05000387/FIN-2010005-08
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Finding | |
|---|---|
| Title | Licensee-Identified Violation |
| Description | PPL CRs 1072993 and 1091573 (September and November 2008) questioned the configuration and TS aspects of the Susquehanna secondary containment airlock dampers. Further evaluation was conducted in CR 1095433. CRs 1072993 and 1091573 questioned whether the airlock dampers were Zone III containment isolation valves (they are listed in Table B. 3.6.4.2-1 as secondary containment system automatic isolation dampers) and noted they were not consistent with the FSAR design description of two dampers in series powered from independent trains. Per the FSAR, the only safety-related function of the RB heating, ventilation, and air-conditioning (HVAC) system is the automatic isolation function on high drywell pressure, low reactor vessel level, and high radiation in the refuel floor exhaust duct or railroad access shaft. Thus, only the Zone III automatic isolation dampers in the HVAC system would be considered SCIVs. The evaluation identified that for most airlocks, the series isolation valves separate the safety-related and nonsafety-related sides of the Zone III ventilation piping (HD 17502 A&B for Unit 1 and HD 27502 A&B for Unit 2). Thus, the airlock dampers do not perform the Zone III isolation function in these cases and the FSAR design basis does not apply. This is consistent with the guidance in NUREG 800, NRC Standard Review Plan. However for airlocks I-707 and II-707, the ducting from those airlocks is routed downstream of the HD 17502 or 27502 dampers (the nonsafety-related side) and therefore HD 17534 C for Unit 1 and HD 27534 C for Unit 2 in conjunction with the outer airlock door provide isolation of the safety-related and nonsafety-related side to the system. Thus, the damper/door pair perform the Zone III isolation function. Therefore, HD 17534 C and 27534 C are Zone III isolations valves and are SCIVs. This design is not consistent with the FSAR design basis and TS Limiting Condition for Operation (LCO) Action Statement for TS 3.6.4.2 should be entered when either the outer airlock door or damper for the I-707 and II-707 airlocks are inoperable for maintenance. CR 1095433 conducted a past operability review and identified that door 715 of airlock I-707 was propped open between September 9, 2003 and September 10, 2003 and door 716 of airlock II-707 was proper open between January 21, 2003 and April 18, 2003. Both of these instances exceeded the TS 3.6.4.2 Action Statement LCO time limits and would have required the plant be shut down to Mode 4 until the secondary containment isolation damper/door pair could be restored to an operable status or failed in the closed position. Therefore, PPL had operated in a condition prohibited by TS on two occasions in 2003. CR 1095433 also conducted a review for reportability. PPL correctly determined that 10 CFR 50.73 only requires an LER to be submitted for events which occurred within three year of the date of discovery unless the event involved an actuation of the RPS while the reactor was critical. Thus, an LER was not required. Operating in a condition prohibited by TS is a performance deficiency that was reasonably within PPLs ability to foresee and prevent. The issue is more than minor since it affects the configuration control attribute of the Barrier Integrity cornerstone objective to provide reasonable assurance that physical design barriers (fuel cladding, reactor coolant system (RCS), and containment) protect the public from radionuclide releases caused by accidents or events. Specifically, the performance deficiency represented a non-secured penetration in secondary containment. The issue screens to very low safety-significance (Green) when evaluated using IMC 0609, Attachment 4, Phase 1 - Initial Screening and Characterization of Findings, because the finding only impacts secondary containment, does not affect the integrity of primary containment, and did not represent an actual open pathway. This issue is documented in PPL CAP as CR 1334937. |
| Site: | Susquehanna  |
|---|---|
| Report | IR 05000387/2010005 Section 4OA7 |
| Date counted | Dec 31, 2010 (2010Q4) |
| Type: | NCV: Green |
| cornerstone | Mitigating Systems |
| Identified by: | Licensee-identified |
| Inspection Procedure: | |
| Inspectors (proximate) | M Patel J Furia A Rosebrook P Finney P Krohn T Hedigan J Greives |
| INPO aspect | |
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Finding - Susquehanna - IR 05000387/2010005 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Susquehanna) @ 2010Q4
Self-Identified List (Susquehanna)
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