05000461/FIN-2012004-03
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Finding | |
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| Title | Past Operability/Reportability Determination for Inoperable Division 1 Diesel Generator Due to Ventilation System Damper Failure |
| Description | On March 1, 2012, operators started the Division 1 DG for a monthly surveillance test and immediately noted a lack of expected air flow in the room from the ventilation supply fan and that the doors between the DG rooms did not have the usual high differential pressure between them. Operators secured the Division 1 DG and DG room supply fan (1VD01CA) after the engine had been running for about 45 minutes. With the ventilation fan secured, the licensee discovered that the ventilation supply damper hydramotor coupling was disconnected, causing the damper not to open (or to fail closed) when the ventilation fan started. Operators declared the Division 1 DG inoperable upon discovering the failed damper. As discussed in Section 1R12.1.b.1 of this inspection report, the licensee completed an equipment apparent cause evaluation for the damper failure and concluded that maintenance craftsmen had failed to sufficiently tighten a locknut on the coupling when the hydramotor was replaced on September 29, 2010, due to inadequate guidance in the maintenance procedure. The Division 1 DG and DG room supply fan had last operated satisfactorily during monthly testing on January 25, 2012. The inspectors noted that the licensee had not considered this to be a demand or run failure for the DG and had not reported the event in accordance with 10 CFR 50.73, Licensee Event Report System, Paragraph (a)(2)(i)(B), as a condition which was prohibited by the plants TS for an inoperable DG longer than the TS completion time for restoration. The inspectors reviewed the guidance in NUREG 1022, Event Reporting Guidelines 10 CFR 50.72 and 50.73, Revision 2 and questioned the licensees conclusion that the event was not reportable based on the time of discovery. NUREG 1022, Section 3.2.2, states in part: Generally, an operation or condition prohibited by the technical specifications existed and is reportable if surveillance testing indicates that equipment (e.g., one train of a multiple train system) was not capable of performing its specified safety functions (and thus was inoperable) for a period of time longer than allowed by technical specifications (i.e., LCO [limiting condition for operation] allowed outage time, or completion time for restoration of equipment in ISTS [Improved Standard Technical Specifications]). The guidance further states: For the purposes of evaluating the reportability of a discrepancy found during surveillance testing that is required by the technical specifications... it should be assumed that the discrepancy occurred at the time of its discovery unless there is firm evidence, based on a review of relevant information such as the equipment history and the cause of failure, to indicate that the discrepancy existed previously. Based on the known cause of failure, it appeared to the inspectors that had there been an event involving a LOOP with a demand for the Division 1 DG to run at any time after it was last successfully tested on January 25th, the damper would have failed at that time; and, therefore the DG had been inoperable since it was last demonstrated to be operable on January 25th. The inspectors discussed this issue with the licensee and in response to the inspectors questions, the licensee initiated AR 01401926 to further review its past operability/reportability conclusion. This issue is considered to be an unresolved item (URI 05000461/2012004-3, Past Operability/Reportability Determination for Inoperable Division 1 DG Due to Ventilation System Damper Failure) pending additional review to determine whether this issue was reportable in accordance with 10 CFR 50.73(a)(2)(i)(B) as a condition which was prohibited by the plants TS. |
| Site: | Clinton  |
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| Report | IR 05000461/2012004 Section 1R15 |
| Date counted | Sep 30, 2012 (2012Q3) |
| Type: | TEV: Severity level IV |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71111.15 |
| Inspectors (proximate) | B Kemker D Lords D Passehl J Beavers J Bozga J Draper M Ring R Ruiz S Mischkea Shaikh B Kemker B Orlikowski D Lords D Reeser J Draper J Laughlin S Mischke V Myer |
| CCA | H.13, Consistent Process |
| INPO aspect | DM.1 |
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Finding - Clinton - IR 05000461/2012004 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Clinton) @ 2012Q3
Self-Identified List (Clinton)
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