J0^^7O^ ORNL-5711 ^ The Bold Venture Computation System for Nuclear Reactor Core Analysis, Version III D. R. Vondy T. B. Fowler G. W. Cunningham III V W"" MTNWJIMIF MS NCHKiT ft MOTH 111 CONTENTS PAGE ABSTRACT vl I. INTRODUCTION 1 II. SOME APPLICATION CONSIDERATIONS 2 A. CONSISTENCY 3 B. ACCURACY 4 C. BLACK BOXES . 4 D. NEUTRONICS. 4 E. EXPOSURE 5 III. COMPUTATICil SYSTEM 6 IV. CONTROL NODULE 8 V. INTERFACE DATA FILES 14 A. FILES REQUIRED BY THE MODULES 14 B. THE FILE ,CONTRL' 16 C. STANDARD FILES 17 D. NEWLY DEFINED FILES 17 E. FILE VERSION NUMBERS. 17 F. COMMENTS ABOUT THE FILES 20 VI. INPUT DATA PROCESSOR. 22 A. FILE AND RECORD CONTROL CARDS 26 1. File Control Cards - nVFILEID 26 2. Record Type Control Cards - nD 27 3. STOP Card ..27 4. FLAG Card 27 B. DATA FIELDS 28 1. Allowable Data Form 28 a. Numeric Word* . 28 b. Hollerith Words 29 2. Card Structure •.•••••3D 3. Control Options ............. .....30 a. Repeat Option ,30 b. Skip Option 31 c. Interpolation Option. ............. 31 d. Section Repeat Option ..... 31 IV contents (con't) PAGE C. COMMENTS 32 VII. FILE EDITOR 33 VIII. SPECIAL PROCESSORS 33 A. DVENTR 36 B. DCRSPR 61 C. DMTLIN 66 D. DCMACR 67 E. DENKAN 68 F. DMISLY 72 IX. JOB CONTROL INSTRUCTIONS 76 A. THE CATALOG PROCEDURE 76 B. USER SUPPLIED JOB CONTROL INSTRUCTIONS 76 C. PROBLEM DEPENDENT DATA FILE PARAMETERS 82 X. SUPER SAMPLE PROBLEM 84 XI. RECENT EXTENSIONS , 128 A. VENTURE NEUTRONICS, VERSION III . 128 1. The Uncommon Reactor Core Neutronlcs Problem . 128 2. Space-energy Rebalance 131 3. Other Extensions 133 4. Equilibrium Xenon 135 B. PERTUBAT PERTURBATION ANALYSIS 135 C. TEMPERATURE CORRELATION 137 D. SPECIAL MODULES 137 REFERENCES 138 APPENDIX A A-l APPENDIX B B-l APPENDIX C C-l V LIST OF FIGURES Figure Page 1. Components of the Computation System 7 2. User Input Instructions to the Control Nodule 9 3. Interface Data Files Required . 14 4. Files Milch Can be Generated by the Input Processor. ... 24 5. The Catalog Procedure 78 5. User Supplied Job Control Instructions 81 7. Determining the Values of L, N, and B 83 8. Cross Section Through Core Assemblies 85 9. Zone Placement 86 10. Transmutation Scheme 87 11. Module Accesses and Results 88 12. Input For Super Sample Problem 90 13. Selected Output From Super Sample Problem 103 14. Eigenvalue Separation for the Dominant Harmonics 130 A.l. Input For VENTURE Storage Requirements *-2 A.2. Edit for Sample CalculatIon-VENTURE Storage Requirements . A-4 A.3. Input For BURNER Storage Requirements A-7 A.4. Edit For Sample Calculatlon-BURNER Storage Requirements. A-10 B.l. JCL Required to Create the System B-? C.l. Interface File CONTRL C-2 C.2. Correspondence of Data: DYENTR-DTNINS ......... C-51 C.3. Standard Files C-53 C.4. Newly Defined Files C-101 vi ABSTRACT This report is a condensed docunentatiorv for VERSION III of the BOLD VENTURE COMPUTATION SYSTEM for nuclear reactor core analysis. An experienced analyst should be able to use this systea routinely for solving probleas by referring to this docuaent. Individual reports aust be referenced for details. This report covers basic Input instructions and describes recent extensions to the aodules as well as to the interface data file specifications. Soae application con­ siderations are discussed and an elaborate saaple problea is used as an Instruction aid. Instructions for creating the systea on IBM coa- puters are also given. 1 I. INTRODUCTION The BOLD VENTURE COMPUTATION SYSTEM2 for nuclear reactor core ana- lysis Is a Modular system In which Individual Modules are accessed In a desired sequence by a CONTROL Module. Each Module reads Interface data files which Hay have been written ay other Modules In the system, or supplied externally to the run. Except for the Input data pro­ cessor and special Modules, no Input data are read froM cards. The Input oata processor reads free forn card Input In a one-to-one correspondence with the Interface data file specifications and writes the files in binary form for use by the other MDtales. Special Modules read fixed forw card Input data for direct use or to create additional files. Individual reports documenting the Modules1'8 and the system have been published. With continuing extension of the Modules to enhance the capability has cone the need to extend the Interface data file specifications. We have found Increasing need for a compact set of user Input data Instructions and Interface data file specifications. Basic data requirements are collected here for this computation system. We do run the risk of Inconsistencies with duplicate publication. The reader 1s to assume that the document having the rest recent date Is accurate and supersedes any earlier publication. We expect never to hear the end of any discrepancy that nay have crept through. The following sections address some of the application requirements, present Input data requirements, define the Interface data file contents, address control, show an elaborate sanple problem, and describe recent extensions. Oata storage requirements for the VENTURE neutronlcs and BURNER exposure codes an discussed In Appendix A. Creation of a computation system from compiled routines on an IBM or equivalent computer Is discussed 1n Appendix B. aTh1$ system of codes was previously nt§rrtd to as VENTURE (versions I and II). Thp VENTURE ruaitronlcs nodule Is but one of the mny nodules which comprise the system. ! iI i I 2 II. SOKE APPLICATION CONSIDERATIONS The experienced analyst needs no special instructions for appli­ cation in a familiar area. The novice is beyond help, lie try here to help the experienced user by pointing out certain requirements. That •ay not be obvious if the application is in a new area. He recommend that the novice be allowed or be instructed to solve a large number and wide variety of siaple and inexpensive problem to gain familiarization. If a high level of reliability is to be placed ir» calculated results, then attention aust be paid to the following aspects: is the 1. Physical theory adequate 2. Mathematical representation of the theory adequate 3. Error associated with numerical approximations and discretizations acceptable 4. Modeling adequate 5. Problem description defining the intended problem 6. Problem solved the one Intended 7. Data transaitted and processed properly 8. Proper selection aade from among paralleled procedures 9. Error associated with termination of iterative procedures acceptable 10. Result realistic He believe that the codes in this system can be used to produce results that have a high level of reliability. The system members have been subjected to extensive verification tests. Still this does not ensure either that they are entirely error free, especiclly when auxiliary results are produced, or that the user Instructions may not be misinterpreted. You will be using that verlson of each code having the highest available level of quality assurance, along with others In the user community, not some other version. The codes In this system Individually and collectively have been qualified for nuclear reactor core analysis over a broad range of application. Still large voids can generally not be modeled 3 accurately with diffusion theory, ami if jou tell the exposure code not to consume U235 fuel, it won't and the results will not be correct. The large amount of freedom allowed in describing core analysis problems was deemed necessary in the local environment of broad application. The result is a trcnendous amount of capability. However, the impact on the analyst is quite severe. It is essential in a specific area of application for the user(s) to establish viable decks of input data. Special attention must be paid to the geometric description, to the coupled nuclide chain descriptions, to everythioq. Quite generally a viable data deck must evolve that is known to produce reliable results. It applies the proper boundary conditions, assigns materials correctly, describes such aspects as depletion and fuel management accurately, etc. Key results may be adjusted by bias factors developed from a comparison of calculated results with experimental results. And then there is the cross section data. We note that expertise in this area comes only from experience. No advice is offered here deliberately to avoid creating the impression that the difficulties are less than they really are. A. CONSISTENCY To some extent many of these codes are forced to be consistent. They use and Interpret most of the input data the same way. A notable exception is the correlation of microscopic cross sections on local temperature that must be specified in each of the Instructions to the individual codes and is not available in the perturbation code (except In a macroscopic sense). The continuous fueling model assumes that the fuel moves from zone n to n + 1 starting with n - 1, and subzone m to m + 1 starting with m « 1, Obviously a problem could be described that was physi­ cally Impossible. 4 The available thermal hydraulics model assumes coolant flow along increasing mesh number (j = 1 at top to j = J^x at bottom). A ver­ tical traverse of the reactor might go up or down without altering the neutronics, but the top and the bottom might be incorrectly reversed for the thermal hydraulics, their locations depending on the direction of coolant flow, down or up. B. ACCURACY Quite generally the accuracy %.. 1 calculation has been carefully considered and factored into the development of these codes. Double precision arithmetic (rather than IBM half-precision) has been used extensively to avoid serious loss of significance, not everywhere and not in basic data interfacing, but in iterative and series calcula­ tions where hexadecimal rounding to less than six digit decimal accuracy can be serious.