ML14283A121

ANP-3284NP, Results of Analysis & Benchmarking of Methods for Monticello ATWS-1.

ML14283A121
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Site:	Monticello
Issue date:	04/30/2014
From:	AREVA
To:	Office of Nuclear Reactor Regulation
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ML14283A125	List: L-MT-14-044, ANP-3135NP, Applicability of Areva BWR Methods to Extended Flow Window for Monticello. ML14283A120 ML14283A121
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L-MT-14-044 ANP-3284NP
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L-MT-14-044 Enclosure 10Enclosure 10AREVA Report ANP-3284NP (Non-Proprietary)

Results of Analysis and Benchmarking of Methodsfor Monticello ATWS-IRevision 0April 2014124 pages follow Controlled DocumentANP-3284NP Revision 0Results of Analysis andBenchmarking of Methodsfor Monticello ATWS-lApril 2014AAREVAAREVA Inc.

Controlled DocumentAREVA Inc.ANP-3284NP Revision 0Results of Analysis andBenchmarking of Methodsfor Monticello ATWS-I Conty'Ltrcies, DocumentAREVA Inc.ANP-3284NP Revision 0Results of Analysis andBenchmarking of Methodsfor Monticello ATWS-ICopyright

© 2014AREVA Inc.All Rights ReservedAREVA Inc.

Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-lANP-3284NP Revision 0Page iNature of ChangesItem1AIPageThis is a new documeDescription and Justification IAREVA Inc.

Controlled DocumentANP-3284NP Results of Analysis and Benchmarking of Revision 0Methods for Monticello ATWS-l Page iiContents1.0 Introduction and Scope .................................................................................................

1-12.0 Benchmarking the Code AISHA ....................................................................................

2-12.1 Test Suite and Acceptance Criteria

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2-22.2 Benchmarking AISHA to KATHY Stability Tests ................................................

2-32.3 Benchmarking AISHA to Regional Oscillations in BW Rs ...................................

2-62.4 Sensitivity and Verification of Trends for an ATWS-l with RegionalO sc illa tio n s .......................................................................................................

2-63.0 Benchmarking the Code SINANO .................................................................................

3-13.1 Benchmark Results ...........................................................................................

3-43.2 Discussion of SINANO Benchmarking Results ................................................

3-644.0 ATW S-l Calculations for Monticello Extended Flow W indow .........................................

4-14.1 Peak Clad Temperature Results .....................................................................

4-125 .0 C o n clu sio n s ..................................................................................................................

5-16 .0 R efe re n ce s ...................................................................................................................

6-1This document contains a total of 124 pages.AREVA Inc.

Controlled DocumentANP-3284NP Results of Analysis and Benchmarking of Revision 0Methods for Monticello ATWS-I Page iiiTablesTable 2-1 Measured and AISHA calculated regional mode stability

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2-6Table 3-1 [ ] ................................

3-4Table 3-2 Figures for ATRIUM 1OXM KATHY test simulations

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3-6Table 4-1 M onticello ATW S-I calculations

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4-2Table 4-2 Calculated peak clad temperatures during ATWS-I .........................................

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Conrt1Y:c DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-IANP-3284NP Revision 0Page ivFiguresFigure 2-1 Comparison between ATRIUM-10 KATHY test and AISHAcalculated decay ratios ..................................................................................

.2-4Figure 2-2 Comparison between ATRIUM-10 KATHY test and AISHAcalculated frequencies

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2-5Figure 2-3 Hydraulic type map where type (1) is ATRIUM 1OXM, types (5)and (6) are G E 14 ..............................................................................................

2-7Figure 2-4 Example calculated bundle power as function of time .......................................

2-9Figure 2-5 Example calculated bundle inlet flow rate as function of time ..........................

2-10Figure 2-6 Example calculated bundle power as function of time, zoom fromF ig u re 2 -4 .......................................................................................................

2 -1 1Figure 2-7 Example calculated bundle power as function of time, zoom fromF ig u re 2 -5 .......................................................................................................

2 -12Figure 2-8 Example calculated bundle power as function of time for base andreduced tim e step cases .................................................................................

2-13Figure 2-9 Example calculated bundle inlet flow rate as function of time forbase and [ ] .............................................................

2-14Figure 2-10 Example calculated bundle power as function of time for base andFigure 2-11Figure 2-12Figure 2-13Figure 2-14Figure 2-15Figure 2-16Figure 2-17Figure 2-18[ ] .........................................

2 -15Example calculated bundle inlet flow rate as function of time forbase and [ ] .........................

2-16Example calculated bundle power as function of time for twoadjacent bundles of different fuel types ...........................................................

2-17Example calculated bundle inlet flow rate as function of time fortwo adjacent bundles of different fuel types .....................................................

2-18Example calculated bundle power as function of time for twoadjacent bundles of different fuel types, zoom from Figure 2-12 .....................

2-19Example calculated bundle inlet flow rate as function of time fortwo adjacent bundles of different fuel types, zoom from Figure2 -1 3 ................................................................................................................

2 -2 0Example calculated bundle power as function of time for twosymmetrically opposite bundles ......................................................................

2-21Example calculated bundle inlet flow rate as function of time fortwo symmetrically opposite bundles ................................................................

2-22Example calculated bundle power as function of time for twosymmetrically opposite

bundles, zoom from Figure 2-16 .................................

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Controlled DocumentANP-3284NP Results of Analysis and Benchmarking of Revision 0Methods for Monticello ATWS-l Page vFigure 2-19 Example calculated bundle inlet flow rate as function of time fortwo symmetrically opposite

bundles, zoom from Figure 2-17 ..........................

2-24Figure 2-20 Example calculated bundle power as function of time for nominaland [ ] ...............................

2-25Figure 2-21 Example calculated bundle inlet flow rate as function of time for[ ] .................

2-26Figure 2-22 Example calculated bundle power as function of time for nominaland [I ...........................................................................................

2 -2 7Figure 2-23 Example calculated bundle inlet flow rate as function of time fornominal and [] .................................................................................

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Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-lFigure 3-12......................................

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Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-lFigure 3-28.......................................

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Controlled DocumentANP-3284NP Results of Analysis and Benchmarking of Revision 0Methods for Monticello ATWS-l Page viiiFigure 3-44..............................................................................

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3 -6 4Figure 4-1 ATW S-I conditions for GE14 core hot bundle at BOC .......................................

4-3Figure 4-2 ATW S-I conditions for GE14 core hot bundle at MOC .......................................

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Controlled DocumentANP-3284NP Results of Analysis and Benchmarking of Revision 0Methods for Monticello ATWS-I Page ixFigure 4-3 ATWS-I conditions for mixed core hot ATRIUM 10XM bundle atB O C ..................................................................................................................

4 -5Figure 4-4 ATWS-I conditions for mixed core hot GE14 bundle at BOC .............................

4-6Figure 4-5 ATWS-I conditions for mixed core hot ATRIUM 1OXM bundle atM O C .. ..............................................................................................................

4-7Figure 4-6 ATWS-I conditions for mixed core hot GE14 bundle at MOC ............................

4-8Figure 4-7 ATWS-I conditions for ATRIUM 1OXM core hot bundle at BOC .........................

4-9Figure 4-8 ATWS-I conditions for ATRIUM 1OXM core hot bundle at MOC ......................

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Controlled DocumentANP-3284NP Results of Analysis and Benchmarking of Revision 0Methods for Monticello ATWS-I Page xAbstractThis report presents the results of analysis needed for licensing the Extended Flow Window(EFW) operation of Monticello BWR plant with regard to Anticipated Transient without Scramwith Instability (ATWS-I).

The analysis focuses on the fuel specific differences needed tolicense Monticello with AREVA fuel type ATRIUM IOXM. The comparative analysis described inthis report covers a full core loaded with GE14, an equilibrium cycle fully loaded with ATRIUM1OXM, as well as a transition cycle of mixed GE14 and ATRIUM 1OXM fuel types.The analysis presented in this report utilizes two computer codes: AISHA and SINANO. AISHAis a detailed core model capable of simulating severe power and flow oscillations that areassociated with core instabilities unsuppressed with scram. The AISHA code is I] pertaining to the limitingplant response to an ATWS event. Selected bundles for which the operating conditions are themost severe under unstable oscillations were analyzed further using the single channel codeSINANO. SINANO is[ I.The code SINANO applies advanced models for post-dryout heat transfer for the calculation ofthe cladding temperature excursion in the highest power rod.SINANO models are based on, and benchmarked

against, data obtained from Karlstein hydraulic loop KATHY where a full scale electrically heated ATRIUM 1OXM bundle has beentested under realistic ATWS-I conditions of severe unstable density waves with simulated reactivity and power feedback.

The AISHA code has been benchmarked against measured stability data obtained from KATHYloop for ATRIUM-10 fuel type. AISHA was also benchmarked against all the regionalinstabilities in actual BWR plants contained in AREVA database.

The benchmarking of AISHA and SINANO codes against experimental data is presented in thisreport preceding the presentation of representative ATWS-l transient analysis results forMonticello.

The analysis, supported by the benchmarking, concludes that the peak cladtemperature reached during ATWS-I transient is well below the acceptance limit.AREVA Inc.

Controlled DocumentANP-3284NP Results of Analysis and Benchmarking of Revision 0Methods for Monticello ATWS-I Page 1-11.0 Introduction and ScopeThis document presents the results of calculated BWR instability transients that are notterminated by scram and thus power and flow oscillations are allowed to grow to largeamplitudes (see References 1 and 2). This class of transients is the so-called Anticipated Transients Without Scram with Instability (ATWS-I).

The instability of the regional mode type isspecified.

The code used for calculating the regional mode instability and the large power andflow oscillations in the fuel bundles of the core is AISHA, which is described in Reference 3.Selected bundles identified as limiting are used to provide data for the single channel codeSINANO for calculation of the clad temperature excursion and determine the peak cladtemperature.

SINANO is described in Reference 3 Appendix B.The scope of the analysis includes several core loadings for Monticello plant. The analysis ofthese different cores is specified to highlight the impact of the fuel design on the peak cladtemperature response.

To accomplish this objective, three cores were analyzed:

a core loadedwith GE14 fuel type, a mixed core representing the transition from GE14 to ATRIUM 1OXM, andan equilibrium core loaded with ATRIUM 1OXM.The ability of the codes AISHA and SINANO to perform the calculations is demonstrated bypresenting benchmark results comparing code calculations with experimental data. Thebenchmark results and the Monticello ATWS-I analysis suite constitute a consistent demonstration of the consequences of an ATWS-l.AREVA Inc.

Controlled DocumentANP-3284NP Results of Analysis and Benchmarking of Revision 0Methods for Monticello ATWS-I Page 2-12.0 Benchmarking the Code AISHAThe AISHA code theory is described in Reference 3 Appendix A. The code calculates thetransient thermal-hydraulic response of a BWR core with a detailed representation of onechannel per fuel assembly.

It applies a [] There are no limitations with respect to flow direction, and the severe flow oscillations accompanied with inlet flow reversal can be simulated.

AISHA applies [J The steady state simulator providesautomated input coupling for the hydraulic and neutron cross section parameters.

[] The dynamic functionality of thealgorithms which is important in stability and oscillation calculations is verified by benchmarking to stability specific data.The benchmarking of AISHA is divided into three parts. The first part is focused on the purethermal-hydraulic modeling and is accomplished by comparing the code results with the stability tests of ATRIUM-10 performed at the KATHY loop (Reference 7). The measured decay ratioand frequency for a large number of test points are compared with the AISHA calculated values.The agreement provides the needed proof of the validity of the AISHA thermal-hydraulic models.The second part of the benchmarking is an integral exercise where both the thermal-hydraulic and the neutron kinetics are coupled in the simulation of regional mode oscillations thatoccurred in actual BWR plants. The set of regional mode oscillations is the same used toAREVA Inc.

Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-IANP-3284NP Revision 0Page 2-2benchmark the NRC-approved frequency domain stability code STAIF (Reference 5), and thetime-domain code RAMONA5-FA (Reference 6).The third part of benchmarking AISHA is testing the general core performance againsttheoretically predicted trends. This is accomplished by running an ATWS-l transient andperforming checks to demonstrate the ability of the code to generate very large oscillations inpower and flow of regional type and demonstrate large amplitude inlet flow reversal in somebundles.

Sensitivity calculations for key parameters are examined.

2.1 Test Suite and Acceptance CriteriaThe AISHA code validation includes the following cases:* Comparison for ATRIUM-10 KATHY loop stability tests. Comparisons include the decayratio and frequency for all the runs in the test suite. [" Benchmarking to all the stability tests and events of regional mode unstable oscillations in actual BWR plants included in the RAMONA5-FA test suite. These are:LThe acceptance criteria are satisfied if the AISHA code results agree with the experimental results.

Quantitatively, the criteria are-I" Calculated decay ratios are within [I* Calculated frequencies are within [trends IJ of the measured value. Conservative trendsI are acceptable.

] Hz of the measured values. Conservative I are acceptable.

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Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-IANP-3284NP Revision 0Page 2-32.2 Benchmarking AISHA to KATHY Stability TestsThe data collected from the stability testing of the ATRIUM-1 0 bundle in the KATHY loop areused for benchmarking AISHA. The KATHY loop is a general purpose test apparatus wheretest sections of PWR and BWR fuel bundles can be connected.

The loop can operate underforced or natural circulation modes. It is capable of various types of measurements such as voidfraction and pressure profiles and critical heat flux under steady state conditions.

Different reactor transients including BWR stability can be simulated.

In the test used for this benchmark, a full-scale ATRIUM-10 electrically heated bundle with bottom-skewed axial power distribution isoperated under natural circulation.

The operating conditions of power and inlet subcooling were varied and data were collected foreach operating point. [The number of data points used in this benchmarking is [ ]. The measured operating parameters for each test point are used as input to AISHA. [] The decay ratio and frequency for each test point are compared with thecorresponding measured values.The following figures depict good agreement between the measured and calculated decay ratiosand frequencies.

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Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-lANP-3284NP Revision 0Page 2-4Figure 2-1 Comparison between ATRIUM-10 KATHY test andAISHA calculated decay ratiosAREVA Inc.

Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-IANP-3284NP Revision 0Page 2-5Figure 2-2Comparison between ATRIUM-10 KATHY test andAISHA calculated frequencies It is important to notice that the excellent agreement between measured and calculated frequencies is of particular significance to the fidelity of simulating density waves. This pointhas been discussed in more details in the DIVOM methodology report, Reference 7.AREVA Inc.

Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-IANP-3284NP Revision 0Page 2-62.3 Benchmarking AISHA to Regional Oscillations in BWRsThe table below shows good agreement between AISHA calculated and test measured decayratio and frequency for all the cases.Table 2-1Measured and AISHA calculated regional mode stability 2.4 Sensitivity and Verification of Trends for an A TWS-I with Regional Oscillations A representative set of calculations were performed to verify the capability of AISHA to simulatevery large oscillation amplitudes.

These runs include []The core loading map showing the hydraulic types is shown below where hydraulic type (1) isATRIUM 1OXM, and types (5) and (6) are GEl4. Type (6) refers to the peripheral tight orificedGE14 bundles.AREVA Inc.

Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-IANP-3284NP Revision 0Page 2-7Figure 2-3Hydraulic type map where type (1) is ATRIUM 1OXM, types (5) and (6)are GEl4.The time step is set to [I run to very large oscillation amplitudes with large reverse flow. A subcooling transient was specified where the subcooling is linearly increased from [] initial value to thevery large magnitude of []. A regional power perturbation is introduced

[IRepeated runs of the base case were made where the selected bundle is different from thebase case. In one run, a GE14 is selected.

In another run, a bundle which is the symmetric opposite of the base ATRIUM 1 OXM assembly has been selected for output to verify that theoscillation is of the regional type if these bundles are shown to oscillate out-of-phase.

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Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-IANP-3284NP Revision 0Page 2-8Sensitivity runs to vary [I were made.The first sensitivity case is identical to the base case with the one difference of using [I.The second sensitivity case is the same as the base case, but selects a GE14 bundle for thespecial output (adjacent to the special output bundle in the base case).The third sensitivity case is the same as the base case, but selects the bundle symmetric to thebase ATRIUM 1 OXM assembly for the special output.The fourth sensitivity case is identical to the base case with the exception that []The fifth sensitivity case is also identical to the base case with the exception that []The results are presented and discussed below using the selected bundle output for the testcases to plot power and inlet flow. For some plots the time range spans the entire run, and forothers a zoom is shown for better visualization of details.The following two figures show the base case selected bundle power and inlet flow respectively.

Notice that the significant power peaking is produced.

Notice also that the inlet mass flowoscillation is large with significant reverse flow of [ I.AREVA Inc.

ý,o&.b ak-c' DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-lANP-3284NP Revision 0Page 2-9Figure 2-4 Example calculated bundle power as function of time.AREVA Inc.

.e DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-lANP-3284NP Revision 0Page 2-10Figure 2-5Example calculated bundle inlet flow rate as functionof time.AREVA Inc.

Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-IANP-3284NP Revision 0Page 2-11The following two figures show the [Figure 2-6Example calculated bundle power as function of time,zoom from Figure 2-4AREVA Inc.

Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-lANP-3284NP Revision 0Page 2-12Figure 2-7 Example calculated bundle inlet flow rate as functionof time, zoom from Figure 2-5AREVA Inc.

Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-IANP-3284NP Revision 0Page 2-13The following two figures depict comparisons between the base case and the [Figure 2-8Example calculated bundle power as function of timefor base and [ IAREVA Inc.

Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-lANP-3284NP Revision 0Page 2-14Figure 2-9 Example calculated bundle inlet flow rate as functionof time for base and [ I.AREVA Inc.

Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-IANP-3284NP Revision 0Page 2-15The following two figures depict comparisons between the base case and the [Figure 2-10 Example calculated bundle power as function of timefor base and [ ]AREVA Inc.

Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-lANP-3284NP Revision 0Page 2-16Figure 2-11 Example calculated bundle inlet flow rate as functionof time for base and [ ]AREVA Inc.

Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-lANP-3284NP Revision 0Page 2-17The following two figures depict comparison of power and flow between the base case [Figure 2-12 Example calculated bundle power as function of timefor two adjacent bundles of different fuel types.AREVA Inc.

Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-IANP-3284NP Revision 0Page 2-18Figure 2-13 Example calculated bundle inlet flow rate as functionof time for two adjacent bundles of different fuel types.AREVA Inc.

Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-lANP-3284NP Revision 0Page 2-19The following two figures depict comparison of power and flow between the base case [Figure 2-14 Example calculated bundle power as function of timefor two adjacent bundles of different fuel types, zoom from Figure 2-12AREVA Inc.

Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-lANP-3284NP Revision 0Page 2-20Figure 2-15 Example calculated bundle inlet flow rate as function of timefor two adjacent bundles of different fuel types, zoom from Figure 2-13.AREVA Inc, Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-lANP-3284NP Revision 0Page 2-21The following two figures depict comparison of power and flow between the base case [Figure 2-16 Example calculated bundle power as function of timefor two symmetrically opposite bundles.AREVA Inc.

ont e ° DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-IANP-3284NP Revision 0Page 2-22Figure 2-17 Example calculated bundle inlet flow rate as functionof time for two symmetrically opposite bundles.AREVA Inc.

Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-lANP-3284NP Revision 0Page 2-23The following two figures depict comparison of power and flow between the base case [Figure 2-18 Example calculated bundle power as function of timefor two symmetrically opposite

bundles, zoom from Figure 2-16AREVA Inc.

Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-lANP-3284NP Revision 0Page 2-24Figure 2-19 Example calculated bundle inlet flow rate as function of timefor two symmetrically opposite

bundles, zoom from Figure 2-17AREVA Inc.

DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-lANP-3284NP Revision 0Page 2-25The following two figures depict comparisons between the base case and the [Figure 2-20 Example calculated bundle power as function of timefor nominal and [ IAREVA Inc.

Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-lANP-3284NP Revision 0Page 2-26Figure 2-21time for [Example calculated bundle inlet flow rate as function of]1.AREVA Inc.

Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-lANP-3284NP Revision 0Page 2-27The following two figures depict comparisons between the base case and [Figure 2-22 Example calculated bundle power as function of timefor nominal and []i.AREVA Inc.

Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-lANP-3284NP Revision 0Page 2-28Figure 2-23 Example calculated bundle inlet flow rate as functionof time for nominal and []AREVA Inc.

Controlled DocumentANP-3284NP Results of Analysis and Benchmarking of Revision 0Methods for Monticello ATWS-I Page 3-13.0 Benchmarking the Code SINANOThe data used for the development and benchmarking of the code SINANO is obtained from thestability testing campaign for the ATRIUM 1OXM at the KATHY loop. The KATHY loop is ageneral purpose test apparatus where test sections of PWR and BWR fuel bundles can beconnected.

The loop can operate under forced or natural circulation modes. It is capable ofvarious types of measurements such as void fraction and pressure profiles and critical heat fluxunder steady state conditions.

Different reactor transients including BWR stability can besimulated.

For stability and severe oscillation testing of ATRIUM 1OXM, a full scale electrically heated testsection is used. The axial power shape is bottom-peaked

[ J. The heatedrods include full-length and part-length rods. [The tests include stable operation under different power and subcooling conditions where thestability is determined from [ I and also include a large number ofcases where the stability threshold was crossed and oscillations were allowed to grow. Some ofthe oscillation tests were pure thermal-hydraulic tests, and some others included powerfeedback to simulate reactivity-to-power and [ ] processes.

The procedure in the pure thermal-hydraulic testing is similar to the previous stability testingcampaigns with ATRIUM-9 and ATRIUM-10.

[] These fluctuations are not purely random and carry information regarding the system stability.

The stability state is measured online using a noise analysisAREVA Inc.

Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-IANP-3284NP Revision 0Page 3-2program.

[Information about dryout behavior is extracted from the pure thermal-hydraulic stability testingby simply allowing the flow oscillations to increase, and apply additional power increase stepsas needed. Cyclical dryout and rewetting were observed in these tests by recording theresponses of the many thermocouples attached to the heater rods at different elevations.

[It is well-known from numerical and theoretical studies of density waves in BWRs that thereactivity-to-power feedback has a destabilizing effect. By implementing such feedback in theKATHY test loop, the loop is operated at conditions closely resembling the actual conditions inan unstable BWR. With the power feedback turned on, []oscillations of the flow and now power to reach high amplitudes with significant inlet flowreversal

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Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-lANP-3284NP Revision 0Page 3-3The test results were studied and important data were extracted.

These data allowed thetransient extraction of [] Themeasured and extracted information from the tests were essential in developing the models inthe code SINANO, and serve to benchmark it.The entire test run database was reviewed with regard to dryout occurrence under oscillation.

All the test runs that were identified as experiencing dryout at any spacer, with or without failureto rewet, are processed and used for the benchmarking of SINANO. [IAREVA Inc.

Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-IANP-3284NP Revision 0Page 3-4Table 3-1 [IThe identified cases were run using SINANO and the comparison between the measured andcalculated results forms the base benchmark.

Sensitivity studies to model input parameters arealso performed.

3.1 Benchmark ResultsThe calculation results for all I] test cases are presented in the following Figures.

Thesefigures depict comparison of measured and calculated IIAREVA Inc.

Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-lANP-3284NP Revision 0Page 3-5IFigure 3-1 through Figure 3-7 present measured and model calculated results for [IFigure sets similar to Figure 3-1 through Figure 3-7 similarly present measured and modelcalculated results for [ ] test runs. In order to reduce the volume of the plotted data,IIThe cases and figure numbers are given in the table below.AREVA Inc.

Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-lANP-3284NP Revision 0Page 3-6Table 3-2 Figures for ATRIUM 1OXM KATHY test simulations AREVA Inc.

Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-lANP-3284NP Revision 0Page 3-7Figure 3-1 [IAREVA Inc.

Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-lANP-3284NP Revision 0Page 3-8Figure 3-2IIAREVA Inc.

Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-lANP-3284NP Revision 0Page 3-9Figure 3-3IIAREVA Inc.

Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-lANP-3284NP Revision 0Page 3-10Figure 3-4IAREVA Inc, Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-lANP-3284NP Revision 0Page 3-11Figure 3-5 [AREVA Inc.

Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-lANP-3284NP Revision 0Page 3-12Figure 3-6IAREVA Inc.

Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-lANP-3284NP Revision 0Page 3-13(Figure 3-7 [AREVA Inc.

Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-lANP-3284NP Revision 0Page 3-14Figure 3-8 [AREVA Inc.

Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-IANP-3284NP Revision 0Page 3-15Figure 3-9[IAREVA Inc.

Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-lANP-3284NP Revision 0Page 3-16Figure 3-10 [IAREVA Inc.

Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-IANP-3284NP Revision 0Page 3-17Figure 3-11 [IAREVA Inc.

Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-lANP-3284NP Revision 0Page 3-18Figure 3-12 [AREVA Inc.

Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-IANP-3284NP Revision 0Page 3-19Figure 3-13 1IAREVA Inc.

Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-lANP-3284NP Revision 0Page 3-20Figure 3-14AREVA Inc.

Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-IANP-3284NP Revision 0Page 3-21Figure 3-15 [AREVA Inc.

Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-lANP-3284NP Revision 0Page 3-22Figure 3-16 [AREVA Inc.

Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-lANP-3284NP Revision 0Page 3-23Figure 3-17 [AREVA Inc.

Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-IANP-3284NP Revision 0Page 3-24Figure 3-18 [IAREVA Inc.

Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-lANP-3284NP Revision 0Page 3-25Figure 3-19 [IAREVA Inc.

Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-lANP-3284NP Revision 0Page 3-26Figure 3-20 [AREVA Inc.

Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-lANP-3284NP Revision 0Page 3-27Figure 3-21 [AREVA Inc.

Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-IANP-3284NP Revision 0Page 3-28Figure 3-22 [IAREVA Inc.

Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-IANP-3284NP Revision 0Page 3-29Figure 3-23 [AREVA Inc.

Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-lANP-3284NP Revision 0Page 3-30Figure 3-24IIAREVA Inc.

Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-lANP-3284NP Revision 0Page 3-31Figure 3-25[IAREVA Inc.

Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-lANP-3284NP Revision 0Page 3-32Figure 3-26 [IAREVA Inc.

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Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-lANP-3284NP Revision 0Page 3-34Figure 3-28 [IAREVA Inc.

Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-IANP-3284NP Revision 0Page 3-35Figure 3-29AREVA Inc.

Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-lANP-3284NP Revision 0Page 3-36Figure 3-30 [AREVA Inc.

Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-IANP-3284NP Revision 0Page 3-37Figure 3-31IAREVA Inc.

Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-IANP-3284NP Revision 0Page 3-38Figure 3-32IAREVA Inc.

Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-IANP-3284NP Revision 0Page 3-39Figure 3-33 [IAREVA Inc.

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Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-IANP-3284NP Revision 0Page 3-42Figure 3-36 [AREVA Inc.

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Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-IANP-3284NP Revision 0Page 3-44Figure 3-38 [IAREVA Inc.

Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-IANP-3284NP Revision 0Page 3-45Figure 3-39 [AREVA Inc.

Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-lANP-3284NP Revision 0Page 3-46Figure 3-40[IAREVA Inc.

Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-IANP-3284NP Revision 0Page 3-47Figure 3-41 [AREVA Inc.

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Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-IANP-3284NP Revision 0Page 3-56Figure 3-50 [AREVA Inc.

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Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-lANP-3284NP Revision 0Page 3-58Figure 3-52 [AREVA Inc.

Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-lANP-3284NP Revision 0Page 3-59VFigure 3-53 [AREVA Inc, Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-lANP-3284NP Revision 0Page 3-60Figure 3-54IAREVA Inc.

Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-lANP-3284NP Revision 0Page 3-61Figure 3-55 [AREVA Inc.

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Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-lANP-3284NP Revision 0Page 3-63Figure 3-57 [IAREVA Inc.

Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-lANP-3284NP Revision 0Page 3-64Figure 3-58 [I3.2 Discussion of SINANO Benchmarking ResultsBoiling transition under oscillatory power and/or flow conditions is shown to follow a consistent pattern.

[AREVA Inc.

Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-lANP-3284NP Revision 0Page 3-65The first temperature pulses indicating the initial inception of dryout are observed

[] The temperature pulses indicate dryout as marked bypositive temperature time derivative, followed by rewetting as indicated by the turnaround andtemperature falling.

The cyclical dryout and rewetting produced periodic temperature pulseswhere (under steady oscillation with fixed amplitude) the temperature oscillates between thesame minima and maxima. [J Failure to rewet was observed to occur [A mathematical conception of the above observations can be made to aid in the modeling effort.The heat transfer processes as indicated by the response of the thermocouples form adynamical system [AREVA Inc.

Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-lANP-3284NP Revision 0Page 3-66[The model described in this report is consistent with the characterization of the dryout andrewetting processes provided above. The model describes a dynamical system which uponintegration is capable of producing

[]. The other important output parameter of the model is the peaktemperature upon failure to rewet. (A general survey of the results as depicted in Figure 3-1 through Figure 3-58 shows generalgood agreement between the measured and model calculated rod surface temperatures.

Moredetails describing the nature of agreement and behavior of the model are presented here.AREVA Inc.

Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-IANP-3284NP Revision 0Page 3-67Comments regarding representative runs I] are given below.AREVA Inc.

Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-lANP-3284NP Revision 0Page 3-68[IAREVA Inc.

Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-IANP-3284NP Revision 0Page 4-14.0 ATWS-I Calculations for Monticello Extended Flow WindowA total of [ ] transient runs were calculated with AISHA. The main variant in the calculations is the core loading.

These cores are:1. A full core loaded with GE142. An initial transition core loaded with GE14 and ATRIUM 1OXM3. An equilibrium core of ATRIUM 1OXMThe transient scenario is specified as [ ]to simulate a turbinetrip with turbine bypass. The loss of feedwater heating is represented by [] Increasing core inlet subcooling destabilizes the core in two different ways:through its intrinsic destabilizing effect even if other conditions were kept unchanged, andthrough increasing the total reactor power.AREVA Inc.

Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-lANP-3284NP Revision 0Page 4-2The core pressure was [IThere are a total of [] AISHA runs as given in the following table.Table 4-1Monticello ATWS-l calculations For each of the runs, the limiting bundles were identified, and AISHA output for each of theselimiting bundles was processed using the code SINANO to calculate the hot rod temperature response.

[] The peak clad temperature is calculated as the maximum nodal temperature ofthe hot rod of the limiting bundles.AREVA Inc.

Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-IANP-3284NP Revision 0Page 4-3The following figures depict the results for the respective limiting bundle for each of the runs. Ineach figure, the bundle power is shown (RED) as function of time, the inlet mass flow rate isshown (BLUE) as function of time, and the clad temperature at the indicated limiting node(BLACK) is also plotted.Figure 4-1 ATWS-I conditions for GE14 core hot bundle at [AREVA Inc.

Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-IANP-3284NP Revision 0Page 4-4Figure 4-2ATWS-l conditions for GE14 core hot bundle at [AREVA Inc.

Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-lANP-3284NP Revision 0Page 4-5Figure 4-3ATWS-I conditions for mixed core hot ATRIUM 1OXMbundle at [ IAREVA Inc.

Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATVVS-IANP-3284NP Revision 0Page 4-6Figure 4-4 ATWS-I conditions for mixed core hot GE14 bundle at [IAREVA Inc.

Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-lANP-3284NP Revision 0Page 4-7Figure 4-5ATWS-I conditions for mixed core hot ATRIUM IOXMbundle at I IAREVA Inc.

Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-IANP-3284NP Revision 0Page 4-8Figure 4-6 ATWS-l conditions for mixed core hot GE14 bundle at [IAREVA Inc.

Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-IANP-3284NP Revision 0Page 4-9Figure 4-7 ATWS-I conditions for ATRIUM 1OXM core hot bundle at [IAREVA Inc.

Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-IFigure 4-8 ATWS-I conditions for ATRIUM 1OXM core hot bundle at [ANP-3284NP Revision 0Page 4-10IThe general pattern of the ATWS-I transient starts with a regional mode power perturbation.

[] self-sustaining oscillations start to grow exponentially, i.e. with a fixed decay ratiogreater than unity. A characteristic of the regional mode oscillation is that [] It is observed that the power and flow oscillation magnitudes

[AREVA Inc.

Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-lANP-3284NP Revision 0Page 4-11[The temperature response in the limiting bundle starts when the flow oscillation magnitude issufficiently large to cause dryout. This typically starts at the [] Cyclical dryout and rewetting occurs, [] The peak clad temperature is thus governed bythe [AREVA Inc.

Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-lANP-3284NP Revision 0Page 4-124.1 Peak Clad Temperature ResultsThe peak clad temperature for each of the calculations is reported in the table below. For themixed core, the peak clad temperature for each of the two fuel types is reported separately.

Table 4-2 Calculated peak clad temperatures during ATWS-lThe results indicate that:* Peak clad temperature is below the coolability limit of 1204 0C (2200 'F).AREVA Inc.

Controlled DocumentResults of Analysis and Benchmarking ofMethods for Monticello ATWS-lANP-3284NP Revision 0Page 5-15.0 Conclusions The analysis described in this report indicates that the ATWS-l transient in Monticello does notviolate the peak clad temperature criterion.

Due to applying conservative assumptions, significant margin exists. Fuel type has not been identified as a significant factor.AREVA Inc.

Controlled DocumentANP-3284NP Results of Analysis and Benchmarking of Revision 0Methods for Monticello ATWS-I Page 6-16.0 References

1. "ATWS Rule Issues Relative to BWR Core Thermal-Hydraulic Stability,"

NEDO-32047-A, Class I June 1995.2. W. Wulff et al., "BWR Stability Analysis with the BNL Engineering Plant Analyzer,"

NUREG/CR 5816, BNL/NUREG-52312, October 1992.3. ANP-3274P Revision 0, "Analytical Method for Monticello ATWS-I,"

AREVA NP Inc.,December 2013.4. EMF-2158(P)(A)

Revision 0, "Siemens Power Corporation Methodology for Boiling WaterReactors:

Evaluation and Validation of CASMO-4/MICROBURN-B2,"

Siemens PowerCorporation, October 1999.5. EMF-CC-074(P)(A)

Volume 4 Revision 0, BWR Stability Analysis

-Assessment of STAIFwith Input from MICROBURN-B2, Siemens Power Corporation, August 2000.6. EMF-3028(PA)

Vol. 2 Revision 4, "RAMONA5-FA:

A Computer Program for BWR Transient Analysis in the Time Domain -- Theory Manual,"

AREVA NP Inc., January 2011.7. BAW-10255(P)(A)

Rev. 2, "Cycle-Specific DIVOM Methodology Using the RAMONA5-FA Code," AREVA NP Inc., May 2008.8. D. W. Pruitt, K. R. Greene, F. Wehle, R. Velten, J. Kronenberg, A. Beisiegel, and Y. M.Farawila,

" Stability and Void Fraction Measurements for the ATRIUM 1OXM BWR FuelBundle,"

Proceedings of 2010 LWR Fuel Performance Top Fuel WRFPM, Orlando, Florida,Sept. 26-29, 2010.9. F. Wehle, R. Velten, J. Kronenberg, A. Beisiegel, D. Pruitt, K. Greene, and Y. Farawila, "FullScale Stability and Void Fraction Measurements for the ATRIUM 1OXM BWR Fuel Bundle,"2011 Jahrestagung Kerntechnik, Berlin, Germany, May 17-19 2011.AREVA Inc.