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ANP-3316(NP), Revision 0, Millstone, Unit 2, M5 Upgrade, Realistic Large Break Loca Analysis Licensing Report.
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Issue date:	05/25/2016
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Serial No.16-185 Docket No. 50-336 Attachment 5 ANP-3316(NP), Revision 0 MILLSTONE UNIT 2 MS UPGRADE, REALISTIC LARGE BREAK LOCA ANALYSIS LICENSING REPORT (NON-PROPRIETARY)

DOMINION NUCLEAR CONNECTICUT, INC.

MILLSTONE POWER STATION UNIT 2

A AREVA ANP-3316NP Millstone Unit 2 MS Upgrade, Realistic Revision 0 Large Break LOCA Analysis Licensing Report May2016 AREVA Inc.

AREVA Inc. ANP-3316NP Revision 0 Millstone Unit 2 MS Upgrade, Realistic Large Break LOCA Analysis Licensing Report Page i Nature of Changes Section(s)

Item or Page(s) Description and Justification 1 All Initial Issue

AREVA Inc. ANP-3316NP Revision 0 Millstone Unit 2 M5 Upgrade, Realistic Large Break LOCA Analysis Licensing Report Page ii Contents Page 1.0

SUMMARY

........................................................................................................... 1 2.0 RLBLOCA ANALYSIS .......................................................................................... 3 2.1 Acceptance Criteria ................................................................................... 3 2.2 Description of LBLOCA Event.. .................................................................. 3 2.3 Description of Analytical Models ................................................................ 5 2.4 GDC-35 Limiting Condition Determination ................................................. 8 2.5 Overall Statistical Compliance to Criteria ................................................... 8 2.6 Plant Description and Summary of Analysis Parameters ........................... 8 2.7 SE Limitations ............................................................................................ 9 3.0 REALISTIC LARGE BREAK LOCA RES ULTS ................................................... 11

4.0 CONCLUSION

S ................................................................................................. 14

5.0 REFERENCES

................................................................................................... 15 APPENDIX A:

SUMMARY

OF KEY INPUT AND OUTPUT PARAMETERS ..................................................................................................A-1

AREVA Inc. ANP-3316NP Revision 0 Millstone Unit 2 M5 Upgrade, Realistic Large Break LOCA Analysis Licensing Report Page iii List of Tables Table 1 RLBLOCA Analysis - Plant Parameter Values and Ranges ............................ 16 Table 2 Statistical Distribution Used for Process Parameters ...................................... 19 Table 3 Passive Heat Sinks and Material Properties in Containment Geometry .......... 20 Table 4 Draft SE Limitations Evaluation ....................................................................... 21 Table 5 Compliance with 10 CFR 50.46(b) .................................................................. 25 Table 6 Summary of Major Parameters for the Demonstration Case ........................... 26 Table 7 Calculated Event Times for the Demonstration Case ...................................... 27 Table 8 Heat Transfer Parameters for the Demonstration Case .................................. 28 Table 9 Fuel Rod Rupture Ranges of Parameters ....................................................... 29 Table A-1 Summary of Key Input and Output Parameters, Part 1............................... A-1 Table A-2 Summary of Key Input and Output Parameters, Part 2 ............................. A-10

AREVA Inc. ANP-3316NP Revision 0 Millstone Unit 2 M5 Upgrade, Realistic Large Break LOCA Analysis Licensing Report Page iv List of Figures Figure 1 Scatter Plot Operational Parameters .............................................................. 30 Figure 2 PCT versus PCT Time Scatter Plot.. .............................................................. 31 Figure 3 PCT versus Break Size Scatter Plot.. ............................................................. 32 Figure 4 Maximum Local Oxidation versus PCT Scatter Plot.. ..................................... 33 Figure 5 Total Core Wide Oxidation versus PCT Scatter Plot.. .................................... 34 Figure 6 Peak Cladding Temperature (Independent of Elevation) for the Demonstration Case ................................................................................... 35 Figure 7 Break Flow for the Demonstration Case ........................................................ 36 Figure 8 Core Inlet Mass Flux for the Demonstration Case .......................................... 37 Figure 9 Core Outlet Mass Flux for the Demonstration Case ....................................... 38 Figure 10 Void Fraction at RCS Pumps for the Demonstration Case ........................... 39 Figure 11 ECCS Flows (Includes SIT, HPSI and LPSI) for the Demonstration Case ........................................................................................................... 40 Figure 12 Upper Plenum Pressure for the Demonstration Case .................................. 41 Figure 13 Collapsed Liquid Level in the Downcomer for the Demonstration Case ....... 42 Figure 14 Collapsed Liquid Level in the Lower Plenum for the Demonstration Case ........................................................................................................... 43 Figure 15 Collapsed Liquid Level in the Core for the Demonstration Case .................. 44 Figure 16 Containment and Loop Pressures for the Demonstration Case ................... 45 Figure 17 Pressure Differences between Upper Plenum and Downcomer for the Demonstration Case ................................................................................... 46

- . - --- ~ -* .. --- - -* .

Figure 18 Validation of BOCR Time using MPR CCFL Correlation .............................. 47 Figure 19 [ ] ......................................... 48

AREVA Inc. ANP-3316NP Revision 0 Millstone Unit 2 M5 Upgrade, Realistic Large Break LOCA Analysis Licensing Report Paqev Nomenclature Acronym Definition ASI Axial Shape Index BOCR Beginning of Core Recovery CCFL Counter Current Flow Limiting CE Combustion Engineering CFR Code of Federal Regulations CHF Critical Heat Flux CSAU Code Scaling, Applicability and Uncertainty cwo Core-Wide Oxidation ECCS Emergency Core Cooling System ECR Equivalent Cladding Reacted EM Evaluation Model EMDAP Evaluation Model Development and Assessment Process Fa Total Peaking Factor Fr Nuclear Enthalpy Rise Factor FSRR Fuel Swell Rupture and Relocation GDC General Design Criteria HPSI High Pressure Safety Injection LHGR Linear Heat Generation Rate LPSI Low Pressure Safety Injection * * - * --**

LBLOCA Large Break Loss of Coolant Accident LOCA Loss of Coolant Accident LOOP Loss of Offsite Power MLO Maximum Local Oxidation No-LOOP No Loss of Offsite Power NRG U.S. Nuclear Regulatory Commission PCT Peak Clad Temperature PWR Pressurized Water Reactor

AREVA Inc. ANP-3316NP Revision 0 Millstone Unit 2 MS Upgrade, Realistic Large Break LOCA Analysis Licensing Report Page vi Acronym Definition RCP Reactor Coolant Pump RCS Reactor Coolant System RLBLOCA Realistic Large Break Loss of Coolant Accident SE Safety Evaluation SG Steam Generator SIAS Safety Injection Actuation Signal SIT Safety Injection Tank UTL Upper Tolerance Limit wlo Weight Percent

AREVA Inc. ANP-3316NP Revision 0 Millstone Unit 2 MS Upgrade, Realistic Large Break LOCA Analysis Licensing Report Page vii ABSTRACT This report describes and provides results from the RLBLOCA analysis for the Millstone Unit 2 M5 1 fuel upgrade. The plant is a PWR Combustion Engineering 2x4-loop design with an analyzed thermal power of 2754 MWt (includes power calorimetric uncertainty) and dry atmospheric containment. The loops contain four RCPs, two U-tube steam generators and a pressurizer.

The analysis supports operation for Cycle 25 and beyond with AR EVA's 14x14 CE array with HTP' 2 intermediate grids and a lower HMP' 2 grid. The fuel assembly includes a Zirc-4 MONOBLOC' 2 guide tube design, M5 fuel rod design using standard U0 2 fuel with 2%, 4%, 6%, and 8% Gd 20 3 and FUELGUARD' 2 debris-resistant lower tie-plate design. The analysis performed is the Millstone Unit 2 plant-specific implementation of the AREVA's RLBLOCA EM in Reference 1 and the methodology amendments in References 2 and 3. The analysis results confirm that the 10 CFR 50.46(b), paragraphs (1) through (3), acceptance criteria (Reference 5) are met and serve as the basis for operation of the Millstone Unit 2 Power Station with Standard CE14 HTP fuel (advanced fuel geometry).

1 MS is a registered trademark of AREVA 2

HTP, HMP, MONOBLOC and FUELGUARD are trademarks of AREVA

AREVA Inc. ANP-3316NP Revision 0 Millstone Unit 2 M5 Upgrade, Realistic Large Break LOCA Analysis Licensing Report Page 1 1.0

SUMMARY

This report describes and provides results from the Realistic Large Break Loss of Coolant (RLBLOCA) for the Millstone Unit 2 M5 fuel upgrade. The plant is a Pressurized Water Reactor (PWR) Combustion Engineering (CE) 2x4-loop design. The parameter specification for this analysis is provided in Table 1. The analysis assumes full-power operation at 2754 MWt (includes power calorimetric uncertainty), a tube plugging level of 5.87 percent per steam generator, a peak linear heat generation rate (LHGR) of 15.1 kW/ft, and a radial peaking factor of 1.854 (includes uncertainty). The analysis supports operation with AREVA Standard CE14 HTP fuel (advanced fuel geometry) design using standard U02 fuel with 2, 4, 6, and 8 weight percent Gd203.

This analysis also addresses typical operational ranges or technical specification limits (whichever is applicable) with regard to pressurizer pressure and level; safety injection tank (SIT) pressure, temperature (containment temperature), and level; core inlet temperature; core flow; containment pressure and temperature; and refueling water storage tank temperature. The analysis explicitly analyzes fresh and once-burned fuel assemblies. The analysis also uses the Fuel Swelling, Rupture, and Relocation (FSRR) model to determine if cladding rupture occurs and evaluate the consequences of FSRR on the transient response.

[

]

AREVA Inc. ANP-3316NP Revision 0 Millstone Unit 2 M5 Upgrade, Realistic Large Break LOCA Analysis Licensing Report Page2 The UTL results providing 95/95 simultaneous coverage from this evaluation meet the 10 CFR 50.46(b) criteria with a PCT of 1615°F, a maximum local oxidation of 2.01 percent and a total core-wide oxidation of 0.025 percent. The PCT of 1615°F occurred in a Fresh 4 weight percent Gd 2 0 3 fuel rod with an assembly burnup of 18.4 GWd/mtU.

AREVA Inc. ANP-3316NP Revision 0 Millstone Unit 2 MS Upgrade, Realistic Large Break LOCA Analysis Licensing Report Page 3 2.0 RLBLOCA ANALYSIS 2.1 Acceptance Criteria The purpose of the analysis is to verify the adequacy of the Millstone Unit 2 Emergency Core Cooling System (ECCS) by demonstrating compliance with the following 10 CFR 50.46(b) criteria (Reference 5):

1. The calculated maximum fuel element cladding temperature shall not exceed 2200°F.

2. The calculated total oxidation of the cladding shall nowhere exceed 0.17 times the total cladding thickness before oxidation.

3. The calculated total amount of hydrogen generated from the chemical reaction of the cladding with water or steam shall not exceed 0.01 times the hypothetical amount that would be generated if all of the metal in the cladding cylinders surrounding the fuel excluding the cladding surrounding the plenum volume were to react.

Note: Reference 4 states that the 17% value in the second acceptance criterion for MLO was based on the usage of the Baker-Just correlation. For present reviews on ECCS Evaluation Model (EM) applications, the NRG staff is imposing a limitation specifying that the equivalent cladding reacted (ECR) results calculated using the Cathcart-Pawel correlation are considered acceptable in conformance with 10 CFR 50.46(b)(2) if the ECR value is less - than

-- - 13%.

- - The

- limitation is addressed -in Table 4.

2.2 Description of LBLOCA Event A Large Break Loss of Coolant Accident (LBLOCA) is initiated by a postulated rupture of the Reactor Coolant System (RCS) primary piping. The most challenging break location is in the cold leg piping between the reactor coolant pump and the reactor vessel for the RCS loop. The plant is assumed to be operating normally at full power prior to the accident and the break is assumed to open instantaneously. A worst case single-failure is also assumed to occur during the accident. The single-failure for this analysis is the loss of one ECCS pumped injection train without the loss of containment spray.

AREVA Inc. ANP-3316NP Revision 0 Millstone Unit 2 MS Upgrade, Realistic Large Break LOCA Analysis Licensing Report Paqe4 The LBLOCA event is typically described in three phases: blowdown, refill, and reflood.

Following the initiation of the break, the blowdown phase is characterized by a sudden depressurization from operating pressure down to the saturation pressure of the hot leg fluid. For larger cold leg breaks, an immediate flow reversal and stagnation occurs in the core due to flow out the break, which causes the fuel rods to pass through critical heat flux (CHF), usually within 1 second following the break. Following this initial rapid depressurization, the RCS depressurizes at a more gradual rate. Reactor trip and emergency injection signals occur when either the low pressure setpoint or the containment high-pressure setpoint are reached. However, for LBLOCA, reactor trip and scram are essentially inconsequential, as reactor shutdown is accomplished by moderator feedback. During blowdown, core cooling is supported by the natural evolution of the RCS flow pattern as driven by the break flow.

When the system pressure falls below the SIT pressure, flow from the SIT is injected into the cold legs ending the blowdown period and initiating the refill period. Once the system pressure falls below the respective shutoff heads of the safety injection systems and the system startup time delays are met, flow from the safety injection systems is injected into the RCS. While some of the ECCS flow bypasses the core and goes directly out of the break, the downcomer and lower plenum gradually refill until the mixture in the lower head and lower plenum regions reaches the bottom of the active core and_the __reJlood_p_erio_d_begios~C_o_re_c_o_oling_is_s_upp_ode_d_by_tb_e_natural _______________ _

evolution of the RCS flow pattern as driven by the break flow and condensation on the emergency coolant being injected. Towards the end of the refill period, heat transfer from the fuel rods is relative low, steam cooling and rod-to-rod radiation being the primary mechanisms.

Once the lower plenum is refilled to the bottom of the fuel rod heated length, refill ends and the reflood phase begins. Substantial ECCS fluid is retained in the downcomer during refill. This provides the driving head to move coolant into the core.

As the mixture level moves up the core, steam is generated and liquid is entrained, providing cooling in the upper core regions. The two-phase mixture expands into the

AREVA Inc. ANP-3316NP Revision 0 Millstone Unit 2 MS Upgrade, Realistic Large Break LOCA Analysis Licensing Report Pages upper plenum and some liquid may de-entrain and flow downward back into the cooler core regions. The remaining entrained liquid passes into the steam generators where it vaporizes, adding to the steam that must be discharged through the break and out of the system. The difficulty of venting steam is, in general, referred to as steam binding. It acts to impede core reflood rates. With the initiation of reflood, a quench front starts to progress up the core. With the advancement of the quench front, the cooling in the upper regions of the core increases, eventually arresting the rise in fuel rod surface temperatures. Later the core is quenched and a pool cooling process is established that can maintain the cladding temperature near saturation, so long as the ECCS makes up for the core boil off.

2.3 Description of Analytical Models The RLBLOCA methodology is documented in EMF-2103 Realistic Large Break LOCA

/

Methodology for Pressurized Water Reactors (Reference 1) and supplemented in the RAI responses and Errata in References 2 and 3. The methodology follows the Code Scaling, Applicability and Uncertainty (CSAU) evaluation methodology (Reference 6) and the requirements of the Evaluation Model Development and Assessment Process (EMDAP) documented in Reference 7. The CSAU method outlines an approach for defining and qualifying a best-estimate thermal-hydraulic code and quantifies the uncertainties in a LOCA analysis.

The RLBLOCA methodology consists of the following computer codes:

COPERNIC for computation of the initial fuel stored energy, fission gas release, and the transient fuel-cladding gap conductance.

S-RELAP5 for the thermal-hydraulic system calculations (includes ICECON for containment response).

The governing two-fluid (plus non-condensable) model with conservation equations for mass, energy, and momentum transfer is used. The reactor core is modeled in S-RELAP5 with heat generation rates determined from reactor kinetics equations (point kinetics) with reactivity feedback, and with actinide and decay heat.

AREVA Inc. ANP-3316NP Revision 0 Millstone Unit 2 MS Upgrade, Realistic Large Break LOCA Analysis Licensing Report Page 6 The two-fluid formulation uses a separate set of conservation equations and constitutive relations for each phase. The effects of one phase on the other are accounted for by interfacial friction, and heat and mass transfer interaction terms in the equations. The conservation equations have the same form for each phase; only the constitutive relations and physical properties differ.

The modeling of plant components is performed by following guidelines developed to ensure accurate accounting for physical dimensions and that the dominant phenomena expected during the LBLOCA event are captured. The basic building blocks for modeling are hydraulic volumes for fluid paths and heat structures for heat transfer. In addition, special purpose components exist to represent specific components such as the Reactor Coolant Pumps (RCPs) or the steam generator (SG) separators. All geometries are modeled at the resolution necessary to best resolve the flow field and the phenomena being modeled within practical computational limitations.

The analysis considers blockage effects due to clad swelling and rupture as well as increased heat load due to fuel relocation in the ballooned region of the cladding in the prediction of the hot fuel rod PCT.

A typical calculation using S-RELAP5 begins with the establishment of a steady-state initial condition with all loops intact. The input parameters and initial conditions for this

-- steady-state-calculation--are-chosen- to-reflect- plant -technical specifications-or- to match-- ------- -

measured data. Additionally, the COPERNIC code provides initial conditions for the S-RELAP5 fuel models. Specific parameters are discussed in Section 2.6.

Following the establishment of an acceptable steady-state condition, the transient -

calculation is initiated by introducing a break into one of the loops. The evolution of the transient through blowdown, refill, and reflood is computed continuously using S-RELAP5. Containment pressure is calculated by the ICECON module within S-RELAP5.

AREVA Inc. ANP-3316NP Revision 0 Millstone Unit 2 MS Upgrade, Realistic Large Break LOCA Analysis Licensing Report Page?

A detailed assessment of the S-RELAP5 computer code was made through comparisons to experimental data. These assessments were used to develop quantitative estimates of the ability of the code to predict key physical phenomena in a PWR LBLOCA. The final step of the best-estimate methodology is to combine all the uncertainties related to' the code and plant parameters and estimate the first three criteria of 10 CFR 50.46 with a probability of at least 95 percent with 95 percent confidence. The steps taken to derive the uncertainty estimate are summarized below:

1. Base Plant Input File Development First, base COPERNIC and S-RELAP5 input files for the plant (including the containment input file) are developed. The code input development guidelines documented in Appendix A of Reference 1, as amended by References 2 and 3, are applied to ensure that model nodalization is consistent with the model riodalization used in the code validation.

2. Sampled Case Development The statistical approach requires that many "sampled" cases be created and processed. For every set of input created, each "key LOCA parameter" .is randomly sampled over a range established through code* uncertainty

assessment or expected operating limits (provided* by plant technical specifications or data). Those parameters considered "key LOCA parameters" are listed in Table A-6 of 1, as amended by References 2 and 3. This list includes both parameters related to LOCA phenomena, based on the PIRT provided in Reference 1, and to plant operating parameters. The uncertainty ranges associated with each of the model parameters are provided in Table A-7 of

--Reference 1, as amendecroyReferences 2ana3.

3. Determination of Adequacy of ECCS The RLBLOCA methodology uses a non-parametric statistical approach to determine that the. first three criteria of 10 CFR 50.46 .. are met with .a probability higher than 95 percent with 95 percent confidence.

AREVA Inc. ANP-3316NP Revision 0 Millstone Unit 2 M5 Upgrade, Realistic Large Break LOCA Analysis Licensing Report Page 8 2.4 GDC-35 Limiting Condition Determination GDC-35 requires that a system be designed to provide abundant core cooling with suitable redundancy such that the capability is maintained in either the loss of offsite power (LOOP) or the offsite power available (No-LOOP) condition. [

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2.5 Overall Statistical Compliance to Criteria 2.6 Plant Description and Summary of Analysis Parameters The plant analyzed is the Millstone Unit 2, CE designed PWR, which has 2x4-loop arrangement. There are two hot legs each with an U-tube steam generator and four cold legs each with a RCP. The RCS includes one Pressurizer connected to a hot leg. The ECCS comprises four SITs, one per loop/cold leg, and one full train of Low Pressure Safety Injection (LPSI) and High Pressure Safety Injection (HPSI) (after applying the single failure assumption). The HPSI and LPSI feed into common headers (cross connected) that are connected to the SIT lines. The RLBLOCA transients are of

AREVA Inc. ANP-3316NP Revision 0 Millstone Unit 2 MS Upgrade, Realistic Large Break LOCA Analysis Licensing Report Page 9 sufficiently short duration that the switchover to sump cooling water for ECCS pumped injection does not need to be considered.

The S-RELAP5 model explicitly describes the RCS, reactor vessel, pressurizer, and ECCS. The ECCS includes a SIT path and a LPSl/HPSI path per RCS loop. The HPSI and LPSI feed into a common header that connects to each cold leg pipe downstream of the RCP discharge. The ECCS pumped injection is modeled as a table of flow versus backpressure. This model also describes the secondary-side steam generator that is instantaneously isolated (closed main steam isolation valve and feedwater trip) at the time of the break. The analysis includes AREVA fuel with M5 cladding and utilizes the COPERNIC code for fuel calculations within S-RELAP5. The primary and secondary coolant systems for Millstone Unit 2 were nodalized consistent with code input guidelines in Appendix A of Reference 1, and as amended by References 2 and 3.

As described in Appendix A of Reference 1, as amended by References 2 and 3, many parameters associated with LBLOCA phenomenological uncertai'nties and plant operation ranges are sampled. A summary of those parameters sampled is given in Table A-6 of Reference 1, as amended . by References 2 and 3. The LBLOCA phenomenological uncertainties are provided in Table A-7 of Reference 1, as amended by References 2 and 3. Values for process or operational parameters, including ranges of sampled process parameters, and fuel design parameters used in this analysis are given in Table 1. Table 2 presents a summary of the uncertainties used in the analysis.

Two parameters (refueling water storage tank temperature and diesel start time) are set

.at conservative bounding values for all calculations. The passive heat sinks and material properties used in the containment input model are provided in Table 3.

2. 7 SE Limitations The RLBLOCA analysis for Millstone Unit 2 presented herein is consistent with the submitted RLBLOCA methodology documented in EMF-2103, Revision 3 (Reference 1) and as supplemented in the RAI responses and Errata in References 2 and 3. The

AREVA Inc. ANP-3316NP Revision 0 Millstone Unit 2 M5 Upgrade, Realistic Large Break LOCA Analysis Licensing Report Page 10 limitation and conditions from the draft NRC Safety Evaluation (SE) (Reference 4) are addressed in Table 4.

AREVA Inc. ANP-3316NP Revision O Millstone Unit 2 M5 Upgrade, Realistic Large Break LOCA Analysis Licensing Report Page 11 3.0 REALISTIC LARGE BREAK LOCA RES ULTS

[

] For a simultaneous coverage/confidence level of 95/95, the UTL values

are a PCT of 1615°F, a maximum local oxidation of 2.01 percent, and a total core-wide oxidation of 0.025 percent. The fraction of total hydrogen generated was not directly calculated; however, it is conservatively bounded by the calculated total core wide percent oxidation, which is well below the 1 percent limit.

This analysis assumes a full core of AREVA Standard CE14 HTP fuel design which incorporates M5 clad fuel rod design among other features. However, at the time of the application of this analysis, the Millstone Unit 2 core will be a mixed core of AREVA Standard CE14 HTP fuel design and the resident fuel design which is a CE 14x14 HTP

~---*----- - - - - -- -- ----- -- - --'---- --- --

with Zr-4 cladding. The differences between the two core designs have been assessed.

The differences are such that thermal hydraulic performance is not impacted and modeling the core as a full core of M5 is acceptable and no penalty is required for this analysis.

AREVA Inc. ANP-3316NP Revision 0 Millstone Unit 2 MS Upgrade, Realistic Large Break LOCA Analysis Licensing Report Page 12 Table 6 is a summary of the major input parameters for the demonstration case. The sequence of event times for the demonstration case is provided in Table 7. The heat transfer parameter ranges for the demonstration case are provided in Table 8. [

]

The analysis plots for the case set are shown in Figure 1 through Figure 5. Figure 1 shows linear scatter plots of the key parameters sampled for all cases. Parameter labels appear to the left of each individual plot. These figures illustrate the parameter ranges used in the analysis. Visual examination of the linear scatter plots demonstrates that the spread and coverage of all of the values used is appropriate and within the uncertainty ranges listed in Table 2. Appendix A provides a listing of all the sampled input values for each case. Key results such as the PCT and event timings are also listed for the case set.

Figure 2 and Figure 3 show PCT scatter plots versus the time of PCT and versus break size, respectively. The scatter plots for the maximum loca.1 oxidation and total core-wide oxidation are shown in Figure 4 and Figure 5, respectively .

. Figure 2 shows a gener~I _9~c1ea~il}g__ t~~m;I gf_PQI_"Y.ith inqeasing_PCT time with two distinctive clusters of high PCTs (>1200°F). The first cluster shows PCT timings of less than 15 seconds (blowdown period); the second cluster shows PCT timings between 15 seconds and 50 seconds (early reflood period). Slowdown PCT cases are dominated by rapid RCS depressurization anc;I stored energy content. Early reflood PCT cases are dominated by decay heat removal capacity, which is highly dependent on SIT liquid volume and pressure setpoint. As shown in Figure 3, there is a strong correlation of PCT to break size. From all sampled parameters, the break size is a dominant effect in PCT because of its high influence in the rate of primary depressurization. As such, the high PCT clusters correlate with the larger end of the break sizes. In general, for this plant design, larger breaks peak at either the blowdown phase or the early reflood

AREVA Inc. ANP-3316NP Revision 0 Millstone Unit 2 M5 Upgrade, Realistic Large Break LOCA Analysis Licensing Report Page 13 phase of the transient depending on the influence of various phenomena such as blowdown flow reversal/stagnation, ECCS bypass, and steam binding. Large SITs with low pressure setpoints tend towards delayed injection which results in less ECCS bypass. Therefore, the late reflood PCT cases (> 50 seconds, Figure 2) are typically smaller break sizes with slower depressurizations and lower PCTs. An exception to that is the case inFigure 2 with a late reflood peak (-157 seconds) and relatively high PCT

(>1500°F). This case falls in the larger end of the break sizes (-4.0 ft2/side). However, it is characterized by a combination of sampling parameters leading to an earlier SIT depletion and a relatively slower reflood rate than the surrounding break size cases.

The demonstration case is a blowdown peak case with a PCT timing of 7.4 seconds.

Figure 6 through Figure 17 show key parameters from the S-RELAP5 calculations for the demonstration case. The transient progression for the demonstration case follows that described in Section 2.2.

Figure 4 shows a general increasing trend of MLO with PCT. Since the MLO includes the pre-transient oxidation, the MLO is not only a function of cladding temperature but of time in cycle (burnup), which explains the scatter of the points. A stronger correlation of the CWO to PCT is demonstrated in Figure 5 as higher PCT cases would have a higher oxidation throughout the core.

Figure-18--compares-the-Beginning-of-Gore-Reeovery-(BGGR-)-times-ealeulated-by------

S-RELAP5 to the BOCR times predicted using the Counter Current Flow Limiting (CCFL) correlation developed by MPR Associates. Note that Figure 18 uses the total break area, while previous plots use break area per side.

AREVA Inc. ANP-3316NP Revision O Millstone Unit 2 MS Upgrade, Realistic Large Break LOCA Analysis

Licensing Report Page 14

4.0 CONCLUSION

S This report describes and provides results from the RLBLOCA analysis for the Millstone Unit 2 Ms fuel upgrade. The plant is a PWR Combustion Engineering 2x4-loop design with an analyzed thermal power of 2754 MWt (includes power calorimetric uncertainty) and dry atmospheric containment. The loops contain four RCPs, two U-tube steam generators and a pressurizer. The base model and the design inputs used are representative of the Millstone Unit 2 plant. The application of the AREVA RLBLOCA methodology involves developing input decks, executing the simulations that comprise the uncertainty analysis, retrieving PCT, MLO, and CWO information and determining the simultaneous UTL results for the .criteria. [

] The UTL results providing a 95/95 simultaneous coverage/confidence level from this evaluation meet the 10 CFR 50.46(b) criteria with a PCT of 1615°F, a maximum local oxidation of 2.01 percent and a total core-wide oxidation of 0.025 percent.

AREVA Inc. ANP-3316NP Revision 0 Millstone Unit 2 M5 Upgrade, Realistic Large Break LOCA Analysis Licensing Report Page 15

5.0 REFERENCES

1. EMF-2103(P) Revision 3, Realistic Large Break LOCA Methodology for Pressurized Water Reactors, AREVA Inc., September 2013.

2. U.S. NRC ADAMS Accession No. ML16054A205, "AREVA, Inc. - Transmittal of Response to First and Second Request for Additional Information Regarding EMF-2103(P), Revision 3, 'PWR Realistic Large Break LOCA Methodology for Pressurized Water Reactors,"' NRC: 16:005, February 16, 2016.

3. U.S. NRC ADAMS Accession No. ML16060A062, "Revised Pages for EMF-2103(P), Revision 3, 'Realistic Large Break LOCA Methodology for Pressurized Water Reactors,"' NRC:16:006, February 19, 2016.

4. U.S. NRC ADAMS Accession No. ML16098A366, "Draft Safety Evaluation for AREVA NP Inc. Topical Report EMF-2103(P), Revision 3, 'Realistic Large Break LOCA Methodology for Pressurized Water Reactors,'" April 14, 2016.

5. Code of Federal Regulations, Title 10, Part 50, Section 46, Acceptance Criteria For Emergency Core Cooling Systems For Light-Water Nuclear Power Reactors, August 2007.

6. NUREG/CR-5249, "Quantifying Reactor Safety Margins, Application of Code Scaling, Applicability, and Uncertainty Evaluation Methodology to a Large Break, Loss-of-Coolant Accident," U.S. NRC, _December 1989.

7. Regulatory Guide 1.203, "Transient and Accident Analysis Methods" U.S. NRC, December 2005.

AREVA Inc. ANP-3316NP Revision 0 Millstone Unit 2 MS Upgrade, Realistic Large Break LOCA Analysis Licensing Report Page 16 Table 1 RLBLOCA Analysis - Plant Parameter Values and Ranges Plant Parameter Parameter Value 1.0 Plant Physical Description 1.1 Fuel a) Cladding outside diameter 0.440 in.

b) Cladding inside diameter 0.387 in.

c) Cladding thickness 0.0265 in.

d) Pellet outside diameter 0.3805 in.

e) Initial Pellet density 96 percent of theoretical f) Active fuel length 136.7 in.

g) Gd 2 0 3 concentrations 2, 4, 6, 8 w/o 1.2 RCS a) Flow resistance Analysis b) Pressurizer location

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c) Hot assembly location Anywhere in core d) Hot assembly type 14x14 e) SG tube plugging 5.87 percent 2.0 Plant Initial Operating Conditions 2.1 Reactor Power a) Analyzed reactor power 2754 MWt b) Fa 2.385 1' 2 2

c) Fr 1.854 2.2 Fluid Conditions a) Loop flow 132.2 Mlbm/hr s Ms 160.0 Mlbm/hr b) RCS cold leg temperature 536°F s Ts 554°F 3

c) Upper head temperature -That Temperature d) Pressurizer pressure 2190 psia s P s 2310 psia e) Pressurizer level 35 percents L s 75 percent f) SIT pressure 195 psia s P s 280 psia 3

g) SIT liquid volume 1015 ft3s vs 1255 ft 60°F s Ts 125°F (coupled with containment h) SIT temperature temperature) i) SIT resistance fUD As-built piping configuration j) SIT boron 1720 ppm The value used for Fa is derived from the LHGR Technical Specification value 2

Includes measurement uncertainty.

3 Upper head temperature will change based on sampling of RCS temperature.

AREVA Inc. ANP-3316NP Revision 0 Millstone Unit 2 MS Upgrade, Realistic Large Break LOCA Analysis Licensing Report Page 17 Table 1 RLBLOCA Analysis - Plant Parameter Values and Ranges (Continued)

Plant Parameter Parameter Value 3.0 Accident Boundary Conditions a) Break location Cold leg pump discharge b) Break type Double-ended guillotine or split c) Break size (each side, relative to 0.05 :<O: A :<O: 1.0 full pipe area (split) cold leg pipe area) 0.05 :<O: A :<O: 1.0 full pipe area (guillotine) d) ECCS pumped injection 140°F temperature 10 s (No-LOOP) e) HPSI pump delay 25 s (LOOP) 30 s (No-LOOP) f) LPSI pump delay 45 s (LOOP) g) Initial containment pressure 14.27 psia h) Initial containment temperature 60°F :<O: T :<O: 125°F i) Containment sprays delay Os j) Containment spray water 35°F temperature k) LPSI Flow RCS Cold Leg Broken Loop Intact Loop Flow Intact Loop Flow Intact Loop Pressure (psia) Flow 1A (gpm) 18 (gpm) 2A(gpm) Flow 28 (gpm) 14.7 1369 1314 0 0 50 1214 1164 0 0 100 945 904 0 0 150 546 519 0 0 200 0 0 0 0 300 0 0 0 0 500 0 0 0 0 700 0 0 0 0 900 0 0 0 0 1000 0 0 0 0 1050 0 0 0 0 1100 0 0 0 0 1144.34 0 0 0 0

AREVA Inc. ANP-3316NP Revision 0 Millstone Unit 2 M5 Upgrade, Realistic Large Break LOCA Analysis Licensing Report Page 18 Table 1 RLBLOCA Analysis - Plant Parameter Values and Ranges (Continued)

Plant Parameter Parameter Value I) HPSI Flow RCS Cold Leg Broken Loop Intact Loop Flow Intact Loop Flow Intact Loop Pressure (psia) Flow 1A (gpm) 1B (gpm) 2A (gpm) Flow 2B (gpm) 14.7 138 140 139 140 50 136 138 137 138 100 133 135 134 135 150 131 131 131 131 200 128 128 128 128 300 121 121 121 122 500 106 106 106 106 700 89 89 89 89 900 68 68 68 68 1000 54 54 54 54 1050 43 43 43 43 1100 30 30 30 30 1144.34 0 0 0 0

AREVA Inc. ANP-3316NP Revision 0 Millstone Unit 2 MS Upgrade, Realistic Large Break LOCA Analysis Licensing Report Page 19 Table 2 Statistical Distribution Used for Process Parameters Operational Measurement Parameter Standard Parameter Uncertainty Uncertainty Range Deviation Distribution Distribution Pressurizer Pressure (psia) Uniform 2190 - 2310 Normal 0 Pressurizer Level(%) Uniform 35- 75 Normal 0 SIT Volume (ft3) Uniform 1015 - 1255 N/A N/A SIT Pressure (psia) Uniform 195 - 280 N/A N/A Containment/SIT Uniform 60-125 N/A N/A Temperature (°F)

Containment Volume (x106 ft3) Uniform 1.899 - 2.125 N/A N/A Initial Flow Rate (Mlbm/hr) Uniform 132.2 -160.0 N/A N/A Initial Operating Temperature (oF) Uniform 536 - 554 N/A N/A

AREVA Inc. ANP-3316NP Revision 0 Millstone Unit 2 M5 Upgrade, Realistic Large Break LOCA Analysis Licensing Report Page 20 Table 3 Passive Heat Sinks and Material Properties in Containment Geometry Surface Area, Thickness, Heat Sink ft2 Material ft 0.02083 Carbon Steel Containment Shell and Dome *71870 3.02083 Concrete Unlined Concrete 62800 2.0 Concrete 0.0003 Galvanized Steel Galvanized Steel 120100 0.01697 Carbon Steel Painted Thin Steel 61850 0.01667 Carbon Steel Painted Steel 32600 0.021667 Carbon Steel Painted Steel 25425 0.071667 Carbon Steel Painted Thick Steel 4630 0.245 Carbon Steel 0.0625 Carbon Steel Containment Penetration 3000 3.8125 Concrete 0.020833 Stainless Steel Stainless Lined Concrete 8340 2.020833 Concrete Base Slab 11130 8.0 Concrete Neutron Shield 16270 0.0154 Stainless Steel CEDM Cable Support 1380 0.1094 Stainless Steel Painted Steel 2891 0.031327 Carbon Steel Painted Steel 1856 0.02083 Carbon Steel Painted Steel 624.4 0.0374 Carbon Steel Non Galvanized Carbon Steel 23564 0.02167 Carbon Steel 0.003 Galvanized Steel Galvanized Carbon Steel 5423.4 0.0112 Carbon Steel 0.0115 Galvanized Steel

- Stainless Steel 6948 0:02167 Stainless Steel Aluminum 2300 0.01333 Aluminum Lead 7100 0.0325 Lead Volumetric Heat Thermal Conductivity Heat Sink Material Capacity Btu/hr-ft-°F Btu/ft3-°F Concrete 0.92 22.62 Carbon Steel 27.00 58.80 Stainless Steel 8.47 58.60 Galvanized Steel 65.0 41.00 Aluminum 118 35.2 Lead 19.6 21.2

AREVA Inc. ANP-3316NP Revision 0 Millstone Unit 2 M5 Upgrade, Realistic Large Break LOCA Analysis Licensing Report Page 21 Table 4 Draft SE Limitations Evaluation Limitations (Section 4.0 in Ref. [4]) Response 1 This EM was specifically reviewed, in accordance with This analysis applies only to statements in the LTR, to determine whether EMF- the acceptance criteria set 2103P, Revision 3, is an acceptable EM for determining forth in 10 CFR S0.46(b),

whether plant-specific results comply with the paragraphs (1) through (3).

acceptance criteria set forth in 10 CFR S0.46(b),

paragraphs (1) through (3). The vendor did not request, and the NRC staff did not consider, whether this EM would be considered applicable if used to determine whether the requirements of 10 CFR S0.46(b)(4),

regarding coolable geometry, or (b)(S), regarding long-term core cooling, are satisfied. Thus, this approval does not apply to the use of SRELAPS-based methods of evaluating the effects of grid deformation due to seismic or LOCA blowdown loads, or for evaluating the effects of reactor coolant system boric acid transport. Such evaluations would be considered separate methods.

2 The LTR approval is limited to application for 3-loop and Millstone Unit 2 is a 4-loop Westinghouse-designed nuclear steam supply Combustion systems (NSSSs), and to Combustion Engineering- Engineering-designed NSSS designed NSSSs with cold leg ECCS injection, only. The with cold leg ECCS injection.

NRC staff did not consider model applicability to other NSSS designs in its review.

3 The evaluation model is approved based on models that The analysis supports are specific to AREVA proprietary MS' fuel cladding. operation with MS cladding.

The application of the model to other cladding types has

.. _not been_reviewed, *- -

4 Plant-specific applications will generally be considered The modeling guidelines acceptable if they follow the modeling guidelines contained in Appendix A of contained in Appendix A to EMF 2103, Revision 3. EMF-2103, Revision 3 were Plant-specific licensing actions referencing EMF 2103, followed completely for the Revision 3, analyses should include a statement analysis described in this summarizing the extent to which the guidelines were report.

followed, and justification for any departures.

AREVA Inc. ANP-3316NP Revision 0 Millstone Unit 2 MS Upgrade, Realistic Large Break LOCA Analysis Licensing Report Page 22 Limitations (Section 4.0 in Ref. [4]) Response 5 The approach described in 3.1.3.3. 7 of EMF-2103, [

Revision 3, in addition to the guidelines provided on pp.

A-67 through A-71 ofEMF-2103, Revision 3, regarding the power level assumed for auxiliary rods, will be considered acceptable for generic implementation of the rod-to-rod radiation model. Plant-specific licensing actions referencing EMF-2103, Revision 3, analyses should include a confirmation that these modeling practices bound plant operation.

]

6 The response to RAI 15 indicates that the fuel pellet The analysis supports relocation packing factor is derived from data that extend operation with MS cladding, to currently licensed fuel burnup limits, i.e., rod average which has a licensed limit of burnup of [ ] . Thus, the approval of this [ ] .

method is limited to fuel burnup below this value.

Extension beyond rod average burnup of [

] would require a revision or supplement to the LTR, or plant-specific justification.

7 The response to RAI 15 indicates that the fuel pellet [

relocation packing factor is derived from currently available data. Should new data become available to suggest that fuel pellet fragmentation behavior is other than that suggested by the currently available database, the NRG may request the vendor to update its model to reflect such new data.

]

8 The regulatory limit contained in 10 CFR 50.46(b)(2), The MLO UTL is less than requiring cladding oxidation not to exceed 17-percent of 13% (Table 5). [

the initial cladding thickness prior to oxidation, is based on the use of the Baker-Just oxidation correlation. To account for the use of the Cathc:art-Pawel correlation, this limit shall be reduced to 13 percent, inclusive of pre-transient oxide layer thickness.

]

AREVA Inc. ANP-3316NP Revision 0 Millstone Unit 2 MS Upgrade, Realistic Large Break LOCA Analysis Licensing Report Page 23 Limitations (Section 4.0 in Ref. [4]) Response 9 In conjunction with Limitation 8 above, Cathcart-Pawel [

oxidation results will be considered acceptable, provided plant-specific [

] , or limiting fuel rods with respect to oxidation remain in the first cycle. If second-cycle fuel is identified in a plant-specific analysis, whose [

] , the NRC staff reviewing the plant-specific ]

analysis may request a quantitative assessment, or similar justification, demonstrating that [

].

10 The response to RAI 13 states that all operating ranges [

used in a plant-specific analysis are supplied for review by the NRC in a table like Table B-8 of EMF 2103P, Revision 3. In plant specific reviews, the uncertainty treatment for plant parameters will be considered acceptable if plant parameters [

]

] . Alternative approaches may be used, provided they are supported with appropriate justification.

11 The NRC staff review only considered the application of r-- - - -

[

] . Alternate approaches, such as using [

]'

require plant-specific justification. Such justification would need to address both the acceptability [

]

].

AREVA Inc. ANP-3316NP Revision 0 Millstone Unit 2 M5 Upgrade, Realistic Large Break LOCA Analysis Licensing Report Page 24 Limitations (Section 4.0 in Ref. [4]} Response 12 Plant-specific applications must adhere to the processes [

described in the response to RAls 22 and 23, regarding the determination of the sample size, and dispositioning outlying or unacceptable results. More specifically:

The minimum sample size for the statistical analysis shall be [ ] cases.

The exact sample size shall be selected prior to the

]

initiation of production safety analysis.

When re-analysis is necessary for any purpose other than a significant plant change such as the analysis for an extended power uprate:

o The random number seed and sample size from the initial statistical analysis shall be preserved.

o Prior analyses shall be documented in calculation files at a level of documentation thc:d

allows full reproducibility.

Any submittal to the NRC, based on EMF-2103P, Revision 3, which is based on other than a first statistical calculation must specify that re-analysis has been performed, and must identify what changes were made to the evaluation model and/or input to obtain the submitted, final analysis.

AREVA Inc. ANP-3316NP Revision 0 Millstone Unit 2 M5 Upgrade, Realistic Large Break LOCA Analysis Licensing Report Page 25 Table 5 Compliance with 10 CFR 50.46(b)

UTL for 95/95 Simultaneous Coverage/Confidence Parameter Value Case Number PCT, °F 1615 123 MLO,% 2.01 174 CWO,% 0.025 96 Characteristics of Case Setting the PCT UTL PCT, °F 1615 PCT Rod Type Fresh 4% Gad Rod Time of PCT, s 7.44 Elevation within Core, ft 9.36 Local Maximum Oxidation, % 1.98 Total Core-Wide Oxidation,% 0.006 PCT Rod Rupture Time, s No rod rupture Rod Rupture Elevation within Core, ft No rod rupture

AREVA Inc. ANP-3316NP Revision 0 Millstone Unit 2 M5 Upgrade, Realistic Large Break LOCA Analysis Licensing Report Page 26 Table 6 Summary of Major Parameters for the Demonstration Case Parameter Value Core Power (MWt) 2754 Time in Cycle (hrs) 11619 Limiting Rod Assembly Burnup (GWd/mtU) 18.4 Limiting Rod LHGR (kW/ft) 13.25 Limiting Rod Equivalent Fa 2.09 Limiting Rod Radial Peak, Fr 1.71 Limiting Rod Axial Shape Index -0.076 Break Type Split 2

Break Size (ft /side) 3.6942 Offsite Power Availability LOOP

AREVA Inc. ANP-3316NP Revision 0 Millstone Unit 2 M5 Upgrade, Realistic Large Break LOCA Analysis Licensing Report Page 27 Table 7 Calculated Event Times for the Demonstration Case Event Time (sec)

Break Opens 0.0 RCP Trip 0.0 SIAS Issued 0.7 PCT Occurred 7.4 Start of Broken Loop SIT Injection 16.6 Start of Intact Loop SIT Injection 17.3, 17.3 and 17.3 (Loop 2,3 and 4 respectively)

HPSI Available 25.7 Broken Loop HPSI Delivery Began 25.7 Intact Loops HPSI Delivery Began 25.7, 25.7 and 25.7 Beginning of Core Recovery (Beginning of Reflood) 26.8 LPSI Available 45.7 Broken Loop LPSI Delivery Began 45.7 Intact Loops LPSI Delivery Began 45. 7, N/A and N/A Intact Loop SIT Emptied 62.0, 62.1 and 61.5 (Loop 2, 3 and 4 respectively)

Broken Loop SIT Emptied 63.3 Transient Calculation Terminated 900.0

AREVA Inc. ANP-3316NP Revision 0 Millstone Unit 2 M5 Upgrade, Realistic Large Break LOCA Analysis Licensing Report Page 28 Table 8 Heat Transfer Parameters for the Demonstration Case Time (s)

LOCA Phase Early Long Term Blowdown 1 Refill Reflood Quench Slowdown Cooling 2 Heat Transfer Mode

-~ -~

Heat Transfer Correlations

- ~ - ,__.__

Maximum LHGR kW/ft Pressure (psia)

Core Inlet Mass Flux (lb/s-tt2) 4 Vapor Reynolds Number Liquid Reynolds Number Vapor Prandtl Number Liquid Prandtl Number 0

Vapor Superheat (°F) 1 End of blowdown considered as beginning of refill.

2 Quench to End of Transient 4

[ ]

Not important in pre-CHF heat transfer 5

Vapor superheat is meaningless during blowdown and system depressurization

AREVA Inc. ANP-3316NP Revision 0 Millstone Unit 2 M5 Upgrade, Realistic Large Break LOCA Analysis Licensing Report Page 29 Table 9 Fuel Rod Rupture Ranges of Parameters

AREVA Inc. ANP-3316NP Revision 0 Millstone Unit 2 M5 Upgrade, Realistic Large Break LOCA Analysis Licensing Report Page 30 Figure 1 Scatter Plot Operational Parameters I

Total Loop Flow (Mlb/hr)

I 130.0 140.0 150.0 160.0 SIT Liquid Volume (ft3) t : ' J 1000.0 1100.0 1200.0 1300.0 SIT Pressure (psi a) ~

180.0

I:

200.0 220.0 I:

240.0 I:

260.0 I l 280.0 I

Containment Volume (ft3) 1.90e+06 2.00e+06 2.10e+06 2.20e+06

~

SIT Temperature (oF) [ , : I : I : :

60.0 80.0 100.0 120.0 140.0 L:::I : I I I : I : I : I : : : : ~

FSRR Temperature (C)

-100.0 -80.0 -60.0 -40.0 -20.0 0.0 20.0 40.0 60.0 80.0 100.0

AREVA Inc. ANP-3316NP Revision 0 Millstone Unit 2 M5 Upgrade, Realistic Large Break LOCA Analysis Licensing Report Page 31 Figure 2 PCT versus PCT Time Scatter Plot PCT vs Time of PCT 1800 D

1600 1400 0

LL 1200 I- [II D

(.)

a.. D lj cD D

1000

~. ~-* ... *

800 *

.jD

i!D

~CT D

DD D

D

' D D

DD D

600

Split Break tJ Guillotine Break 400 0 50 100 150 200 250 300 Time of PCT (s)

AREVA Inc. ANP-3316NP Revision 0 Millstone Unit 2 MS Upgrade, Realistic Large Break LOCA Analysis Licensing Report Page 32 Figure 3 PCT versus Break Size Scatter Plot PCT vs One-sided Break Area 1800 D

- ~~~,~DB~

1600

- oil Cillj

~ n cJ'LD C-* /J *

1400 - ** * @§l !iii-. D D .

lifJ D IT CElJ D

-;::- 1200 -

0 LL

()

a..

D

~ltJD

.D di DD D

1000 - ....~. a

-a ** ~ D D g *~[Q]Il D BOO ~ ~ c]5' D "':" IT 600 ~

Split Break I -

I o Guillotine Breakl 400 '---~~~.J__~-'--~~'~~~---'-'~~~__J_'~~~__J 0.0 1.0 2.0 3.0 4.0 5.0 2

Break Area (ft /side)

AREVA Inc. ANP-3316NP Revision 0 Millstone Unit 2 M5 Upgrade, Realistic Large Break LOCA Analysis Licensing Report Page 33 Figure 4 Maximum Local Oxidation versus PCT Scatter Plot MLO vs PCT D

Split Break I D 2.4 ,_ I o Guillotine Break L__------~

2.2 >--

D 2.0 >--

. ~

D

~ -

~

1.8 >--

R 0

c:

~ 1.6 cu

>- ~.i.t!_

D ._

Q,c ~

-.D

~DD fi*

-0 D * *D

~ !l!

m g,,. .

-h!Tlf:+..D *

-=r-"TI n 1.4 >--

~ ot o

ood:ili cil I~

1.2 >--

D~

[)llllEI r

D

D * ~

D D~!~

D .

qfffi1;- ---[] -

1.0 >--

Lf * ~ D 0.8 >--

0.6 c__~_ _,__1~~-"--------'-'---'--~~-"-----~-----'---I_c___,_I_ _,____,

400 600 800 1000 1200 1400 1600 1800 2000 PCT (°F)

AREVA Inc. ANP-3316NP Revision 0 Millstone Unit 2 M5 Upgrade, Realistic Large Break LOCA Analysis Licensing Report Page 34 Figure 5 Total Core Wide Oxidation versus PCT Scatter Plot CWOvs PCT

Split Break D Guillotine Break 0.04 D

D D

0.03 D

-0~

c::

0 D

~

Ctl "C

x D~

0 0.02 D

~-"~

~*on 0.01 -~--D-~

~- ,.

.FJ~ **

- §lg rf

0.00 400 600 800 1000 1200 1400 1600 1800 2000 PCT (°F)

AREVA Inc. ANP-3316NP Revision 0 Millstone Unit 2 MS Upgrade, Realistic Large Break LOCA Analysis Licensing Report Page 35 Figure 6 Peak Cladding Temperature (Independent of Elevation) for the Demonstration Case PCT Trace for Case #123 PCT= 1614.4 °F, at Time= 7.44 s, on Fresh 4% Gad Rod 1800 1600 1400

~ 1200

~

Q) c..

E 100*0

~

c:

"(5

a. 800

..c:

II)

Q)

2 600 400 200 0 '---'-----'----'-~'---'----~~~~~~~~~~~~~

0 100 200 300 400 Time (s)

AREVA Inc. ANP-3316NP Revision 0 Millstone Unit 2 M5 Upgrade, Realistic Large Break LOCA Analysis Licensing Report Page 36 Figure 7 Break Flow for the Demonstration Case Break Flow

- - Vessel Side

- - - - Pump Side

- - - Total

"'0

-10 0 20 40 60 80 100 Time (s)

AREVA Inc. ANP-3316NP Revision 0 Millstone Unit 2 MS Upgrade, Realistic Large Break LOCA Analysis Licensing Report Page 37 Figure 8 Core Inlet Mass Flux for the Demonstration Case Core Inlet Mass Flux

-- Hot Assembly 200 ---- Surround Assembl~

- - - Average Core

- -- Outer Core 150

-200

-250 '-----'----'-'-----'---'----'--'----'----'--------'--L-------'---'-----'----L-~

0 100 200 300 400 Time (s)

AREVA Inc. ANP-3316NP Revision 0 Millstone Unit 2 M5 Upgrade, Realistic Large Break LOCA Analysis Licensing Report Page 38 Figure 9 Core Outlet Mass Flux for the Demonstration Case Core Outlet Mass Flux

-- Hot Assembly

Surround Assembl~

- - - Average Core 200 - -- Outer Core ii

I 100 I 1'\

N I /)

I

.a E

>< 0

J u::: ~

I I I/)

I/) 1, n:I

2: 'I I,

-100

'I

-200

-300 '---~-'---~--'-~--'-~~~~~~~~-'--~-'---~--'-~~

0 20 40 60 80 100 Time (s)

AREVA Inc. ANP-3316NP Revision 0, Millstone Unit 2 M5 Upgrade, Realistic Large Break LOCA Analysis Licensing Report

Page 39 Figure 10 Void Fraction at RCS Pumps for the Demonstration Case Pump Void Fraction 0.6 c:

0 t5

~

LL

"'C

~

OA

-- Broken Lc;>op 1

Intact Loop 2

- - - Intact Loop 3 0.2 -- Intact Loop 4 0.0 lL----'------'-~-'-----'--'---'--~~~~*~~--'---'-~~~~~~~

0 100 200 300 400 Time (s)

AREVA Inc. ANP-3316NP Revision 0 Millstone Unit 2 MS Upgrade, Realistic Large Break LOCA Analysis Licensing Report Paqe40 Figure 11 ECCS Flows (Includes SIT, HPSI and LPSI} for the Demonstration Case ECCS Flows

-- Broken Loop 1

Intact Loop 2

- - - Intact Loop 3

- -- Intact Loop 4 2000

~

.0 E

1500

-Q) ca 0::

0 u:: 1000 -

500. -

l .

0 L__.L__,_____,__""-<--=..::..I-=-..:--::;::-.:.::.-=*-,_-_-.:..::.:::..::===-c:.=:::::-.:..i...-c....:*=--==:.-:....:.-==-=-=-=-_J 0 100 200 300 400 Time (s)

AREVA Inc. ANP-3316NP Revision 0 Millstone Unit 2 M5 Upgrade, Realistic Large Break LOCA Analysis Licensing Report Page41 Figure 12 Upper Plenum Pressure for the Demonstration Case Upper Plenum Pressure 2000

-I/)~

-a.

~

s I/)

I/)

~

a..

1000 0 '--~"'--~-'--~-'-~-'-~-----'--~---'~~'--~_L_~-'--~~

0 20 40 60 80 100 Time (s)

AREVA Inc. ANP-3316NP Revision 0 Millstone Unit 2 M5 Upgrade, Realistic Large Break LOCA Analysis Licensing Report Paqe42 Figure 13 Collapsed Liquid Level in the Downcomer for the Demonstration Case Downcomer Liquid Level 30 Sector 1 (broken)

Sector 2 Sector 3 Sector4 Sector 5

.i' Sector 6 Sector 7 Sector 8 20 I Average I

¢:::

!11!

~* l1ij'

g II f I :

f1I

l O"

III 'I'

.:J '1 !

'1 11

,Ii 10 :I !Ji!Jv'

/~ ili 1

ri 11,

,,li

\I~ I

,'. I~),

I

~~*

0 0 100 200 300 400 Time (s)

AREVA Inc. ANP-3316NP Revision O Millstone Unit 2 M5 Upgrade, Realistic Large Break LOCA Analysis Licensing Report Page 43 Figure 14 Collapsed Liquid Level in the Lower Plenum for the Demonstration Case Lower Vessel Liquid Level 10 j

8 g

(j) 6

~

....J 4 r-

\

0 '---'---'-~-'---'----'-~-'----'--~*~-'----'-----'-~-'----'--~~-'------'

0 100 200 300 400 Time (s)

AREVA Inc. ANP-3316NP Revision 0 Millstone Unit 2 M5 Upgrade, Realistic Large Break LOCA Analysis Licensing Report Page44 Figure 15 Collapsed Liquid Level in the Core for the Demonstration Case Core Liquid Level

--* Hot Assembly

Center Core

- - - Average Core

- -- Outer Core 10 l I'I,

' I

-E.

I'

'I

~1~1,~ I, I,,

I' ! I,'I

~ I l Q)

...J 11 'i

!1 1 l

1 11

/' i\' I'\ '

l I I

I

'v1 Ii, I,'\ /\ I 11 Ii !

I I

' I >

I~

'.'Q I

s *1 O"

11' (1q

w

i I' 1~~ 1 1

<. I ,11, v, 1 l*/'i.J 'I/'11 \I, ~Hr I ~\,'/'1

~~,

I, I 1, i1 1 5

i I

ri I I

I

! /,

1:~'

,!.~~ ,,,' ~

I~ ~!!,\\

0 ~

0 100 200 300 400 Time (s)

AREVA Inc. ANP-3316NP Revision 0 Millstone Unit 2 M5 Upgrade, Realistic Large Break LOCA Analysis Licensing Report Paqe45 Figure 16 Containment and Loop Pressures for the Demonstration Case Containment and Loop Pressures 100 ' I

- - Containment 90 - - - - - SG Outlet (primary side)

I - - - Upper Plenum

- - - Downcomer Inlet 80

!I 70 I I

~

.......... 60 I-ctl , 1 "iii

- 0..

~ 50 I-I

~I 1, ':

)

I II (\

~r~.

J U)

U)

~

a.. . ,I ~.

40

~ ~,I:.,\__....., J 30

~~"'*-~

~-"--.=::."~;:;----.......... .....

'"'- J~'\~,t11-k;.f.~'~v~r..ft::_::....: : : ;.;:....~

20 I-10 -

I I I 0

0 100 200 300 400 Time (s)

AREVA Inc. ANP-3316NP Revision 0 Millstone Unit 2 M5 Upgrade, Realistic Large Break LOCA Analysis Licensing Report Page 46 Figure 17 Pressure Differences between Upper Plenum and Downcomer for the Demonstration Case Delta P 10 I-- Upper Plenum-Downcomerl 8

6 4

- co "ii) 2

-a..

a.

I m 0 Q)

Cl a.

0 0 -2

_J

-4

-6

-8

-10 ~~~~~~~~~~~~-~~~~~~

0 100 200 300 400 Time (s)

AREVA Inc. ANP-3316NP Revision 0 Millstone Unit 2 M5 Upgrade, Realistic Large Break LOCA Analysis Licensing Report Page47 Figure 18 Validation of BOCR Time using MPR CCFL Correlation

AREVA Inc. ANP-3316NP Revision 0 Millstone Unit 2 MS Upgrade, Realistic Large Break LOCA Analysis Licensing Report Page 48 Figure 19

[ ]

AREVA Inc. ANP-3316NP Revision 0 Millstone Unit 2 M5 Upgrade, Realistic Large Break LOCA Analysis Licensing Report Page A-1 APPENDIX A: sqMMARY OF KEY INPUT AND OUTPUT PARAMETERS The following tables contain the samp1e9 input values for all cases analyzed. Key results are also included in columns 2 through 6 in Table A-1 for the case set. In all cases, the core power is 2754 MWth with a decay multiplier of 1.0.

Table A-1 Summary of Key Input and Output Parameters, Part 1

AREVA Inc. ANP-3316NP Revision 0 Millstone Unit 2 MS Upgrade, Realistic Large Break LOCA Analysis Licensing Report PaqeA-2

AREVA Inc. ANP-3316NP Revision 0 Millstone Unit 2 M5 Upgrade, Realistic Large Break LOCA Analysis Licensing Report PageA-3

AREVA Inc. ANP-3316NP Revisfon 0 Millstone Unit 2 M5 Upgrade, Realistic Large Break LOCA Analysis Licensing Report PageA-4

AREVA Inc. ANP-3316NP Revision 0 Millstone Unit 2 MS Upgrade, Realistic Large Break LOCA Analysis Licensing Report PaqeA-5

AREVA Inc. ANP-3316NP Revision 0 Millstone Unit 2 M5 Upgrade, Realistic Large Break LOCA Analysis Licensing Report Page A-6

AREVA Inc. ANP-3316NP Revision 0 Millstone Unit 2 M5 Upgrade, Realistic Large Break LOCA Analysis Licensing Report PageA-7

AREVA Inc. ANP-3316NP Revision 0 Millstone Unit 2 M5 Upgrade, Realistic Large Break LOCA Analysis Licensing Report Page A-8

AREVA Inc. ANP-3316NP Revision O Millstone Unit 2 MS Upgrade, Realistic Large Break LOCA Analysis Licensing Report

PageA-9

AREVA Inc. ANP-3316NP Revision 0 Millstone Unit 2 MS Upgrade, Realistic Large Break LOCA Analysis Licensing Report Page A-10 Table A-2 Summary of Key Input and Output Parameters, Part 2

AREVA Inc. ANP-3316NP Revision 0 Millstone Unit 2 MS Upgrade, Realistic Large Break LOCA Analysis Licensing Report Page A-11

AREVA Inc. ANP-3316NP Revision 0 Millstone Unit 2 MS Upgrade, Realistic Large Break LOCA Analysis Licensing Report Page A-12

AREVA Inc. ANP-3316NP Revision 0 Millstone Unit 2 M5 Upgrade, Realistic Large Break LOCA Analysis Licensing Report Page A-13

AREVA Inc. ANP-3316NP Revision 0 Millstone Unit 2 MS Upgrade, Realistic Large Break LOCA Analysis Licensing Report Page A-14

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Page A-15

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AREVA Inc. ANP-3316NP Revision 0 Millstone Unit 2 M5 Upgrade, Realistic Large Break LOCA Analysis Licensing Report Page A-18