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MVP-BURN User`s Manual

1. In the Member Name column of the above table four characters given by the input data CASEID is entered to case while the burn up step number 01 to 99 is given to UH Sample input SAVEPDS 1 PRINT integer integer Print output control option 0 Simplified output default setting Detailed output 2 Output for debugging 3 Detailed output for debugging Sample input PRINT 1 PDSCHK integer integer Print control of file access information for members under the PDS directory lt 0 Suppresses printing Prints written information only default setting 2 Prints all access information OPEN READ WRITE 3 Detailed output for debugging Sample input PDSCHK 0 48 6 Sample Input The MVP BURN sample input output data and shell script are provided under the burnrun directory The directory has the file configuration shown below burnrun ReadMe HCLWR SURVEY PIE NEAGD MOXBWR SPACE HTTR MTR Description of the MVP BURN execution method and samples Hexagonal unit cell burn up calculation Parametric survey on Vm Vf for HCLWR cell no burn up Analysis of a post irradiation examination Burn up calculation for a small BWR lattice with burnable poison rods Burn up calculation for a MOX BWR 10x10 fuel assembly Control dram worth calculation for a space reactor no burn up Burn up calculation for a HTTR High Temp Gas Cooled Reactor fuel cell inclu
2. 99 For the intermediate steps of the PC method two alphameric characters are used as follows 0A OB OC OJ 1 IB 1C 9J where A 0 5 B 1 5 J 9 5 Members listed by boldface are I O files of MVP The members listed by boldface in Fig 2 7 1 and Table 2 71 1 are corresponding to I O files of separate use of MVP The data structures of these members are the same to those of MVP If a more detailed study becomes necessary after the burn up calculation of the specified case case and step number Z7 a separate MVP calculation is easily possible by using the output member of MVP BURN caseV IZ as a standard input data of MVP 2 7 2 Restart calculation Since the burn up calculation results including material composition data is stored every burn up step restart calculation of MVP BURN is possible even if the burn up calculation unfortunately stops by an accident such as electric power frailer limitation of available computer resources and so on However MVP BURN does not support the restart calculation of MVP itself even if the restart option of MVP is specified in its input data That is to say the MVP calculation stopped on the way is recalculated from the first This is because the computation time for once execution of MVP is thought to be short for users of MVP BURN Other features and points to remember on the restart calculation are described below e The restart capability is effective not only for
3. 2 REGION NAME BU MWD T POWER XE 135 YD 1 135 YD SM 149 YD PM 149 YD 1 FUEL 3 35667e 04 1 00000 02 1 35632e 19 6 31808 02 1 06135e 10 1 35632e 19 4 mode 2 Atomic number densities of all depleting nuclides by material at the specified burn up step MVPBURN CALCULATION SUMMARY CASEID V1E7 TITLE NEACRP BENCHMARK ON HCLWR UNIT CELL BURNUP CASE W VF 1 1 NUMBER DENSITIES FOR BURNUP STEP 1 N REGION NAME 00234 00235 00236 00237 00238 NP237 NP239 PU238 PU239 1 FUEL 0 00000 00 1 51220e 03 0 00000 00 0 00000 00 2 14770 02 0 00000 00 0 00000 00 0 00000 00 0 00000 00 56 5 mode 3 Burn up change of atomic number density by material for the specified nuclide MVPBURN CALCULATION SUMMARY CASEID V1E7 TITLE NEACRP BENCHMARK ON HCLWR UNIT CELL BURNUP CASE W VF 1 1 REGION WISE NUMBER DENSITIES FOR NUCLIDE UO234 ID 1 N REGION NAME 1 2 3 4 5 6 7 8 9 1 FUEL 0 00000 00 3 58973e 10 1 78484e 09 3 55043e 09 8 86512 09 1 75342e 08 3 35148e 08 4 84136e 08 6 22634 08 6 mode 4 Burn up change of material property exposure power etc user selection in the specified material MVPBURN CALCULATION SUMMARY CASEID V1E7 TITLE NEACRP BENCHMARK ON HCLWR UNIT CELL BURNUP CASE W VF 1 1 REGION WISE BURNUP DATA FOR ITEM BU MWD T 10 1 N REGION NAME 1 2 3 4 5 6 7 8 9 1 FUEL 0 00000 00 1 00000 02 5 00000 02 1 00000 03 2 50000 03 5 0
4. Sample input DENINIT float float Sample input value the calculation 1s forcibly terminated When CPUTIME is not specified or float 0 0 is entered the calculation time is regarded as being unlimited CPUTIME 120 0 MVP BURN always outputs the information required for the restart calculation to a member under the PDS directory each time the burn up step is complete Therefore even if the limitations defined by the system including the calculation time are exceeded the burn up calculation can be restarted This data item entry can be omitted if there is no problem with the system management The CPU time limitation TCPU specified by the MVP input data is a time limit for each MVP calculation If the MVP calculation conducted at each burn up step exceeds TCPU it will be forcibly terminated regardless whether the number of batches requested by the user is completed and the calculation of the next burn up step will be started Print output control option Simplified output default setting Detailed output Output for debugging Detailed output for debugging PRINT 1 Specify a maximum length of the burn up chain in linear analysis The default value is set to integer 6 from the experience LCHAO 6 Initial atomic number density 107 cm given to the burn up nuclide which does not exist in the initial burn up state On MVP the microscopic reaction rate required for the depletion calculation can no
5. lt NSTEP gt 1111 lt BURN input option to save source file SEND MVPBURN lt End of the super block for the comment type BURN input data EIGEN VALUE SOURCE OUTPUT lt MVP input option to save source file HH FISSIONFILE lt Specifying source data rewritten by BURN XSEC SOURCE lt Start of the source data block to be used at the first burn up step 25 SEND SOURCE lt End of the source data block Notes The MVP s SOURCE OUTPUT option is effective only for the eigenvalue problem designated by the EIGEN VALUE option and the fission source data in the last batch is output to the binary file on logical unit 9 MVP BURN stores it as a member of PDS and provides it as an MVP input file from logical unit 8 at the next burn up step Therefore if a fission source file member is lost reproducibility by the MVP individual calculation will be lost at each burn up step In addition the fission source file cannot be used during restart calculation If the fission source file is not found in the PDS directory the source data described for the initial step will be used To use the fission source file it is necessary to use the source input format of SOURCE the old input format is incompatible However this need not apply when the same initial source data is given without using the fission source file during the burn up period Even if the fission source file is used the number of discarded batches at the subsequent bur
6. lt VOLF gt TRGNAM PINFUEL lt FTEMP gt U023500900 6 77553E 4 U023800900 2 16308E 2 0001600900 4 46168E 2 SEND XSEC A library actually used by MVP BURN observes the description of the neutron index file given to MVP For example if an MVP library of 300K is assigned to U023500900 in the index file a 300K library will be used If a temperature not listed in the index file is specified in temp an error will be caused during MVP execution Source data of MVP may occasionally be given as a fission spectrum of a specific nuclide as shown below E FISSTION U023500900 2 53E 02 The nuclide ID name of a material for which the MVPBURN line was inserted within the SXSEC block is changed by temp while the nuclide ID name appearing in the source data is not changed Therefore the nuclide ID name given in the source data should be entered according to the 24 temperature changed by temp Alternatively enter each ID name given by the source data to the neutron index file separately The simplest and recommended way is to specify the nuclide ID name with the meta character as shown below E FISSION U02350 2 53E 02 In this case the ID name begins with U02350 and the fission spectrum in the library first appearing in the index file is used as the initial guess value of the fission source spectrum 5 Changing symbolic parameter values MVP BURN allows changing the value of the symboli
7. MVP standard input text casej VI 4H Jo MVP fission source output binary case vs Ja MVP binary output binary case vR 44 J4 MVP standard output text case VP HH In the Member name column of the above table four characters given by the input data CASEID are entered to case while the burn up step number 01 to 99 is given to When this data item entry is omitted only the MVP standard output file is saved for all steps integer 1 In order to save the members of the intermediate step i 1 2 when the PC method is used it is necessary to enter a negative value to the integer at the input specification of the PC of option Sample input SAVE MVP OUTPUT lt NSTEP gt 1111 keep all results Note To use the output source file of the previous burn up step as the MVP initial source data it is necessary to specify 1 To suppress the output file capacity only J4 is set to 1 as the default value However when the disk has a sufficient capacity it is recommended to set J to 1 as well When it is necessary to edit the contents of the binary output file of MVP set J3 1 STDNUC integer integer Specify an integer to denote a nuclide whose fractional depletion rate is used as a 33 Sample input Note IBMOD integer integer burn up indicator Input an integer value calculated by the following equation Integer zz x10000 mmm x10 n where zz 1 99 mmm 1 999 and n 0 1 are integers
8. Name of the tally region for the burnable material 12 characters in maximum Enter a tally region name defined in the DEFINE mode The nuclide depletion calculation for each 23 material is carried out with the microscopic reaction rate obtained for the tally region specified by this tally region name temp Material temperature K The 7th to 10th characters of a 10 digit nuclide ID to be entered in the MVP input are changed to an integer value of the temperature specified by temp in MVP BURN For example when temp 1200 6 is specified the nuclide ID is changed as follows U023500300 10023501200 Notes A material without the MVPBURN line inserted is not subject to the depletion calculation even if it includes a burnable nuclide defined by the burn up chain data For example MVPBURN should not be described for the chemical shim region containing B 10 The MVPBURN line is taken as a comment statement for MVP However volume tally region name and temp can be described with the symbolic parameters which are defined in the lines starting from in the first column given in advance during MVP input Since MVP BURN uses the fixed temperature libraries generated by ART it is not allowed to use an option TEMPMT to specify material temperature in MVP Sample input RF 0 410 PI 3 14159265 VOLF PI RF 2 FTEMP 900 0 XSEC UO2 Fuel amp IDMAT 1 MVPBURN VOLM
9. Therefore when a comment line is inserted within the super block it is mo necessary to specify BURN mode in the first and second columns The following shows an input example in the Sample Input lt the first title line of the MVP input data for MVP BURN lt the second title line of the MVP input data MVPBURN lt Start of the super block for the comment type BURN input data BURNUP lt Start of the input data for the BURNUP mode TITLE1 Benchmark on HCLWR Unit Cell Burn up TITLE2 Vm Vf 1 1 Pu Fissile 7 0wt o CASEID V1E7 VIE7 is the case name Comment line in the super block 1 0 2 1 0E3 5 0E3 1 0 4 1 5E4 2 0 4 2 4 3 0 4 4 0 4 5 0E4 6 0E4 Exposure in MWd t unit SEND BURNUP lt End of the input data for the BURNUP mode SSEND MVPBURN lt End of the super block for the comment type BURN input data NO RESTART FISSION EIGEN VALUE lt Option lines of the MVP input data MVP input data 1 lt End of the MVP input data The start end of the super block must be always specified with MVPBURN and END MVPBURN starting from the first column in capital letters 4 2 2 Separate Type Input Format The separate type input format is used to handle both types of MVP and BURN input data in respective individual files Since only editing of the calculation results is performed in the SUMMARY and AVERAGE modes without using the MVP input data the separate type inpu
10. iii physically rare event and so on In those cases MVP BURN will be stopped with printing of an error message If the user predicts and allows this situation e g test calculation with small histories burn up calculation can be continued by specifying this option even when zero reaction rates are detected This option is effective for testing calculation with small number of neutron histories When the burn up calculation is unfortunately stopped before the last step the restart calculation is possible by using this option At that time IBMOD option is also necessary to change burn up calculation condition Note A warning message will be printed when zero reaction rate is detected Sample input START 0 Restart calculation IBMOD 1 Change burn up calculation condition ACCEPT ZERO RATE Neglect zero reaction rates DEBUG 38 This 1s an option only for the developers of MVP BURN Debug in programming can be done without repeated executions of MVP The procedure is as follows 1 Execute a MVP BURN for one step to get reaction rate distribution 2 Make a copy of the obtained member caseVRO1 and save it in the same PDS by the name for other burn up steps caseVR02 caseVRO3 3 Execute MVP BURN with the DEBUD option Then the initial reaction rates are always used for the depletion calculation as if they are calculated by MVP 39 5 2 BRANCH Mode The BRANCH mode is used to make the calculation by using the
11. 4 Burn up Calculation for Fixed Source Problems Omitted this function is under development 2 5 Special Treatments of Flux Normalization Omitted this function is under development 2 6 Branch off Calculation BRANCH Mode The branch off calculation is used to investigate reactivity changes at any burn up step start points due to instantaneous changes of core parameters like void fraction in coolant fuel temperature control rod position and so on Figure 2 6 1 illustrates an example of the case to calculate 10 void reactivity at the beginning of cycle BOC middle of cycle MOC and end of cycle EOC keff BURNUP mode in operating condition e g 0 void Burn up time BRANCH mode in perturbed condition e g 10 void Fig 2 6 1 Burn up calculation filled circles and branch off calculation white circles Before the branch off calculation we have to perform a usual burn up calculation in operating condition using the function of MVP BURN by the name of BURNUP mode After that the branch off calculation with a perturbed condition is performed using another function by the name of BRACH mode In the BRANCH mode the composition data of burnable materials are given by just copying the calculated results in BURNUP mode Perturbation is given by changing input data of MVP When the reactivity change is too small accurate results can not be expected by the branch off calculation 2 7 Output File Management a
12. 98th step At that time if burn up unit of MWd t is used to specify burn up period PERIOD input value must be multiplied by the inventory ratio Mo Msos 1 0 where and Mss are initial inventory and 98th inventory respectively POWERL float NSTEP always required float i Thermal power MWt of a system to be constant in the i th burn up step period To describe only a part of the system using the reflective or periodic boundary conditions assign thermal power for the described system the range that can be drawn by CGVIEW However for the two dimensional calculation using the top and bottom as the reflection boundary conditions consider the height direction as a unit length 1 cm and give an area of the burnable material For example POWERL should be given for the core with thermal power Q number of fuel assemblies N number of fuel rods in an assembly M active core height H depending on the following calculations 1 Three dimensional whole core calculation POWERL Q 2 Three dimensional half core calculation with a reflective boundary condition 29 Sample input POWERL Q 2 3 Horizontally two dimensional core calculation with reflective boundary conditions for both side of axial directions POWERL Q H 4 Axially finite one dimensional calculation for one fuel assembly with reflective boundary conditions in all horizontal directions POWERL Q N 5 Axially infinite two dimensional one fuel ass
13. Er162 Er164 166 gt 167 gt Er168 Er170 Hf176 gt Hf177 gt Hf178 gt Hf179 gt Hf180 Fig 3 3 Burn up chain model fp50bp16 for fission products and burnable poison nuclides 14 x x Kr83 Kr85 N Se p decay EC fission ny 7193 S 05 32 96 pd ecay IT wa 54 Nb93m Nb95 N x x Mo95 Mo97 x Tc99 3 N E x x x x x Rul00 Ru101 Rul02 gt Rul 03 gt 106 x 103 gt Rh10 106 N x x x 4104 gt Pd105 Pd106 Pd107 Pd108 3 Agl09 30 x x N x x N 4110 gt 4111 gt Cdl12 113 gt Cdll4 0 Cdll6 Ag107 1115 i Sb126m Tel27m x x 5125 Sb126 x E x x 1127 1129 1131 1135 x FA Noy x ga 2 e i x NN x 1 4139 gt La140 8133 gt Cs134 5135 P 73 x 2a N x Ba 37 D E Y PE N Bal40 a x Bal37g 4 x Prl41 gt Prl43 gt 144 0 A VA vA 4 oo Nd 142 gt Nd143 gt Nd144 gt Nd145 gt Nd146 gt 4 E x 0 9 Nd147Nd148 Nd150 3 A 4 X L x x Pm147 151 gt 0 i A x x x M Sm147 gt Sm1483Sm149 gt Sm150Sm151 gt Sm152 0 x x x x x x Eul5 1152 gt Eu153 Eul 543 Eu155 Eu156 Eu157 9 77099 Pseudo x x x E x x Gd152 Gd154 Gd155 Gd156 Gd157 Gd158 Gd160 B10 Erl62 Erl64 Er166 167 gt Er168 Er170 Hf176 Hf177 gt Hf178 gt Hf179 gt Hfl80 Fig 3 4 Burn up chain model fp104bp12 for f
14. MVP at time t t Fact t Normalization factor to convert relative reaction rates to absolute ones If it 1s supposed that the absolute reaction rates do not change in each sub step period Fact t 1s given by the following equation in the m th sub step period tm t tm 1 Past Stef EN TU 2 2 2 where Constant thermal power given by user for each burn up step period t t lt t 1 Energy release per fission of the i th nuclide Then Eq 2 2 1 can be solved analytically by the method of the DCHAIN code for each sub step The method of DCHAIN is based on Bateman s method with a modification for more accurate treatment of cyclic chain caused by a decay and so on It should be noted that the MVP results including eigenvalue are provided at the start point of each burn up step period not at the end point Therefore the MVP results are not provided at the end point of the final burn up step although the composition data is provided 2 2 Predictor Corrector Method As described in the previous section it is assumed that the distribution of microscopic reaction rates obtained at the burn up step start point does not change during the burn up step period Thus accurate results of the burn up calculation may not be obtained because the burn up step period is too long For example this problem occurs in a system where Gd5O is used as a burnable poison Since the absorption cross sectio
15. The statistical processing for multiple sets of MVP BURN results are carried out in the AVERAGE mode of MVP BURN As a result the average values and their errors are stored in PDS as if they are calculated by MVP BURN and the results can be edited with the SUMMARY mode Here we describe the statistical processing method for a physical quantity e g kj atomic number density reaction rate ratio and so on from M sets of MVP BURN results At first the average value of the x is given as follows X Wi 2 9 1 where x is a value obtained by the i th MVP BURN calculation and w is its weight as a function of effective number of neutron histories N w 2 9 2 Although w can be alternatively given as an inverse of variance for x obtained by each MVP calculation The equation 2 9 2 has an advantage to avoid possible bias due to correlations between batches in an eigenvalue calculation The variance of x is estimated as follows ESI 2 9 3 i 1 M 10 This equation 2 9 3 becomes the following expression when the weights are the same w N N 1 M among M sets of results 25 x A LL M1 2 9 4 M M 1 According to the option NODEAV 1 of the AVERAGE mode it is also possible to estimate the apparent but not real variance using the statistical errors obtained by each MVP calculation 2 9 5 In this case errors of atomic number densities are not es
16. a file called as member name under the PDS directory Therefore avoid using any inappropriate special character for the file name CASEID TEST PDS character A128 required if it is not specified as an environment variable character Sample input Note NSTEP integer integer PDS directory path name Enter a path name of the PDS directory where output members are stored using up to 128 characters PDS home user Test pds This path name can be provided by the environment variable MVPBURN_ PDS given by the execution shell script If this environment variable is provided with a path name it is not necessary to input this data Even if a value is assigned to the environment variable priority is given to the contents of this data when it is input The path name can be described with an absolute path or a relative path from the work directory However it should be specified with an absolute path in the environment where the NQS batch is used on a shared computer MVP BURN does not create a directory specified here Thus it is necessary to create a directory using a command mkdir or shell script in advance The path name is limited to up to 128 characters due to the program properties However since the valid range of the standard input data for the current MVP or MVP BURN is from the first to the 72nd columns the path name must be entered in this range If it is possible to enter use the environment
17. and information about sample input data equipped in the MVP BURN files 2 Calculation Scheme 2 1 Depletion Calculation In this section we describe a basic calculation scheme of MVP BURN by assuming a typical burn up calculation where an eigenvalue calculation is done with MVP and neutron flux levels are normalized to a total thermal power of the system under consideration although these conditions are not restrictions for MVP BURN As shown in Fig 2 1 1 MVP BURN employs two kinds of time subtractions since the continuous energy Monte Carlo method is time consuming One is a burn up step with a relatively long time span and the MVP calculation is carried out at the start point of each burn up step Each burn up step is divided into many sub steps for the depletion calculation by BURN The sub step is the other one Power initial fuel composition for n th step MVP LL Y Pn e m th sub step period Se n th burn up step period th tm m 1 Burn up time Fig 2 1 1 Burn up step and sub step in MVP BURN To avoid confusions we call the time span as step or step period while we call the two sides of step period as step start point and step end point which are specified in Fig 2 1 1 by a filled circle and an inverted triangle respectively At each burn up step start point composition data is given and the MVP calculation is executed for an eigenvalue problem Consequ
18. character A128 required if it is not specified as an environment variable character Path name of the output PDS directory When the file output is specified by the SAVEPDS input averaged members are created under the PDS directory specified by this data item The detailed method conforms to the PDS input method in the BURNUP mode When this data input is omitted the path name specified with the environment variable MVPBURN PDS provided by the execution shell script is applied Sample input PDSOUT Test pds4 MODEAVG integer integer Selectable option for the averaging method 0 Real error estimation default setting by Eq 2 9 3 Average of statistical errors of MVP by Eq 2 9 5 Sample input MODEAVG 1 Note The option integer 1 can not be used when number of case is unity Error estimation for atomic number densities is not performed when integer is selected SAVEPDS integer integer Member output option for the averaging result 0 Not output 1 Output default setting When SAVEPDS 1 is specified the members shown below are generated in PDS specified by the PDSOUT input Member name File description case HT MVP BURN burn up calculation result file case COM1 Step common data 1 case COM2 Step common data 2 case COM3 Step common data 3 case REST Restart file 47 Burnable material data case CHAN Burn up chain data binary
19. composition at each burn up step obtained in the BURNUP mode and changing the calculation conditions e g composition and shape other than the fuel specified by the MVP input data However the calculation conditions change must not be concerned with the burn up region and burn up nuclide count The BRANCH mode calculation can be executed even if the BURNUP mode calculation referencing the composition is not yet completed up to the final step If the composition data at the burn up step to be referenced is not found in the PDS directory the BRANCH mode calculation will be interrupted but can be resumed by the restart option BRANCH END BRANCH BRANCH declares the BRANCH mode input start while SEND BRANCH declares the BRANCH mode input end The data between these declarators is the BRANCH mode input data block The following data is inserted into the block in the arbitrary order TITLE character A72 always required character Specify the calculation title 1 of the branch off calculation The detailed method conforms to the TITLE input method in the BURNUP mode TITLE2 character A72 always required character Specify the calculation title 2 of the branch off calculation The detailed method conforms to the TITLE2 input method in the BURNUP mode CASEID character A4 always required character Specify the calculation case ID using four alphanumeric characters without blank The detailed method c
20. including neutron transport calculation An execution of MVP is possible if geometry and material compositions are given As a result of the MVP execution microscopic reaction rates of every nuclide are calculated On the other hand depletion calculation is possible if the microscopic reaction rates are given Therefore the coupling of MVP and BURN can be directly realized only by implementing an interface program between them The BURN code has the functions of depletion calculation file management and interface with MVP Alternate executions of MVP and BURN constitute a whole burn up calculation In MVP BURN an executable of MVP as an independent code is called from BURN The prototype of MVP BURN was developed in the latter half of 1990s and it has been widely used in Japan To meet users requests continuous improvements of MVP BURN and its validations have been carried out until now Together with recent revisions of MVP and extension of available MVP libraries based on various nuclear data files the present version of MVP BURN became a powerful tool for many burn up problems The latest MVP BURN has the following capabilities which may be difficult to be treated by conventional deterministic codes e Burn up calculations for eigenvalue problems and fixed source problems The former is a conventional way of usual burn up calculations The latter can be applied to for example burn up analyses of non fissionable material in the
21. irradiation capsule by giving surface source e Flexible normalization of flux to the tally parameter defined by user e g fast neutron flux of a specified monitoring region as well as usual normalization to a total thermal power or intensity of fixed sources Cooling calculations at zero power condition between burn up periods or after burn up This function is indispensable to analyses of post irradiation examinations e Burn up calculations for non fissionable but burnable materials e g non fissionable burnable poison or absorber materials in cluster or cruciform control rods in PWR or BWR Burn up or parametric survey calculations with changes of geometry size material composition and temperature This allows for example changes of control rod position void fraction soluble boron concentration thermal expansion along burn up 1 e Reactivity calculations along burn up so called branch off calculations using fuel composition obtained by usual burn up calculations e Burn up calculations for the system with randomly distributed many fuel particles using the 8 9 10 statistical geometry model of MVP e g coated fuel particles of HTGRs plutonium spots in MOX fuel pellet etc In this report descriptions are given at first on methods of MVP BURN Successively descriptions are given on available burn up chain models an outline of execution procedure instructions to users about input data requirements
22. possible to verify the final or current if the calculation is in progress burn up step and file save situation 3 Check the MVP output result The MVP standard output result is output as the member caseVPbb in the text format under the PDS directory In the member name case indicates a case name four characters while bb shows the burn up step number two characters Check the content of the file caseVPbb to verify that the calculation of MVP itself has been normally executed 50 4 Check the MVP standard input for each burn up step The MVP standard input is output as the member caseVIbb in the text format under the PDS directory It was actually used by BURN for the MVP calculation by changing data such as the fuel composition Check the content of this member file to verify that the MVP input was correctly created as assumed by the user When members are retained under the PDS directory the MVP BURN restart calculation can be carried out if the burn up calculation has been interrupted by an unforeseen cause such as a electric power failure Care must be taken to prevent indiscreet deletion of the members from the PDS directory even if an error should occur The text members under the PDS directory can be checked for their contents with such a command as cat vi during execution of the MVP BURN execution However any member which is currently at the execution step must not be s
23. that you just answer questions of ReadBURN The followings are image of appeard on the display ReadBURN TEESHSEAHASHSASSEHSESSESHSSTSISESTESESTAA ReadBURN Edit MVP BURN result Enter PDS directory full path home okumura MyMVP burnrun HCLWR pds User input PDS directory home okumura MyMVP HCLWR pds 54 Enter CASEI D 4 words VI E7 User input CASEID is VI E7 Now reading PDS data Compl et e When the following menu is appeared enter 0 at first to confirm the selectable values Enter output mode integer 0 Print PDS information burnup step regi nuclides list 1 Integrated summary Distribution of ITEM at 9 Quit program 0 Enter output file name Default ReadBURN t xt outpu txt Output name is outpu txt Sample output is shown below according to the selected mode number in the menu 1 mode 0 List of burn up steps depleting material names tally region name defined in the MVP input depleting nuclide names MVPBURN PDS INFORMATION CASEID V1E7 TITLE NEACRP BENCHMARK ON HCLWR UNIT CELL BURNUP CASE VM VF 1 1 STEP STEP 1 2 3 4 5 6 7 8 9 10 BURNUP MWD T 0 00e 0 1 00 2 5 00 2 1 00 3 2 50 3 5 00 3 1 00 4 1 50 4 2 00 4 2 50 4 STEP 1 12 13 14 15 16 17 BURNUP MWD T 3 00 4 3 50 4 4 00 4 5 00 4 6 00e 4 7 00 4 7 30 4 REGION No
24. the burn up calculation but also for the branch off calculation e n usual restart calculation BURN automatically confirm the last burn up step number where member files are normally written in the PDS then the restart calculation are carried out for the remaining burn up steps If necessary the restart calculation is possible from the burn up step specified by user This type of restart function is hereafter referred as returned restart calculation when it is necessary to be distinguished from the usual restart calculation e Input parameters for the burn up calculation e g number of burn up steps step period thermal power etc and a template input data of MVP are recorded in the members of PDS to store control data before the burn up calculation See Fig 2 7 1 In the restart calculations the same conditions are forced by reading the control data Therefore changes of input parameters are ineffective for the restart calculation except when a special option IBMOD is specified in the restart input data 2 8 Editing of Burn up Calculation Results SUMMARY Mode MVP BURN provides two easy ways to edit burn up or branch off calculation results from binary data stored in PDS One is to execute a MVP BURN in SUMMARY mode and the other is to use an interactive utility code ReadBURN See Appendix The former is suitable to make a table of all calculated results at once but it may be inconvenient when large amount of data must
25. variable to assign the path name Number of burn up step periods in the burn up calculation 0 lt integer lt 99 For example when NSTEP 10 is assumed MVP results will be output at 10 burn up step start points marked with filled circles shown in Fig 5 1 1 On the other hand the composition data obtained at the end point marked with inversed triangles of burn up step period are stored in PDS as the data at the start point of the next burn up step 28 Sample input Note period Therefore MVP results are not output at the end point of the last 10th burn up step although the composition data are given as an output of the 11th step Initial composition 5 1 step 2 step 3 step 10 step V Stored as 3th No MVP results step member For 11th member Burn up Fig 5 1 1 MVP calculation points filled circles If NSTEP is not specified the NSTEP value will be automatically determined by the count of input data POWER PERIOD SUBSTEPS or that 1s first entered If the NSTEP value is already assigned due to entry of these input data types it can be referenced as symbolic parameter Y NSTEP during subsequent data input NSTEP 10 For the burn up calculation with 99 or more steps it is necessary to terminate the burn up calculation at the 98th step and resume the burn up calculation as a case with a different name using the MVP input data output at the
26. 00 00 4 84202 04 2 42101 03 4 84202 03 1 21050e 02 2 42101e 02 4 84201 02 7 26302e 02 9 68402 02 POWER MW 1 79000 04 1 79000e 04 1 79000e 04 1 79000 04 1 79000 04 1 79000e 04 1 79000e 04 1 79000 04 1 79000 04 TON HM 4 84202e 06 4 84152e 06 4 83951 06 4 83700 06 4 82950 06 4 81699e 06 4 79203e 06 4 76712e 06 4 74225 06 R NORM FAC 9 83447e 12 9 86012e 12 9 96078 12 1 01238 13 1 03770 13 1 08813e 13 1 13599 13 1 17616 13 1 22126 13 FIS ABSOR 6 56089 12 6 55849 12 6 56936 12 6 58045 12 6 62186 12 6 67647e 12 6 75465 12 6 80538 12 6 84471 12 FIS DECAY 0 00000 00 0 00000 00 0 00000 00 0 00000 00 0 00000 00 0 00000 00 0 00000 00 0 00000 00 0 00000 00 FER 2 40353 12 2 454506 12 2 47322 12 2 48247 12 2 53673 12 2 64031 12 2 87432 12 3 09567 12 3 30586 12 PRE DECAY 0 00000 00 0 00000 00 0 00000 00 0 00000 00 0 00000 00 0 00000e 00 0 00000 00 0 00000 00 0 00000 00 AVNORM FACT 1 00056e 00 1 00038 00 9 99645 01 9 99249 01 1 00029 00 1 00414 00 1 00748 00 1 00981 00 1 01148 00 3 mode 2 Thermal power exposure and averaged fission yield of Xe135 1135 Sm149 Pm149 by material at the specified burn up step MVPBURN CALCULATION SUMMARY CASEID V1E7 TITLE NEACRP BENCHMARK ON HCLWR UNIT CELL BURNUP CASE VM VF 1 1 NUMBER DENSITIES FOR BURNUP STEP
27. 0000 03 1 00000 04 1 50000 04 2 00000 04 7 mode 5 Burn up change of all depleting nuclides in the specified material MVPBURN CALCULATION SUMMARY CASEID V1E7 TITLE NEACRP BENCHMARK ON HCLWR UNIT CELL BURNUP CASE VM VF 1 1 NUMBER DENSITIES FOR REGION FUEL N NUCLIDE 1 2 3 4 5 6 7 8 9 00234 0 00000 00 3 58973 10 1 78484 09 3 55043 09 8 86512e 09 1 753426 08 3 35148e 08 4 84136 08 6 22634 08 00235 1 51220 03 1 50933 03 1 49787 03 1 48369 03 1 44198 03 1 37499e 03 1 24923e 03 1 13291 03 1 02493 03 00236 0 00000e 00 5 93096e 07 2 96191 06 5 89571 06 1 45017 05 2 827376 05 5 38450e 05 7 71023 05 9 82371 05 00237 0 00000 00 4 74684e 09 1 67024 08 2 49298 08 4 17883 08 6 741776 08 1 09991 07 1 472126 07 1 81040 07 00238 2 14770 02 2 14758 02 2 14709 02 2 14648 02 2 14462 02 2 141476 02 2 13496e 02 2 12819 02 2 12116 02 NP237 0 00000 00 6 82556e 10 1 33330 08 4 24471 08 1 80393 07 5 46934e 07 1 673266 06 3 21786 06 5 08129 06 NP239 0 00000 00 7 35499e 07 1 33050 06 1 36457 06 1 37395 06 1 39941e 06 1 450546 06 1 51431 06 1 57362 06 PU238 0 00000 00 4 01864 13 4 15439 11 2 74686 10 3 01547 09 1 81294 08 1 10635 07 3 21643 07 6 88413 07 PU239 0 00000 00 3 30167e 07 3 2 1 6 1 7 6 6 4 99630 06 9 16985e 06 PU240 0 00000e 00 6 23004e 10 2 45910 08 1 0962
28. 1 07 PU241 0 00000 00 2 43428e 12 4 86995e 10 4 43885e 09 PU242 0 00000 00 8 47265e 16 8 32475 13 1 54812 11 38772 05 4 58534 05 8 22223 05 1 10990e 04 1 339326 04 84642e 07 2 40466 06 7 44950 06 1 34509 05 1 99591605 19991e 08 5 03023 07 2 85585 06 6 95008 06 1 20925 05 48244e 10 9 33042 09 1 10572 07 4 21586e 07 1 02208 06 57
29. 4 Tasaka et al JNDC Nuclear Data Library of Fission Products Second Version JAERI 1320 52 Japan Atomic Energy Research Institute 1990 53 Appendix ReadBURN ReadBURN a utility code to edit calculated results ReadBURN is an interactive utility code to extract necessary calculated results from binary data in PDS Although all calculated results can be edit by using the SUMMARY mode it may be inconvenient when number of depleting materials are many and data size is too large In such cases selected data by user can be printed in a table format with no linefeed for column The table data can be easily exported into a spread sheet software on the market e g Excel The MVP system contains ReadBURN under the directory MVP_DIR burnrun util A 1 Installation of ReadBURN ReadBURN has the following file structure ReadBURN ReadMe Makefile bin empty obj empty src f To install ReadBURN edit Makefile and change compile driver name F77 and its option FFLAGS as they are suitable for your computer The defaulted setting is as flows 77 77 FFLAGS Enter make command on the same directory where Makefile is located then object modules obj o and an executable bin ReadBURN will be generated They are all deleted by make clean command Set the command path to the executable then it becomes to be available 2 How to use ReadMVP Enter the command ReadBURN After
30. 63 x x nbus E 134 gt 135 gt PRAE lad Pa CAS 77 EY EY E n 6 d EY 141 gt 0 p Pr144 x x N E E Nd142 gt Nd143 93144 41459 Nd146 5 x N x 2 Nd150 gt 0 Losey x 147 149 151 p o A x SoS m151 gt Sm152 gt iara N N N bus d Eul 2 uA Eul56 gt Eu1573 0 x S x Gd152 PAPAE Gd160 T6160 o X X by Dy161 gt Dy162 gt Dy1 ES dii 7 Ho 166m x Hof63 Holt E uz YS S x E 162 gt Erl64 gt Er166 gt 167 gt Er168 Er170 10 BP Hf176 gt Hf177 gt Hf178 79 gt 80 Fig 3 5 Part2 Burn up chain model fp193bp6 for fission products and burnable poison nuclides 17 4 Execution Procedure and Input Data Format 4 1 Execution procedure 1 2 3 4 5 6 MVP BURN is generally executed with the procedure shown below Confirm the nuclide wise MVP libraries necessary for the solution of user s problem by consulting the burn up chain model to be used Generate nuclide wise MVP libraries for the requested temperature fixed temperature libraries from the original MVP libraries arbitrary temperature library by using ART which is one of the MVP utilities As a result of the ART execution user s fixed temperature libraries in binary form and user s index file in text form for the fixed temperature libraries will be made The inde
31. BURNUP mode input data block The following data is inserted into the block in the arbitrary order However the data may occasionally reference the contents and or count of data which was previously input In this case the data to be referenced will be located prior to the data which references TITLE character A72 always required character Specify the calculation title 1 using up to 72 characters It will be printed as the standard MVP BURN output If the specified title contains one or more blanks or special characters it is necessary to put a single quotation mark before and after the blank s or special character s Sample input TITLE1 Sample Input Data for MVP BURN Note The title is limited to up to 72 characters due to the program properties However since the valid range of the standard input data for the current MVP or MVP BURN is from the first to the 72nd columns and a data name must be entered character must actually consist of approximately 60 characters 27 TITLE2 character A72 always required character Sample input Specify the calculation title 2 using up to 72 characters The input conditions conform to those for TITLEI TITLE2 Data created by OKUMURA Feb 9 CASEID character A4 always required character Sample input Specify the calculation case ID using four alphanumeric characters without blank CASEID is used for the leading four characters of
32. Draft report for JAEA Data Code to be submitted in 2007 Last update 28 Jan 2005 MVP BURN Burn up Calculation Code Using A Continuous energy Monte Carlo Code MVP tentative title Keisuke OKUMURA Yasunobu NAGAYA Takamasa MORI Japan Atomic Energy Agency JAEA Tokai mura Naka gun Ibaraki ken 319 1195 Japan E mail okumura keisuke 2 jaea go p nagaya yasunobu g jaea go p mori takamasa a jaea go jp Note Input instructions for the functions below are not described in this draft report 1 Burn up calculation for fixed source problems 2 Flux normalization to the tally parameter defined by user 1 Introduction The continuous energy Monte Carlo method is the most reliable method in the field of neutron transport problems because of its precise geometrical modeling and continuous energy treatment Recent progress of fast computers has made it possible to apply the method to burn up problems In spite of still expensive computation costs the Monte Carlo method is very useful in solving special burn up problems for which we have few calculation experiences or difficult problems to treat with conventional deterministic neutron transport codes The MVP BURN code enables the burn up calculations using a continuous energy Monte Carlo code and an auxiliary code BURN which calculates the buildup and decay of nuclides in irradiated materials hereafter called depletion calculation in distinction from the burn up calculation
33. NAME FUEL NUCL IDE ID 1 2 3 4 5 6 7 8 9 10 NAME 00234 U0235 00236 00237 00238 237 NP239 PU238 PU239 PU240 ID 1 12 13 14 15 16 17 18 19 20 NAME 0241 PU242 241 242 242 AM243 242 CM243 CM244 245 55 2 mode 1 Integrated burn up parameters keff conversion ratio etc by step MVPBURN CALCULATION INTEGRATED SUMMARY CASEID V1E7 TITLE NEACRP BENCHMARK ON HCLWR UNIT CELL BURNUP CASE VM VF 1 1 STEP 1 2 3 4 5 6 7 8 9 DAYS 0 00000 00 2 70504 00 1 35252e 01 2 70504 01 6 76259 01 1 35252 02 2 70504 02 4 05755e 02 5 41007 02 MWD TON 0 00000 00 1 00000 02 5 00000 02 1 00000 03 2 50000 03 5 00000 03 1 00000 04 1 50000 04 2 00000 04 U0235 0 00000e 00 1 900226 01 9 47433e 01 1 88557 00 4 64345 00 9 07367e 00 1 73901 01 2 50820 01 3 22225 01 K EFF 1 419385 1 382428 1 373257 1 366505 1 350037 1 323166 1 273358 1 229662 1 192416 ERROR 0 067504 0 060953 0 058896 0 063954 0 065841 0 047946 0 070752 0 067263 0 048005 HISTORY 300000 300000 300000 300000 300000 300000 300000 300000 300000 NO OF BATCH 30 30 30 30 30 30 30 30 30 INST C R 0 366343 0 374248 0 376478 0 377249 0 383085 0 395465 0 425532 0 454886 0 482980 ERROR 0 159386 0 204381 0 173895 0 186617 0 164889 0 155396 0 165388 0 183035 0 156320 INTE C R 0 366343 0 372666 0 374573 0 376180 0 379646 0 387619 0 400451 0 414316 0 428339 MWD 0 000
34. RT Sample input IBMOD 1 PDSCHK integer integer Print control of file access information for members in PDS lt 0 Suppresses printing Prints written information only default setting 2 Prints all access information OPEN READ WRITE Sample input PDSCHK 0 DEF CONV END DEF CONV MVP BURN allows calculation of the conversion ratio which can be expanded to enable calculating two types of any reaction rates optionally defined by user and their reaction rate ratio The reaction rate ratio represented by the Conversion ratio 1s defined by the following equation 5 Fissile nuclides production rate Conversion ratio Fissile nuclides consumption rate The reaction rates to be calculated are not necessarily the real production rate and consumption rates of fissile nuclides For convenience these two reaction rates are subsequently called Fissile nuclides production rate and nuclides consumption rate When the user defines these reaction rates it is necessary to input the following data to the line between DEF CONV and END DEF CONV character NFIS Enter the necessary number NFIS of combinations of a nuclide and a reaction type to define the Fissile nuclides consumption rate using alphanumeric characters in the form of zzmmmn r When it is necessary to input multiple data items each character string should be placed between single quotation marks and delimite
35. be treated with because of a lot of depleting materials The other On the other hand the latter is suitable to make a table of reby extracting necessary data exselected 9 data of the calculated results requested by uses Both of them are available even when the burn up calculation is in execution Although the output table as a text file has not linefeed on fixed column it is convenient to if to be fixed data record is edited has no for the data display line is In such cases that is convenient to be read by 2 9 Statistical Error Treatment AVERAGE Mode The errors printed in SUMMARY mode or printed by ReadBURN are the errors estimated by MVP at each burn up step start point In fact statistical errors of reaction rates give some errors for atomic number density of depleting nuclides Thus the statistical errors of MVP calculations propagate along burn up Although a formulation was established by Takeda et al to estimate the propagation of the statistical errors we have still several difficulties to introduce it to MVP BURN due to computation costs to tally many sensitivity parameters Therefore we often neglect the propagation of statistical errors based on our experiences If we care little for computation costs it is possible to directly estimate the statistical errors including their propagation along burn up from multiple sets of MVP BURN results where the MVP calculations are done with different initial random numbers
36. but the NSTEP value assigned in the BURNUP mode can be used as the symbolic parameter NSTEP The step number specified by STOP must be larger than or equal to the step number specified by START STEPS integer NBR integer i Sample input Note CPUTIME float float PRINT integer Specify the burn up step number for performing the branch off calculation in the range of step numbers specified by START and STOP NBR is an arbitrary number of steps for the branch off calculation When this data item input is omitted the branch off calculation is carried out for all the steps specified by START and STOP STEPS 1 5 10 branch off at BOL MOL and EOL MVP calculation is conducted at the start point of each burn up step period not at the end point For example at the final burn up step NSTEP in the BURNUP mode the composition at the end point is obtained as well However the branch off calculation result obtained as integer NSTEP is the one using the start point composition not the end point composition CPU time min for interruption of the branch off calculation The detailed method conforms to the CPUTIME input method in the BURNUP mode 41 integer Print output control option 0 Simplified output default setting Detailed output 2 Output for debugging 3 Detailed output for debugging Sample input PRINT 1 SAVE MVP OUTPUT integer NSTEP integer i Specify whether or not to save the prima
37. c parameters defined by the MVP input data for each burn up step Each symbolic parameter of which value is changed for the burn up calculation should be entered separately on a single line must not be input with another symbolic parameter The name of a symbolic parameter of which value can be changed for the burn up calculation must consist of 1 to 16 characters Invalid input sample Value of symbolic parameter RADIUS will be changed by MVP BURN RADIUS 2 0 3 1416 VOLUME PI RADIUS 2 Valid input sample Value of symbolic parameter RADIUS will be changed by MVP BURN RADIUS 2 0 PI 3 1416 VOLUME PI RADIUS 2 6 Using the fission source file Although being not mandatory MVP BURN allows using the source data obtained at a previous burn up step as the initial fission source data of the next step To use this feature it is necessary to specify the SOURCE OUTPUT option in the MVP input data as well as adding the FISSIONFILE line to the data line prior to the material composition data XSEC block Data for the initial burn up step should be entered to the source data block In addition it is necessary to specify the storage option SAVE MVP OUTPUT for the MVP fission source file in the BURN input data Sample input XSEC SMVPBURN lt Start of the super block for the comment type BURN input data SBURNUP lt Start of the input data for the BURNUP mode SAVE MVP OUTPUT
38. condition Prepare a shell script or a batch file in Windows OS to execute MVP BURN Sample files are equipped in the distributed files Execute MVP BURN with the shell script In the environment without using the NQS batch on the EWS and so on MVP BURN can be also executed by using the run mvpburn command If the burn up calculation stops at an intermediate step add the restart option to the input data and execute MVP BURN again 7 Prepare a SUMMARY mode input data and execute MVP BURN to edit burn up calculation results in text formatted table Perform the following procedures if necessary 8 For editing of the burn up calculation results it is convenient to import the table printed by SUMMARY mode into a commercially available spreadsheet software e g Excel A utility ReadBURN is also available to extract and edit necessary data from the binary files of MVP BURN 9 If you need the burn up dependent reactivity temperature coefficient void coefficient control rod worth and so on execute MVP BURN in the BRANCH mode 10 If you need detailed analysis of a specific burn up step point edit the MVP input data retained in the PDS directory and then carry out the individual MVP calculation 4 20 Input Data Format For the execution of MVP BURN it is required to provide both of input data for the Monte Carlo calculation and the burn up calculation Hereinafter the former is called as MVP input data while the latter is
39. cording to the PERIOD variable type MWDT 500 0 1000 0 9 1000 0 NSTEP 11 up to 10000MWd t When PERIOD is MWDT MWD or U235BURN input the number of cooling days using a negative value for the step with POWERL provided with the zero value cooling calculation Input the zero value 0 0 for the step with POWERL provided with a negative value For the U235BURN the default nuclide U 235 used as the burn up indicator can be changed with the STDNUC option 30 SUBSTEPS integer NSTEP integer i Sample input Note START integer integer Sample input Note STOP integer integer Sample input Note CPUTIME float float Specify the number of sub step divisions in the i th burn up step period When this data input is omitted 20 is set for all the steps as the default value SUBSTEPS 30 20 20 when NSTEP 3 The entered value is ineffective for the burn up step of lt 0 skipping the cooling or nuclide depletion calculation Start step number of the burn up calculation 0 Restart calculation Cold start calculation default setting 0 1 Returned restart calculation START 0 Restart Burn up Calculation It is general to start the burn up calculation by assigning integer 1 When the restart calculation integer 0 is specified the step number for which the calculation is already completed is automatically determined by the code from the contents of members unde
40. d with blank character i zzmmmn zzgmmmn integer to represent a nuclide zz x 10000 mmm x10 n 22 atomic number mmm mass number 35 n number to indicate ground state 0 or excited state 71 r character to indicate a reaction type F Fission C Capture reaction defined as Absorption Fission A Absorption P Production v x Fission n 2n reaction D Decay Sample input NAMFIS 922330A 922350A 942390F 942410D IFISFLG integer NFIS Specify whether or not to multiply the above reaction rate by the atomic number density of the nuclide specified by NAMFIS Integer i 0 Dose not multiply by the atomic number density Microscopic reaction rate gt 0 Multiplies by the atomic number density Macroscopic reaction rate Sample input IFISFLG 10 1 1 no physical meaning FISFACT float NFISI float i Specify a coefficient for multiplying the above reaction rate i specified by NAMEIS to make the settings of a sign branching ratio and so on Sample input FISFACT 1 0 0 5 1 0 0 2 no physical meaning The entry for definitions of the Fissile nuclides consumption rate is complete In the above input examples this consumption rate does not have a physical meaning but can be calculated with the following equation Fissile nuclides consumption rate NU o V V j 0 5 c V V N P999 o7 7 6V V 0 2224 y Pu241 The item in th
41. de it is possible to change a symbolic parameter value for the step where the branch off calculation 42 Sample input Note VOID lt NSTEP gt 99 0 99 Void for all steps To implement the branch off calculation under the same conditions as in the BURNUP mode that the symbolic parameter value is set to be step dependent it is necessary to change the same symbolic parameter value as in the BURNUP mode However this need not apply when the symbolic parameter is used for the branch off conditions Even if the branch off calculation is not performed for all burn up steps according to the START STOP and STEPS values input data must be provided according to the NSTEP value specified in the BURNUP mode Any symbolic parameter value change for the step where the branch off calculation is not carried out is ignored 43 5 3 SUMMARY Mode The SUMMARY mode has a function to edit a burn up history member caseHT 44 in PDS obtained by the BURNUP or BRANCH mode and to print the primary result in a table form The SUMMARY mode calculation can be executed even if the BURNUP or BRANCH mode calculation is not yet completed up to the final step In this case up to the step with the calculation completed is subject to editing SUMMARY END SUMMARY BSUMMARY and END SUMMARY declare the SUMMARY mode input start and end respectively The data between these declarators becomes the SUMMARY mode input data TITLE charact
42. dels 0234 lt gt 235 lt gt 0236 lt gt 4237 lt gt 0238 0 u a s N N S N N MS 40 lt 1 23 X EC B A s N 4 238 lt Pu23Q lt gt N N N Cm242 lt gt Cm243 lt gt Cm244 lt gt Cm245 gt Cm246 Fig 3 1 Burn up chain model for actinides u4cm6 model Ih232 35 a My EC B 231 gt 2 lt 233 EN p lt gt U233 lt gt lt gt ru bn a EN AN x Np236 N M Np236g 2 236 S N N Cm242 lt gt Cm243 lt gt Cm244 lt gt Cn245 Cm246 Fig 3 2 Burn up chain model for actinides th2cm6 model 13 Kr83 p decay EC 3795 V ny Nb95 74 B decay x Mo95 Tc99 x N Rul0l Rul03 x x Rh103 Rh105 N N x Pd105 dr d x x 3 Agl07 Agl09 ee i d RI 131 133 135 5 d X N E 8133 gt Cs134 gt 5135 Cs137 Nd143 gt Nd145 N N x 4147 gt 54148 go A x La 48m N Lal40 Pm147 p 149 gt Te d x x x x x N Sm144 gt Sm148 gt Sm149 gt Sm150 gt Sm151 gt Sm152 0 N NI x 153 gt 5 1154 Eul55 gt Eul56 gt 0 x x gt x x x x 77050 Pseudo Gd154 gt Gd155 gt Gd156 gt Gd157 gt Gd158 Gd160 B10 Cd113 gt Cdl A Gd152 1115
43. ding randomly distributed particle fuels Burn up calculation for the plate type fuel cell including small diameter of Cd wire as burnable poison material More detailed information for the sample problems and related files are described in the ReadMe file under the burnrun directory To learn the MVP BURN application method intensively first read the basic description in the ReadMe file and then reference the input data in the order of HCLWR basic SURVEY symbolic parameter change PIE cooling and NEAGD multi fuel rod burnable poison PC method which are rather simple to input The geometric form of each sample input can be verified with CGVIEW The input data can be for the individual MVP as is For the input data contents and execution method refer to the ReadMe file or the comment for each sample data 49 7 Troubleshooting If an error should occur during execution of MVP BURN use the following procedure to identify the calculation step with the error caused and find the error cause 1 Confirm the contents of the MVP BURN standard output file Check the current burn up step number For example when the fifth step has been started the current step number is indicated as shown below XXXXXXXXXXXXXXXXXXXXXXXX x CURRENT STEP 05 x XXXXXXXXXXXXXXXXXXXXXXXX Find the error message The error message is output together with the subroutine name with the error caused in the following format with the up
44. e parentheses is value calculated by normalizing the microscopic reaction rate with the thermal power while Al is a decay constant defined in the burn up chain data Next enter the data for defining the Fissile nuclides production rate The input method is the same as for defining the Fissile nuclides consumption rate NAMFRT character NFER Enter the necessary number NFER of combinations of a nuclide and a reaction type to define the Fissile nuclides production rate using alphanumeric characters in the form of zzmmmn r Make an input data in the similar way to NAMFIS 36 IFRTFLG integer NFER Specify whether or not to multiply the above reaction rate by the atomic number density of the nuclide specified by NAMFRT Make an input data in the similar way to IFISFLG integer i 0 Dose not multiply by the atomic number density Microscopic reaction rate 20 Multiplies by the atomic number density Macroscopic reaction rate FRTFACT float NFER float i Specify a coefficient for multiplying the above reaction rate i specified by NAMFRT to make the settings of a sign branching ratio and so on Make an input data in the similar way to NAMFIS The entry for definitions of the conversion ratio reaction rate ratio is complete Two types of reaction rate and reaction rate ratio defined above are printed for each step in the SUMMAEY mode For the conversion ratio the time integrated conversion ra
45. e reads the microscopic fission reaction rate capture reaction rate and n 2n reaction rate from the MVP binary file To output these read values integer values 1 to 4 are given to N3 N5 and NT Sample input EDIT MICROSCOPIC DATA 00303030 4 Making correspondence between the MVP input material and the burn up region The nuclide depletion calculation is implemented for each material with the MVP input data Whether the input material is burnable or not is determined by the presence of the MVPBURN line beginning from the first column before the material composition designation immediately after 6 IDMAT MVPBURN VOLM volume TRGNAM tally region name TEMP temp In which volume Volume of burnable material tally region The volume integral reaction rate n sec of the tally region is output to the MVP binary file volume is used to convert in the BURN module the volume integral reaction rate obtained from MVP to the reaction rate density n cm sec needed for the nuclide depletion calculation To describe only a part of the system using the reflective of periodic boundary conditions it is necessary to provide a volume for the described system range that can be drawn by CGVIEW However for the two dimensional calculation using the top and bottom as the reflective boundary conditions consider the height direction as a unit length 1 cm and specify an area of the burnable material tally region name
46. embly calculation with reflective boundary conditions in all horizontal directions POWERL Q N H 6 Two dimensional unit pin cell calculation POWERL Q N M H As a special case the cooling calculation is performed in the step period provided with the zero value 0 0 and the depletion calculation is skipped at the step provided with a negative value and the MVP calculation is carried out with the composition unchanged POWERL 3 1 8E 04 0 0 3 1 5E 04 0 0 4 1 8E 04 0 0 3 time cooling when NSTEP 13 To use the same thermal power value throughout all burn up steps it is also possible to describe in the symbolic parameter format as shown below POWERL NSTEP 1 8E 4 PERIOD float NSTEP always required PERIOD is a variable for specifying a burn up period Specify one of the following five variable names according to user s intended purpose MWDT MWD DAY DAYINT Accumulated burn up in units of MWd t at each step end point Accumulated burn up in units of MWd at each step end point Number of burn up days in each burn up step period Accumulated number of burn up days at each step end point U235BURN Fractional depletion rate of U 235 at each step end point 0 0 to 100 0 float i Sample input Note The fractional depletion rate at time t is calculated by N t 20 N t N t 0 x 100 where is atomic number density Assign an appropriate value for the i th burn up step period ac
47. ently the microscopic fission reaction rate F capture reaction rate C and n 2n reaction rate W of a nuclide i existing in the burn up region z are obtained by the track length estimator or collision estimator However these reaction rates are relative values in the eigenvalue problems thus it is necessary for the depletion calculation to make a normalization using a total thermal power of the system Here we assume that 1 the total thermal power is constant in each burn up step period and that 2 the relative distribution of the microscopic reaction rates dose not change in the burn up step period although their absolute values may change to keep the total thermal power constant Under these assumptions the depletion equation for nuclide 7 in the n th burn up step period f lt t 1 is expressed by the following equation T fau WE NEO j i zi ums 4 Faaola where i j k Depleting nuclide number z Burn up region number N Burn up nuclide number density A f Decay constant and branch ratio g h Yield fraction of each transmutation Relative microscopic fission reaction rate calculated with MVP at time t t A Relative microscopic absorption reaction rate calculated with MVP at time t f C Relative microscopic capture reaction rate A F calculated with MVP at t t W Relative microscopic n 2n reaction rate calculated with
48. er A72 always required character Specify the title 1 of the SUMMARY mode TITLE2 character A72 always required character Specify the title 2 of the SUMMARY mode CASEID character A4 always required character ID of a case subject to editing four alphanumeric characters specified by the CASEID input in the BURNUP or BRANCH mode PDS character A128 required if it is not specified as an environment variable character PDS directory path name The detailed method conforms to the PDS input method in the BURNUP mode Note The members subject to editing must exist in PDS by this data item OUT STEP integer NSM integer i Specify the step number subject to editing when it is necessary to edit only a part of the burn up step for the calculation conducted in the BURNUP or BRANCH mode NSM indicates an arbitrary number of steps subject to editing When the OUT STEPS input is omitted a list is printed for all the steps of the calculation implemented in the BURNUP or BRANCH mode Sample input OUT STEPS 1 5 10 Summary Table only for BOL MOL and EOL Note It is not necessary to input the step number in the ascending order but the print output is performed in the ascending order If all the calculations in the BURNUP or BRANCH mode are not completely finished the processing for a step without a burn up history member caseHT in PDS will 44 be skipped PRINT integer integer Print outpu
49. er and the constant output density over the burn up period can be expected as observed in a fast reactor or graphite moderated reactor a region which is geometrically asymmetric may be defined as the same burn up region Burn up region division should be carried out based on the user s determination in accordance with the characteristics of the concerned problem by considering calculation costs and statistical accuracy 2 Designating the tally region in the DEFINE mode The BURN module references the reaction rate value used for depletion calculation in units of tally regions spatial areas where the tally result is output defined by the MVP input data Therefore it is necessary to make one to one correspondence between the burn up region and the tally region in the same way as the material composition data This method is described in 4 below To facilitate the one to one correspondence the tally region designation function using the DEFINE mode is used This function allows the user to define the tally region using the lattice and region name defined by the user Sample input TALLY REGION DEFINE UO2PIN1 LAT PIN1 FUEL UO2PIN2 LAT PIN2 FUEL UO2PIN3 LAT PIN3 FUEL LAT PIN4 FUEL MOXPINS5 LAT PINS FUEL 2 YH In the sample input above the tally region named UO2PIN1 exists in region named as PIN1 defined in the lattice LAT and indicates all regions with names beg
50. inning with FUEL The character 663499 means a wildcard meta character like in UNIX commands Notes MVP allows using the ADD mode as well as the DEFINE mode while MVP BURN does not MVP allows entering more than two lines beginning with DEFINE while MVP BURN allows entering only one line beginning with DEFINE If data needs more than one line it should be defined in continuous lines as shown in the above sample MVP BURN allows defining the TALLY REGION name for example UO2PIN1 using up to 12 characters When a name exceeds 12 characters only the leading 12 characters are valid If the invalid portion consists of the same character string an error will occur The TALLY REGION name after the DEFINE statement begins with and ends with a blank or lt immediately before The following three types of descriptions are allowed 22 DEFINE UO2PIN1 LAT PIN1 FUEL DEFINEQGUO2PIN1 LAT 1PIN1 FUEL DEFINE UO2PIN1 LAT PINI1 FUEL 3 Designating the EDIT MICROSCOPIC DATA option The EDIT MICROSCOPIC DATA option is used to select the output item for MVP standard output and binary file output on logical unit 30 and assigns an 8 digit integer value N to the argument Thus the following is established N N1 107 N2 10 N3 10 NA 10 N5 10 N6 10 NT 10 N8 In which N1 to N8 correspond to the reaction types and the output control is performed with each value The BURN modul
51. is taken as a relative reaction rate obtained with MVP and the depletion calculation is redone from time f f to obtain the final composition N 4 t 1 for the next burn up step 6 The number of a burn up step is updated to n 1 and the above steps 1 to 5 are repeated 2 3 Cooling Calculation In MVP BURN a cooling calculation is performed for the burn up step period in which zero power is given as shown in Fig 2 3 1 Hereafter the step is referred to as cooling step MVP execution Burn up ti Cooling step Cooling step Fig 2 3 1 Burn up calculation including cooling step In the cooling step all reaction rates induced by neutrons are set to be zero in Eq 2 2 1 Thus the nuclide composition at the end point of the cooling step can be calculated by solving the following decay equation dN t LF iA NGO ANI 2 3 1 j i Although the MVP calculation at the start point of the cooling step is not necessary to solve the above equation it is done because the user may need the MVP results at the end point of the previous burn up step In such case the calculation conditions of MVP in the cooling step should be set in the same condition to those of the previous burn up step except for thermal power Anyway the MVP results in the cooling step do not affect to the material compositions at the end point of the cooling steps It should be also noted that the PC method is always skipped for the cooling steps 2
52. ission products and burnable poison nuclides 15 x x x Ge73 gt Ge74 2 Ge76 decay fission x 575 N nj x x x x x x Se76 gt 5 77 gt 5 78 gt Se79 gt 5 80 gt 0 Se82 d p decay x Br81 gt o uA A a Kr82 gt Kr83 gt Kr84 gt E86 gt 85 x x x Rb85 gt Rb86 gt Rb87 x A A x x 4 i 6186 gt Sr87 gt 5188 gt S189 gt F Q 3 y 7195 gt 7196 x x Y89 gt 90 gt Y91 gt SIND 354 x E N 7 2 9 7191 2192 1 x x x x x Mo92 we TA 096 gt Mo97 gt Mo98 gt Mo99 100 x PA 99 gt x x Ruido 102 gt n BD gt Rul 06 pai0s gt Pdl0 P MS 4108 gt 0 BT B gt 107 P ui x aj Lamy x Cd110 gt Cd111 gt Cd112 OOo Cane det 47 i 2 x Y ET pm N 501169501179 Suc y 5112 1249 851126 8071907 A Y n12377 v bI 05 5012575 Sb126g 2 pe N Lae Zn Ty 12 ATE PQS N Same CN LP Rs c0 132 il Y 7 J 13 Fa 1129 131 3 3077 E EI ave 126 128 gt 129 gt 130 gt 13 lt gt 2 Fig 3 5 Partl Burn up chain model fp193bp6 for fission products and burnable poison nuclides to be continued on the next page continued from the previous page A 9 Xel33 9 Xe134 135 gt 136 x 4 o x Cs135 3 Cs134 9 E Cs13
53. mbolic 37 parameter value change must not be concerned with the burn up region and burn up nuclide count and are input to assign a value depending on the burn up step to a symbolic parameter defined by the MVP input data is used to change the value of the symbolic parameter to which a floating point value is provided and is used to change the symbolic parameter to which an integer value is given character float NSTEP character Specify the name of a symbolic parameter defined by the MVP input data and to change a floating point value for each burn up step using up to 16 characters float i Enter a value given to the symbolic parameter character at the i th burn up step Sample input VMVF 0 5 1 0 1 5 2 0 3 0 Vm Vf value by step character float NSTEP character Specify the name of a symbolic parameter defined by the MVP input data and to change an integer value for each burn up step using up to 16 characters float i Enter a value given to the symbolic parameter character at the i th burn up step The entered value will be rewritten to the most approximate integer value Sample input NSKIP 20 lt NSTEP 1 gt 5 initial skipped batches ACCEPT ZERO RATE The microscopic reactions calculated by MVP may become zero in some situations 1 the MVP input data is not provided appropriately ii small number of neutron histories compared with system volume
54. n of Gd is large in the thermal energy range and thus the burn up speed is fast the temporal change in the effective microscopic cross sections and the flux distribution is large Therefore it is necessary to make the burn up step period small enough to obtain the accurate results for systems where is contained This is a well known example but the same attention should be paid especially for the any new reactor concepts where the same situation is forecasted Among methods in which a relatively longer burn up step period can be used is the Predictor Corrector method PC method In this method an average value is obtained for microscopic reaction rates of the start and end points of a burn up step and then the depletion calculation for the step is redone from the start point with the average value Since it is necessary to perform transport and depletion calculations for the same burn up step twice the calculation time doubles in the PC method comparing with the calculation without the PC method Even so it will be more efficient to use the PC method for cases where sufficient accuracy cannot be obtained without making the burn up step less than half MVP BURN has a capability of the PC method and the method can be applied to any burn up step optionally For example let us consider a case where is used as a burnable poison The burn up calculation can be performed more efficiently by applying the PC method to the early burn up steps and
55. n up step does not change the accuracy is improved but the calculation time is not reduced To reduce the number of discarded batches it is necessary to describe the desired number of discarded batches in the symbolic parameter and define it for each burn up step using the feature in 5 26 5 Input Instruction of MVP BURN This chapter describes how to describe the input data for each mode of BURNUP BRANCH SUMMARY and AVERAGE The description assumes the use of the separate type input format When the comment type input format is used it is necessary to add in the first column of all input data lines Unless otherwise specified data is input according to the rules of the free format with a data name for MVP The subsequent portion of is regarded as a comment in the same way as the MVP input data The valid data input entry size 1s from the first column to 72nd column If the data requires more than one line the continuous line defined by MVP should be used The data to be input should be described in the following format VARIABLE type VARIABLE input data name type integer N N items of integer data float N N items of floating point data character AN Character type data of N characters if N 1 N can be omitted 51 BURNUP Mode BURNUP END BURNUP BURNUP declares the BURNUP mode input start while SEND BURNUP declares the BURNUP mode input end The data between these declarators is the
56. named BURN input data The MVP input data is the standard input data itself of the MVP code For the BURN input data there are two types of preparation methods using the comment type input format or separate type input format Either may be used however it is convenient to use the comment type input format in the BURNUP or BRANCH mode and the separate type input format in the SUMMARY or AVERAGE mode 4 2 1 Comment Type Input Format The comment type input format allows us to describe BURN input data as comment lines of MVP 663499 input data In the MVP input data a line beginning with in the first column is regarded as a comment 663499 Therefore in the comment type input format BURN input data is described after in the first column and integrated with the MVP input data Since the contents of MVP and BURN input data are not necessarily independent of each other they can be stored to advantage in a single input data file In addition the input data prepared in this way can be used for CGVIEW and for the MVP code The BURN input data should be inserted after the first two title lines of the MVP input data It is necessary to define an input area called super block beginning with MVPBURN and ending with SSEND MVPBURN and to enter the BURN input data necessary for each calculation mode Data should be entered in the free form with a data name defined by the MVP code excepting that is required in the first column
57. nd Restart Calculation 2 7 1 PDS File When a MVP calculation is time consuming restart functions are important for burn up calculations In order to achieve certain restarting and to make handling of massive data easy MVP BURN employs the file structure called as PDS Partitioned Data Set file or PDS PDS is just the same to a file directory on the UNIX or Windows operating system As shown in Fig 2 7 1 all output files of MVP BURN are stored in PDS every burn up step Each of the output files is called as member file or member and member name is given by BURN on the rule shown in Table 2 7 1 PDS file Control data for burn up calculation TESTMVPI TESTCOM1 TESTCOM2 TESTCOM3 TESTCHAN TESTMATD Preprocessing before MVP calculation Results in each burn up step bold MVP results 5 01 5 01 5 01 5 501 5 01 TESTVI02 TESTVP02 TESTVR02 TESTVS03 TESTHTO2 Step2 TESTVIO3 TESTVPO3 TESTVRO3 TESTVS03 TESTHT03 Step3 e e e Fig 2 71 Output file management in MVP BURN Table 2 7 1 Output files member of MVP BURN stored in a PDS Member name Data type Contents Case VI text Standard input data of MVP in each burn up step start point Case VP text Standard output data of MVP in each burn up step start point Case VR 4H binary Binar
58. not applying the method to the steps where the poison is almost completely burnt The procedure of the PC method in MVP BURN is described in the following 1 calculation is performed with composition tn at time t t to obtain four types of relative microscopic reaction rate distributions C F W A All the distributions are denoted together as R t in the following is multiplied by the normalization factor Fact t to obtain the absolute value reaction rate R t 2 The normalization factor is updated at each sub step point and is multiplied by R t to obtain the absolute microscopic reaction rate R t With R t the depletion calculation is performed sequentially to obtain a composition at time 1 1 1 The procedure up to here is the same as for not applying the PC method In the PC method this time is taken as an intermediate point of the burn up step n 1 2 and the composition obtained here is defined as Ny 1 2 tn 1 3 An MVP calculation is performed with composition 2 to obtain the relative microscopic reaction rate distribution R 1 2 t 1 at the intermediate point of the step Then the thermal output P is used to obtain normalization factor Fact 15 t 1 Facty 1 2 tn 1 is multiplied by Ryp 1 2 tr 1 to obtain Rata 4 A relative reaction rate R averaged in the burn up step period is calculated with the following equation R R Gi Rpa tna 2 2 2 3 5 R
59. o file output is specified in the SAVEPDS input CASEIN character A4y NCASE Must character i Specify two or more case Ids subject to the averaging using each four characters Each case ID should be placed between single quotation marks 7 and delimited with blank NCASE refers to an arbitrary number of cases for the processing Sample input CASEIN CSO1 CSO2 CS03 Note The output members of each calculation case must exist under the PDS directory specified by the PDSIN input The number of cases that can be processed at a time maximum number of NCASEs is determined by the parameter value of the included file and the maximum value is initially set to 16 PDSIN character A128 NCASE required if it is not specified as an environment variable character i Path name of the input PDS directory 46 Specify the PDS directory path names according to the number of NCASEs where the result of i th calculation case specified by the CASEIN input is stored by placing between single quotation marks 7 and delimiting with blank When this data input is omitted the path name specified with the environment variable MVPBURN PDS provided by the execution shell script is applied to all calculation cases according to the number of NCASEs Sample input PDSIN Test pds1 Test pds2 Test pds3 Note The members subject to the averaging must exist under the PDS directory specified by this data item PDSOUT
60. onforms to the CASEID input method in the BURNUP mode Note This must not be the same as the case ID specified by CASEREF CASEREF character A4 always required character Case ID of the burn up calculation BURNUP mode which references the composition data during the branch off calculation Sample input CASEID TEST Note A member beginning with four characters specified by this data item must not exist in the PDS directory PDS character A128 required if it is not specified as an environment variable character PDS directory path name The detailed method conforms to the PDS input method in 40 Note START integer integer Sample input STOP integer integer Sample input Note the BURNUP mode The members specified by CASEID and CASEREF are read written under the same PDS directory as specified by this data item Specify the start step number of the branch off calculation using a value from 1 to NSTEP NSTEP refers to the step count entered in the burn up calculation specified by CASEREF When this data item input is omitted integer 1 is used as the default value To perform the restart calculation specify integer 0 START 1 Specify the end step number of the branch off calculation using a value from 1 to NSTEP When this data item input is omitted integer NSTEP is used as the default value STOP NSTEP default setting NSTEP is not entered in the BRANCH mode
61. percase characters XXX subroutine name ERROR STOP error description or troubleshooting A warning message is output in the following format with 111 subroutine name WARNING warning description Check the error code The error code is classified as shown below 777 Indicates a case such as the time out state which cannot practically be considered as an error 888 Indicates a case which is determined to be caused by user s incorrect input 999 Indicates a case which is caused by insufficient available memory or file access error In addition to the above message there are error messages output by the system These messages are caused by an MVP BURN program bug or unexpected input When an invalid memory access zero division overflow and so on are generated corresponding system specific messages are output When the message content is not sure first contact your system administrator No message is output When the calculation is interrupted since the upper limit calculation time specified by the system is exceeded or due to an unforeseen reason such as disk capacity overflow and system down no message may occasionally be generated the calculation can be resumed 2 Check the member files created under the PDS directory Check the output members by combining the 15 command and meta characters The fifth and sixth characters of the member name indicate the burn up step With these characters it is always
62. r the PDS directory and the burn up calculation is resumed In this case if there is no restart member caseREST or burn up history member caseHT in the PDS directory the calculation is resumed in the cold start mode For the restart calculation it is not necessary to change any input data other than this data For the returned restart calculation it is necessary to assign an integer value which satisfies 1 lt integer NowStep NSTEP NowStep is the final step number when the burn up composition at the step end point has been completely calculated End step number of the burn up calculation 1 lt integer lt NSTEP This option is used to temporarily stop the burn up calculation by specifying the step number The burn up calculation can be continued with the restart option START The default value is integer NSTEP calculating up to the final burn up step STOP NSTEP default setting For the burn up step specified by the integer option the composition data at the step end point is output but the MVP calculation result at the step end point and the input data are not output CPU time min for interruption of the burn up calculation MVP BURN checks the total time when CPU has run so far prior to execution of the MVP calculation at each burn up step If the total CPU running time exceeds this input 31 Sample input Note PRINT integer integer Sample input LCHAO integer integer
63. ry input output data text and binary files of the MVP code as a member under the PDS directory at the i th burn up step Input an integer value calculated by the following equation in the same way as in the BURNUP mode Integer J x10 J x10 J x10 J4 SJ Jo J3 Ja J to J4 are assigned MVP input output files respectively shown in the table below and should be provided with 0 not saved or saved Digit Saved file File type Member name JA MVP standard input text case VI MVP fission source output binary case VS J MVP binary output binary case VR Ja MVP standard output text case VP The detailed method conforms to the SAVE MVP OUTPUT input method in the BURNUP mode Sample input SAVE MVP OUTPUT lt NSTEP gt 1001 Note Even if the branch off calculation is not performed for all burn up steps according to the START STOP and STEPS values input data must be provided according to the NSTEP value specified in the BURNUP mode The data for the step where the branch off calculation is not carried out is ignored PDSCHK integer integer Print control of file access information for members under the PDS directory lt 0 Suppresses printing Prints written information only default setting x Prints all access information OPEN READ WRITE Sample input PDSCHK 0 9 changing symbolic parameter values In the same way as in the BURNUP mo
64. s Benchmark Problem for the LWR Next Generation Fuels JAERI Research 2004 004 Japan Atomic Energy Research Institute 2004 in Japanese T Mori Y Nagaya K Okumura K Kaneko Production of MVP Neutron Cross Section Libraries Based on the Latest Evaluated Nuclear Data Files JAERI Data Code 2004 011 2004 T Mori K Okumura Y Nagaya H Ando Monte Carlo Analysis of HTTR with the MVP Statistical Geometry Model Trans Am Nucl Soc 83 pp 283 284 2000 Y Nagaya K Okumural T Mori W Nakazato Analysis of the HTR 10 Initial Core with A Monte Carlo Code MVP Proc Int Conf on The Physics of Fuel Cycles and Advanced Nuclear Systems Global Developments Chicago Illinois USA Apr 35 29 2004 on CD ROM 2004 10 T Yamamoto K Kawashima K Kamimura Effect of Pu rich Agglomerate on Lattice in MOX Fuel Proc 2004 Fall Meeting of the Atomic Energy Society of Japan Kyoto Univ Japan Sept 34 26 B50 2003 in Japanese 11 K Tasaka DCHAIN Code for Analyses of Build up and Decay of Nuclides JAERI 1250 Japan Atomic Energy Research Institute 1977 in Japanese 12 T Takeda N Hirokawa T Noda Estimation of Error Propagation in Monte Carlo Burnup Calculations J Nucl Sci Technol 36 9 pp 738 745 1999 13 T Ueki T Mori M Nakagawa Error Estimations and Their Biases in Monte Carlo Eigenvalue Calculations Nucl Sci Eng 125 1 11 1997 1
65. s the number of steps NSTEP burn up period PERIOD and thermal power POWERL in a member under the PDS directory In the restart or returned restart calculation the data in this member is referenced and the burn up conditions provided by the BURN input data are ignored This is conducted to prevent an unforeseen error which will be caused when the burn up conditions are indiscreetly changed during a burn up step However there may be a case in which it is necessary to change the burn up conditions after checking the result of the cold started burn up calculation For example you may want to continue the burn up calculation by increasing the number of steps or to restart the calculation by reducing the burn up period from the intermediate step In those cases this option can be used to change the burn up conditions The burn up conditions which can be changed by IBMOD include 34 NSTEP POWERL PERIOD unit cannot be changed SUBSTEPS PC and ACCEPT ZERO RATE to be appeared below The burn up conditions can be changed by entering a new value to these input variables in the restart or returned restart calculation Note For the restart calculation the burn up conditions can be changed only for the steps subsequent to NowStep Any value change for the step with the calculation completed is ignored For the returned restart calculation the burn up conditions can be changed only for the steps subsequent to the step number specified by ISTA
66. t be obtained for the nuclide provided with no material composition data Thus the burn up nuclides those included in the burn up chain model such as F P and actinide which do not exist in the burn up material in the initial state are added to each burn up material in such a number density that they can be ignored MVP BURN carries out the calculation by rewriting the MVP input data provided by the user using the number density given by this data item When this data entry is omitted float 1 0E 20 is used as the default value DENINIT 1 0E 15 32 PC integer NSTEP integer i Specify 0 or 1 to select whether or not to apply the Prediction Correction PC method to the i th burn up step period 0 PC method is not applied default setting PC method is applied When this data item is not specified the PC method is not applied at all burn up steps Sample input PC NSTEP 1 PC Method for all steps SAVE MVP OUTPUT integer NSTEP integer i Specify whether or not to save the primary input output data text and binary files of the MVP code as a member of PDS at the i th burn up step Input an integer value calculated by the following equation Integer J 10 J x10 J x104 J4 Ji Jo Ja Ja to J4 are assigned MVP input output files respectively shown in the table below and should be provided with 0 not saved or 1 saved Digit Saved file File type Member name
67. t control option 0 Simplified output default setting Detailed output 2 Output for debugging Sample input PRINT 1 PDSCHK integer integer Print control of file access information for members under the PDS directory lt 0 Suppresses printing Prints written information only default setting 2 Prints all access information OPEN READ WRITE Sample input PDSCHK 0 45 5 4 AVERAGE Mode The AVERAGE mode is used to make the averaging by editing the result of the calculation performed in the BURNUP or BRANCH mode several times with the random numbers or traced particle count changed It is possible as an option to store the result of the averaging as a member under the PDS directory and print it in a list form in the SUMMARY mode AVERAGE END AVERAGE and SEND AVERAGE declare the AVERAGE mode input start and end respectively The data between these declarators becomes the AVERAGE mode input data TITLE character A72 Must character Specify the title 1 of the AVERAGE mode TITLE2 character A72 Must character Specify the title 2 of the AVERAGE mode CASEID character A4 Must character ID name of a case for the AVERAGE mode arbitrary four alphanumeric characters This ID name is used for the leading four characters of a member name under the output PDS directory Sample input CASEID AVRG Note It is necessary to input this data item even if n
68. t format is used in these modes When the separate type input format is used in the BURN or BRANCH mode it is necessary to provide the BURN input data as standard input in the shell script for the MVP BURN execution and to specify the MVP input data separately In the separate type input format to clearly show that the standard input data is a separate type it is necessary to enter MVPBURN in the first to ninth columns of the first input line Subsequently the BURN input data needed for each calculation mode should be entered in free format with a data name defined by the MVP code Unlike the comment type input format all lines beginning with 4 in the first column are regarded as a comment The data input in the BURN mode shown in the previous section can be described as shown below in the separate type input format MVPBURN Designation of the separate type BURN input data SBURNUP lt Start of the input data for the BURNUP mode TITLE1 Benchmark on HCLWR Unit Cell Burn up TITLE2 Vm Vf 1 1 Pu Fissile 7 0wt o 20 CASEID V1E7 V1E7 is the case name lt Comment line MWDT 1 0 2 1 0E3 5 0E3 1 0 4 1 5E4 2 0 4 2 5E4 3 0 4 4 0E4 5 0E4 6 0E4 Exposure in MWd t unit BURNUP lt End of the input data for the BURNUP mode The MVP input data should be separately prepared The input data has the same description excluding the super block portion of the comment type input data 4 2 3 Restric
69. timated because their errors are not obtained by MVP 3 Burn up Chain Models Several burn up chain models shown in Table 3 1 are available in MVP BURN according to user s purposes and reactor types Figures 3 1 to 3 5 show production paths of depleting nuclides in each burn up chain mode For general uses of nuclear calculations the standard chain model is recommended from the view point of saving required memory size The general purpose chain model is designed to allow us to apply it most of post irradiation examination analyses It is well confirmed that the burn up calculation results with the above two chain models show good agreements with the results of the detailed chain mode in typical LWR and FBR lattices The differences between the chain models for thermal and fast reactors are not appeared in the figures The differences are values of fission yield of F P nuclides and isomeric ratios The values of fission yield and decay chain models are made based on the JNDC V2 library Table3 1 Available burn up chain models for MVP BURN Type of burn up chain models Name of chain model file name of burn up chain data main purpose for thermal reactors for fast reactors Standard chain model u4cm6fp50bp16T u4cm6fp50bp16F nuclear calculations th2cm6fp50bp16T th2cm6fp50bp16F General purpose chain model u4cm6fp104bp12T PIE analyses and so on Detailed chain model th2cm6fp193bp6T th2cm6fp193bp6F validation of other chain mo
70. tio defined by the following equation is also output as well as the instantaneous conversion ratio at the start point f of each burn up step t Fissile nuclides production rate v d v 0 Time int egrated conversion ratio t Fissile nuclides consumption rate t dt When the entry of the DEF CONV block is omitted the Fissile nuclides production rate is defined as the neutron capture reaction rate of typical fertile nuclides while the Fissile nuclides consumption rate is defined as the absorption rate of fissile nuclides The fissile nuclides and fertile nuclides are depending on vary with the contents of the burn up chain data For example when the burn up chain data UA4CMSFP34 for U 235 series fuels is used the conversion ratio with the same definition as the sample input shown below is calculated Sample input DEF CONV NAMFIS 922350A 942390A 942410A Fissile Absorption IFISFLG NFIS 1 5 lt 5 gt 1 0 ck ck k kk kkkk NAMFRT 922380C 942400C Fertile Capture IFRTFLG lt NFER gt 1 FRTFACT NFER 1 0 END DEF CONV changing symbolic parameter values MVP BURN allows changing the symbolic parameter value used for MVP input data composition and geometric form input for each burn up step Use of this function enables the burn up calculation by moving the control rod or changing the boron density of a chemical shim However the sy
71. tions on MVP Input Data When the MVP input data is prepared it is necessary to presuppose the burn up calculation The MVP input data generated without assuming the burn up calculation cannot always be used as is To implement the burn up calculation it is necessary to create MVP input data with attention to the key points shown in 1 to 7 below 1 Dividing of the burn up region As shown in Fig 4 2 1 if a region consisting of the same material as under the pre burn up conditions fresh state changes to other material as the burn up proceeds it must be divided as a burn up region Thus the MVP material composition input data specified within the XSEC block must be given for each burn up area even if each has the same composition Reflective Reflective OIO OIO OD Reflective Reflective Reflective Reflective Reflective Reflective Fresh Problem Burn up Problem Fig 4 2 1 Difference of material specification between input data for MVP left and MVP BURN right T Technical terms used in MVP is specified with T 21 If a region has a constant material composition due to the symmetric property of a material type after the burn up advances it should be defined as the same burn up region to increase the tally accuracy and to prevent expansion of asymmetric burn up caused by statistical error However when the neutron range is long
72. to represent atomic number mass number and an indicator to distinguish ground state n 0 or meta stable n 1 respectively For example in the case of Integer 922350 the default setting nuclide U 235 will be taken for the burn up indicator If U235BURN is selected for the input variable of PERIOD input value to this variable should be given by the fractional depletion rate of the nuclide defined here Even when PERIOD is not specified by U235BURN the depletion fraction rate of the nuclide defined here will be printed as a part of the burn up information in the SUMMARY mode STDNUC 942390 Pu 239 for Burn up index The fractional depletion rate at time t is calculated by N t 20 N t N t 0 100 where N is atomic number density If N 0 is an extremely small value an overflow will be occurred Therefore it is necessary for this data item to specify a nuclide of which initial composition is large to a certain extent If a nuclide not registered in the burn up chain data is entered to STDNUC it will be regarded that the fissionable nuclide appearing first in the burn up chain data has been specified Specify whether or not to change the burn up conditions set for the cold start for the restart or returned restart calculation 0 Burn up conditions are not changed default setting Burn up conditions are changed If the cold start is specified MVP BURN will save the data concerning the burn up conditions such a
73. ubject to editing including overwriting deletion and file name change 51 2 3 4 5 6 7 8 9 References T Mori M Nakagawa MVP GMVP General Purpose Monte Carlo Codes for Neutron and Photon Transport Calculations based on Continuous Energy and Multigroup Methods JAERI Data Code 94 007 Japan Atomic Energy Research Institute 1994 in Japanese Y Nagaya T Mori K Okumura M Nakagawa MVP2 General Purpose Monte Carlo Codes for Neutron and Photon Transport Calculations based on Continuous Energy and Multigroup Methods to be published in JAERI 1348 Japan Atomic Energy Research Institute 2005 K Okumura M Nakagawa K Kaneko Development of Burn up Calculation Code System MVP BURN Based on Continuous Energy Monte Carlo Method and Its Validation Proc Joint Int Conf on Mathematical Methods and Supercomputing for Nuclear Applications Saratoga Springs New York Oct 5 9 1997 Vol 1 pp 495 508 1997 K Okumura T Mori M Nakagawa K Kaneko Validation of a Continuous Energy Monte Carlo Burn up Code MVP BURN and Its Application to Analysis of Post Irradiation Experiment J Nucl Sci Technol 37 2 pp 128 138 2000 OECD Nuclear Energy Agency Physics of Plutonium Recycling Volume VII BWR MOX Benchmark Specification and Results ISBN 92 64 19905 5 OECD Publication France 2003 Research Committee on Reactor Physics Study on the Analyses of the Reactor Physic
74. x file play a role to allocate the nuclide index name i e U023500900 to be used in a MVP input and the corresponding user s library in binary form i e U02350J33 T0900 M Y MVPLIB For example the index file for the fixed temperature libraries has the following contents Directory path for the generated user s MVP libraries PATH home user MyMVP burnrun sample mylib Fuel for 900 x xxk kk kk kk kkk ke ke ke KEK U023500900 U02350033 T0900 MY MVPLIB U023500900 002350233 0900 023600900 002360233 0900 It should be noted that MVP BURN requires large memory size to treat continuous energy library data in proportion to numbers of nuclides and material temperatures Therefore too small differences of material temperatures should not be distinguished and use of simpler burn up chain model is suggested if available memory is limited Prepare a MVP input data to be used in MVP BURN Pay attention to some restrictions specific to burn up calculations See Section 4 2 3 Input data related to the burn up calculation are embedded in the same MVP input data as comment lines Thus the input data for MVP BURN can be commonly used as the input data of MVP for the fresh not burned condition If the input geometry is complicated it is suggested to draw it by using the MVP utility CGVIEW to confirm that the input data is correct In addition execute the test calculation with MVP for the fresh
75. y output of MVP calculation results in each burn up step start point This data is written on I O unit 30 in a separate use of MVP Case VS binary Fission source output of MVP eigenvalue calculation in each burn up step start point This data is written on I O unit 9 in a separate use of MVP Case HT binary Burn up calculation results in each burn up step start point keff power and exposure distribution material composition etc Note The material composition data is calculated by depletion calculation at the end of previous burn up step period Case MVPI text Control data for the burn up calculation Template file to generate standard input data of MVP Case COM1 binary Control data for a burn up calculation burn up calculation conditions Case COM2 binary Control data for a burn up calculation data on burn up calculation conditions part 2 Case COM3 binary Control data for a burn up calculation data on burn up conditions part 3 Case CHAN binary Control data for burn up calculation data on burn up chain Case MATD binary Control data for burn up calculation data on material property Case REST binary Control data for burn up calculation data on restart burn up calculation This member is generated according to internal need but it is indispensable for restart burn up calculation case case index four alphameric characters defined by user two digits to denote burn up step start point 01 02 03

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