L-PI-05-026, Response to Requests for Additional Information (Rals) Regarding the 4th Interval Lnservice Testing Plan

Response to Requests for Additional Information (Rals) Regarding the 4th Interval Lnservice Testing Plan

ML051040488
Person / Time
Site:	Prairie Island
Issue date:	04/13/2005
From:	Solymossy J Nuclear Management Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
L-PI-05-026, TAC MC4509, TAC MC4510
Download: ML051040488 (3)

Text

N Committed to Nuclear Excellence Prairie lsland Nuclear Generating Plant Operated by Nuclear Management Company, LLC APR 1 3 2005 L-P1-05-026 10CFR50.55a U S Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Prairie lsland Nuclear Generating Plant Units Iand 2 Dockets 50-282 and 50-306 License Nos. DPR-42 and DPR-60 Response to Requests for Additional Information (RAls) Regarding the 4th Interval lnservice Testing Plan (TAC Nos.- MC4509 and MC4510)

On June 28,2004, Nuclear Management Company, LLC (NMC) submitted the Prairie lsland Nuclear Generating Plant (PINGP) 4th Interval Inservice Testing Plan. On March 23, 2005, NMC received RAls regarding the PINGP 4th Interval lnservice Testing Plan.

Attached to this letter are the RAls along with the information requested (Enclosure 1).

Summarv of Commitments This letter contains no new commitments and no revisions to existing commitments.

ie lsland Nuclear Generating Plant Enclosure (1) cc: Administrator, Region Ill, USNRC Project Manager, Prairie Island, USNRC Resident Inspector, Prairie Island, USNR 1717 Wakonade Drive East Welch, Minnesota 55089-9642 Telephone: 651.388.1121

ENCLOSURE Response to Requests for Additional Information (RAls) Regarding the 4th Interval lnservice Testing Plan (NRC questions are in bold font, NMC responses are in normal font)

NRC RAI 1 The staff accepted Code Case OMN-9, with the condition that (1) when the repair, replacement, or routine servicing of a pump may have affected a reference curve, the licensee must determine a new reference curve, or reconfirm an existing reference curve, in accordance with Section 3 of Code Case OMN-9; and (2) if it is necessary or desirable, for some reason other than that stated in Section 4 of Code Case OMN-9, to establish an additional reference curve or set of curves, the licensee must determine the new curves in accordance with Section 3 of Code Case OMN-9. Please discuss how these conditions will be implemented when utilizing Code Case OMN-9 as requested in Relief Requests 6,7, and 83 Please verify that the comprehensive pump test will be performed within plus or minus 20 percent of pump design flow as required by ISTB.

Res~onseto RAI 1:

In Relief Requests 6, 7 , and 8, Nuclear Management Company, LLC, (NMC) requests NRC approval to follow the provisions of Code Case OMN-9 for pump testing including the requirements of Section 3 of Code Case OMN-9. Through these Relief Requests NMC proposes to use a reference curve in lieu of a reference point for pump testing.

NMC does not request relief from the ISTB-5223, "Comprehensive Test Procedure",

requirement for performing the test within plus or minus 20 percent of pump design flow.

NRC RAI 2 Relief Request # I 1 states the valves will be disassembled, manually stroke exercised and inspected once each fuel cycle. Will the valves be inspected each cycle on a refueling outage frequency (i.e., 18 months)? Please provide a qualitative or quantitative discussion of the risk associated with testing the check valves on line versus during an outage. Please provide an overview of the program controlling on line maintenance. Please provide a time estimate to perform the valves inspection and the technical specifications allowed outage time. If the inspection is to be performed in conjunction with other maintenance activities please provide a time estimate to perform the other maintenance activities and discuss whether the valve inspection will impact the work window duration.

Response to RAI 2:

This question relates to Cooling Water (CL) System pump discharge check valves. The CL System is a shared system common to both units. During normal operation, and a normal shutdown, the CL System provides a heat sink for the removal of process and Page 1 of 2

IST RAI Response operating heat from various safety related and non-safety related components.

The CL System consists of a common CL pump discharge header for the five CL (2 non-safeguards horizontal motor driven pumps, 2 vertical diesel driven safeguards pumps, 1 vertical motor driven pump that can be designated as safeguards or non-safeguards) pumps that directs flow into two separate, 100% capacity, CL headers.

Each header then supplies loops in the turbine and auxiliary buildings and containments for the two units. Thus, there are two Technical Specification (TS) required CL trains which supply the needs of both units with each train consisting of one safeguards pump, one header and the associated piping and instrumentation.

The vertical motor driven pump (121) may be directed to supply either CL header when aligned in its safeguards mode of operation. In this case, the vertical motor driven pump (121) may replace a vertical diesel driven pump (12 or 22).

NMC plans to perform CL pump preventive maintenance each operating cycle and proposes via Relief Request # I 1 to perform the CL pump discharge check valve testing when preventive maintenance is performed on the associated pump.

Since there are two CL trains which provide the required cooling for both units during plant operation and shutdown, there is no benefit to perform required testing during a refueling outage. Due to the design flexibility provided by three safeguards pumps, there is no need to perform maintenance or testing during a refueling outage. Each safeguards CL pump can be removed from service to perform preventive maintenance while the other two safeguards pumps continue to provide the required cooling. Both trains remain fully operable and no TS Condition is entered while the maintenance is performed. Thus, performance of the CL pump discharge valve testing online does not incur additional risk compared to performance of the testing during a refueling outage.

lnspection of the diesel driven safeguards CL pump discharge valves generally requires 4 to 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> to perform. lnspection of the vertical motor driven CL pump discharge valve generally requires 5 to 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> to perform. These inspections are performed concurrent with the associated CL pump preventive maintenance. As explained above, since the vertical motor driven CL pump can substitute for the diesel driven safeguards pump on either train, the TS Limiting Condition for Operation (LCO) is met during the discharge valve inspections and no TS Condition is entered. Thus there are no TS Completion Time (allowed outage time) limitations.

The diesel driven CL pump preventive maintenance generally takes between 24 to 96 hours0.00111 days <br />0.0267 hours <br />1.587302e-4 weeks <br />3.6528e-5 months <br /> to complete depending on the scheduled scope of inspection and maintenance activities. The vertical motor driven CL pump preventive maintenance generally takes between 8 to 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br /> depending on the scheduled scope of inspection and maintenance activities. Since the CL pump discharge valves' inspections are performed concurrent with the pump inspection and maintenance activities, and the valve inspection time is less than or equal to the pump inspection and maintenance time, the discharge check valve does not impact the work window duration.

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