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Gnf Additional Information Regarding the Requested Changes to the Technical Specification SLMCPR - Cooper Nuclear Station Cycle 30 (Non-Proprietary)
	ML16120A371
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Site:	Cooper
Issue date:	04/21/2016
From:	; Nebraska Public Power District (NPPD)
To:	; Office of Nuclear Reactor Regulation
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ML16120A367	List: ML16120A370; NLS2016021, Gnf Additional Information Regarding the Requested Changes to the Technical Specification SLMCPR - Cooper Nuclear Station Cycle 30 (Non-Proprietary);
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NLS2016021 Page 1 of 14 Enclosure 1 GNF Additional Information Regarding the Requested Changes to the Technical Specification SLMCPR - Cooper Nuclear Station Cycle 30 (Non-Proprietary)

Cooper Nuclear Station, Docket No. 50,..298, License No. DPR-46

March2016 GNF-OOON6035-Rl-NP PLM Specification OOON6035 RI Non-Proprietary Information - Class I (Public)

GNF Additional Information Regarding the Request~~

.'.r

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GNF-OOON6035-Rl-NP Non-Proprietary Information- Cla.ss I (Public)

Information Notice This is a non-proprietary version of the document GNF-OOON6035-Rl-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 Repo~t 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 Cooper Nuclear Station. The only undertakings of GNF-A with respect to information in this document are contained in the contract between GNF-A and Nebraska Public Power District, and nothing contained in this document shall be construed,,. as changing .that contract. The use of this information by anyone other than Nebraska Public Power Distri,9ts,10r **:.

for purposes other than those for which it is intended is not authorized; and with respect .tq_~.any unauthorized use, GNF-A makes no representation or warranty, and assumes no liapility as to the completeness, accuracy, or usefulness of the information contained in this document.

Information Notice Page 2of13

GNF-OOON6035-Rl-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 SLMCPR Change .......................................................................... 6 4.2. Deviations from Standard Uncertainties ........................ :................................................... 6 4.2.1. R-factor ....................................................................................................................... 6 4.2.2. Core Flow Rate and Random Effective TIP Reading ................................................. 7 4.2.3. Flow Area Uncertainty ................................................................................................ 7 4.2.4. Fuel Axial Power Shape Penalty........................................................................... ,;c** 7 5.0 References ............................................................................................................................. 9 List of Tables Table 1. Monte Carlo SLMCPR .................................................................................................. 11 Table 2. Description of Core ........................................................................................................ 12 Table 3. Deviations from Standard Uncertainties ........................................................................ 13 Table of Contents Page 3of13

GNF-OOON6035-Rl-NP Non-Proprietary Information - Class I (Public) 1.0 Summary The requested changes to the Technical Specification (TS) Safety Limit Minimum Critical Power Ratio (SLMCPR) values are 1.12 for Two-Loop Operation {TLO) and 1.14 for Single Loop Operation (SLO) for Cooper Nuclear Station Cycle 30. Additional details are provided in Table 1.

The primary reason for the change is that in the limiting case the core bundle-by-bundle Minimum Critical Power Ratio (MCPR) distribution is generally flatter than the limiting case in the previous cycle. This difference caused the SLMCPR values to increase.

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 purpose of the SLMCPR is to ensure that Specified Acceptable Fuel D_~~ign Limits (SAFDLs) are not exceeded during steady state .operation and analyzed transients. <:;,

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 SAFDLs are not exceeded.

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 Sy~tem 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 SLMCPR calculations in accordance with NEDE-24011-P-A, "General Electric Standard Application for Reactor Fuel (GESTAR II)" (Reference 1) for plants such as Cooper Nuclear Station*that are equipped with a non-GNF supplied core monitoring system, by using the following Nuclear Regulatory Commission (NRC) approved methodologies and Certainties:

NEDC-32601P-A, "Methodology and Uncertainties for Safety Limit MCPR Evaluations," August 1999. (Reference 2) e NEDE-10958-P A, "General Electric Thermal Analysis Basis Data, Correlation and

summary Page4 of13

GNF-OOON6035-Rl-NP Non-Proprietary Information - Class I (Public)

Design Application," January 1977. (Reference 3)

NEDC-32505P-A, "R-Factor Calculation Method for GE11, GE12 and GE13 Fuel,"

Revision 1, July 1999. (Reference 4)

These methodologies were used for the Cooper Nuclear Station Cycle 29 and Cycle 30 SLMCPR calculations.

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

The four restrictions were addressed for GE14 in FLN-2001-016 "Confirmation of lOxlO 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 GNF4'f 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 uncertaino/ 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 lOxlO). 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 1Oxl0, and the evaluations in NEDC-32694P-A include lOxlO, then these four actions are not applicable to GNF2."

In an NRC audit report (Reference 9) for this document, Section 3.4.l page 59 states:

"The NRC staffs SE of NEDC-32694P-A (Reference 19 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."

Methodology Page 5of13

GNF-OOON6035-Rl-NP Non-Proprietary Information - Class I (Public)

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 GESTAR 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: (1) 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 SLMCPR methodology accounts for these factors.

The Cycle 30 core bundle-by-bundle MCPR distribution is generally flatter than that in Cycle 29, which tends to make the final SLMCPR higher. All of the 0.10% of rods susceptible to boiling transition were from GNF2-type bundles in Cycle 29 and Cycle 30.

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 phenomena called control blade shadow corrosion-induced channel bow, which is* not accounted for in the channel bow uncertainty Discussion Page 6of13

GNF-OOON6035-Rl-NP Non-'"Proprietary Information- Class I (Public) 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 Cooper Nuclear Station Cycle 30 analysis shows an expected channel bow uncertainty of (( _ )), which is bounded by a 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 in SLMCPR).

4.2.2. Core Flow Rate and Random Effective TIP Reading In Reference 14 GNF coinmitted to the expansion of the state points used in the determination of the SLMCPR. Consistent with the Reference 14 commitments, GNF performs analyses at the rated core power and minimum licensed core flow point in addition to analyses at the rated core power and rated core flow point. The approved SLMCPR methodology is applied at each state point that is analyzed.

For the TLO calculations performed at 76.8% core flow, the approved uncertainty values fo;,the core flow rate (2.5%) and the random effective Traversing In-Core Probe (TIP) reading.(l.?,2%)

are conservatively adjusted by dividing them by 76.8/100. . ~,: .. !~f:

The core flow and random TIP reading uncertainties used in the SLO minimum core flow SLMCPR analysis remain the same as in the rated core flow SLO SLMCPR analysis because these uncertainties (which are substantially larger than used in the TLO analysis) already account ' ... ~ .

for the effects of operating at reduced core flow.

4.2.3. Flow Area Uncertainty GNF has calculated the flow area uncertainty for GNF2 and GE14 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 in SLMCPR) ..

4.2.4. 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-apprpved methodology values (References 15, 16, 17, and 18). The GE14 and GNF2 product lines are potentially affected in this manner only by Double-Hump (D-H) axial power shapes.

Discussion Page 7of13

GNF-OOON6035-Rl-NP Non-Proprietary Information - Class I (Public)

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 8of13

GNF-OOON6035-RI-NP Non-Proprietary Information - Class I (Public) 5.0 References I. Global Nuclear Fuel, "General Electric Standard Application for Reactor Fuel,"

NEDE-240I I-P-A, Revision 22, November 20I5.

2. GE Nuclear Energy, "Methodology and Uncertainties for Safety Limit MCPR Evaluations," NEDC-3260IP-A, August I999.

3. General Electric Company, "General Electric Thermal Analysis Basis Data, Correlation and Design Application," NEDE-10958-PA, January I977.

4. GE Nuclear Energy, "R-Factor Calculation Method for GEl I, GEI2 and GE13 Fuel,"

NEDC-32505P-A Revision I, July I999.

5. Letter, Frank Akstulewicz (NRC) to Glen A. Watford (GNF-A), "Acceptance for Referencing of Licensing Topical Reports NEDC-3260 IP, Methodology and Uncertainties for Safety Limit MCPR Evaluations; NEDC-32694P, Power Distribution Uncertainties for Safety Limit MCPR Evaluation; and Amendment 25,, to NEDE-240I I-P-A on Cycle-Specific Safety Limit MCPR (TAC Nos. M97490, M99069 and M9749I)," MFN-003-099, March I I, 1999. -z.,

6. Letter, Glen A. Watford (GNF-A) to NRC Document Control Desk with attention to.R.

Pulsifer (NRC), "Confirmation of IOxlO Fuel Design Applicability to Improved SLMCPR, Power Distribution and R-Factor Methodologies," FLN-200I-OI6, September 24, 200 I.

7. Letter, Glen A. Watford (GNF-A) to NRC Document Control Desk with attention to J. Donoghue (NRC), "Confirmation of the Applicability of the GEXLI4 Correlation-and Associated R-Factor Methodology for Calculating SLMCPR Values in Cores Containing GEI4 Fuel," FLN-2001-0I 7, October I, 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-240IIP-A (GESTAR II), NEDC-33270P, March 2007, and GEXLI 7 Correlation for GNF2 Fuel, NEDC-33292P, March 2007," FLN-2007-011, March I4, 2007.

9. Memorandum, Michelle C. Honcharik (NRC) to Stacy L. Rosenberg (NRC), "Audit Report for Global Nuclear Fuels GNF2 Advantage Fuel Assembly Design GESTAR II Compliance Audit," September 25, 2008. (ADAMS Accession Number ML08I630579)

10. Letter, Thomas H. Essig (NRC) to Glen A. Watford (GNF-A), "Acceptance for Referencing of Licensing Topical Report NEDC-32505P Revision I, R-factor Calculation Method for GEI 1, GE12 and GE13 Fuel, (TAC Nos. M99070 and References Page 9of13

GNF-OOON6035-Rl-NP Non-Proprietary Information - Class I (Public)

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, "GEXLl 7 Correlation for GNF2 Fuel," NEDC-33292P, Revision 3, April 2009.

13. 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.

14. Letter, Jason S. Post (GENE) to NRC Document Control Desk with attention to Chief, Information Management Branch, et al. (NRC), "Part 21 Final Report: Non-Conservative SLMCPR," MFN 04-108, September 29, 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 Presentatj()n .- _,

."l.

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 _1, 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 GE14 Critical Power Correlation for Outlet Peaked Axial Power Shapes," FLN-2007-031, September 18, 2007.

References Page 10of13

GNF-OOON6035-Rl-NP Non-Proprietary Information - Class I (Public)

Table 1. Monte Carlo SLMCPR Previous, Cycle '.

Curre)Jt Cy~ie Limitiqg Cases . ' Lillliting Cases

- - *- -** -*** .* r*-* .. . . .

" ~ . . - - ., ... ...

.. -- -~

.. Rat.ed fower . Rated -Fower Rated -

RatedPqwer }lat~d J>9w~r Rated P¢s~rip,tfon

" : . . -*-, "* ' " ' *~ ~ '

Mi~imum Core lflO"f Core Flow lV(lnhnum ()~re,J,i'low Core Flow Limiting Cycle Exposure Point Beginning of Cycle (BOC) I BOC MOC BOC BOC Middle of Cycle (MOC) I End of Cycle (BOC)

Cycle Exposure at Limiting Point 12000 6500 12000 12000 (MWd/STU) -

((

))

Requested Change to the TS NIA 1.12 (TLO) I 1.14 (SLO)

SLMCPR "

Table 1. Monte Carlo SLMCPR Page 11of13

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Table 2. Descr'iption of Core Descriptio~ P:r~:vjoµs Cy~!~

CurreiB.t Cycle Core Rated Power (MWt) 2419 2419 Minimum Flow at Rated Power 76.8 76.8

(% rated core flow)

Number of Bundles in the Core 548 548 Batch Sizes and Types:

(Number of Bundles in the Core)

Fresh 176 GNF2 184 GNF2 Once-Burnt 180 GNF2 176 GNF2 Twice-Burnt 140GE14 180 GNF2 Thrice-Burnt or more 52 GE14 8GE14 Fresh Fuel 3.91 3.92 Batch Average Enrichment (Weight%)

Core Monitoring System GARDEL (Non-GNF) GARDEL (Non-GNF)

Table 2. Description of Core Page 12of13

GNF-OOON6035-Rl-NP Non-Proprietary Information - Class I (Public)

Table 3. Deviations from Standard Uncertainties NRC Approved* V~lue Description, Previous Cycle Current Cycle

t Q' (%)

Power Distribution Unce:rtainties GEXL R-Factor (( )) (( )) (( ))

Random Effective TIP Reading All TLO Cases at Rated Power and 1.2 1.5625 1.5625 Minimum Flow Non-Power Distribution Uncertainties Channel Flow Area Variation (( )) (( )) (( ))

Total Core Flow Measurement All TLO Cases at Rated Power and 2.5 3.26 3.26 Minimum Flow Table 3. Deviations from Standard Uncertainties Page 13of13

NLS2016021 Page 1 of 14 Enclosure 1 GNF Additional Information Regarding the Requested Changes to the Technical Specification SLMCPR - Cooper Nuclear Station Cycle 30 (Non-Proprietary)

Cooper Nuclear Station, Docket No. 50,..298, License No. DPR-46

March2016 GNF-OOON6035-Rl-NP PLM Specification OOON6035 RI Non-Proprietary Information - Class I (Public)

GNF Additional Information Regarding the Request~~

.'.r