No abstract

The ETOE-2/MC 2 -2/SDX multigroup cross-section processing codes have been designed to provide a comprehensive neutron cross-section processing capability for a wide range of applications including critical experiment analysis and core design calculations. Fundamental nuclear data from ENDF/B provide the primary input to the code system and the output consists of a user-specified CCCC ISOTXS multigroup cross-section data file, Great flexibility has been provided to the user in specifying the rigor of the calculation so that a unified cross-section processing system with a single data base is available which may be used for both preliminary survey scoping studies and rigorous design calculations.The principal program blocks of the code system include: a library processor and format converter between ENDF/B data and the KC 2 -2/SDX library; an ultra-fine-group fundamental mode calculation (MC 2 -2) which provides a composition dependent spectrum calculation and broad-group collapsing capability; a rigorous hyper-fine-group spatially heterogeneous resolved resonance calculation (RABANL) to supplement the more approximate NR approximation used in the ultra-fine-group treatement; and an intermediate group space-dependent capability (SDX).

Contents of CI16.CCCC.MASTER Library 16 2. Contents of C116.CCCC.SYSLIB 18 3. Contents of C116.CCCC.SYSLIB (from C116.ARC.SYSLIB) 19 4. Utility Modules in C116.CCCC.MODLIB 21 5. Object Code Segments in C116.CCCC.SEGLIB 24 6.

No abstract

Since we do not live in an idealized world with infinite computational and monetary resources, the question of dollars worth of difference between ENDF/B cross-section processing codes for fast reactor calculations must be addressed with respect to both the accuracy required in the multigroup constants and the cost of obtaining that accuracy. Unfortunately, no single processing code is an obvious choice since the practical effect of different processing techniques on important reactor parameters is problem dependent* Therefore, it is the purpose of this paper to discuss the range of applicability of several multigroup averaging programs widely used in the United States, as well as the effort that must be expended in using them. Th° programs selected from the authors' experience include AMPX (1), MOIX( i 2 J .3)/SPHINX(4), ETOE-2/MC 2 -2/SDX(5), and ETGX(6) /1DX(2) • As is apparent these programs are often systems of linked computer codes and such distinctions will be highlighted in the discussion. Several articles (8-lfJ) have already been published which discuss the different techniques and computer programs employed in cross-section processing. Much of this work, however, is of a survey nature and without numerical detail sufficient to quantitatively contrast the differences between processing codes. Others (11)(12)(13)(14) are more quantitative but either do not involve all the programs considered herein, review only a limited number of reaction types, or contain integral results, but limited information on specific group-wise cress sections.In the next section, a brief summary is given of the status and current capabilities for the programs under discussion. This is followed by a section in which, some of the more important processed multigroup constants, obtained with the aforementioned codes (for a particular model of ZPR-6/7) are tabulated to illustrate the magnitude of the differences obtained for Individual cross sections and transfer matrix elements. It is essential to note that all of the programs involved have several options and no attempt was made to exploit these options to "fine-tune" or "optimize"