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

200 Exelon Way Kennett Square. PA 19348 Exelon Generation www.exeloncorp.com 10 CFR 50.90 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

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 81h day of January 2016.

Respectfully, J~. J t- 4. J y.-

David T. Gudger Manager - Licensing & Regulatory Affairs Exelon Generation Company, LLC : Response to Request for Additional Information : Mark-Up of Proposed Technical Specification and Bases Pages w/attachments cc: USNRC Region I Regional Administrator USNRC Senior Resident Inspector - NMP USNRC Project Manager, NRR - NMP A. L. Peterson, NYSERDA

ATTACHMENT 1 Response to Request for Additional Information

Response to Request for Additional Information Attachment 1 Relocation of Secondary Containment Bypass Leakage Paths Page 1of2 RAI STSB-1:

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 to~ 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 Attachment 1 Relocation of Secondary Containment Bypass Leakage Paths Page 2 of 2 Exelon Response to RAI STSB-1 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 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 10 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. 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 10 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 Secondary Containment Bypass 3.6.1.3 Leakage Valve 3.6 CONTAINMENT SYSTEMS DELETE 3.6.1.3 Primary Containment Isolation Valves Va (PCIVs)

LCO 3.6.1.3 Each PCIV and each non-PCIV llisted in Table 3.6.1.3-1 3 6 1 3-1 shall be OPERABLE.

APPLICABILITY: MODES 1, 2, and 3, When associated instrumentation is required to be OPERABLE per LCO 3.3.6.1, "Primary Containment Isolation Instrumentation."

ACTIONS

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NOTES-----------------------------------------------------------

1. Penetration flow paths may be unisolated intermittently under administrative controls.

2. Separate Condition entry is allowed for each penetration flow 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.

CONDITION REQUIRED ACTION COMPLETION TIME A. -------------NOTE-------------- A.1 Isolate the affected 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> except Only applicable to penetration flow path for main steam penetration flow paths by use of at least line with two or more one closed and PCIVs. de-activated AND

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automatic valve, closed manual valve, 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> for main One or more blind flange, or steam line penetration flow paths check valve with flow with one PCIV through the valve inoperable except due secured.

to leakage not within limit. AND (continued)

NMP2 3.6.1.3-1 Amendment 91

PCIVs 3.6.1.3 SURVEILLANCE REQUIREMENTS (continued)

SURVEILLANCE FREQUENCY SR 3.6.1.3.6 Perform leakage rate testing for each 184 days primary containment purge valve with resilient seals. AND Once within 92 days after opening the valve SR 3.6.1.3.7 Verify the isolation time of each MSIV is In accordance t 3 seconds and d 5 seconds. with the Inservice Testing Program SR 3.6.1.3.8 Verify each automatic PCIV actuates to 24 months the isolation position on an actual or simulated isolation signal.

SR 3.6.1.3.9 Verify a representative sample of reactor 24 months instrumentation line EFCVs actuates to the isolation position on an actual or simulated instrument line break signal.

SR 3.6.1.3.10 Remove and test the explosive squib from 24 months on a each shear isolation valve of the TIP STAGGERED TEST System. BASIS SR 3.6.1.3.11 Verify the leakage rate for the secondary In accordance containment bypass leakage paths is with 10 CFR 50 within the limits of Table 3 3.6.1.3-1 6 1 3-1 when Appendix J pressurized to t 40 psig. Testing Program Plan (continued) the 10 CFR 50 Appendix J Testing Program Plan NMP2 3.6.1.3-12 Amendment 91, 96

PCIVs DELETE 3.6.1.3 Table 3.6.1.3-1 (page 1 of 2)

Secondary Containment Bypass Leakage Paths Leakage Rate Limits VALVE NUMBER PER VALVE LEAK RATE (SCFH) 2MSS*MOV111 1.875 2MSS*MOV112 2MSS*MOV208 0.625 2CMS*SOV74A, B (d) 0.2344 2CMS*SOV75A, B (d) 2CMS*SOV76A, B (d) 2CMS*SOV77A, B (d) 2DER*MOV119 (a) 2DER*RV344 2DER*MOV120 1.25 2DER*MOV130 0.625 2DER*MOV131 2DFR*MOV120 1.875 2DFR*MOV121 (b) 2DFR*RV228 2DFR*MOV139 0.9375 2DFR*MOV140 2WCS*MOV102 2.5 2WCS*MOV112 2FWS*V23A, B 12.0 2FWS*V12A, B 2CPS*AOV104 4.38 2CPS*AOV106 2CPS*AOV105 3.75 2CPS*AOV107 (continued)

(a) The combined leakage rate for these two valves shall be d 1.25 SCFH.

(b) The combined leakage rate for these two valves shall be d 1.875 SCFH.

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.

NMP2 3.6.1.3-14 Amendment 91, 104, 106

DELETE PCIVs 3.6.1.3 Table 3.6.1.3-1 (page 2 of 2)

Secondary Containment Bypass Leakage Paths Leakage Rate Limits VALVE NUMBER PER VALVE LEAK RATE (SCFH) 2CPS*SOV119 0.625 2CPS*SOV120 2CPS*SOV121 2CPS*SOV122 2IAS*SOV164 0.9375 2IAS*V448 2IAS*SOV165 0.9375 2IAS*V449 2GSN*SOV166 (c) 2GSN*V170 2IAS*SOV166 (c) 2IAS*SOV184 2IAS*SOV167 (c) 2IAS*SOV185 2IAS*SOV168 (c) 2IAS*SOV180 2CPS*SOV132 (c) 2CPS*V50 2CPS*SOV133 (c) 2CPS*V51 (c) The combined leak rate for these penetrations shall be d 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.

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.

NMP2 3.6.1.3-15 Amendment 91, 106

PCIVs B 3.6.1.3 B 3.6 CONTAINMENT SYSTEMS Secondary Containment Bypass B 3.6.1.3 Primary Containment Isolation Valves (PCIVs)

Leakage Valves DELETE BASES BACKGROUND The function of the PCIVs and the non-PCIVs llisted in Table 3.6.1.3-1 T 3 6 1 3-1 (2CMS*SOV74A, (2CMS SOV74A 74B, 74B 75A, 75A 75B, 75B 76A, 76A 76B, 77A, 76B 77A 77B), in combination with other accident mitigation and 77B) systems, is to limit fission product release during and following postulated Design Basis Accidents (DBAs) to within DELETE 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)

NMP2 B 3.6.1.3-1 Revision 0

PCIVs B 3.6.1.3 BASES BACKGROUND A two inch bypass line is provided when the primary (continued) containment full flow line to the Standby Gas Treatment (SGT) System is isolated.

Secondary Containment Bypass ss Leakage Valves APPLICABLE The PCIVs P LCO was derived from the assumptions related SAFETY ANALYSES to minimizing nim the loss of reactor coolant inventory, and establishing sh the primary containment boundary during major accidents.s. As part of the primary containment boundary, PCIV (and d non-PCIVs listed in Table 3 3.6.1.3-1) 6 1 3-1) OPERABILITY supports leak tightness of primary containment. tt. Therefore, The the safety analysis of any event requiring isolation of DELETE 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 Secondary (MSLB) (Refs. 2 and 3). In the analysis for each of these Containment Bypass a accidents, it is assumed that PCIVs are either closed or Leakage Valves un function to close within the required isolation time following low event initiation. This ensures that potential pathss to the environment through PCIVs (including primary containment nm purge valves) are minimized. Of the events DELETE analyzed d in References 2 and 3, the LOCA is the most st The Secondary Containment limiting event ven due to radiological consequences. In Bypass Leakage paths addition, the hee non-PCIVs listed in Table 3 3.6.1.3-1 6 1 3-1 are also leakage rate limits are assumed to be closed during the LOCA. The closure time of relocated to the Technical the main steam isolation valves (MSIVs) is a significant Requirements Manual (TRM) variable from a radiological standpoint. The MSIVs are Table 3.6.1-3 and the Alternate required to close within 3 to 5 seconds since the 3 second Source Term (AST) closure clos time is assumed in the MSIV closure (the most severe established leak rate values overpressurization press transient) analysis (Ref. 4) and 5 second are maintained in accordance closure time me is assumed in the MSLB analysis (Ref. 3).

with the 10 CFR 50 Appendix J Likewise, it is assumed assum that the primary containment Testing Program Plan. isolates such that release eleas of fission products to the environment is controlled. d.

The DBA analysis assumes that isolation of the primary containment is complete and leakage terminated, except for the maximum allowable leakage, La, 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)

NMP2 B 3.6.1.3-2 Revision 0

PCIVs B 3.6.1.3 BASES APPLICABLE PCIVs satisfy Criterion 3 of Reference 5.

SAFETY ANALYSES (continued)

LCO PCIVs 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 valves must meet additional Secondary leakage rate requirements. Other PCIV leakage rates are Containment Bypass addressed add by LCO 3.6.1.1, "Primary Containment," as Type B Leakage Valves or C te testing.

This LCO provi provides assurance that the PCIVs will perform their designed safety safe functions to minimize the loss of reactor coolant inventory entor and establish the primary containment boundary durin duringg accidents. In addition, the LCO ensures leakage through the ennon-PCIVs listed in Table 3.6.1.3-1 3 6 1 3-1 are within the limits assumed in the accident analysis.

APPLICABILITY In MODES 1, 2, and 3, a DBA could cause a release of radioactive 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. Certain valves are required to be OPERABLE, however, to prevent inadvertent reactor vessel draindown. These valves are (continued)

NMP2 B 3.6.1.3-3 Revision 0

INSERT Primary Containment Isolation Valves TRM 3.6.1 TRM Table 3.6.1-3 (page 1 of 2)

Secondary Containment Bypass Leakage Paths Leakage Rate Limits VALVE NUMBER VALVE DESCRIPTION PER VALVE LEAK RATE (SCFH)

Main steam drain line 2MSS*MOV111 (inboard) 1.875 2MSS*MOV112 Main steam drain line 2MSS*MOV208 (outboard) 0.625 2CMS*SOV74A, B (d) 0.2344 2CMS*SOV75A, B (d) 4 Post-accident sampling 2CMS*SOV76A, B (d) lines 2CMS*SOV77A, B (d) 2DER*MOV119 Drywell equipment drain (a) 2DER*RV344 lines 2DER*MOV120 1.25 2DER*MOV130 Drywell equipment vent line 0.625 2DER*MOV131 2DFR*MOV120 1.875 Drywell floor drain line 2DFR*MOV121 (b) 2DFR*RV228 2DFR*MOV139 Drywell floor vent line 0.9375 2DFR*MOV140 2WCS*MOV102 RWCU line 2.5 2WCS*MOV112 2FWS*V23A, B Feedwater line 12.0 2FWS*V12A, B 2CPS*AOV104 CPS supply line to drywell 4.38 2CPS*AOV106 2CPS*AOV105 CPS supply line to supp. 3.75 2CPS*AOV107 chamber (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.

NMP2 TRM 3.6-23a TRM Markup provided for information only.

INSERT Primary Containment Isolation Valves TRM 3.6.1 TRM Table 3.6.1.3-1 (page 2 of 2)

Secondary Containment Bypass Leakage Paths Leakage Rate Limits VALVE NUMBER VALVE DESCRIPTION PER VALVE LEAK RATE (SCFH) 2CPS*SOV119 CPS supply line to supp. chamber 0.625 2CPS*SOV120 2CPS*SOV121 2CPS*SOV122 Inst. air to ADS accumulators 2IAS*SOV164 0.9375 2IAS*V448 Inst. air to ADS accumulators 2IAS*SOV165 0.9375 2IAS*V449 N2 purge to TIP index mechanism 2GSN*SOV166 (c) 2GSN*V170 Inst. air to SRV accumulators 2IAS*SOV166 (c) 2IAS*SOV184 Inst. air to drywell 2IAS*SOV167 (c) 2IAS*SOV185 Inst. air to CPS valve in supp.

2IAS*SOV168 chamber (c) 2IAS*SOV180 Inst. air to CPS valve in supp.

2CPS*SOV132 chamber (c) 2CPS*V50 Inst. air to CPS valve in supp.

2CPS*SOV133 chamber (c) 2CPS*V51 (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.

TRM Markup provided for NMP2 TRM 3.6-23b information only.