regulatory commitments contained in this letter or its enclosure. The actions described represent intended or planned actions and are described for information only. If there are any questions or if additional information is required, please contact Mr. Patrick J. McCloskey, Manager, Site Regulatory Compliance, at (419) 321-7274.
Sincerely, Barry S. Allen GMW Enclosure: LER 2012-001 cc:
NRC Region III Administrator NRC Resident Inspector NRR Project Manager Utility Radiological Safety Board
NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB NO. 3150-0104 EXPIRES 10/31/2013 (10-2010)
, the NRC may (See reverse for required number of not conduct or sponsor, and a person is not required to respond to, the digits/characters for each block) information collection.
- 3. PAGE Davis-Besse Nuclear Power Station 05000346 1 OF 5
- 4. TITLE Direct Current Source for Diesel Generator Transferred to Inoperable Source During Fuel Movement
- 5. EVENT DATE
- 6. LER NUMBER
- 7. REPORT DATE 1
- 8. OTHER FACILITIES INVOLVED REV FACILITY NAME DOCKET NUMBER EAR YEAR NUMBER NO MONTH DAY YEAR 05000 zMONTHf DOCKE NUMBERNO 000 05 19 2012 2012 001 00 07 23 20121FACILITYNAME DOCKETNU05000
- 9. OPERATING MODE
- 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check all that apply)
F1 20.2201(b)
El 20.2203(a)(3)(i)
[1 50.73(a)(2)(i)(C)
E]
50.73(a)(2)(vii) 6 20.2201(d)
[E]
20.2203(a)(3)(ii)
[] 50.73(a)(2)(ii)(A)
E]
50.73(a)(2)(viii)(A)
El 20.2203(a)(1)
E]
20.2203(a)(4)
El 50.73(a)(2)(ii)(B)
El 50.73(a)(2)(viii)(B)
E]
20.2203(a)(2)(i)
[] 50.36(c)(1)(i)(A)
E] 50.73(a)(2)(iii)
E]
50.73(a)(2)(ix)(A)
- 10. POWER LEVEL E]
20.2203(a)(2)(ii)
E]
50.36(c)(1)(ii)(A)
[] 50.73(a)(2)(iv)(A)
El 50.73(a)(2)(x)
[
20.2203(a)(2)(iii)
[]
50.36(c)(2)
E] 50.73(a)(2)(v)(A)
[-]
73.71(a)(4) 000 El 20.2203(a)(2)(iv)
E]
50.46(a)(3)(ii)
[] 50.73(a)(2)(v)(B)
[j 73.71(a)(5)
El 20.2203(a)(2)(v)
E]
50.73(a)(2)(i)(A)
E] 50.73(a)(2)(v)(C)
El OTHER Specify in Abstract below
__20.2203(a)(2)(vi) 50.73(a)(2)(i)(B)
[
50.73(a)(2)(v)(D) or in
ANALYSIS OF EVENT
For the time period when Battery 1 P was functioning as part of the DC electrical power source for EDG 1 to provide the loss of power start function without the necessary surveillance testing being completed, the battery was in service and available. Testing completed approximately 1.5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> after the transfer of panel D1 P to its normal power source documented that Battery 1 P had sufficient charge to perform all required functions. The battery had been on equalizing charge for over three days following the battery performance discharge test, and was removed from equalizing charge prior to the source transfer of panel D1P to Battery 1 P. Completion of required surveillance testing on May 22, 2012, at 1144 hours0.0132 days <br />0.318 hours <br />0.00189 weeks <br />4.35292e-4 months <br /> confirmed all required equipment was operable. Additionally during this time, the Station Blackout Diesel Generator, which has its own DC system and does not rely on the station DC System for its loss of power start function, was available. Therefore this event was of very low safety significance.
Reportability Discussion:
From the time when panel D1P was transferred to its untested normal power source until completion of all required testing, it could not be confirmed that that Battery 1 P was operable when D1 P was transferred to the normal power supply. Therefore, EDG 1 was inoperable during this time period.
Because EDG 2 was also inoperable at this time, no EDGs were Operable as required by the Technical Specifications. TS LCO 3.8.2 Action B requires that with the one required EDG inoperable, movement of irradiated fuel assemblies shall be suspended immediately (any Modes). Because fuel movement continued during this timeframe, the plant operated in a condition prohibited by the Technical Specifications, which is reportable per 10 CFR 50.73(a)(2)(i)(B).
Also, with no EDGs operable during this timeframe, this represents a condition that could have prevented fulfillment of a safety function for a system needed to mitigate the consequences of an accident (fuel handling accident). This is also reportable per 10 CFR 50.73(a)(2)(v)(D). Because this condition was discovered while the plant was defueled and no fuel movement in progress, no immediate reporting per 10 CFR 50.72(b)(3)(v)(D) was required because the EDGs provided no safety function at the time of discovery.
CORRECTIVE ACTIONS
Required surveillance testing was completed on May 22, 2012, to confirm train 1 of the DC System and EDG 1 were operable as required for the existing plant conditions.
Procedure DB-OP-06321, "250/125 VDC Station DC Switching Procedure," will be revised for the live transfer of essential distribution panels to add a prerequisite for ensuring operability of the DCMCC being transferred to, or to ensure both EDGs are operable. Procedure DB-OP-06316, "Diesel Generator Operating Procedure," will be revised to include the affect of the operability of the DC distribution subsystem on the operability of the EDG.
Procedures regarding returning systems and components to service will be revised to be applicable at all times when systems or components are required to be functional or operable.
Existing pre-job briefs will be revised and additional pre-job briefs will be created for the live transfer of DC distribution panels to alternate/normal feed so that the impact on the DC System operability is addressed and this event is identified as operating experience.
==CORRECTIVE ACTIONS==The outage schedule will be enhanced by including an activity to verify operability of power sources /
loads between surveillance testing and transfer of DC system distribution panels between normal and alternate alignments.
A case study will be disseminated to licensed operators on the intended restoration of the DC system during outages that highlights the problem, causes, and corrective actions identified for this event. The key aspects of this case study will be reinforcement of the expected behaviors during outages with respect to return to service guidance, tracking alternate configurations of key shutdown safety defense in depth systems, and use of the questioning attitude human performance event-free tools.
PREVIOUS SIMILAR EVENTS
DBNPS Licensee Event Report 2005-002 documented the inoperability of a DC System Battery during a plant shutdown that was not detected during surveillance testing. This resulted in the station starting up without the required operable batteries, which was a condition prohibited by the Technical Specifications. The corrective actions for the 2005 event focused on improving test procedures to ensure all battery cells met operability requirements, and would not be expected to have prevented the current event that involved the interface between the DC System and its effect on the operability of the EDGs. There have been no Licensee Event Reports submitted for the DBNPS in the past three years regarding similar issues where an electrical system alignment was transferred from alternate to normal supply prior to surveillance test completion.