NMP2L2660, License Amendment Request - Safety Limit Minimum Critical Power Ratio Change

License Amendment Request - Safety Limit Minimum Critical Power Ratio Change

ML17307A019
Person / Time
Site:	Nine Mile Point
Issue date:	11/03/2017
From:	Jim Barstow Exelon Generation Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
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ML17307A018	List: NMP2L2660, License Amendment Request - Safety Limit Minimum Critical Power Ratio Change
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NMP2L2660
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PROPRIETARY INFORMATION-WITHHOLD UNDER 10 CFR 2.390 Exelon Generation NMP2L2660 November 3, 2017 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555 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:

License Amendment Request - Safety Limit Minimum Critical Power Ratio Change In accordance with 1 O CFR 50.90, Exelon Generation Company, LLC (Exelon) requests a proposed change to modify Technical Specification (TS) 2.1.1 ("Reactor Core Sls").

The proposed change revises the Safety Limit Minimum Critical Power Ratios (SLMCPRs) due to the cycle specific analysis performed by Global Nuclear Fuel for Nine Mile Point Nuclear Station, Unit 2 (NMP2), Cycle 17.

There are four attachments to this letter. Attachment 1 contains the evaluation of the proposed changes. Attachment 2 provides the marked-up TS page. Attachment 3 (letter from C. Fung (Global Nuclear Fuel) to A. Johnson (Exelon Generation Company, LLC), dated September 25, 2017) specifies the new SLMCPRs for NMP2, Cycle 17. Attachment 3 contains information proprietary to Global Nuclear Fuel. Global Nuclear Fuel requests that the document be withheld from public disclosure in accordance with 1 o CFR 2.390. An affidavit supporting this request is also contained in Attachment 3. Attachment 4 contains a non-proprietary version of the Global Nuclear Fuel document.

The proposed changes have been reviewed by the Nine Mile Point Nuclear Station Plant Operations Review Committee, in accordance with the requirements of the Exelon Quality Assurance Program.

In order to support the upcoming refueling outage in Spring 2018 (N2R16) at NMP2, Exelon requests approval of the proposed amendment by March 19, 2018. Once approved, this amendment shall be implemented prior to startup from the refueling outage. transmitted herewith contains Proprietary Information.

When separated from Attachment 3, this document is decontrolled.

U.S. Nuclear Regulatory Commission License Amendment Request Safety Limit Minimum Critical Power Ratio Change November 3, 2017 Page2 There are no commitments contained within this letter.

In accordance with 1 O CFR 50.91, "Notice for public comment; State consultation,"

paragraph (b), Exelon is notifying the State of New York of this application of license amendment by transmitting a copy of this letter and its attachments to the designated State Official.

Should you have any questions concerning this letter, please contact Ron Reynolds at (610) 765-5247.

I declare under penalty of perjury that the foregoing is true and correct. Executed on the 3rd day of November 2017.

Respectfully, 1J._JJ ¢{___Jr-4----

James Barstow Director - Licensing & Regulatory Affairs Exelon Generation Company, LLC Attachments:

1. Evaluation of Proposed Changes

2. Proposed Technical Specifications Marked-Up Page

3. Proprietary Version of Global Nuclear Fuel Letter

4. Non-Proprietary Version of Global Nuclear Fuel Letter cc:

USNRC Region I, Regional Administrator USNRC Senior Resident Inspector, NMP USNRC Project Manager, NMP A. L. Peterson, NYSERDA (w/o Attachment 3)

ATTACHMENT 1 License Amendment Request Nine Mile Point Nuclear Station, Unit 2 Docket No. 50-41 O EVALUATION OF PROPOSED CHANGES

SUBJECT:

Safety Limit Minimum Critical Power Ratio Change 1.0

SUMMARY

DESCRIPTION 2.0 DETAILED DESCRIPTION

4.0 REGULATORY EVALUATION

4.1 Applicable Regulatory Requirements/Criteria 4.2 Precedent 4.3 No Significant Hazards Consideration 4.4 Conclusions

6.0 REFERENCES

License Amendment Request Safety Limit Minimum Critical Power Ratio Change Docket No. 50-41 O Evaluation of Proposed Changes 1.0

SUMMARY

DESCRIPTION Page 1 of 4 In accordance with 1 O CFR 50.90, Exelon Generation Company, LLC (Exelon) requests a proposed change to modify Technical Specification (TS) 2.1.1 ("Reactor Core Sls").

The proposed change modifies Technical Specification (TS) 2.1.1 ("Reactor Core Sls").

Specifically, this change incorporates revised Safety Limit Minimum Critical Power Ratios (SLMCPRs) due to the cycle specific analysis performed by Global Nuclear Fuel for GE14 and GNF2 fuel types for NMP2, Cycle 17.

2.0 DETAILED DESCRIPTION The proposed change involves revising the SLMCPRs contained in TS 2.1.1 for two recirculation loop operation and single recirculation loop operation. The SLMCPR value for two recirculation loop operation is being changed from ~ 1.15 to~ 1.17. The SLMCPR value for single recirculation loop operation is being changed from ~ 1.15 to~ 1.17. This change supports GE14 and GNF2 fuel types in NMP2 reactor core for Cycle 17.

Marked up TS page 2.0-1, showing the requested changes, is provided in Attachment 2.

3.0 TECHNICAL EVALUATION

The proposed TS change will revise the SLMCPRs contained in TS 2.1.1 for two recirculation loop operation and single recirculation loop operation to reflect the changes in the cycle specific analysis performed by Global Nuclear Fuel for NMP2, Cycle 17.

The new SLMCPRs are calculated using NRG-approved methodologies described in NEDE-24011-P-A, "General Electric Standard Application for Reactor Fuel (GESTAR II)," Revision 25.

A listing of the associated NRG-approved methodologies for calculating the SLMCPRs is provided in Section 3.0 ("Methodology") of Attachment 3.

The SLMCPR analysis establishes SLMCPR values that will ensure that during normal operation and during abnormal operational transients, at least 99.9% of all fuel rods in the core do not experience transition boiling if the limit is not violated. The SLMCPRs are calculated to include cycle specific parameters and, in general, are dominated by two key parameters: 1) flatness of the core bundle-by-bundle MCPR distribution, and 2) flatness of the bundle pin-by-pin power/R-Factor distribution. Information supporting the cycle specific SLMCPRs is included in. That attachment summarizes the methodology, inputs, and results for the change in the SLMCPRs. The NMP2, Cycle 17, core will consist of GE14 and GNF2 fuel types as documented in table 2 of Attachment 3.

No plant hardware or operational changes are required with this proposed change.

License Amendment Request Safety Limit Minimum Critical Power Ratio Change Docket No. 50-41 O Evaluation of Proposed Changes

4.0 REGULATORY EVALUATION

4.1 Applicable Regulatory Requirements/Criteria Page 2 of 4 1 O CFR 50.36, "Technical specifications," paragraph (c)(1 ), requires that power reactor facility TS include safety limits for process variables that protect the integrity of certain physical barriers that guard against the uncontrolled release of radioactivity. The SLMCPR analysis establishes SLMCPR values that will ensure that during normal operation and during abnormal operational transients, at least 99.9% of all fuel rods in the core do not experience transition boiling if the limit is not violated. Thus, the SLMCPR is required to be contained in TS.

4.2 Precedent The NRC has previously approved SLMCPR changes for several BWR plants with a core composition of GE14 and GNF2 fuel including NMP2:

1)

Letter from B. Mozafari (U.S. Nuclear Regulatory Commission) to B. Hanson (Exelon),

"Nine Mile Point Nuclear Station, Unit 2 - Issuance of Amendment RE: Technical Specifications for Safety Limit Minimum Critical Power Ratio (CAC NO. MF6714)," dated January 5, 2016.

2)

Letter from R. Martin (U.S. Nuclear Regulatory Commission) to C. R. Pierce (Southern Nuclear Operating Company, Inc.), "Edwin I. Hatch Nuclear Plant, Unit No. 2, Issuance of Amendment Regarding Minimum Critical Power Ratio (TAC NO. MF4588)," dated February 18, 2015.

3)

Letter from P. Bamford (U.S. Nuclear Regulatory Commission) to M. J. Pacilio (Exelon Generation Company, LLC), "Limerick Generating Station, Unit 2 - Issuance of Amendment RE: Safety Limit Minimum Critical Power Ratio Changes (TAC NO.

ME5182)," dated April 5, 2011.

4)

Letter from J. Hughey (U.S. Nuclear Regulatory Commission) to M. J. Pacilio (Exelon Generation Company, LLC), "Peach Bottom Atomic Power Station, Unit 2 - Issuance of Amendment RE: Safety Limit Minimum Critical Power Ratio Value Change (TAC NO.

ME3994)," dated September 28, 2010.

4.3 No Significant Hazards Consideration Exelon Generation Company, LLC (Exelon) has evaluated whether or not a significant hazards consideration is involved with the proposed amendment by focusing on the three standards set forth in 1 O CFR 50.92, "Issuance of amendment," as discussed below:

1.

Does the proposed amendment involve a significant increase in the probability or consequences of an accident previously evaluated?

Response: No.

License Amendment Request Safety Limit Minimum Critical Power Ratio Change Docket No. 50-41 O Evaluation of Proposed Changes Page 3 of 4 The derivation of the cycle specific Safety Limit Minimum Critical Power Ratios (SLMCPRs) for incorporation into the Technical Specifications (TS), and their use to determine cycle specific thermal limits, has been performed using the methodology discussed in NEDE-24011-P-A, "General Electric Standard Application for Reactor Fuel," Revision 25.

The basis of the SLMCPR calculation is to ensure that during normal operation and during abnormal operational transients, at least 99.9% of all fuel rods in the core do not experience transition boiling if the limit is not violated. The new SLMCPRs preseNe the existing margin to transition boiling.

The MCPR safety limit is reevaluated for each reload using NRG-approved methodologies. The analyses for NMP2, Cycle 17, have concluded that a two-recirculation loop MCPA safety limit of ~ 1.17, based on the application of Global Nuclear Fuel's NRG-approved MCPR safety limit methodology, will ensure that this acceptance criterion is met. For single recirculation loop operation, a MCPR safety limit of ~ 1.17 also ensures that this acceptance criterion is met. The MCPR operating limits are presented and controlled in accordance with the NMP2 Core Operating Limits Report (COLA).

The requested TS changes do not involve any plant modifications or operational changes that could affect system reliability or performance or that could affect the probability of operator error. The requested changes do not affect any postulated accident precursors, do not affect any accident mitigating systems, and do not introduce any new accident initiation mechanisms. Therefore, the proposed TS changes do not involve a significant increase in the probability or consequences of an accident previously evaluated.

2.

Does the proposed amendment create the possibility of a new or different kind of accident from any accident previously evaluated?

Response: No.

The SLMCPR is a TS numerical value, calculated to ensure that during normal operation and during abnormal operational transients, at least 99.9% of all fuel rods in the core do not experience transition boiling if the limit is not violated. The new SLMCPRs are calculated using NRG-approved methodology discussed in NEDE-24011-P-A, "General Electric Standard Application for Reactor Fuel," Revision 25. The proposed changes do not involve any new modes of operation, any changes to setpoints, or any plant modifications. The proposed revised MCPR safety limits have been shown to be acceptable for Cycle 17 operation. The core operating limits will continue to be developed using NRG-approved methods. The proposed MCPR safety limits or methods for establishing the core operating limits do not result in the creation of any new precursors to an accident. Therefore, this change does not create the possibility of a new or different kind of accident from any previously evaluated.

License Amendment Request Safety Limit Minimum Critical Power Ratio Change Docket No. 50-410 Evaluation of Proposed Changes Page 4 of 4

3.

Does the proposed amendment involve a significant reduction in a margin of safety?

Response: No.

There is no significant reduction in the margin of safety previously approved by the NRC as a result of the proposed change to the SLMCPRs. The new SLMCPRs are calculated using methodology discussed in NEDE-24011-P-A, "General Electric Standard Application for Reactor Fuel," Revision 25. The SLMCPRs ensure that during normal operation and during abnormal operational transients, at least 99.9% of all fuel rods in the core do not experience transition boiling if the limit is not violated, thereby preserving the fuel cladding integrity. Therefore, the proposed TS changes do not involve a significant reduction in the margin of safety previously approved by the NRC.

Based on the above, Exelon concludes that the proposed amendment does not involve a significant hazards consideration under the standards set forth in 10 CFR 50.92(c), and, accordingly, a finding of no significant hazards consideration is justified.

4.4 Conclusions In conclusion, based on the considerations discussed above, (1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.

5.0 ENVIRONMENTAL CONSIDERATION

A review has determined that the proposed amendment would change a requirement with respect to installation or use of a facility component located within the restricted area, as defined in 1 O CFR 20, or would change an inspection or surveillance requirement. However, the proposed amendment does not involve (i) a significant hazards consideration, (ii) a significant change in the types or significant increase in the amounts of any effluent that may be released offsite, or (iii) a significant increase in individual or cumulative occupational radiation exposure. Accordingly, the proposed amendment meets the eligibility criterion for categorical exclusion set forth in 10 CFR 51.22(c)(9). Therefore, pursuant to 10 CFR 51.22(b), no environmental impact statement or environmental assessment need be prepared in connection with the proposed amendment.

6.0 REFERENCES

1) NEDE-24011-P-A, "General Electric Standard Application for Reactor Fuel," Revision 25.

ATTACHMENT 2 License Amendment Request Nine Mile Point Nuclear Station, Unit 2 Docket No. 50-410 PROPOSED TECHNICAL SPECIFICATION MARKED-UP PAGE Revised TS Page 2.0-1

2.0 SAFETY LIMITS (SLs) 2.1 SLs 2.1.1 Reactor Core SLs 1.17 2.1.1.1 With the reactor steam dome pressure < 700 psia or core flow < 10% rated core flow:

THERMAL POWER shall be :;; 23% RTP.

2.1.1.2 With the reactor steam dome pressure ;:: 700 psia and core flow;:: 10% rated core flow~

CPR shall be ;:: 1-:45-f&: two recirculation loop operation for single recirculation loop operation.

2.1.1.3 Reactor vessel water level shall be greater than the top of active irradiated fuel.

2.1.2 Reactor Coolant System Pressure SL Reactor steam dome pressure shall be :;; 1325 psig.

2.2 SL Violations With any SL violation, the following actions shall be completed within 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />s:

2.2.1 Restore compliance with all SLs; and 2.2.2 Insert all insertable control rods.

SLs 2.0 NMP2 2.0-1 Amendment91, 105, 112, 140, 151, 15J, 164

ATTACHMENT 4 License Amendment Request Nine Mile Point Nuclear Station, Unit 2 Docket No. 50-410 NON-PROPRIETARY VERSION OF GLOBAL NUCLEAR FUEL LETTER

September 2017 GNF-004N4798-RO-NP PLM Specification 004N4 798 RO Non-Proprietary Information - Class I (Public)

GNF Additional Information Regarding the Requested Changes to the Technical Specification SLMCPR Nine Mile Point Unit 2Cycle17 Copyright 2017 Global Nuclear Fuel-Americas, LLC All Rights Reserved

GNF-004N4 798-RO-NP Non-Proprietary Information - Class I (Public)

Information Notice This is a non-proprietary version of the document GNF-004N4798-RO-P, which has the proprietary information removed.

Portions of the document that have been removed are indicated by an open and closed bracket as shown here ((

)).

Important Notice Regarding Contents of this Report Please Read Carefully The design, engineering, and other information contained in this document is furnished for the purpose of providing information regarding the requested changes to the Technical Specification SLMCPR for Exelon Corporation Nine Mile Point Unit 2. The only undertakings of GNF-A with respect to information in this document are contained in the contract between GNF-A and Exelon Corporation, and nothing contained in this document shall be construed as changing that contract. The use of this information by anyone other than Exelon Corporation, or for purposes other than those for which it is intended, is not authorized; and with respect to any unauthorized use, GNF-A makes no representation or warranty, and assumes no liability as to the completeness, accuracy, or usefulness of the information contained in this document.

Information Notice Page 2of13

GNF-004N4 798-RO-NP Non-Proprietary Information - Class I (Public)

Table of Contents 1.0 Summary.............................................................................................................................. 4 2.0 Regulatory Basis.................................................................................................................. 4 3.0 Methodology........................................................................................................................ 4 3.1.

Methodology Restrictions................................................................................................. 5 4.0 Discussion............................................................................................................................. 6 4.1.

Major Contributors to SLM CPR Change.......................................................................... 6 4.2.

Deviations from Standard Uncertainties............................................................................ 6 4.2.1.

R-Factor...................................................................................................................... 7 4.2.2.

Flow Area Uncertainty................................................................................................ 7 4.2.3.

Fuel Axial Power Shape Penalty................................................................................. 7 4.3.

Additional SLM CPR Licensing Conditions...................................................................... 8 5.0 References............................................................................................................................ 9 List of Tables Table 1. Monte Carlo SLM CPR.................................................................................................. 11 Table 2. Description of Core........................................................................................................ 12 Table 3. Deviations from Standard Uncertainties........................................................................ 13 Table of Contents Page 3of13

1.0 Summary GNF-004N4 798-RO-NP Non-Proprietary Information - Class I (Public)

The requested changes to the Technical Specification (TS) Safety Limit Minimum Critical Power Ratio (SLMCPR) values are 1.17 for both Two Loop Operation (TLO) and Single Loop Operation (SLO) for Nine Mile Point Unit 2 Cycle 17. Additional details are provided in Table 1.

The primary reason for the change is that the core bundle-by-bundle Minimum Critical Power Ratio (MCPR) distribution is flatter than the limiting case in the previous cycle. The flatter distribution is a result of a different core loading strategy being used for Cycle 17.

2.0 Regulatory Basis 10 Code of Federal Regulations (CFR) 50.36(c)(l), "Technical Specifications," requires that power reactor facility TS include safety limits for process variables that protect the integrity of certain physical barriers that guard against the uncontrolled release of radioactivity. The fuel cladding is one of the physical barriers that separate the radioactive materials from the environment. The SLMCPR analysis establishes SLMCPR values that will ensure that during normal operation and during abnormal operational transients, at least 99.9% of all fuel rods in the core do not experience transition boiling if the limit is not violated. Thus, the SLMCPR is required to be contained in TS.

General Design Criterion (GDC) 10, "Reactor Design," of Appendix A to 10 CFR 50 states that the reactor core and associated coolant, control, and protection systems shall be designed with appropriate margin to assure that the Specified Acceptable Fuel Design Limits (SAFDLs) are not exceeded during any condition of normal operation, including the effects of anticipated operational occurrences.

Guidance on the acceptability of the reactivity control systems, the reactor core, and fuel system design is provided in NUREG-0800, "Standard Review Plan [SRP] for the Review of Safety Analysis Reports for Nuclear Power Plants." Specifically, SRP, Section 4.2, "Fuel System Design," specifies all fuel damage criteria for evaluation of whether fuel designs meet the SAFDLs. SRP Section 4.4, "Thermal Hydraulic Design," provides guidance on the review of thermal-hydraulic design in meeting the requirement of GDC 10 and the fuel design criteria established in SRP Section 4.2.

3.0 Methodology GNF performs SLM CPR calculations in accordance with NEDE-24011-P-A "General Electric Standard Application for Reactor Fuel, (GEST AR II)" (Reference l) for plants such as Nine Mile Point Unit 2 that are equipped with the GNF 3DMonicore core monitoring system, by Summary Page 4of13

GNF-004N4 798-RO-NP Non-Proprietary Information - Class I (Public) usmg the following Nuclear Regulatory Commission (NRC)-approved methodologies and uncertainties:

NEDC-32601P-A, "Methodology and Uncertainties for Safety Limit MCPR Evaluations" (Reference 2).

NEDC-32694P-A, "Power Distribution Uncertainties for Safety Limit MCPR Evaluations" (Reference 3).

NEDC-32505P-A, "R-Factor Calculation Method for GEl 1, GE12 and GE13 Fuel" (Reference 4).

These methodologies were used for the Nine Mile Point Unit 2 Cycle 16 and Cycle 17 SLMCPR calculations.

3.1.

Methodology Restrictions Four restrictions were identified on page 3 of NRC's Safety Evaluation (SE) relating to the General Electric (GE) Licensing Topical Reports (LTRs) NEDC-32601P, NEDC-32694P, and Amendment 25 to NEDE-24011-P-A (Reference 5).

The four restrictions were addressed for GE 14 in FLN-2001-016, "Confirmation of 1Ox10 Fuel Design Applicability to Improved SLMCPR" (Reference 6), and FLN-2001-17, "Power Distribution and R-Factor Methodologies" (Reference 7).

The following statement was extracted from the generic compliance report for the GNF2 fuel assembly design (Reference 8) that GNF sent to the NRC in March of 2007:

"The NRC Safety Evaluation (SE) for NEDC-32694P-A provides four actions to follow whenever a new fuel design is introduced. These four conditions are listed in Section 3 of the SE. In the last paragraph of Section 3.2.2 of the Technical Evaluation Report included in the SE are the statements "GE has evaluated this effect for the 8x8, 9x9, and lOxlO lattices and has indicated that the R-Factor uncertainty will be increased... to account for the correlation of rod power uncertainties" and "it is noted that the effect of the rod-to-rod correlation has a significant dependence on the fuel lattice (e.g., 9x9 versus l Ox l 0). Therefore, in order to insure the adequacy of the R-Factor uncertainty, the effect of the correlation of rod power calculation uncertainties should be reevaluated when the NEDC-32601P methodology is applied to a new fuel lattice." Therefore, the definition of a new fuel design is based on the lattice array dimensions (e.g., NxN). Because GNF2 is a lOxlO, and the evaluations in NEDC-32694P-A include 1Oxl0, then these four actions are not applicable to GNF2."

Methodology Page 5of13

GNF-004N4798-RO-NP Non-Proprietary Information - Class I (Public)

In an NRC audit report (Reference 9) for this document, Section 3.4.1 page 59 states:

"The NRC staffs SE of NEDC-32694P-A (Reference 18 of NEDC-33270P) provides four actions to follow whenever a new fuel design is introduced. These four conditions are listed in Section 3.0 of the SE. The analysis and evaluation of the GNF2 fuel design was evaluated in accordance with the limitations and conditions stated in the NRC staffs SE, and is acceptable."

Another methodology restriction is identified on page 4 of the NRC's SE relating to the GE LTR NEDC-32505P (Reference 10). Specifically, it states that "if new fuel is introduced, GENE must confirm that the revised R-Factor method is still valid based on new test data."

NEDC-32505P addressed the GE12 lOxlO lattice design (i.e., how the R-Factor for a rod is calculated based upon its immediate surroundings (fuel rods, water rods or channel wall)).

Validation is provided by the fact that the methodology generates accurate predictions of Critical Power Ratio (CPR) with reasonable bias and uncertainty.

The applicability of the R-Factor method is coupled and documented (along with fuel specific additive constants) with the GEXL correlation development (References 11 and 12), which is submitted as a part of GEST AR II compliance for each new fuel product line.

4.0 Discussion In this discussion, the TLO nomenclature is used for two recirculation loops in operation, and the SLO nomenclature is used for one recirculation loop in operation.

Table 2 provides the description of the current cycle and previous cycle for the reference loading pattern as defined by NEDE-24011-P-A (Reference 1).

4.1.

Major Contributors to SLMCPR Change In general, for a given power-flow state point, the calculated safety limit is dominated by two key parameters: ( l) flatness of the core bundle-by-bundle MCPR distribution, and (2) flatness of the bundle pin-by-pin power/R-Factor distribution. Greater flatness in either parameter yields more rods susceptible to boiling transition and thus a higher calculated SLMCPR. Therefore, the calculated SLMCPR may change whenever there are changes to the core configuration or to the fresh fuel designs. The plant-cycle specific SLM CPR methodology accounts for these factors.

Comparing Nine Mile Point Unit 2 Cycle 17 to Cycle 16, the Cycle 17 core has a much flatter core bundle-by-bundle MCPR distribution. The bundle pin-by-pin power/R-Factor distribution for the Cycle 17 core is not much different from Cycle 16. Consistent with Reference 13, the TLO SLMCPR for rated power I minimum core flow point is analyzed using the larger core flow and random Traversing In-Core Probe (TIP) uncertainties previously applied only to SLO SLMCPR calculations, and a new point at off-rated power I off-rated flow is analyzed with these larger uncertainties.

Discussion Page 6of13

GNF-004N4 798-RO-NP Non-Proprietary Information - Class I (Public) 4.2.

Deviations from Standard Uncertainties Table 3 provides a list of deviations from NRC-approved uncertainties (References 2 and 3).

A discussion of deviations from these NRC-approved values follows; all of which are conservative relative to NRC-approved values.

4.2.1. R-Factor GNF has generically increased the GEXL R-Factor uncertainty from ((

)) to account for an increase in channel bow due to the phenomenon called control blade shadow corrosion-induced channel bow, which is not accounted for in the channel bow uncertainty component of the approved R-Factor uncertainty. Reference 14 technically justifies that a GEXL R-Factor uncertainty of ((

)) accounts for a channel bow uncertainty of up to

((

)). The Nine Mile Point Unit 2 Cycle 17 analysis shows an expected channel bow uncertainty of ((

)), which is bounded by the GEXL R-Factor uncertainty of ((

)).

Thus, the use of a GEXL R-Factor uncertainty of ((

)) adequately accounts for the expected control blade shadow corrosion-induced channel bow. The effect of this change is considered not significant (i.e., < 0.005 increase on SLMCPR).

4.2.2. Flow Area Uncertainty GNF has calculated the flow area uncertainty for GNF2 and GE 14 using the process described in Section 2.7 of Reference 2. It was determined that the flow area uncertainty for GNF2 and GE14 is conservatively bounded by a value of ((

)). Because this is larger than the Reference 2 value of ((

)) the bounding value was used in the SLMCPR calculations. The effect of this change is considered not significant (i.e., < 0.005 increase on SLMCPR).

4.2.3. Fuel Axial Power Shape Penalty The GEXL correlation critical power uncertainty and bias are established for each fuel product line according to a process described in NEDE-24011-P-A (Reference 1).

GNF determined that higher uncertainties and non-conservative biases in the GEXL correlations for certain types of axial power shapes could exist relative to the NRC-approved methodology values (References 15, 16, 17, and 18). The GE 14 and GNF2 product lines are potentially affected in this manner only by Double-Hump (D-H) axial power shapes.

The D-H axial shape did not occur on any of the limiting bundles (i.e., those contributing to the 0.1 % rods susceptible to transition boiling) in the current and/or prior cycle limiting cases.

Therefore, D-H power shape penalties were not applied to the GEXL critical power uncertainty or bias.

Discussion Page 7of13

GNF-004N4 798-RO-NP Non-Proprietary Information - Class I (Public) 4.3.

Additional SLMCPR Licensing Conditions As shown in Table 1, 0.02 has been added to the calculated SLMCPR in accordance with requirements for MELLLA+ applications, as specified in Reference 19.

Discussion Page 8of13

5.0 References GNF-004N4 798-RO-NP Non-Proprietary Information - Class I (Public)

1.

Global Nuclear Fuel, "General Electric Standard Application for Reactor Fuel,"

NEDE-24011-P-A, Revision 25, August 2017.

2.

GE Nuclear Energy, "Methodology and Uncertainties for Safety Limit MCPR Evaluations," NEDC-32601P-A, August 1999.

3.

GE Nuclear Energy, "Power Distribution Uncertainties for Safety Limit MCPR Evaluations," NEDC-32694P-A, August 1999.

4.

GE Nuclear Energy, "R-Factor Calculation Method for GEl l, GE12 and GE13 Fuel,"

NEDC-32505P-A, Revision 1, July 1999.

5.

Letter, Frank Akstulewicz (NRC) to Glen A. Watford (GNF-A) "Acceptance for Referencing of Licensing Topical Reports NEDC-32601P, Methodology and Uncertainties for Safety Limit MCPR Evaluations; NEDC-32694P, Power Distribution Uncertainties for Safety Limit MCPR Evaluation; and Amendment 25 to NEDE-24011-P-A on Cycle-Specific Safety Limit MCPR (TAC Nos. M97490, M99069 and M97491)," MFN-003-099, March 11, 1999.

6.

Letter, Glen A. Watford (GNF-A) to NRC Document Control Desk with attention to R. Pulsifer (NRC), "Confirmation of lOxlO Fuel Design Applicability to Improved

SLMCPR, Power Distribution and R-Factor Methodologies,"

FLN-2001-016, September 24, 2001.

7.

Letter, Glen A. Watford (GNF-A) to NRC Document Control Desk with attention to J. Donoghue (NRC), "Confirmation of the Applicability of the GEXL14 Correlation and Associated R-Factor Methodology for Calculating SLMCPR Values in Cores Containing GE14 Fuel," FLN-2001-017, October 1, 2001.

8.

Letter, Andrew A. Lingenfelter (GNF-A) to NRC Document Control Desk with cc to MC Honcharik (NRC), "GNF2 Advantage Generic Compliance with NEDE-24011 P-A (GESTAR II), NEDC-33270P, March 2007, and GEXL17 Correlation for GNF2 Fuel, NEDC-33292P, March 2007," FLN-2007-011, March 14, 2007.

9.

Memorandum, Michelle C. Honcharik (NRC) to Stacy L. Rosenberg (NRC), "Audit Report for Global Nuclear Fuels GNF2 Advantage Fuel Assembly Design GEST AR II Compliance Audit," September 25, 2008, (ADAMS Accession Number ML08 l 630579).

10.

Letter, Thomas H. Essig (NRC) to Glen A. Watford (GNF-A), "Acceptance for Referencing of Licensing Topical Report NEDC-32505P, Revision 1, 'R-factor References Page 9of13

GNF-004N4 798-RO-NP Non-Proprietary Information - Class I (Public)

Calculation Method for GEl l, GE12 and GE13 Fuel,"' (TAC Nos. M99070 and M95081)," MFN-046-98, January 11, 1999.

11.

Global Nuclear Fuel, "GEXL14 Correlation for GE14 Fuel," NEDC-32851P-A, Revision 5, April 2011.

12.

Global Nuclear Fuel, "GEXL 17 Correlation for GNF2 Fuel," NEDC-33292P, Revision 3, April 2009.

13.

GE Nuclear Energy, "Licensing Topical Report General Electric Boiling Water Reactor Maximum Extended Load Line Limit Analysis Plus," NEDC-33006P-A, Revision 3, June 2009.

14.

Letter, John F. Schardt (GNF-A) to NRC Document Control Desk with attention to Mel B. Fields (NRC), "Shadow Corrosion Effects on SLMCPR Channel Bow Uncertainty," FLN-2004-030, November 10, 2004.

15.

Letter, Glen A. Watford (GNF-A) to NRC Document Control Desk with attention to Joseph E. Donoghue (NRC), "Final Presentation Material for GEXL Presentation -

February 11, 2002," FLN-2002-004, February 12, 2002.

16.

Letter, Glen A. Watford (GNF-A) to NRC Document Control Desk with attention to Alan Wang (NRC), "NRC Technology Update-Proprietary Slides -July 31 -August l, 2002," FLN-2002-015, October 31, 2002.

17.

Letter, Jens G. Munthe Andersen (GNF-A) to NRC Document Control Desk with attention to Alan Wang (NRC), "GEXL Correlation for lOXlO Fuel," FLN-2003-005, May 31, 2003.

18.

Letter, Andrew A. Lingenfelter (GNF-A) to NRC Document Control Desk with cc to MC Honcharik (NRC), "Removal of Penalty Being Applied to GE 14 Critical Power Correlation for Outlet Peaked Axial Power Shapes," FLN-2007-031, September 18, 2007.

19.

GE Hitachi Nuclear Energy, "Licensing Topical Report Applicability of GE Methods to Expanded Operating Domains," NEDC-33173P-A, Revision 4, November 2012, MFN 12-124.

References Page 10of13

Description Off-rated Power Off-rated Core Flow Limiting Cycle Exposure Point Beginning of Cycle (BOC) I EOC Middle of Cycle (MOC) I End of Cycle (EOC)

Cycle Exposure at Limiting 15,000 Point (MWd/STU)

((

Additional SLMCPR Licensing 0.02 Conditions Requested Change to the TS SLM CPR Table 1. Monte Carlo SLMCPR GNF-004N4798-RO-NP Non-Proprietary Information - Class I (Public)

Table 1. Monte Carlo SLMCPR Previous Cycle Limitinl! Cases Rated Rated Rated Off-rated Power Power Power Power Minimum Rated Increased Off-rated Core Flow Core Flow Core Flow Core Flow EOC EOC EOC EOC 15,000 15,000 15,000 14,000 0.02 0.02 0.02 0.02 NIA Current Cycle Limitine: Cases Rated Rated Rated Power Power Power Minimum Rated Increased Core Flow Core Flow Core Flow EOC EOC EOC 14,000 14,000 14,000

))

0.02 0.02 0.02 1.17 (TL0)/1.17 (SLO)

Page 11 of 13

Description Core Rated Power (MWt)

Maximum Flow at Rated Power

(%rated core flow)

Minimum Flow at Rated Power

(% rated core flow)

Number of Bundles in the Core Batch Sizes and Types:

(Number of Bundles in the Core)

Fresh Once-Burnt Twice-Burnt Thrice-Burnt or more Fresh Fuel Batch Average Enrichment (Weight%)

Core Monitoring System Table 2. Description of Core GNF-004N4798-RO-NP Non-Proprietary Information - Class I (Public)

Table 2. Description of Core Previous Cycle 3,988 105 85 764 320 (GNF2) 336 (GE14) 108 (GE14) n/a 4.05 3DMonicore Current Cycle 3,988 105 85 764 296 (GNF2) 320 (GNF2) 148 (GE14) n/a 4.08 3DMonicore Page 12of13

GNF-004N4 798-RO-NP Non-Proprietary Information - Class I (Public)

Table 3. Deviations from Standard Uncertainties Description NRC Approved Value Previous Cycle

+/- (J (%)

Power Distribution Uncertainties GEXL R-Factor

((

))

((

))

Non-Power Distribution Uncertainties Channel Flow Area Variation

((

))

((

))

Table 3. Deviations from Standard Uncertainties Current Cycle

((

))

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))

Page 13of13