ML102170184

Response to Request for Additional Information Regarding License Amendment Request for Extended Power Uprate Operation - Reactor System and Health Physics RAI Responses, and Evaluation of Indications in Steam Dryer Hood Support Attachment

ML102170184
Person / Time
Site:	Nine Mile Point
Issue date:	07/30/2010
From:	Belcher S Constellation Energy Group, Nine Mile Point
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
TAC ME1476
Download: ML102170184 (28)

Text

This letter forwards proprietary information in accordance with 10 CFR 2.390. The balance of this letter may be considered non-proprietary upon removal of Attachments 9 through 12.

Sam Belcher P.O. Box 63 Vice President-Nine Mile Point Lycoming, New York 13093 315.349.5200 315.349.1321 Fax CENG a joint venture of 0l Constellation S eDF wEnergy- ,,D NINE MILE POINT NUCLEAR STATION July 30, 2010 U. S. Nuclear Regulatory Commission Washington, DC 20555-0001 ATTENTION: Document Control Desk

SUBJECT:

Nine Mile Point Nuclear Station Unit No. 2; Docket No. 50-410 Response to Request for Additional Information Regarding Nine Mile Point Nuclear Station, Unit No. 2 - Re: The License Amendment Request for Extended Power Uprate Operation (TAC No. ME1476) - Reactor Systems and Health Physics RAI Responses, and Evaluation of Indications in the Steam Dryer Hood Support Attachment

REFERENCES:

(a) Letter from K. J. Polson (NMPNS) to Document Control Desk (NRC), dated May 27, 2009, License Amendment Request (LAR) Pursuant to 10 CFR 50.90:

Extended Power Uprate (b) E-mail from R. Guzman (NRC) to T. H. Darling (NMPNS), dated June 15, 2010, NMP2 EPU Follow-Up RAIs - Reactor Systems (c) E-mail from R. Guzman (NRC) to T. H. Darling (NMPNS), dated July 14, 2010, NMP Unit 2 RAI - License Amendment Request for EPU Operation: Health Physics Review (TAC No. ME1476)

(d) Letter from S. Belcher (NMPNS) to Document Control Desk (NRC), dated June 30, 2010, Response to Request for Additional Information Regarding Nine Mile Point Nuclear Station, Unit No. 2 - Re: The License Amendment Request for Extended Power Uprate Operation (TAC No. ME1476) - Steam Dryer and Probabilistic Risk Assessment Nine Mile Point Nuclear Station, LLC (NMPNS) hereby transmits supplemental information in support of a previously submitted request for amendment to Nine Mile Point Unit 2 (NMP2) Renewed Operating License (OL) NPF-69. The request, dated May 27, 2009 (Reference a), proposed an amendment to This letter forwards proprietary information in accordance with 10 CFR 2.390. The balance of this letter may be considered non-proprietary upon removal of Attachments 9 through 12.

Document Control Desk July 30, 2010 Page 2 increase the power level authorized by OL Section 2.C.(l), Maximum Power Level, from 3467 megawatts-thermal (MWt) to 3988 MWt. By e-mails dated June 15, 2010 and July 14, 2010 (References b and c), the NRC staff provided requests for additional information (RAIs) from the Reactor Systems and Health Physics groups, respectively. The NMPNS responses to those RAIs are provided in Attachments 1 (Non-proprietary) and 9 (Proprietary), with supporting information in Attachments 3 and 10.

In addition, by letter dated June 30, 2010 (Reference d), NMPNS provided responses to NRC RAIs, including a commitment to submit its evaluation and conclusions regarding recently identified indications in the steam dryer hood support attachment by July 30, 2010. Attachment 2 provides a summary of the results of the Structural Integrity Associates, Inc (SIA) evaluation of recently identified indications in the steam dryer hood support attachment (Attachments 4 and 11) and the Continuum Dynamics, Inc. (CDI) design and stress evaluation of NMP2 steam dryer modifications for extended power uprate (EPU) operation (Attachments 5 and 12).

Attachments 9 through 12 are considered to contain proprietary information exempt from disclosure pursuant to 10 CFR 2.390. Therefore, on behalf of GE-Hitachi Nuclear Energy Americas LLC (GEH),

Global Nuclear Fuel - Americas LLC (GNF-A) and CDI, NMPNS hereby makes application to withhold information from public disclosure in accordance with 10 CFR 2.390(b)(1). Affidavits from GEH, GNF-A, and CDI detailing the reason for the requests to withhold the proprietary information are provided in Attachments 6 through 8, respectively.

No new regulatory commitments are identified in this submittal.

Should you have any questions regarding the information in this submittal, please contact J. J. Dosa, Licensing Director (Acting), at (315) 349-5219.

Very truly yours,

Document Control Desk July 30, 2010 Page 3 STATE OF NEW YORK TO WIT:

COUNTY OF OSWEGO I, Sam Belcher, being duly sworn, state that I am the Vice President-Nine Mile Point, and that I am duly authorized to execute and file this response on behalf of Nine Mile Point Nuclear'Station, LLC. To the best of my knowledge and belief, the statements contained in this document are true and correct. To the extent that these statements are not based on my personal knowledge, they are based upon information provided by other Nine Mile Point employees and/or consultants. Such information has been reviewed in accordance with company practice and I believe it to be reliable.

Subscribed and sworn before me, a Notary Public in and for the State of New York and County of (26 this &____ day of ] t 1 2010.

WITNESS my Hand and Notarial Seal: ,-/i Nota e, kulic My Commission Expires:

Date('OswegoTONYA L JONEB Datfy* Nbi b theI 04 State of NewyoN*

My ounty Reg. No. 014* r981*,

My Cohia*n ExpiresmL gl~O Attachments:

1. Responses to Requests for Additional Information Regarding License Amendment Request for Extended Power Uprate Operation (Non-proprietary)

2. Summary of the Structural Integrity Associates, Inc (SIA) Evaluation of Recently Identified Indications in the Steam Dryer Hood Support Attachment and the Continuum Dynamics, Inc. (CDI)

Design and Stress Evaluation of NMP2 Steam Dryer Modifications for EPU Operation (Non-proprietary)

3. Global Nuclear Fuel - Americas LLC, MCNP01A Low Enriched U0 2 Pin Lattice in Water Critical Benchmark Evaluations Using ENDF/B-V Nuclear Cross-Section Data, Revision 1 (Non-proprietary)

4. Structural Integrity Associates, Inc, Flaw Evaluation of Indications in the Nine Mile Point Unit 2 Steam Dryer Vertical Support Plates Considering Extended Power Uprate Flow Induced Vibration Loading (Non-proprietary)

5. Continuum Dynamics, Inc., CDI Report No. 10-12NP, Design and Stress Evaluation of Nine Mile Point Unit 2 Steam Dryer Modifications for EPU Operation (Non-proprietary)

6. Affidavit Justifying Withholding Proprietary Information from GE-Hitachi Nuclear Energy Americas LLC

7. Affidavit Justifying Withholding Proprietary Information from Global Nuclear Fuel - Americas LLC

Document Control Desk July 30, 2010 Page 4

8. Affidavit Justifying Withholding Proprietary Information from Continuum Dynamics, Inc.

9. Responses to Requests for Additional Information Regarding License Amendment Request for Extended Power Uprate Operation (Proprietary)

10. Global Nuclear Fuel - Americas LLC, MCNP01A Low Enriched U0 2 Pin Lattice in Water Critical Benchmark Evaluations Using ENDF/B-V Nuclear Cross-Section Data, Revision 1 (Proprietary)

11. Structural Integrity Associates, Inc, Flaw Evaluation of Indications in the Nine Mile Point Unit 2 Steam Dryer Vertical Support Plates Considering Extended Power Uprate Flow Induced Vibration Loading (Proprietary)

12. Continuum Dynamics, Inc., CDI Report No.10-12P, Design and Stress Evaluation of Nine Mile Point Unit 2 Steam Dryer Modifications for EPU Operation (Proprietary) cc: NRC Regional Administrator, Region I NRC Resident Inspector NRC Project Manager A. L. Peterson, NYSERDA (w/o Attachments 9 through 12)

ATTACHMENT 1 RESPONSES TO REQUESTS FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST FOR EXTENDED POWER UPRATE OPERATION (NON-PROPRIETARY)

Certain information, considered proprietary by GE-Hitachi Nuclear Energy Americas LLC has been deleted from this Attachment. The deletions are identified by double square brackets.

Nine Mile Point Nuclear Station, LLC July 30, 2010

ATTACHMENT 1 RESPONSE TO REQUESTS FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST FOR EXTENDED POWER UPRATE OPERATION (NON-PROPRIETARY)

By letter dated May 27, 2009, as supplemented on August 28, 2009, December 23, 2009 February 19, 2010, April 16, 2010, May 7, 2010, June 3, 2010, June 30, 2010, and July 9, 2010, Nine Mile Point Nuclear Station, LLC (NMPNS) submitted for Nuclear Regulatory Commission (NRC) review and approval, a proposed license amendment requesting an increase in the maximum steady-state power level from 3467 megawatts thermal (MWt) to 3988 MWt for Nine Mile Point Unit 2 (NMP2).

By e-mails dated June 15, 2010 and July 14, 2010, the NRC provided requests for additional information (RAIs) from the Reactor Systems and Health Physics groups, respectively. The NMPNS responses to those RAIs are provided in this Attachment. The NRC request is repeated (in italics), followed by the NMPNS response.

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ATTACHMENT 1 RESPONSE TO REQUESTS FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST FOR EXTENDED POWER UPRATE OPERATION (NON-PROPRIETARY)

RAI HP-1 Provide an analysis demonstrating that there will be continued access to vital areas within the plant (consistent with NUREG 0737 item II.B.2) under EPUaccident conditions. This analysis should include the full mission dose to each vital area necessary during the course of the accident.

NMPNS Response RAI HP-1, Table 1 is a summary of the calculated maximum post-accident total travel doses for the worst case activity for the original licensed thermal power (OLTP) and for operation at extended power uprate (EPU) conditions. The EPU dose is 120% of the OLTP dose; this is based on a post accident dose rate increase attributable to the power level increase. This table demonstrates that these doses are less than the 10 CFR 50, Appendix A limits.

RAI lP-1, Table 1 Maximum Total Travel Dose (REM) for Worst Case Activity (Operator Dispatched from the Operations Support Center (OSC) to the North or South Auxiliary Bay)

OLTP EPU 10 CFR 50, App. A Limit (OLTP Plus 20%)

Gamma 2.76 3.31 5 Thyroid 1.84 2.21 30 Beta 0.28 0.34 30 RAI lIP-1, Table 2 is a summary of the calculated post-accident doses for various tasks in vital access areas for the OLTP and for operation at EPU. The EPU dose is 120% of the OLTP dose; this is based on a post accident dose rate increase attributable to the power level increase. This table demonstrates that these doses are less than the 10 CFR 50, Appendix A limits. The doses for the Main Control Room and Relay and Computer Room and the Technical Support Center (TSC) were calculated for alternative source term at 4067 MWt, which bounds the OLTP and EPU power levels. Therefore, they are applicable for both power levels.

RAI HP-1, Table 2 Doses Associated with Work in Vital Access Areas Gamma Thyroid Beta Gamma Thyroid Beta 10 CFR 50, Appendix. A Limit 5 30 30 5 30 30 Area Task(s) OLTP Dose EPU Dose (OLTP Plus 20%)

Main Control Room Safe Shutdown7 The post-accident doses to personnel in The post-accident doses to personnel in and Relay and the Main Control Room and Relay and the Main Control Room and Relay and Computer Room Computer Room are calculated for Computer Room are calculated for alternative source term. The doses are alternative source term. These doses are less than 5 REM Total Effective Dose applicable to EPU. The doses are less Equivalent (TEDE), which satisifies than 5 REM TEDE, which satisifies the the requirements of 10 CFR 50.67. requirements of 10 CFR 50.67.

Health Physics / Sample Analysis 0.237t2) 186() 3.36I ) 0.284(2) 223.27, 4.0312)

Counting Room 2 of 20

ATTACHMENT 1 RESPONSE TO REQUESTS FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST FOR EXTENDED POWER UPRATE OPERATION (NON-PROPRIETARY)

RAI HP-1. Table 2 Doses Associated with Work in Vital Access Areas Gamma Thyroid Beta Gamma Thyroid Beta 10 CFR 50, Appendix. A Limit 5 30 30 5 30 30 Area Task(s) OLTP Dose EPU Dose(OLTP Plus 20%)

Radwaste Sample Obtain and 1.844 43.57 0.859(9) 1.86(-,4,) 52.2 3(4)

(PASS) Room and Analyze Dilute Unit 1 Chemistry Reactor Coolant Laboratory (RC) Samples Obtain and 2.07 4 33. 0.670(y 2.26,T Analyze Atmosphere Samples Obtain and 0.638(, 85.2,71) 1.68 0.634(, 102. (,7 2.02(4 Analyze Gas in RC Samples Obtain and 4.41 54.7 1.05T4 4.45 64.94,7T 1.267 Analyze Undilute RC Samples Online Isotopic Replace N2 Supply 0.362 1.01 0.00113 0.434 1.21 0.00136 Monitors (Turbine Dewer Building)

Online Isotopic Replace Large N 2 2.44 16.8 0.361 2.93 20.2 0.433 Monitors (Main Supply Dewer and Stack) Refill Sample Cartridge Feed Hopper Manual Sampling 2.73() 32.4(7) 0.650 3.28(') 38.9(7) 0.78 Radwaste Control Turn Off Reactor 0.596 13.7(4) 0.210M) 0.715(T 1_6.4(4) 0.252(4)

Room Building Floor and Equipment Drains Pumps Service 0.805714 26.44 0.404ZT 0.9667 78 Emergency Response Facility (ERF) Computer Technical Support Continuous The post-accident doses to personnel in The post-accident doses to personnel in Center Occupancy To the TSC are calculated for alternative the TSC are calculated for alternative Provide Plant source term for the EPU power. The source term for the EPU power. These Management And doses are less than 5 REM TEDE. doses are applicable to EPU. The doses Technical Support are less than 5 REM TEDE.

To Plant Operations Personnel.

1. Continuous 30 Day occupancy

2. Maximum 8-hour shift

3. Whole body gamma doses

4. Includes doses traveling to and from the Operations Support Center

5. Use a multiplier of 1.009 for liquid reactor coolant sampling and analysis doses.

6. The gamma doses received by personnel performing vital post accident functions are all below the 5 REM limit.

7. Some of the thyroid doses received by personnel performing vital post-accident functions exceed the 30 REM limit.

Therefore the use of breathing apparatus is required. The use of breathing apparatus will provide approximately a factor of 10 reduction in the thyroid doses.

8. The beta doses received by personnel performing vital post accident functions are all below the 30 REM limit.

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ATTACHMENT 1 RESPONSE TO REQUESTS FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST FOR EXTENDED POWER UPRATE OPERATION (NON-PROPRIETARY)

RAI HP-2 Table 2.10-2 lists current annualdose at the NMP2 site boundary. Describe the basisfor the "current" dose numbers listed. Verify that these doses arefor the site boundary location with the maximum dose.

Provide a rationalefor why the combined dose from NMP Unit I and Fitzpatrickplants is less than one third of the NMP2 dose contribution.

NMPNS Response The "current" dose numbers presented in the top portion of Table 2.10-2 of NEDC-33351, Revision 0, Safety Analysis Report for Nine Mile Point Nuclear Station Unit 2 Constant Pressure Power Uprate (LAR Attachments 3 and 11) are from Table 12.4-1 of the NMP2 Updated Safety Analysis Report (USAR).

The doses presented in the top portion of Table 2.10-2 of NEDC-33351, Revision 0, Safety Analysis Report for Nine Mile Point Nuclear Station Unit 2 Constant Pressure Power Uprate (LAR Attachments 3 and 11) are measured doses (from Nine Mile Point Unit 1 (NMP 1) and J. A. Fitzpatrick (JAF) taken in 1985 prior to NMP2 operation) and calculated doses (from NMP2).

The NMP2 doses are calculated at the restricted area boundary at the lake shore. This is considered the location for the maximum dose.

These calculated doses are adjusted for EPU conditions (the waste liners and effluent are based on expected activity and are scaledby 20% and the N-16 contribution (skyshine from the turbine building) is scaled by 30%).

The dose contribution from NMP1 and JAF is smaller than the dose contribution from NMP2 because the NMP1 and JAF dose is a measured value while the NMP2 contribution to the dose is a dose calculation that includes additional conservatisms.

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ATTACHMENT 1 RESPONSE TO REQUESTS FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST FOR EXTENDED POWER UPRATE OPERATION (NON-PROPRIETARY)

RAI HP-3 Provide ajustificationfor using 2004 reportingdatafor offsite doses listed in Table 2.10. These values appear low compared to the 2007 & 2008 NMP2 Effluent Reports (both reported greater than 0.4 millirem (mrem) whole body dose vice the 0.02 mrem listed in Table 2.10).

NMPNS Response The offsite doses from JAF, NMPl and NMP2 that were reported from 2004 through 2009 to the NRC in the Radioactive Effluent Release Reports for CLTP and the corresponding estimated EPU doses, are summarized below. The EPU doses are estimated by scaling the reported doses (1.2 times for skin and maximum organ and 1.3 for whole body). This is conservative because the contributions from NMP1 and JAF are included, whereas the dose from only NMP2 will increase.

Dose Receptor JAF, NMP1 and NMP2 Reported CLTP Doses NMP2 EPU Dose (mrem) Dose, Including JAF and NMP1 Contributions (mrem) 2004 2005 2006 2007 2008 2009 2004-09 Max Whole Body 0.180 1.51 2.01 1.52 0.492 2.76 2.76 3.59 Skin 0.0201 0.0131 0.00938 0.0169 0.00490 0.0202 0.0202 0.0242 Maximum 0.112 0.155 0.0928 0.0932 0.0108 0.146 0.155 0.186 Organ Note: The dose receptor data listed for calendar year 2004 in Table 2.10-2 of the Plant Uprate Safety Analysis Report was not correct. The data values were transposed. This information is corrected in the above table.

The above table supersedes the data regarding reported CLTP doses in Table 2.10-2 of NEDC-33351, Revision 0, Safety Analysis Report for Nine Mile Point Nuclear Station Unit 2 Constant Pressure Power Uprate (LAR Attachments 3 and 11).

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ATTACHMENT 1 RESPONSE TO REQUESTS FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST FOR EXTENDED POWER UPRATE OPERATION (NON-PROPRIETARY)

RAI HP-4 Page 2-366 of the Safety Analysis Report (SAR) indicates that moisture carryover in the steam is estimated to double. Discuss the potential impact of this increased carryover of non-volatile radionuclides (e.g., soluble iodines, and cesiums, and non-soluble activated corrosion and wear products) on dose rates around the balance-of-plantsystems.

NMPNS Response The moisture carryover used to calculate the main steam radiation sources for EPU is 0.1%. This is a factor of 2 increase in the predicted carryover for CLTP of 0.05%.

For the EPU, radiation sources during normal operation are expected to increase slightly; however, this increase is not significant. The change from 0.05% to 0.1% carryover, including soluble iodines, cesiums, non-soluble activated corrosion and wear products, will not have a significant effect on the doses in the plant because the shielding design is conservative. The shielding design is based on radiation sources that are conservative compared to those calculated for EPU based on 0.1% carryover.

As stated in the EPU SAR, shielding aspects of the plant were conservatively designed using design basis activity. The sum of the expected activated corrosion product activity and the fission product activity for EPU remains a small fraction (<12% for water, <15% for steam) of the original total design basis activity.

Thus, the increase in radiation sources does not affect radiation zoning or shielding and plant radiation area procedural controls will compensate for any slight increase in normal radiation sources.

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ATTACHMENT 1 RESPONSE TO REQUESTS FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST FOR EXTENDED POWER UPRATE OPERATION (NON-PROPRIETARY)

RAI FIP-5 Page 2-367 of the SAR indicates that NMP2 has already implemented Hydrogen Water Chemistry (HWC) with noble metal injection. How long has NMP2 been using HWC? Verify that the currentsite boundary doses listed in Table 2.10 reflect the increased N-16 release from the reactor resulting from the associatedhydrogen injection.

NMPNS Response NMP2 implemented HWC and noble metal injection in calendar year 2000. Noble metal injection was developed to make the HWC more efficient and minimize the N-16 increases while providing Intergranular Stress Corrosion Cracking (IGSCC) mitigation. HWC plus noble metal injection for IGSCC mitigation requires on the order of 0.1 - 0.3 parts per million (ppm) 1-H2 in feedwater. This is below the level at which Main Steam Line Radiation Monitor (MSLRM) readings start increasing (as compared to no HWC values). Since the required H2 concentration in the feedwater will not change due to EPU, no increase in N- 16 release due to HWC following EPU implementation is expected.

After noble metal injection at NMP2, the plant experiences an expected period of elevated MSLRM readings:

• Noble metal application was initially performed during a plant shutdown and resulted in a less than 50% increase in MSLRM readings for approximately six months after startup.

• Since 2007, NMP2 has performed online noble metal injection, which mitigates the transient N-16 increase and duration previously seen. After the transient ends in approximately one month, MSLRM readings return to baseline levels. These baseline levels are comparable to the levels that existed prior to HWC and noble metal injection.

This transient is not impacted by EPU conditions, because, as discussed above, the hydrogen concentration will not change due to EPU.

The value of N-16 presented in the top portion of Table 2.10-2 of NEDC-33351, Revision 0, Safety Analysis Report for Nine Mile Point Nuclear Station Unit 2 Constant Pressure Power Uprate (LAR Attachments 3 and 11) was calculated prior to the implementation of HWC and noble metal injection (see response to RAI HP-2). As established above, this value is not impacted by HWC and noble metal injection. In addition, the table in the response to RAI HP-3 provides the actual offsite doses for calendar years 2004 - 2009 (the doses include contributions from HWC and noble metal injection).

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ATTACHMENT 1 RESPONSE TO REQUESTS FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST FOR EXTENDED POWER UPRATE OPERATION (NON-PROPRIETARY)

NMP2-SRXB-RAI-4 Who performed the currentdepletion and criticalityanalyses (GE, Holtec, NETCO, etc.)?

Previous NMPNS Response Provided in NMPNS Letter Dated June 3, 2010 GE/GNF performed the depletion and criticality analyses in 2004 as reflected in Section 2.8.6 of NEDC-3335 1P, Revision 0.

NMPNS Supplemental Information The previous response refers to the technical approach used to address the impact of EPU on spent fuel pool (SFP) criticality relied upon in NEDC-33351, Revision 0, Safety Analysis Report for Nine Mile Point Nuclear Station Unit 2 Constant Pressure Power Uprate (LAR Attachments 3 and 11). This evaluation concluded that EPU did not adversely impact SFP criticality consistent with the GEH Licensing Topical Report for Constant Pressure Power Uprate. It utilized a GEH analysis that was performed for the transition from GEl 1 to GE 14 fuel in 2004 and is consistent with the EPU cores that are being designed with GEl4 fuel. The evaluation concluded that there is no adverse impact on SFP criticality. However, the GEH criticality evaluation is not part of the current licensing basis for the NMP2 spent fuel pool. The Holtec criticality analysis referenced in Section 9.1.2 of the NMP2 Updated Safety Analysis Report (USAR) is the current analysis of record. The Holtec criticality analysis was retained as the analysis of record, because, at the transition to GE 14 fuel, the Holtec criticality analysis already addressed GEl 4 fuel types (as well as earlier fuel types utilized at NMPNS, which were shown to be bounded by GEl4 fuel).

NMPNS will add the GEH criticality analysis utilized in the EPU License Application to Section 9.1.2 of the NMP2 USAR, during the design basis reconciliation for EPU implementation. This will include incorporation of the GEH analysis assumption of a maximum fuel pellet enrichment of 4.9 weight percent (w/o) U-235. This change does not have an impact on the current operation of the SFP, because there is no fuel stored in the NMP2 SFP that has an enrichment greater than 4.9 w/o. NMPNS will also retain the Holtec criticality analysis currently in the USAR as the analysis of record demonstrating that earlier fuel types irradiated under pre-EPU conditions are bounded by GE14 fuel.

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ATTACHMENT 1 RESPONSE TO REQUESTS FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST FOR EXTENDED POWER UPRATE OPERATION (NON-PROPRIETARY)

Follow-up Reactor Systems RAI-1 RegardingNMPNS response to NMP2-SRXB-RAI-5: Please submit the MCNPO1A validation document to support the completion of the NRC staff's safety evaluation and review.

NMPNS Response The MCNP01A validation documentation evaluated 22 critical experiments. The report ("MCNP: Light Water Reactor Critical Benchmarks," GE Nuclear Energy, NEDO-32028) includes a description of the critical experiments and the corresponding MCNP input files. In preparing the response to this question, GE-Hitachi Nuclear Energy Americas LLC (GEH) / Global Nuclear Fuel - Americas LLC (GNF-A) validation of the response included calculations from a file that could not be retrieved by GEH/GNF-A.

However, the MCNP01A validation documentation has been superseded by a more recent and thorough documentation ("MCNP01A Low Enriched U02 Pin Lattice in Water Critical Benchmark Evaluations Using ENDF/B-V Nuclear Cross-Section Data") that incorporates 190 critical experiments. This later, more rigorous, study is now utilized to support the NMP2 EPU analysis (see the response to follow-up Reactor Systems RAI-2).

((I

,3)]

MCNPO1A, Low Enriched U02 Pin Lattice in Water Critical Benchmark Evaluations Using ENDF/B-V Nuclear Cross-Section Data, Revision 1 is provided in Attachments 3 (Non-proprietary) and 10 (Proprietary).

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ATTACHMENT 1 RESPONSE TO REQUESTS FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST FOR EXTENDED POWER UPRATE OPERATION (NON-PROPRIETARY)

Results of 190 Criticality Experiments Expt. Benchmark Experimental MCNP01A Bias

1. Eigenvalue Uncertainty MCNP01A Uncertainty Bias Uncertainty 1 LEU-COMP-THERM-001 1 0.9998 0.0031 d 2 LEU-COMP-THERM-001 2 0.9998 0.0031 3 LEU-COMP-THERM-001 3 0.9998 0.0031 4 LEU-COMP-THERM-001 4 0.9998 0.0031 5 LEU-COMP-THERM-001 5 0.9998 0.0031 6 LEU-COMP-THERM-001 6 0.9998 0.0031 7 LEU-COMP-THERM-001 7 0.9998 0.0031 8 LEU-COMP-THERM-001 8 0.9998 0.0031 9 LEU-COMP-THERM-002 1 0.9997 0.002 10 LEU-COMP-THERM-002 2 0.9997 0.002 11 LEU-COMP-THERM-002 3 0.9997 0.002 12 LEU-COMP-THERM-002 4 0.9997 0.002 13 LEU-COMP-THERM-002 5 0.9997 0.002 14 LEU-COMP-THERM-006 1 1 0.002 15 LEU-COMP-THERM-006 2 1 0.002 16 LEU-COMP-THERM-006 3 1 0.002 17 LEU-COMP-THERM-006 4 1 0.002 18 LEU-COMP-THERM-006 5 1 0.002 19 LEU-COMP-THERM-006 6 1 0.002 20 LEU-COMP-THERM-006 7 1 0.002 21 LEU-COMP-THERM-006 8 1 0.002 22 LEU-COMP-THERM-006 9 1 0.002 23 LEU-COMP-THERM-006 10 1 0.002 24 LEU-COMP-THERM-006 11 1 0.002 25 LEU-COMP-THERM-006 12 1 0.002 26 LEU-COMP-THERM-006 13 1 0.002' 27 LEU-COMP-THERM-006 14 1 0.002 28 LEU-COMP-THERM-006 15 1 0.002 29 LEU-COMP-THERM-006 16 1 0.002 30 LEU-COMP-THERM-006 17 1 0.002 10 of 20

ATTACHMENT 1 RESPONSE TO REQUESTS FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST FOR EXTENDED POWER UPRATE OPERATION (NON-PROPRIETARY)

Results of 190 Criticality Experiments Expt. Benchmark Experimental MCNP01A Bias

1. Eigenvalue Uncertainty MCNP01AUncertainty Bias Uncertainty 31 LEU-COMP-THERM-006 18 1 0.002 32 LEU-COMP-THERM-009 1 1 0.0021 33 LEU-COMP-THERM-009 2 1 0.0021 34 LEU-COMP-THERM-009 3 1 0.0021 35 LEU-COMP-THERM-009 4 1 0.0021 36 LEU-COMP-THERM-009 5 1 0.0021 37 LEU-COMP-THERM-009 6 1 0.0021 38 LEU-COMP-THERM-009 7 1 0.0021 39 LEU-COMP-THERM-009 8 1 0.0021 40 LEU-COMP-THERM-009 9 1 0.0021 41 LEU-COMP-THERM-009 24 1 0.0021 42 LEU-COMP-THERM-009 25 1 0.0021 43 LEU-COMP-THERM-009 26 1 0.0021 44 LEU-COMP-THERM-009 27 1 0.0021 45 LEU-COMP-THERM-016 1 1 0.0031 46 LEU-COMP-THERM-016 2 1 0.0031 47 LEU-COMP-THERM-016 3 1 0.0031 48 LEU-COMP-THERM-016 4 1 0.0031 49 LEU-COMP-THERM-016 5 1 0.0031 50 LEU-COMP-THERM-016 6 1 0.0031 51 LEU-COMP-THERM-016 7 1 0.0031 52 LEU-COMP-THERM-016 8 1 0.0031 53 LEU-COMP-THERM-016 9 1 0.0031 54 LEU-COMP-THERM-016 10 1 0.0031 55 LEU-COMP-THERM-016 11 1 0.0031 56 LEU-COMP-THERM-016 12 1 0.0031 57 LEU-COMP-THERM-016 13 1 0.0031 58 LEU-COMP-THERM-016 14 1 0.0031 59 LEU-COMP-THERM-016 18 1 0.0031 60 LEU-COMP-THERM-016 28 1 0.0031 11 of 20

ATTACHMENT 1 RESPONSE TO REQUESTS FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST FOR EXTENDED POWER UPRATE OPERATION (NON-PROPRIETARY)

Results of 190 Criticality Experiments Expt. Benchmark Experimental MCNP01A Bias Experiment # Eigenvalue Uncertainty Uncertainty Bias Uncertainty 61 LEU-COMP-THERM-016 29 1 0.0031 62 LEU-COMP-THERM-016 30 1 0.0031 63 LEU-COMP-THERM-016 31 1 0.0031 64 LEU-COMP-THERM-016 32 1 0.0031 65 LEU-COMP-THERM-034 1 1 0.0047 66 LEU-COMP-THERM-034 2 1 0.0047 67 LEU-COMP-THERM-034 3 1 0.0039 68 LEU-COMP-THERM-034 4 1 0.0039 69 LEU-COMP-THERM-034 5 1 0.0039 70 LEU-COMP-THERM-034 6 1 0.0039 71 LEU-COMP-THERM-034 7 1 0.0039 72 LEU-COMP-THERM-034 8 1 0.0039 73 LEU-COMP-THERM-034 10 1 0.0048 74 LEU-COMP-THERM-034 11 1 0.0048 75 LEU-COMP-THERM-034 12 1 0.0048 76 LEU-COMP-THERM-034 13 1 0.0048

77. LEU-COMP-THERM-034 14 1 0.0043 78 LEU-COMP-THERM-034 15 1 0.0043 79 LEU-COMP-THERM-039 1 1 0.0014 80 LEU-COMP-THERM-039 2 1 0.0014 81 LEU-COMP-THERM-039 3 1 0.0014 82 LEU-COMP-THERM-039 4 1 0.0014 83 LEU-COMP-THERM-039 5 1 0.0014 84 LEU-COMP-THERM-039 6 1 0.0014 85 LEU-COMP-THERM-039 7 1 0.0014 86 LEU-COMP-THERM-039 8 1 0.0014 87 LEU-COMP-THERM-039 9 1 0.0014 88 LEU-COMP-THERM-039 10 1 0.0014 89 LEU-COMP-THERM-039 11 1 0.0014 90 LEU-COMP-THERM-039 12 1 0.0014 12 of 20

ATTACHMENT 1 RESPONSE TO REQUESTS FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST FOR EXTENDED POWER UPRATE OPERATION (NON-PROPRIETARY)

Results of 190 Criticality Experiments Expt. Benchmark Experimental MCNP01A Bias

1. Eigenvalue Uncertainty MCNP01A Uncertainty Bias Uncertainty 91 LEU-COMP-THERM-039 13 1 0.0014 92 LEU-COMP-THERM-039 14 1 0.0014 93 LEU-COMP-THERM-039 15 1 0.0014 94 LEU-COMP-THERM-039 16 1 0.0014 95 LEU-COMP-THERM-039 17 1 0.0014 96 LEU-COMP-THERM-062 1 1 0.0016 97 LEU-COMP-THERM-062 2 1 0.0016 98 LEU-COMP-THERM-062 3 1 0.0016 99 LEU-COMP-THERM-062 4 1 0.0016 100 LEU-COMP-THERM-062 5 1 0.0016 101 LEU-COMP-THERM-062 6 1 0.0016 102 LEU-COMP-THERM-062 7 1 0.0016 103 LEU-COMP-THERM-062 8 1 0.0016 104 LEU-COMP-THERM-062 9 1 0.0016 105 LEU-COMP-THERM-062 10 1 0.0016 106 LEU-COMP-THERM-062 11 1 0.0016 107 LEU-COMP-THERM-062 12 1 0.0016 108 LEU-COMP-THERM-062 13 1 0.0016 109 LEU-COMP-THERM-062 14 1 0.0016 110 LEU-COMP-THERM-062 15 1 0.0016 111 LEU-COMP-THERM-065 1 1 0.0014 112 LEU-COMP-THERM-065 2 0.9999 0.0014 113 LEU-COMP-THERM-065 3 0.9996 0.0015 114 LEU-COMP-THERM-065 4 0.9997 0.0015 115 LEU-COMP-THERM-065 5 1 0.0014 116 LEU-COMP-THERM-065 6 0.9998 0.0014 117 LEU-COMP-THERM-065 7 0.9991 0.0014 118 LEU-COMP-THERM-065 8 1 0.0016 119 LEU-COMP-THERM-065 9 1.0001 0.0015 120 LEU-COMP-THERM-065 10 1.0002 0.0016 13 of 20

ATTACHMENT 1 RESPONSE TO REQUESTS FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST FOR EXTENDED POWER UPRATE OPERATION (NON-PROPRIETARY)

Results of 190 Criticality Experiments Expt. Benchmark Experimental MCNP01A Bias

1. Eigenvalue Uncertainty MCNP01A Uncertainty Bias* Uncertainty 121 LEU-COMP-THERM-065 11 1.0005 0.0016 122 LEU-COMP-THERM-065 12 1 0.0017 123 LEU-COMP-THERM-065 13 1.0001 0.0016 124 LEU-COMP-THERM-065 14 1.0003 0.0016 125 LEU-COMP-THERM-065 15 0.9994 0.0016 126 LEU-COMP-THERM-065 16 0.9998 0.0017 127 LEU-COMP-THERM-065 17 1.0003 0.0016 3)))

128 L[

129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 14 of 20

ATTACHMENT 1 RESPONSE TO REQUESTS FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST FOR EXTENDED POWER UPRATE OPERATION (NON-PROPRIETARY)

Results of 190 Criticality Experiments Expt. Benchmark Experimental MCNP01A Bias Experiment # Eigenvalue Uncertainty MCNP01A Uncertainty Bias Uncertainty 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 15 of 20

ATTACHMENT 1 RESPONSE TO REQUESTS FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST FOR EXTENDED POWER UPRATE OPERATION (NON-PROPRIETARY)

Results of 190 Criticality Experiments Expt. Benchmark Experimental MCNP01A Bias

1. Eigenvalue Uncertainty Uncertainty Bias Uncertainty 181 182 183 184 185 186 187 188 189 190 {3}))

~Bias=Benchmark-MCNPOI1A 16 of 20

ATTACHMENT 1 RESPONSE TO REQUESTS FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST FOR EXTENDED POWER UPRATE OPERATION (NON-PROPRIETARY)

The following figure is a histogram (frequency distribution) of the results of all 190 benchmark eigenvalues treated as a single population sample. The analysis shows that the data passes the normality test (P-value=(( (3}))). The fitted normal curve is shown in red color.

{3)]

The bias and bias uncertainty from the 190 critical experiments were calculated per NUREG/CR-6698 and are incorporated in the response to follow-up Reactor Systems RAI-2.

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ATTACHMENT 1 RESPONSE TO REQUESTS FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST FOR EXTENDED POWER UPRATE OPERATION (NON-PROPRIETARY)

Follow-up Reactor Systems RAI-2 RegardingNMPNS response to NMP2-SRXB-RAI-5." Simply stating that "mflission products benchmarks were not available and thus were not included in the validation set," is not appropriate. Table 12 of NEDC-33374P,Rev. 3, "Safety Analysis Report for Fuel Storage Racks CriticalityAnalysis for ESBWR Plants," addresses the validation gaps associated with fission products and actinides. Address these validationgapsfor NMP2.

NMPNS Response To address the validation gaps associated with the extension of MCNP01A validation to include spent fuel bundles, the negative reactivity contribution of fission products to the cold, in-core peak reactivity statepoint of the spent fuel rack design basis lattice was determined. ((

(3})), is a conservative uncertainty that will be applied to the spent fuel racks studies to cover the isotopic benchmarking validation gap. The table below incorporates the effect of the MCNPO 1A validation gap as well as the depletion uncertainty and the new MCNPO 1A bias and bias uncertainty.

The fuel depletion uncertainty and the benchmarking gap uncertainty were included in the roll-up as bias for additional conservatism.

[1 1]

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ATTACHMENT 1 RESPONSE TO REQUESTS FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST FOR EXTENDED POWER UPRATE OPERATION (NON-PROPRIETARY)

The above table supersedes the data provided in Table 2.8-12 of NEDC-33351, Revision 0, Safety Analysis Report for Nine Mile Point Nuclear Station Unit 2 Constant Pressure Power Uprate (LAR Attachments 3 and 11).

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ATTACHMENT 1 RESPONSE TO REQUESTS FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST FOR EXTENDED POWER UPRATE OPERATION (NON-PROPRIETARY)

Follow-up Reactor Systems RAI-3 Regarding NMPNS response to NMP2-SRXB-RAI-9: Table 12 of NEDC-33374P, Rev. 3, "Safety Analysis Reportfor Fuel Storage Racks CriticalityAnalysis for ESBWR Plants," included a rack sliding bias of approximately 1500 pcm. The NRC staff understands that the ESBWR criticality analysis also assumed a no leakage condition. Pleaseprovide a discussion explaining why the NMP2 analysisdoes not need to accountfor this bias.

NMPNS Response The spent fuel storage racks at NMP2 have neutron poison (Boral) panels on the periphery. The storage rack model for NMP2 is based on an infinite array of storage cells loaded with the most reactive lattice analyzed, and does not incorporate any radial or axial leakage. Due to the presence of external Boral sheathing in the NMP2 storage racks, the model used bounds the rack-sliding configuration. Thus, no bias was added for this accident condition.

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ATTACHMENT 2

SUMMARY

OF THE STRUCTURAL INTEGRITY ASSOCIATES, INC (SIA) EVALUATION OF RECENTLY IDENTIFIED INDICATIONS IN THE STEAM DRYER HOOD SUPPORT ATTACHMENT AND THE CONTINUUM DYNAMICS, INC. (CDI)

DESIGN AND STRESS EVALUATION OF NMP2 STEAM DRYER MODIFICATIONS FOR EPU OPERATION (NON-PROPRIETARY)

Nine Mile Point Nuclear Station, LLC July 30, 2010

ATTACHMENT 2

SUMMARY

OF THE STRUCTURAL INTEGRITY ASSOCIATES, INC (SIA) EVALUATION OF RECENTLY IDENTIFIED INDICATIONS IN THE STEAM DRYER HOOD SUPPORT ATTACHMENT AND THE CONTINUUM DYNAMICS, INC. (CDI) DESIGN AND STRESS EVALUATION OF NMP2 STEAM DRYER MODIFICATIONS FOR EPU OPERATION (NON-PROPRIETARY)

The following provides a summary of the evaluation of the recently identified indications in the steam dryer hood support attachment for the extended power uprate (EPU) conditions. This evaluation applies Revision 4.1 of the Continuum Dynamics Inc.'s (CDI's) Acoustic Circuit Model (ACM) stress analysis results discussed in the Nine Mile Point Nuclear Station, LLC (NMPNS) responses to Requests for Additional Information (RAI) NMP2-EMCB-SD-RAI-6 and NMP2-EMCB-SD-RAI-8 provided in the submittal dated June 30, 2010. The flaw evaluation is included as Attachments 4 and 11.

In addition, the attached CDI Report 10-12 (Attachments 5 and 12) provides' an updated list of modifications required for the steam dryer to meet the 100% margin at EPU conditions. The modifications listed in CDI Report 10-12 supersede the previous list of modifications discussed in CDI Report 09-26 provided as Attachments 5 and 15 in the NMPNS Response to Requests for Additional Information dated December 23, 2009.

Summary:

The structural model predicts that the design weld geometry for the steam dryer hood support attachment has sufficient margin to the fatigue crack endurance limit such that crack initiation from flow induced vibration (FIV) is not predicted by current loads or by EPU loads. The steam dryer inspection performed during the recent refueling outage identified that the as-welded condition at the bottom of the hood supports shows evidence of rework, grinding and fit-up induced biased mean stresses that have created localized regions above the endurance limit. This is consistent with similar cracking at this location documented in BWRVIP-139-A, "Steam Dryer Inspection and Flaw Evaluation Guidelines." The BWRVIP-139-A operating experience (OE) discussion notes "indications are associated with local stress concentration points, but appear to grow only a limited length. The distribution of the crack locations and relatively consistent length of these cracks suggest that they are stable (not growing) and might have resulted from relieving residual fabrication stresses or stresses from initial thermal expansion of the steam dryer."

The cracking at the hood support locations was first detected in April 2010 with the first baseline inspection of this location since the dryer was placed in service in 1.988. This steam dryer was operated at Original Licensed Thermal Power (OLTP) conditions for 6 years before Nine Mile Point Unit 2 (NMP2) implemented the 5% stretch power uprate. NMP2 has operated at 105% OLTP from 1995 through 2010.

The flaw evaluation for this location at Current Licensed Thermal Power (CLTP) conditions predicts that the FIV related stresses are sufficient to propagate a flaw in the location identified in the outer hood locations. The flaw evaluation concludes that crack propagation of approximately 2.25 inches is predicted in a relatively short period of time (months) and that the loading is displacement controlled such that the loads drop significantly as the flaw grows. The maximum observed flaw of less than 2 inches after 22 years of operation (15 years at current 105% stretch power uprate steam flow rates) is consistent with the flaw evaluation and the BWRVIP-139-A assessment of similar OE.

The cracks on the middle and inner hoods are less than /2 inch in length and the cracking orientation is characteristic of the primary initiation mechanism as fabrication. The small cracks and relatively non-uniform orientation indicates non-FIV crack growth early in operation likely dominated by fabrication stresses or thermal loading as the crack initiation mechanism. The results of the shell model stress comparison discussed in CDI Report 10-12 (Attachments 5 and 12) demonstrate that the stress, after 2 1 of 2

ATTACHMENT 2

SUMMARY

OF THE STRUCTURAL INTEGRITY ASSOCIATES, INC (SIA) EVALUATION OF RECENTLY IDENTIFIED INDICATIONS IN THE STEAM DRYER HOOD SUPPORT ATTACHMENT AND THE CONTINUUM DYNAMICS, INC. (CDI) DESIGN AND STRESS EVALUATION OF NMP2 STEAM DRYER MODIFICATIONS FOR EPU OPERATION (NON-PROPRIETARY) shell elements are disconnected (approximately 4 inches), is reduced to one third that of the outer hood which is indicative of displacement-controlled stress.

==

Conclusions:==

The potential crack growth is anticipated to be minor and not affect the integrity of the hood support to ensure margin for EPU service conditions. Repair is warranted to provide robust margin to further crack growth under EPU conditions consistent with the NRC mandated 100% margin to the onset of FIV cracking. As access to the steam dryer is required to complete the hood support repairs, NMPNS will also implement the group 4 repairs previously noted as non-mandatory in the NMPNS submittal dated June 30, 2010.

In the NMPNS submittal dated June 30, 2010, CDI Report 10-11 P identified that with ACM Revision 4.1 loads, additional modifications to the steam dryer are required. It included scoping modifications that demonstrated that NMP2 can meet the NRC mandated 100% margin. The attached CDI Report 10-12 (Attachments 5 and 12) provides an updated list of modifications required for the steam dryer to meet the 100% margin at EPU conditions and associated detailed submodel results. The modifications listed in CDI Report 10-12 supersede the previous list of modifications discussed in CDI Report 09-26 provided as Attachments 5 and 15 in NMPNS Response to Requests for Additional Information dated December 23, 2009.

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