ML16264A036

Licensee Presentation Regarding Columbia Presubmittal Meeting - Change 7-Day Completion Time to Support Replace RHR-A Pump, Motor Affects TS 3.5.1A, 3.6.1.5.A, 3.6.2.3.A (CAC No. MF8302)

ML16264A036
Person / Time
Site:	Columbia
Issue date:	09/20/2016
From:	John Klos Plant Licensing Branch IV
To:	Energy Northwest
Klos J, DORL/LPLIV-1, 415-5136
References
CAC MF8302
Download: ML16264A036 (17)

Text

License Amendment Request for One-Time 7 Day Extension of Completion Time for TS 3.5.1.A, 3.6.1.5.A, and 3.6.2.3.AEnergy NorthwestSeptember 22, 2016 Presentation OutlineProposed ChangeReason for RequestPrecedentRHR System Modes of OperationLAR ApproachTechnical EvaluationConclusion2 Proposed ChangeRevise the completion time specified in Columbia Generating Station (Columbia) Technical Specification (TS) 3.5.1.A, 3.6.1.5.A, and 3.6.2.3.A, by adding a footnote for restoring residual heat removal (RHR) Train A to each of the required actions to allow a one-time 7 day extension (14 day completion time).The proposed change also deletes a footnote associated with TS 3.5.1.A, 3.6.1.5.A, and 3.6.2.3.A which expired at 05:00 PST on February 9, 2015.3 Proposed Footnote"The Completion Time that one subsystem of RHR (RHR-A) can be inoperable as specified by Required Action A.1 may be extended beyond the 7 day completion time up to 7 days to support restoration of RHR-A following the modification activity governed by EC 14635. Upon successful restoration of RHR-A, this footnote is no longer applicable."4 Reason for RequestThis amendment request will support preventive maintenance to replace the RHR Train A pump and motor. Previous experience from replacing just the RHR Train B pump resulted in approximately 6 days out of the 7 day completion time (CT). It is expected that the work needed to replace the RHR Train A pump and motor may not be able to be completed in the current 7 day CT and would necessitate a plant shutdown. 5 PrecedentA one-time 7 day extension to Columbia TS actions 3.5.1.A, 3.6.1.5.A, and 3.6.2.3.A completion times (ML15031A002)was approved for use at Columbia under license amendment number 230 (ML15030A501) in February 2015.When the station is on-line, more emergency core cooling system (ECCS) systems and/or subsystems are available to mitigate a design basis accident such as high pressure core spray (HPCS),

low pressure core spray (LPCS), low pressure coolant injection mode (LPCI) of RHR and the automatic depressurization system (ADS).A mode transition from operating to shutdown brings inherent riskOnly one RHR train would be available for shutdown coolingRisk exposure is reduced by staying online6 Residual Heat Removal (RHR) systemThe RHR system is comprised of three independent loops. Each loop contains its own motor-driven pump, piping, valves, instrumentation, and controls. In addition, Loops A and B have heat exchangers which are cooled by standby service water (SW).The RHR system has the following Modes of OperationLow-pressure coolant injection (LPCI) modeSuppression pool cooling (SPC) modeContainment spray cooling (CSC) modeShutdown cooling mode7 RHR LPCI Mode of Operation8 RHR SPC Mode of Operation9 RHR CSC Mode of Operation10 RHR Shutdown Cooling Mode of Operation11 LAR ApproachThis LAR is a risk-informed submittal compatible with current Standard Review Plan (SRP) 5.4.7, 6.2.1.1.C, 6.3, and 16.1SRP review areas and acceptance criteria will be addressedRegulatory Guide (RG) 1.177 and RG 1.174 will be used to develop the LAR12 SRP ConsiderationsSRP 5.4.7 There are no changes in the design of the RHR system associated with this LARSRP 6.2.1.1.C There are no changes in the design of the Containment associated with this LARSRP 6.3 There are no changes to the ECCS systems associated with this LARSRP 16.1The proposed change used the risk-informed approach of RG 1.177 and RG 1.17413 Technical EvaluationDefense in Depth for Heat RemovalRedundant RHR Train BVentingComp Measures to ProtectRHR Trains B and C and support systemsDiverse ECCS systems HPCS and LPCS and support systemsReactor Core Isolation CoolingStartup TransformerDivision 2 & 3 Diesels and Service Water Systems14 Technical EvaluationPreliminary Risk Results14-DAY ALLOWED OUTAGE TIME (AOT) PREVENTIVE MAINTENANCEAverage Maintenance Model without Protected TrainsRisk MetricAcceptance GuidelineRisk Assessment ResultsICCDP< 1.0E-68.32E-7ICLERP< 1.0E-71.23E-91514-DAY AOT PREVENTIVE MAINTENANCEAverage Maintenance Model with Protected Trains & Compensatory MeasuresRisk MetricAcceptance GuidelineRisk Assessment ResultsICCDP< 1.0E-63.95E-7ICLERP< 1.0E-76.90E-10 Technical EvaluationColumbia PRA Technical AdequacyColumbia Internal Events (with internal flooding) PRA satisfies RG 1.200NRC SAMA Review Documented in ML12096A334PSA currently under additional review for Energy Northwest's LAR to adopt TSTF-425 ML15093A178*Responses to Requests for Additional Information (RAIs) related to Columbia's PSA model ML15260A570, ML15302A492, ML160984A387 and ML16174A432Fire and seismic PRAdo not meet RG 1.200 PRAs have been updated to use the current internal events PRAInsights into dominant risk contributors are applicable16 ConclusionThe proposed one time 7 day extension of completion time for TS 3.5.1.A, 3.6.1.5.A, and 3.6.2.3.A meets the five key RG 1.177 principles for risk-informed TS changes as follows:meets the current regulations,is consistent with the defense-in-depth philosophy,maintains sufficient safety margins,quantitative results for ICCDP and ICLERP application are less than the guidance thresholds and are consistent with the intent of the Commission's Safety Goal Policy Statement, andimpact will be monitored using performance measurement strategies associated with the Mitigating Systems Performance Index and Columbia's Maintenance Rule a(4) program.17