USER`S MANUAL OF THE COUPLED CORE SIM NEUTRONIC
Contents
1. 25 Chapter 9 HOW TO USE CORE SIM 26 Variable EIG_M ET Variable allowing choosing whether the Explicitely Restarted Arnoldi Method ER AM or the power iteration method POW is to be used Please note that the power iteration method uses Wielandt s method to calculate the different eigenmodes and a first guess of the eigenvalues is required Such a guess of the eigenvalues is provided by an Arnoldi run without restart In case of convergence problem for ERAM it is recommended to switch to POW EIG M ET 1 for ERAM default or EIG_MET 2 for POW Variable BY P Variable allowing getting the results even if some of the eigenmodes have not con verged BY P 0 default if you want to interrupt the program when the eigen modes have not converged after MAX_NUM_RESTARTS restarts for ERAM or after MAX_NUM_NEUT_ITER iterations for POW BY P 1 permits the execution of the program even if the eigenmodes have not converged Variables DIM K RY L SUBSPACE MAX_NUM_RESTARTS and CONV NEUT ITER ERAM Parameters used for the Explicitely Restarted Arnoldi Method ERAM If the user is not familiar with ERAM it is recommended not to change these settings Nev ertheless if convergence problems are experienced during the calculation of the eigenmodes changing the following parameters could help resolve such problems DIM KRYL SUBSPACE 150 default dimension of the Krylov subspace MAX NUM REST ARTS 20 default number of ma2. SPECIAL FUNCTIONS a directory containing special functions for calculating additional input data MANUALS USERS GUIDE CS COUPLED PDF a PDF file of this document MANUALS METHODOLOGY CS COUPLED PDF a PDF file giving an overview of the algorithms used in CORE SIM MANUALS DEMONSTRATION CS COUPLED PDF a PDF file giving an overvi ew of the demonstration cases of CORE SIM EXAMPLES a directory containing some examples of the CORE SIM runs for a BWR and a PWR FILE ARCHITECTURE AND REQUIRED INPUT In the same directory where all the above directories and files are located a directory called INPUT should exist All the necessary input files should be created by the user in this directory Only mat files are accepted as input files The user has thus to convert all input data into mat files using for instance MATLAB for reading various types of ASCII or binary files In the input directory the following files might exist e XS DATA REF mat file describing the three dimensional distributions of the ref erence extracted from core simulator macroscopic cross sections throughout the system this file is compulsory KIN DATA REF mat file describing the size of an elementary node in the x y and z directions this file is compulsory this file also contains some additional data necessary for calculating the neutron noise these data are optional and only required if the neutron noise has to be estimated TH VARS
3. CONV mat calculations respectively 27 owe LQ EXAMPLES CORE SIM is delivered with a couple of examples located in the directory called exam ples as detailed in the table below In this directory subdirectories each containing one example of a CORE SIM run are located In each of these subdirectories the input output directories and corresponding files for each of the run examples are available as well as the SETTINGS m file All the examples correspond to a heterogeneous core i e the input data are spatially heterogeneous i e node wise quantities throughout the core Table 10 1 Description of the examples provided with the code package name of the subdirectory description of the case calculation of the static STATIC SIM PWR neutronic and thermo hydraulic quantities for a PWR calculation of the noise in both neutronic and thermo hydraulic quantities induced by a perturbation in the inlet flow fora PWR two examples one for an out of phase and one for a point wise perturbations calculation of the static STATIC_SIM_BWR neutronic and thermo hydraulic quantities fora BWR calculation of the noise in both neutronic and thermo hydraulic quantities induced by a perturbation in the inlet flow fora BWR two examples one for an out of phase and one for a point wise perturbations DYNAMIC SIM PWR DYNAMIC SIM BWR 29 nil SUPPORT BUG REPORTS In case of problem ques
4. V 1 6 defines the thermo hydraulic quantity to be used as an interpo lation variable in the present case these are density V 3 and fuel temperature V 5 I 1 M J 1 N K 1 K spatial coordinates where M N K are the number of nodes in x y and z direction respectively All four indexes V I J and K are strictly positive integer numbers XS MESH DATA mat This file contains only one variable called XS_MESH representing a structure with grid points of all cross sections which will be used as interpolated variables in the three dimensional interpolation of the cross sections Structure of variable XS MESH XS MESH V vec I vec J vec K 1 whe re V 1 6 defines the cross section type to be used as an interpolated variable in the present case these are diffusion coefficient in the fast V 1 and thermal These perturbed cross sections are calculated by adding a fixed node wise perturbation either in the coolant moderator density or fuel temperature see the Table on page 16 to the respective static values The perturbed cross sections are thereafter used in the linear cross section model and coupled noise calculations 18 groups V 2 removal cross section V 3 absorption cross section in the fast V 4 and thermal V 5 groups fission cross section times the averaged number of neutrons per fission in the fast V 6 and thermal V 7 groups the averaged number of neutro
5. its maximum and minimum val ues The interpolation vectors the pressure and fuel temperature will be automatically generated by dividing the corresponding interpolation ranges into Q intervals specified by the size of RHO FUEL TAB and SPEC HEAT FUEL TAB For the interpola tion the MATLAB built in function interp2 performing a two dimensional interpolation is used 19 AVAILABLE VARIABLES IN THE OUTPUT FILES The following table describes the variables that can be found in the output file Note that some of the listed variables are only available when the corresponding calculations are required by the user 21 Chapter 8 AVAILABLE VARIABLES IN THE OUTPUT FILE Table 8 1 Content of the output files Input file Variable Description Dimension Unit name name of variable of the variable ABS1 Fast macroscopic 3 ned absorption cross section ABS2 Thermal macroscopic 3 ad absorption cross section D1 Fast diffusion 3 um coefficient D2 Thermal diffusion 3 pn coefficient NUFISI Fast macroscopic fission 3 p cross section times y NUFIS2 Thermal macroscopic fis 3 p sion cross section times v KAPPAFIS1 Fast macroscopic fission 3 mde cross section times K KAPPAFIS2 Thermal macroscopic fis 3 Pa sion cross section times k DN oua 3 em STAT VAR Fast stati CONV mat FLX1 FE 3 em 2 8 neutron flux FLX2 Thermal static 3 PE E neutron flux KEFF Effective multiplica
6. required software hardware what the code package contains the file architecture and required input the created output the format of the input and output variables the variables necessary in the input files and the available variables in the output file a description of how to use the code some examples available within the code package a description of how to obtain code support and to report bugs REQUIRED SOFTWARE Since CORE SIM is a MATLAB code access to MATLAB is necessary CORE SIM was developed and tested with MATLAB Version 8 2 0 701 R2013b Depending on the types of problems investigated access to large RAM or swap space might be required In case of Out of Memory errors within MATLAB useful tips can be obtained on the Math Works website http www mathworks com in order to resolve such problems search for Resolving Out of Memory Errors CODE PACKAGE The coupled neutronic thermo hydraulic CORE SIM package is made of the following files and directories CORE_SIM_MAIN m the main executable MATLAB M file in order to run the cou pled neutronic thermo hydraulic CORE SIM tool SETTINGS m a MATLAB M file containing some parameters used by the CORE SIM tool and that the user might change depending on his her needs ADDING NEW PATHS m a MATLAB M file specifying the paths to the necessary files and directories MODULE a directory containing the main code modules of the CORE SIM tool
7. ARAM REF mat file containing the information about the thermo hydraulic parameters together with the three dimensional distributions of required reference extracted from core simulator thermo hydraulic variables throughout the system this file is compulsory FUE TAB mat file containing the fuel tables used for calculating the three dimen sional distributions of fuel density and fuel specific heat this file is optional and only required if the noise in thermo hydraulic quantities has to be determined XS DATA PERT RHO LM mat file describing the three dimensional distributions of the perturbed macroscopic cross sections throughout the system the perturba tion is induced by perturbations in the coolant moderator density this file is only compulsory if no separate cross section model is provided and is optional other wise XS DATA PERT TFU LM mat file describing the three dimensional distributions of the perturbed macroscopic cross sections throughout the system the perturba tion is induced by perturbations in the fuel temperature this file is only compulsory if no separate cross section model is provided and is optional otherwise dTH DATA REEmat file containing the definition of the thermo hydraulic noise source this file is optional and only required if the noise has to be determined from the external perturbations of the boundary conditions in the thermo hydraulic variables CREATED OUTPUT A directory called OUTPUT
8. CTH NT 302 August 2014 USER S MANUAL OF THE COUPLED CORE SIM NEUTRONIC AND THERMO HYDRAULIC TOOL VICTOR DYKIN AND CHRISTOPHE DEMAZIERE Division of Nuclear Engineering Department of Applied Physics Chalmers University of Technology SE 412 96 Gothenburg Sweden 2014 ABSTRACT This report presents how to use the coupled CORE SIM neutronic thermo hydraulic tool The models and algorithms used in the coupled version of CORE SIM as well as the demonstration of the tool were already presented in two companion reports 1 2 The novelty of the tool resides in its versatility since many different systems can be investi gated and different kinds of calculations can be performed More precisely both critical systems and subcritical systems with an external neutron source can be studied static and dynamic cases in the frequency domain i e for stationary fluctuations can be con sidered For each situation the three dimensional distributions of static neutron fluxes all thermo hydraulic parameters their respective first order noise are estimated as well as the effective multiplication factor of the system The main advantages of the tool which is entirely MATLAB based lie with the robustness of the implemented numeri cal algorithms its high portability between different computer platforms and operative systems and finally its ease of use since no input deck writing is required The present version of the tool which is based on two grou
9. H ITER and E dVAR TH ITER VAR RHO VEL PRES Parameters used for the dynamical thermo hydraulic inner iterations CONV dVAR_TH_ITER 107 VAR RHO VEL PRES default maximum allowed error in coolant moderator density velocity and pressure in dynamical TH iterations E dVAR TH ITER 1 VAR RHO V EL PRES default no need to be changed by the user initial error in coolant moderator density velocity and pressure in dynamical TH Thermo Hydraulic iterations Variables CONV dVAR and E dVAR VAR RHO VEL TFU ENTH PRES Parameters used for the dynamical coupled iterations CONV dVAR 107 VAR RHO VEL TFU ENTH PRES default maximum allowed error in coolant mo derator density velocity fuel temperature coolant moderator enthalpy and pres sure in dynamical coupled iterations EdVAR 1 VAR RHO VEL TFU ENTH PRES default no need to be changed by the user initial error in coolant mo derator density velocity fuel temperature coolant moderator enthalpy and pres sure in dynamical coupled iterations CORE SIM has then to be run within the MATLAB command window by simply typing CORE_SIM_MAIN once being in the directory containing the code CORE SIM then creates a mat output file located in the directory OUTPUT if this directory does not exist it will be automatically created All the results of the calcu lations are saved in the file named STAT_VAR_CONV mat for static and for dynamic DYN VAR
10. MESH DATA mat file containing grid points of thermo hydraulic quan tities which will be used as interpolation variables in the three dimensional inter polation of the cross sections this file is compulsory for using a tabulated cross section model e XS MESH DATA mat file containing grid points of cross sections which will be used as interpolated variables in the three dimensional interpolation of the cross sections this file is compulsory for using a tabulated cross section model e S DATA mat file containing the definition of an external neutron source for the problem this file is optional and only required if the static neutron flux in the prob lem of a subcritical system with external neutron source has to be determined e DF DATA mat file describing the three dimensional distributions of the disconti nuity factors throughout the system this file is optional if this file is not provided all discontinuity factors are automatically set to unity FLX DATA REEmat file describing the three dimensional distributions of both fast and thermal reference extracted from core simulator neutron fluxes through out the system this file is compulsory Chapter 4 FILE ARCHITECTURE AND REQUIRED INPUT dS_DATA mat file containing the definition of the cross section neutronic noise source this file is optional and only required if the neutron noise has to be deter mined from the external perturbations of the cross sections TH P
11. aluate additional relationships between different thermo hydraulic parameters These perturbations are given in relative terms i e in percentage from a static value 16 Input file Variable Description Dimension Unit name name of variable of the variable acer EL UO fuel density 2 g cm SPEC HEAT Specific heat gt Jeg FUEL_TAB of UO fuel Rc PMAX Upper limit 0 Bar FUE_ for pressure TAB mat PMIN Lower limit 0 Bus for pressure TFUMAX Upper limit for 0 K fuel temperature TFUMIN Lower limit for 0 K fuel temperature Perturbed fast ABS1_RHO macroscopic absorption 3 em cross section Perturbed thermal ABS2 RHO macroscopic absorption 3 em cross section Perturbed fast 9 pre diffusion coefficient 5 id Perturbed thermal 9 PREDHO diffusion coefficient ay Perturbed fast XS DATA Rn macroscopic fission 3 en PERT_RHO_ cross section times y LM mat NUFIS2 Perturbed thermal RHO macroscopic fission 3 em cross section times y KAPPAFIS1 Perturbed fast RHO macroscopic fission 3 J em cross section times amp KAPPAFIS2 Perturbed thermal RHO 5 macroscopic fission 3 Sem cross section times amp Perturbed macroscopic REM RHO removal 3 cm cross section Perturbed fast ABS1_TFU macroscopic absorption 3 em cross section Perturbed thermal A ll ABS2 TFU macroscopic absorption 3 ar LM ia t E cross section y Perturbed fast 9 DIE diffusion
12. coefficient is D2 TEU Perturbed thermal 3 um diffusion coefficient 17 Chapter 7 NECESSARY AND OPTIONAL VARIABLES IN THE INPUT FILES Input file Variable Description Dimension Unit name name of variable of the variable NUFIS1 Perturbed fast TFU 2 macroscopic fission 3 emt cross section times y NUFIS2 Perturbed thermal TFU macroscopic fission 3 cm cross section times y KAPPAFISI u t TFU macroscopic fission 3 J cm cross section times amp KAPPAFIS2 Perturbed thermal TFU G macroscopic fission 3 J em cross section times K Perturbed macroscopic REM TFU removal 3 em cross section dPOUT i 2 Bar core exit pressure dTH DATA dTINL External perturbation in gt K REEmat core inlet temperature dVINL External perturbation in 2 dns External perturbation in core inlet velocity Description of tabulated cross section model All the files related to the table based cross section model are placed in the INPUT direc tory in a separate folder called XS MODEL INPUT This folder contains two files e TH VARS MESH DATA mat This file contains only one variable called TH VARS MESH representing a struc ture with grid points of thermo hydraulic quantities which will be used as interpo lation variables in the three dimensional interpolation of the cross sections Structure of variable TH VARS MESH TH VARS MESH V vec 1 vec vec K 1 where
13. ns per fission v V 8 and the energy released per fission event y V 9 the rest of the notations are similar to the ones described above For the interpolation the MATLAB built in function griddata performing three dimensi onal interpolation is used Description of fuel tables All the data necessary for the fuel tables are summarized in one mat file called FUE TAB mat placed directly in the INPUT directory As was shown in Table 7 1 this file contains 6 variables two are two dimensional and the remaining 4 variables are of zero dimen sion The first two variables RHO FU EL TAB and SPEC HEAT FUEL T AB have the following format VAR I J with I J 1 Q where Q is the total number of elements in the corresponding vectors and provide the grid points of the fuel density and fuel spe cific heat which will be used as interpolated variables in a two dimensional interpolation of these quantities respectively Both quantities ie the fuel density and fuel specific heat are assumed to be two dimensional variables and depend on both the pressure and fuel temperature They thus will be interpolated in a two dimensional space The two indexes J and J are strictly positive integer numbers The other two variables PM AX and PMIN specify the range of the first interpolating variable the pressure i e its maxi mum and minimum values The last two variables T FU M AX and TFU MIN define the range of the interpolation for the fuel temperature i e
14. oss section model two files XS DATA PERT RHO LM mat and XS_DATA_PERT_TFU_LM mat with perturbed cross sections with re spect to both density and fuel temperature should be provided by the user X M 1 for launching table based cross section model default files with cross section ta bles should be provided by the user and placed in the directory XS MODEL INPUT otherwise X SM 2 for launching linear cross section model based on tabulated cross sections files with cross section tables should be provided by the user and placed in the directory XS MODEL INPUT Variable FLAG NOISE SWITCH Variable allowing choosing whether noise calculations should be performed FLAG NOISE SWITCH 0 for launching noise calculations default other wise FLAG NOISE SWITCH 1 Variable MAX NUM ITER STATC AL MAX NUM ITER ST ATCAL 10 default maximum number of iterations in static coupled calculations Variable MAX NUM ITER DYNCAL MAX NUM ITER DYNCAL 10 default maximum number of iterations in dynamical noise coupled calculations Variable MAX NUM TH ITER STATCAL MAX NUM TH ITER STATCAL 10 default maximum number of itera tions in static thermo hydraulic inner calculations Variable MAX NUM TH ITER DYNC AL MAX_NUM_TH_ITER_DY NCAL 10 default maximum number of itera tions in dynamical noise thermo hydraulic inner calculations Variable FREQ FREQ 0 5 default frequency at which noise calculations should be performed
15. p diffusion theory is mostly suited to in vestigate thermal systems both Pressurized and Boiling Water Reactors PWR and BWR respectively The tool is freely available on direct request to the authors of the present report Contents 1 INTRODUCTION 1 2 REQUIRED SOFTWARE 3 3 CODE PACKAGE 5 4 FILE ARCHITECTURE AND REQUIRED INPUT 7 5 CREATED OUTPUT 9 6 UNDERSTANDING THE FORMAT OF THE INPUT AND OUTPUT VARIABLES 11 7 NECESSARY AND OPTIONAL VARIABLES IN THE INPUT FILES 13 8 AVAILABLE VARIABLES IN THE OUTPUT FILE 21 9 HOW TO USE CORE SIM 25 10 EXAMPLES 29 11 SUPPORT BUG REPORTS 31 References 35 III INTRODUCTION This report describes how to use the coupled version of the CORE SIM code CORE SIM is a MATLAB code which allows calculating for a given set of input data the two group static neutron fluxes of the corresponding critical system and all respective thermo hydraulic quantities In addition CORE SIM also calculates the static neutron flux of the subcritical system with an external neutron source Finally CORE SIM estimates the first order noise in both neutronic and thermo hydraulic quantities in the frequency domain The main feature of CORE SIM is its flexibility and its simplicity in use since there is no need in writing any input deck The models and algorithms used in CORE SIM as well as the demonstration of the tool were already presented in two companion reports 1 2 This reports presents in more details the
16. riable MESH TH VARS MESH with TH grid points 6 DATA mat used for the interpolation Structure variable with SM XS_MESH cross section grid points 9 DATA mat used for the interpolation 1v stands for the average number of neutrons released per fission event 2 stands for the energy released per fission event Since these structure variables contain the spatial distributions of different kinds of quantities the units of the variables can not be specified explicitly 14 Input file Variable Description Dimension Unit name name of variable of the variable S1 Fast jdm oxen 0 ims aed S DAS mat Thermal external neutron rx I S2 0 cm s Source Fast discontinuity DN factor north face Fast discontinuity s factor south face s FIE Fast discontinuity 3 1 factor east face FIW Fast discontinuity 3 1 factor west face DE Thermal discontinuit DATA mat F2S y 3 1 factor south face Thermal discontinuity 1 TAN factor north face 2 FOE Thermal discontinuity 3 1 factor east face F2W Thermal discontinuity 3 1 factor west face FLX1 Reference fast static 3 EE neutron flux FLX DATA Reference thermal static 2 1 REF mat FLAA neutron flux Tao NE KEFF Reference multiplication 0 1 REF factor Perturbation of the fast dABS1 macroscopic absorption 3 em cross section Perturbation of the thermal dABS2 macroscopic absorption 3 em cross section Perturbation of
17. s Ringhals AB research contracts 522351 003 531970 003 543672 002 557700 003 566379 003 and 578254 003 the Swedish Radiation Safety Authority SSM formerly the Swedish Nuclear Power Inspectorate SKI research contracts 14 5 991060 99180 14 5 000983 00156 14 5 010892 01161 14 5 011142 01261 SSM 2012 3299 and SSM 2013 903 and the Nordic Thermal Hydraulic Network NORTHNET research contracts 4500131026 Forsmark Kraftgrupp AB 581422 025 Ringhals AB SKI 2007 1588 20070 5015 Swedish Radiation Safety Authority SSM formerly the Swedish Nuclear Power In spectorate and SE 08 018 Westinghouse Electric Sweden AB 33 References 1 Dykin V and Demazi re C Description of the models and algorithms used in the coupled CORE SIM neutronic thermo hydraulic tool CTH NT 300 report Chalmers University of Technology 2014 2 Dykin V and Demazi re C Demonstration of the coupled CORE SIM neutronic thermo hydraulic tool CTH NT 301 report Chalmers University of Technology 2014 3 Holmgren M XSTEAM MATLAB based programm for water tables http fwww x eng com 1997 35
18. s terms TINL Core inlet coolant 0 K This input parameter is optional and required only in case of tabulated linear cross section model 5If the reference moderator temperature is not provided as an input data it will be automatically calcu lated by using the reference calculated from reference data enthalpy core exit pressure and water tables for the water table a MATLAB based tool by 3 was used If the reference moderator temperature is given as an input parameter it will be used instead in the calculations whereas the reference density will be ignored STf the effective heat transfer coefficient is not provided as an input data it will be automatically calculated by using the reference neutron flux fission cross sections fuel temperature and moderator temperature These node wise perturbations induced in the static coolant moderator density and fuel temperature are used to calculate the perturbed cross sections see the Tables on pages 17 18 which thereafter are used in the linear cross section model and coupled noise calculations to evaluate the relationship between the perturbations in the thermo hydraulic parameters and the respective perturbations in the cross sections SThese node wise perturbations induced in the static coolant moderator density and pressure are used to calculate the corresponding perturbations in other thermo hydraulic quantities which thereafter are used in thermo hydraulic noise calculations to ev
19. t like i e zero dimensional or three dimensional The three dimensional variables use the same conventions as the input variables 11 NECESSARY AND OPTIONAL VARIABLES IN THE INPUT FILES The following table describes the variables that needs to be defined can be defined in each input file Chapter 7 NECESSARY AND OPTIONAL VARIABLES IN THE INPUT FILES Table 7 1 Content of the input files Input file Variable Description Dimension Unit name name of variable of the variable ABS1 Fast macroscopic l 3 p absorption cross section ABS2 Thermal macroscopic 3 a absorption cross section D1 Fast diffusion 3 m coefficient D2 er 3 m Dole Fast TEE ic fission REEmat NUFIS1 T 3 em cross section times y NUFIS2 Thermal macroscopic UR 3 um cross section times y KAPPAFIS1 Fast macroscopic Bion 3 E cross section times amp KAPPAFIS2 Thermal macroscopic um 3 Jed cross section times K REM Macroscopic removal 3 mE cross section Size of the elementary E node in the x direction o in Size of the elementary phe node in the y direction i ud Size of the elementary DX node in the z direction d KIN DATA Effective fraction of delay REF mat betaetf ed neutrons one group Ends Decay constant of the neu 0 NE tron precursors one group vi Average neutron speed 0 PD in the fast group v2 Average neutron speed 0 m in the thermal group TH VARS Structure va
20. the fast dNUFIS1 macroscopic fission 3 cm cross section times y as Perturbation of the thermal 2E 1 DATA mat dNUFIS2 macroscopic fission times y 3 cm cross section Perturbation of the macro dREM scopic removal 3 em cross section Perturbation of the fast dS1 external neutron source 3 cm s if any Perturbation of the thermal dS2 external neutron source 3 cm s7 if any Chapter 7 NECESSARY AND OPTIONAL VARIABLES IN THE INPUT FILES moderator temperature Input file Variable Description Dimension Unit name name of variable of the variable RHO REF Reference coolant 3 gms moderator density TFU REF Reference fuel 3 K temperature TMO REP Reference coolant 3 K moderator temperature SLIP Slip ratio 3 1 Reference effective HEFF heat transfer 3 rar cm 3 K 1 coefficient FLOW AREA Coolant moderator 0 sind PER NODE flow area per node FUEL VOL Fuel volume 0 d PER NODE per node HYD DIA Hydraulic diameter 0 cm TH PARAM GRAV CONST Gravitational constant 0 cm s REE mat MASS FLUX Mass flux 0 hg em s HINL Core inlet coolant 0 J kg moderator enthalpy PEXIT Core exit coolant 0 Bar moderator pressure THERM Total core POW REF thermal power i a Perturbation in coolant 7 3 a moderator density Rt dTEU7 Perturbation in fuel 0 K temperature dTHVARS Perturbation in thermo 0 relative hydraulic quantitie
21. tion please contact Victor Dykin Chalmers University of Technology Department of Applied Physics Division of Nuclear Engineering SE 412 96 Gothenburg Sweden Tel 46 31 772 3086 Fax 46 31 772 3079 E mail victor nephy chalmers se Professor Christophe Demazi re Chalmers University of Technology Department of Applied Physics Division of Nuclear Engineering SE 412 96 Gothenburg Sweden Tel 46 31 772 3082 Fax 46 31 772 3079 E mail demaz chalmers se As a registered user of the coupled CORE SIM tool you are endorsed to provide bug reports when such bugs are detected In such a case please send your input files to the above e mail address Feedback about the tool its use and the accompanying manuals is also greatly ap preciated 31 ACKNOWLEDGEMENTS The development of the reported computational tool would not have been possible with out active discussions with and participations of some students from the Division of Nu clear Engineering Department of Applied Physics Chalmers University of Technology The authors thus wishe to express their appreciation to Dr Augusto Hern ndez Solis Dr Viktor Larsson Dr Carl Sunde and MSc Filippo Zinzani Prof Imre P zsit is acknowledged for his long term support during this project The continued financial support from the Swedish nuclear industry via different pro jects for which the development of the tool was necessary is also deeply acknowledged and among other
22. tion 0 1 factor ALPHA Coolant moderator 3 1 void fraction QUAL Flow quality 3 1 ENTH Coolant moderator 3 Jg enthalpy TMO Coolant moderator 3 K temperature VEL Coolant moderator 3 me velocity PRES Coolant moderator 3 Bar pressure FRIC Two phase friction 3 1 COEFF coefficient TFU Fuel temperature 3 K 22 Input file Variable Description Dimension Unit name name of variable of the variable Noise in fast dABS1 macroscopic absorption 3 em cross section Noise in thermal dABS2 macroscopic absorption 3 em cross section Noise in fast dNUFIS1 macroscopic fission 3 em cross section times v Noise in thermal dNUFIS2 macroscopic fission 3 em cross section times v Noise in macroscopic dREM removal 3 cm DYN VAR cross section CONV mat dFLX1 Fast neutron 3 E noise dFLX2 Thermal neutron 3 MU noise dENTH Noise in coolant 3 Jg moderator enthalpy dTMO Noise in coolant 3 K moderator temperature dVEL Noise in coolant 3 mm moderator velocity dPRES Noise in coolant 3 Bar moderator pressure ATFU Noise in fuel 3 K temperature 23 HOW TO USE CORE SIM Prior to use CORE SIM the user might want to fine tune some parameters in the file named SETTINGS m default parameters will be used if the user does not modify anything in this file e Variable XSM Variable allowing choosing the type of cross section model X SM 0 for launching linear cr
23. will be created if it does not already exist In this direc tory all output variables are saved in two mat files called STAT VAR CONV mat and DYN VAR CONV mat for the static and dynamic calculations respectively UNDERSTANDING THE FORMAT OF THE INPUT AND OUTPUT VARIABLES Input variables can be point like i e zero dimensional two or three dimensional Any three dimensional variable represents a space dependent variable written in a cartesian coordinate system and is generically denoted as VAR I J K where I J and K are strictly positive integers representing the node number in the z y and z directions respectively Similarly any two dimensional variable is denoted as VAR I J where I and J are strictly positive integers representing the node number in the x and y respectively In addition there are two structure variables of much higher dimension specified for the tabulated cross section model The geometry of the core is defined by the set of macroscopic cross sections defined in the file XS DATA REF mat It is assumed that the core has a cylindrical shape with the axis of the cylinder being along the z axis Radially nodes not containing any cross section data are assumed not to belong to the system being modelled i e are considered as being outside of the system being modelled This thus provides a relatively easy way to define the radial layout of the core Output variables can be poin
24. ximum restarts CONV NEUT_ITER_ERAM 100 x eps default convergence criteria on the residuals with eps being the machine precision Variables MAX NUM N EUT ITER and CONV_NEUT_ITER_POW Parameters used for the power iteration method POW MAX NUM N EUT IT ER default maximum number of iterations CONV NEUT ITER POW de fault convergence criteria on the residual with eps being the machine precision Variables CONV VAR TH ITER and E VAR TH ITER V AR RHO VEL PRES Parameters used for the static thermo hydraulic inner iterations CONV VAR TH ITER 10 VAR RHO VEL PRES default maximum allowed error in cool ant moderator density velocity and pressure in static TH iterations E VAR TH ITER 1 VAR RHO VEL PRES default no need to be changed by the user initial error in coolant moderator density velocity and pressure in static TH iterati ons Variables CONV VAR and E VAR V AR RHO VEL PRES Parameters used for the static coupled iterations CONV VAR 1074 VAR RHO VEL TFU ENTH PRES default maximum allowed error in coolant moderat or density velocity fuel temperature coolant moderator enthalpy and pressure in static coupled iterations E VAR 1 VAR RHO VEL TFU ENTH PRES de fault no need to be changed by the user initial error in coolant moderator den sity coolant velocity fuel temperature coolant moderator enthalpy and pressure in static coupled iterations Variables CONV dVAR T
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