NMP2L2611, Response to Request for Additional Information by NRR to Support Review of Relocation of Secondary Containment Bypass Leakage Paths Table from Technical Specifications to the Technical Requirements Manual

Response to Request for Additional Information by NRR to Support Review of Relocation of Secondary Containment Bypass Leakage Paths Table from Technical Specifications to the Technical Requirements Manual

ML16008A171
Person / Time
Site:	Nine Mile Point
Issue date:	01/08/2016
From:	David Gudger Exelon Generation Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
CAC MF5900, NMP2L2611
Download: ML16008A171 (15)

Text

Exelon Generation NMP2L2611 January 8, 2016 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Nine Mile Point Nuclear Station, Unit 2 Renewed Facility Operating License No. NPF-69 NRC Docket No. 50-410 200 Exelon Way Kennett Square. PA 19348 www.exeloncorp.com 10 CFR 50.90

Subject:

Response to Request for Additional Information by the Office of Nuclear Reactor Regulation to Support Review of Nine Mile Point Nuclear Station, Unit 2, Relocation of Secondary Containment Bypass Leakage Paths Table from Technical Specifications to the Technical Requirements Manual

References:

1. Letter from J. Barstow (Exelon Generation Company, LLC) to U.S. Nuclear Regulatory Commission, "Relocation of Secondary Containment Bypass Leakage Paths Table from Technical Specifications to the Technical Requirements Manual," dated March 23, 2015. 2. Letter from Brenda Mozafari (Senior Project Manager, U.S Nuclear Regulatory Commission) to Mr. Bryan Hanson (Exelon), "Nine Mile Point Nuclear Station, Unit 2 -Request for Additional Information Regarding (CAC MF5900)," dated December 17, 2015. By letter dated March 23, 2015, (Reference

1) Exelon Generation Company, LLC (Exelon) requested to change the Nine Mile Point Unit 2 (NMP2) Technical Specifications (TS). The proposed amendment request would modify NMP2 TS by relocating the secondary containment bypass leakage paths table from Technical Specifications to the Technical Requirements Manual. On December 8, 2015, the U.S. Nuclear Regulatory Commission (NRC) emailed a draft Request for Additional Information (RAI). On December 11, 2015, a clarification teleconference was held between NRC and Exelon personnel.

The formal RAI (Reference

2) was provided on December 17, 2015. Attachment 1 to this letter contains the NRC's request for additional information immediately followed by Exelon's response.

Exelon has reviewed the information supporting a finding of no significant hazards consideration and the environmental consideration provided to the NRC in Reference

1. The additional U.S. Nuclear Regulatory Commission Response to Request for Additional Information Relocation of Secondary Containment Bypass Leakage Paths January 8, 2016 Page 2 information provided in this response does not affect the bases for concluding that the proposed license amendment does not involve a significant hazards consideration.

Furthermore, the additional information provided in this response does not affect the bases for concluding that neither an environmental impact statement nor an environmental assessment needs to be prepared in connection with the proposed amendment.

There are no commitments contained in this response.

If you should have any questions regarding this submittal , please contact Ron Reynolds at 610-765-5247.

I declare under penalty of perjury that the foregoing is true and correct. Executed on the 8 1 h day of January 2016. Respectfully, 4.J y.-Dav i d T. Gudger Manager -Licensing

& Regulatory Affairs Exelon Generation Company, LLC Attachment 1: Response to Request for Addit i onal Information Attachment 2: Mark-Up of Proposed Technical Specificat i o n and Bases Pages cc: USNRC Region I Regional Administrator USNRC Senior Resident Inspector

-NMP USNRC Project Manager, NRR -NMP A. L. Peterson , NYSERDA w/attachments ATTACHMENT 1 Response to Request for Additional Information Response to Request for Additional Information Relocation of Secondary Containment Bypass Leakage Paths RAI STSB-1: Attachment 1 Page 1of2 In the existing NMP2 TS, Table 3.6.1.3-1 specifies a numerical value tor allowable leakage tor each leakage path in standard cubic feet per hour. Surveillance Requirement (SR) 3.6.1.3.11 states: Verify the leakage rate tor the secondary containment bypass leakage paths is within the limits of Table 3.6.1.3-1 when pressurized 40 psig. The proposed change is deletion of Table 3.6.1.3-1 and revision of SR 3.6.1.3.11 to state: Verify the leakage rate tor the secondary containment bypass leakage paths is within the limits when pressurized to 40 psig. The staff requests additional information to explain why a numerical value limit on the secondary containment bypass leakage is not retained within the proposed SR 3.6.1.3.11 itself. Typically, the safety analysis tor a facility assumes a specific amount of bypass leakage when calculating dose consequences.

This leakage limit is reflected in the TS to ensure operation within the bounds of the safety analysis.

The regulation at 10 CFR 50.36(c)(3) requires TSs to include items in the category of surveillance requirements, which are requirements relating to test, calibration, or inspection to assure that the necessary quality of systems and components is maintained, that facility operation will be within safety limits, and that the Limiting Conditions tor Operations will be met. The leakage limit for the pathways to be considered operable must be specified in the TS. The staff compared the proposed revision of SR 3.6.1.3.11 with the guidance provided in Generic Letter 91-08. The Generic Letter recommended that the limitation on containment leakage rate be revised to state: A combined leakage rate of less than or equal to [0.1 O La] for all penetrations that are secondary containment bypass leakage paths when pressurized to Pa. This requirement has also been retained in the Standard TS. Provide a technical justification tor not retaining a numerical limit on allowable leakage on the secondary containment bypass pathways or propose a change to SR 3.6.1.3.11 to reflect the appropriate limit. If it is proposed to specify the leakage limit in terms of a combined leakage rate, please review LCO 3.6.1.3 Condition D and its associated Required Actions to ensure consistency with the proposed change to SR 3.6.1.3.11.

Response to Request for Additional Information Relocation of Secondary Containment Bypass Leakage Paths Exelon Response to RAI STSB-1 Attachment 1 Page 2 of 2 The secondary bypass leakage paths and limits specified in the current TS Table 3.6.1.3-1 are incorporated into the approved Alternative Source Term (AST) licensing basis for Nine Mile Point Unit 2 (NMP2) for the Loss of Coolant Accident (LOCA) evaluation as submitted in Attachment 7 to License Amendment Request dated May 31, 2007 (Reference

1) and approved by Amendment 125 (Reference 2). These pathways release activity across four different release points; each release point having unique atmospheric dispersion coefficients.

Additionally, each pathway has unique flow and fission product removal characteristics.

As a result of these varying release pathway characteristics, the current approved LOCA AST licensing basis is not configured to transform the multiple leakage limits into a single value for use in the proposed Surveillance Requirement (SR) 3.6.1.3.11.

The revision to SR 3.6.1.3.11 as shown in Attachment 2 reflects that the AST analyzed bypass leakage paths limits are within 10 CFR 50 Appendix J Testing Program Plan leakage criteria.

Reference to the TS Section 5.5.12 1 O CFR 50 Appendix J Testing Program Plan refers directly to the NMP2 AST calculation, which demonstrates that the allowable leak rates found in the current TS Table 3.6.1.3-1 are acceptable.

The TS Table 3.6.1.3-1 will be relocated to the Technical Requirements Manual (TAM) and acceptable leakage values will be maintained by the 10 CFR 50 Appendix J Testing Program Plan. Changes to the allowed leak rates and TAM are performed under the 10 CFR 50.59 process. Attachment 2 to this submittal includes the revised TS and Bases marked-up pages and supersedes the previously submitted Attachment 2 in its entirety.

References:

1. Letter from Kevin J. Nietmann (Nine Mile Point Nuclear Station) to Document Control Desk (U.S. NRC), "License Amendment Request Pursuant to 1 O CFR 50.90: Application of Alternate Source Term," dated May 31, 2007 (ML071580314).

2. Letter from Richard V. Guzman (Senior Project Manager, U.S Nuclear Regulatory Commission) to Mr. Keith J. Polson (Nine Mile Point Nuclear Station), "Nine Mile Point Nuclear Station, Unit 2 -Issuance of Amendment RE: Implementation of Alternative Radiological Source Term (TAC NO. MD5758)," dated May 29, 2008 (ML081230439).

ATTACHMENT 2 Mark-Up of Proposed Technical Specification and Bases Pages TS Pages 3.6.1.3-1, -12, -14 and -15 Bases Pages B3.6.1.3-1 through -3 TRM Pages 3.6-23a and -23b PCIVs 3.6.1.3NMP23.6.1.3-1Amendment 913.6 CONTAINMENT SYSTEMS3.6.1.3Primary Containment Isolation Valves (PCIVs)LCO 3.6.1.3Each PCIV and each non-PCIV listed in Table 3.6.1.3-1 shall be OPERABLE.APPLICABILITY:MODES 1, 2, and 3,When associated instrumentation is required tobe OPERABLE per LCO 3.3.6.1, "Primary Containment Isolation

Instrumentation." ACTIONS---------------------------------------------------------NOTES-----------------------------------------------------------1.Penetration flow paths may be unisolated intermittently under administrative controls.2.Separate Condition entry is allowed for each penetrationflow path.3.Enter applicable Conditions and Required Actions for systems made inoperable by PCIVs.4.Enter applicable Conditions and Required Actions of LCO 3.6.1.1, "Primary Containment," when PCIV leakage results in exceeding overall containment leakage rate acceptance criteria.

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CONDITIONREQUIRED ACTIONCOMPLETION TIMEA.-------------NOTE--------------

Only applicable topenetration flow paths with two or more

PCIVs.

---

One or more penetration flow paths with one PCIV

inoperable except due

to leakage not within

limit.A.1Isolate the affected penetration flow path by use of at least one closed and de-activated

automatic valve, closed manual valve, blind flange, or check valve with flow through the valve

secured.AND 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> except for main steam line AND8 hours for main steam line (continued)listedinTable3613

-1 DELET E Va S econdar y C ontainment B y pass Leaka g e Valv e non-PCIVl l PCIVs 3.6.1.3NMP23.6.1.3-12Amendment 91 , 96SURVEILLANCE REQUIREMENTS (continued)SURVEILLANCEFREQUENCYSR 3.6.1.3.6Perform leakage rate testing for each primary containment purge valve with resilient seals.

184 days AND Once within 92 days after opening the valveSR 3.6.1.3.7Verify the isolation time of each MSIV is 3 seconds and 5 seconds.In accordance with the Inservice Testing ProgramSR 3.6.1.3.8Verify each automatic PCIV actuates to the isolation position on an actual or

simulated isolation signal.

24 monthsSR 3.6.1.3.9Verify a representative sample of reactorinstrumentation line EFCVs actuates to the isolation position on an actual or

simulated instrument line break signal.

24 monthsSR 3.6.1.3.10Remove and test the explosive squib from each shear isolation valve of the TIP

System.24 months on a STAGGERED TEST

BASISSR 3.6.1.3.11Verify the leakage rate for the secondary containment bypass leakage paths is within the limits of Table 3.6.1.3-1 when pressurized to 40 psig.In accordance with 10 CFR 50

Appendix J

Testing Program

Plan (continued) the 10 C FR 50 Appendix J Testin g Pro g ram Pla nTable3613-1 PCIVs 3.6.1.3NMP23.6.1.3-14Amendment 91,104, 106Table 3.6.1.3-1 (page 1 of 2)Secondary Containment Bypass Leakage Paths Leakage Rate LimitsVALVE NUMBERPER VALVE LEAK RATE (SCFH)2MSS*MOV111

2MSS*MOV112 1.8752MSS*MOV2080.625 2CMS*SOV74A, B (d) 2CMS*SOV75A, B (d)

2CMS*SOV76A, B (d)

2CMS*SOV77A, B (d) 0.2344 2DER*MOV1192DER*RV344 2DER*MOV120 (a)1.25 2DER*MOV130 2DER*MOV131 0.625 2DFR*MOV120 2DFR*MOV1212DFR*RV228 1.875 (b)2DFR*MOV139 2DFR*MOV140 0.9375 2WCS*MOV102 2WCS*MOV112 2.52FWS*V23A, B2FWS*V12A, B 12.0 2CPS*AOV104 2CPS*AOV106 2CPS*AOV105 2CPS*AOV107 4.38 3.75 (continued)(a) The combined leakage rate for these two valves shall be 1.25 SCFH.(b) The combined leakage rate for these two valves shall be 1.875 SCFH.

DELETE The information from this Technical Specification section has been relocated to the TRM and maintained in accordance with the 10 CFR 50 Appendix J Testing Program Plan.

PCIVs 3.6.1.3NMP23.6.1.3-15Amendment 91 , 106Table 3.6.1.3-1 (page 2 of 2)Secondary Containment Bypass Leakage Paths Leakage Rate LimitsVALVE NUMBERPER VALVE LEAK RATE (SCFH)2CPS*SOV119 2CPS*SOV120 2CPS*SOV121 2CPS*SOV122 0.6252IAS*SOV164 2IAS*V448 0.93752IAS*SOV165 2IAS*V449 0.9375 2GSN*SOV166 2GSN*V170 (c)2IAS*SOV1662IAS*SOV184 (c)2IAS*SOV1672IAS*SOV185 (c)2IAS*SOV1682IAS*SOV180 (c)2CPS*SOV132 2CPS*V50 (c)2CPS*SOV133 2CPS*V51 (c)(c)The combined leak rate for these penetrations shall be 3.6 SCFH. The assigned leakage rate through a penetration shall be that of the valve with the highest leakage rate in that penetration. However, if a penetration is isolated by one closed and de-activated automatic valve, closed manual valve,or blind flange, the leakage through the penetration shall be the actual pathway leakage.(d)The LCO requirements and leakage rate limit shall apply until such time as a modification eliminates the potential secondary containment bypass leakage path.

DELETE The information from this Technical Specification section has been relocated to the TRM and

maintained in accordance with the 10 CFR 50

Appendix J Testing Program Plan.

PCIVs B 3.6.1.3NMP2B 3.6.1.3-1Revision 0 B 3.6 CONTAINMENT SYSTEMSB 3.6.1.3 Primary Containment Isolation Valves (PCIVs)

BASESBACKGROUNDThe function of the PC IVs and the non-PCIVs listed in Table 3.6.1.3-1(2CMS*SOV74A, 74B, 75A, 75B, 76A, 76B, 77A, and 77B), in combination with other accident mitigation systems, is to limit fission product release during and following postulated Design Basis Accidents (DBAs) to within

limits. Primary containment isolation within the time limits specified for those PCIVs designed to close automatically ensures that the release of radioactive material to the environment will be consistent with the assumptions used in the analyses for a DBA.The OPERABILITY requirements for PCIVs help ensure that an adequate primary containment boundary is maintained during and after an accident by minimizing potential paths to the environment. Therefore, the OPERABILITY requirements provide assurance that the primary containment function assumed in the safety analysis will be maintained. These isolation devices consist of either passive devices or

active (automatic) devices. Manual valves, de-activated automatic valves secured in their closed position (including check valves with flow through the valve secured), blind

flanges (which include plugs and caps as listed in Reference 1), and closed systems are considered passive devices. Check valves, or other automatic valves designed to close without operator action following an accident, are considered active devices. Two barriers in series are provided for each penetration, except for penetrations isolated by excess flow check valves, so that no single credible failure or malfunction of an active component can result in a loss of isolation or leakage that exceeds limits assumed in the safety analysis. One of these barriers may be a closed system.The 12 and 14 inch primary containment purge valves are PCIVs that are qualified for use during all operational conditions. The 12 and 14 inch primary containment purge valves are normally maintained closed in MODES 1, 2, and 3 to ensure the primary containment boundary is maintained.

However, the purge valves may be open when being used for pressure control, inerting, de-inerting, ALARA, or air

quality considerations since they are fully qualified.(continued)listedinTable3613-1 T T DELET E DELET E non-PCIVsl l S econdar y C ontainment B y pass Leaka g e Valves(2CMSSOV74A74B75A75B76A76B77Aand77B)

PCIVs B 3.6.1.3NMP2B 3.6.1.3-2Revision 0 BASESBACKGROUNDA two inch bypass line is provided when the primary(continued)containment full flow line to the Standby Gas Treatment (SGT) System is isolated. APPLICABLEThe PCIVs LCO was derived from the assumptions related SAFETY ANALYSESto minimizing the loss of reactor coolant inventory, and establishing the primary containment boundary during major accidents. As part of the primary containment boundary, PCIV (and non-PCIVs listed in Table 3.6.1.3-1) OPERABILITY supports leak tightness of primary containment. Therefore, the safety analysis of any event requiring isolation of primary containment is applicable to this LCO.The DBAs that result in a release of radioactive material for which the consequences are mitigated by PCIVs are a loss of coolant accident (LOCA) and a main steam line break (MSLB) (Refs. 2 and 3). In the analysis for each of these accidents, it is assumed that PCIVs are either closed or function to close within the required isolation time following event initiation. This ensures that potential paths to the environment through PCIVs (including primary containment purge valves) are minimized. Of the events analyzed in References 2 and 3, the LOCA is the most limiting event due to radiological consequences. In addition, the non-PCIVs listed in Table 3.6.1.3-1 are also assumed to beclosed during the LOCA. The closure time of the main steam isolation valves (MSIVs) is a significant variable from a radiological standpoint. The MSIVs are required to close within 3 to 5 seconds since the 3 second closure time is assumed in theMSIV closure (the most severe overpressurization transient) analysis (Ref. 4) and 5 second closure time is assumed in the MSLB analysis (Ref. 3).

Likewise, it is assumed that the primary containment isolates such that release of fission products to the environment is controlled.The DBA analysis assumes that isolation of the primary containment is complete and leakage terminated, except for the maximum allowable leakage, L a, prior to fuel damage. The single failure criterion required to be imposed in the conduct of unit safety analyses was considered in the original design of the primary containment purge valves.

Two valves in series on each purge line provide assurance that both the supply and exhaust lines could be isolated even if a single failure occurred.(continued)

t. The)t DELET E st In DELET E P nim sh s.d s. d S econdar y C ontainment Bypass Leakage Valves ssLeakageValvesnon-PCIVslistedinTable3613

-1 non-PCIVslistedinTable3613

-1 a un low s nm d ven e he e S econdar y C ontainment B y pass Leaka g e Valves clos press me is assum eleas d d.The S econdar y C ontainment B y pass Leaka g e paths l eaka g e rate limits are re l oca t ed t o th e T ec hni ca l R equirements Manual (TRM)Table 3.6.1-3 and the Alternat e S ource Term (A S T)es t ab li s h ed l ea k r a t e v a l ues a r e m a int a in ed in acco r da n ce with the 10 C FR 50 Appendix J Testin g Pro g ram Plan.

PCIVs B 3.6.1.3NMP2B 3.6.1.3-3Revision 0 BASESAPPLICABLEPCIVs satisfy Criterion 3 of Reference 5.

SAFETY ANALYSES (continued)LCOPCIVs form a part of the primary containment boundary. The PCIV safety function is related to minimizing the loss of reactor coolant inventory and establishing the primary containment boundary during a DBA.The power operated, automatic isolation valves are required to have isolation times within limits and actuate on an

automatic isolation signal. The valves covered by this LCO are listed with their associated stroke times in Ref. 1.The normally closed manual PCIVs are considered OPERABLE when the valves are closed and blind flanges in place, or open under administrative controls. Normally closed automatic PCIVs, which are required by design (e.g., to meet 10 CFR 50 Appendix R requirements) to be de-activated and closed, are considered OPERABLE when the valve is closed and

de-activated. These passive isolation valves and devices are those listed in Reference 1. Purge valves with resilient seals, secondary containment bypass valves, MSIVs, and hydrostatically tested valvesmust meet additional leakage rate requirements. Other PCIV leakage rates are

addressed by LCO 3.6.1.1, "Primary Containment," as Type B or C testing.This LCO provides assurance that the PCIVs will perform their designed safety functions to minimize the loss of reactor coolant inventory and establish the primary containment boundary during accidents. In addition, the LCO ensures leakage through the non-PCIVs listed in Table 3.6.1.3-1 are within the limits assumed in the accident analysis.APPLICABILITYIn MODES 1, 2, and 3, a DBA could cause a release ofradioactive material to primary containment. In MODES 4 and 5, the probability and consequences of these events are reduced due to the pressure and temperature limitations of these MODES. Therefore, most PCIVs are not required to be OPERABLE and the primary containment purge valves are not required to be normally closed in MODES 4 and 5. Certainvalves are required to be OPERABLE, however, to prevent inadvertent reactor vessel draindown. These valves are (continued) non-PCIVslistedinTable 3613-1 add C te provi safe entor durin e g en n S econdar y C ontainment B y pass Leaka g e Valves Primary Containment Isolation ValvesTRM 3.6.1NMP2TRM3.6-23aTRMTable 3.6.1-3(page 1 of 2)Secondary Containment Bypass Leakage Paths Leakage Rate LimitsVALVE NUMBERVALVE DESCRIPTIONPER VALVE LEAK RATE(SCFH)2MSS*MOV111 2MSS*MOV112Main steam drain line(inboard)1.8752MSS*MOV208Main steam drain line(outboard)0.6252CMS*SOV74A, B (d)2CMS*SOV75A, B (d)2CMS*SOV76A, B (d)2CMS*SOV77A, B (d)4 Post-accident sampling lines 0.23442DER*MOV119 2DER*RV3442DER*MOV120Drywell equipment drain lines (a)1.252DER*MOV1302DER*MOV131Drywell equipment vent line0.6252DFR*MOV1202DFR*MOV121 2DFR*RV228Drywell floor drain line 1.875 (b)2DFR*MOV1392DFR*MOV140Drywell floor vent line0.93752WCS*MOV1022WCS*MOV112RWCU line2.52FWS*V23A, B2FWS*V12A, BFeedwater line12.02CPS*AOV1042CPS*AOV1062CPS*AOV1052CPS*AOV107CPS supply line to drywellCPS supply line to supp.chamber 4.38 3.75 (continued)(a)The combined leakage rate for these two valves shall be1.25 SCFH.(b)The combined leakage rate for these two valves shall be1.875 SCFH.

INSERT TRM Markup provided for information only.

Primary Containment Isolation ValvesTRM 3.6.1NMP2TRM3.6-23bTRMTable 3.6.1.3-1 (page 2 of 2)Secondary Containment Bypass Leakage Paths Leakage Rate LimitsVALVE NUMBERVALVE DESCRIPTIONPER VALVE LEAK RATE(SCFH)2CPS*SOV1192CPS*SOV1202CPS*SOV1212CPS*SOV122CPS supply line to supp. chamber0.6252IAS*SOV164 2IAS*V448Inst.air to ADS accumulators 0.93752IAS*SOV165

2IAS*V449Inst.air to ADS accumulators 0.93752GSN*SOV166 2GSN*V170N2 purge to TIP index mechanism (c)2IAS*SOV166 2IAS*SOV184Inst.air to SRVaccumulators (c)2IAS*SOV167 2IAS*SOV185Inst.air to drywell (c)2IAS*SOV1682IAS*SOV180Inst.air to CPS valve in supp.chamber(c)2CPS*SOV132

2CPS*V50Inst.air to CPS valve in supp.chamber(c)2CPS*SOV133

2CPS*V51Inst.air to CPS valve in supp.chamber(c)(c)The combined leak rate for these penetrations shall be3.6 SCFH. The assignedleakage rate through a penetration shall be that of the valve with the highest leakage ratein that penetration. However, if a penetration is isolated by oneclosed and de-activatedautomatic valve, closed manual valve, or blind flange, the leakage through the penetration shall be the actual pathway leakage.(d)The LCO requirements and leakage rate limit shall apply until such time as amodification eliminates the potential secondary containment bypass leakage path.

INSERT TRM Markup provided for information only.