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SABRINA: an interactive solid geometry modeling program for Monte Carlo

Description: SABRINA is a fully interactive three-dimensional geometry modeling program for MCNP. In SABRINA, a user interactively constructs either body geometry, or surface geometry models, and interactively debugs spatial descriptions for the resulting objects. This enhanced capability significantly reduces the effort in constructing and debugging complicated three-dimensional geometry models for Monte Carlo Analysis.
Date: January 1, 1985
Creator: West, J.T.
Partner: UNT Libraries Government Documents Department

MORSE: current status of the two Oak Ridge versions

Description: There are two versions of the MORSE Monte Carlo radiation transport computer code system at Oak Ridge National Laboratory. MORSE-CG is the most well-known and has undergone extensive use for many years. Development of MORSE-SGC was originally begun in order to restructure the cross section handling and thereby save storage, but the more recent goal has been to incorporate some of the KENO ability to handle multiple arrays in the geometry and to improve on 3-D plotting capabilities. New capabilities recently added to MORSE-CG include a generalized form for a Klein Nishina estimator, a new version of BREESE, the albedo package, which now allows multiple albedo materials and a revised DOMINO which handles DOT-IV tapes.
Date: January 1, 1980
Creator: Emmett, M.B. & West, J.T.
Partner: UNT Libraries Government Documents Department

Shipping cask criticality analysis utilizing combinatorial geometry with KENO-IV

Description: KENO-IV/CG represents an important step forward in geometric modeling capability for criticality analysis. With the merging of KENO geometry's repeating cell feature and combinatorial geometry's detailed modeling ability and simplified input specifications, many geometric approximations required for previous criticality calculations are no longer necessary. Also, many of the features in KENO-IV/CG lend themselves to further development. Therefore, it represents a step forward in the state-of-the-art for Monte Carlo criticality analysis. All of the problems analyzed with KENO-IV/CG at ORNL have agreed well with experimental data where results are available. KENO-IV/CG provides industry with a very powerful tool for accurately modeling very complex geometries.
Date: January 1, 1978
Creator: West, J.T. & Petrie, L.M.
Partner: UNT Libraries Government Documents Department

Criticality analyses of disrupted core models of Three Mile Island Unit 2

Description: Three hypothetical disrupted core models were analyzed for the President's Commission on the Accident at Three Mile Island. Soluble boron in the present configuration was assumed to be 3180 weight parts per million (wppM). Positive reactivity effects due to fuel swelling, fuel slumping, and coolant displacement by ZrO/sub 2/ increase the cold, shutdown system multiplication factor from approximately 0.74 to 0.86. The increase in reactivity for the three models can be roughly correlated with a decrease in the borated water-to-fuel volume ratio. Each of the 39,825 pin-lattice locations was modeled explicitly in the Monte Carlo analyses of the reactor core. Parametric studies were performed with one-dimensional discrete-ordinates analyses. The report includes a benchmark critical analysis of the system at hot, zero-power startup, a description of the analytical methods used, and a comprehensive compilation of the data upon which the analytical models were based.
Date: December 1, 1979
Creator: Westfall, R.M.; West, J.T.; Whitesides, G.E. & Thomas, J.T.
Partner: UNT Libraries Government Documents Department

MCNP transport calculations for detector locations

Description: The MCNP code was used to generate time and energy spectra for neutron and photon transport throughout a fictitious facility. Calculations of this type will be utilized to design a new Los Alamos criticality alarm system. 2 refs., 7 figs.
Date: April 4, 1989
Creator: Pruvost, N.L.; Schlesser, J.A.; West, J.T. III & Estes, G.P.
Partner: UNT Libraries Government Documents Department

TMI-2 criticality analysis: parametric studies and overall results

Description: Three hypothetical disrupted core models were analyzed for the President's Commission on the Accident at Three Mile Island Unit 2. The purpose of this paper is to provide a summary of the results obtained from preliminary parametric studies and from the analyses of the disrupted core models. Hopefully, the implications from these results are useful in planning plant recovery operations. However, the scope of this study did not include a quantitative determination of the probable condition of the reactor core or, on the other end, the development of recommendations for specific actions to assure the criticality safety of the plant.
Date: January 1, 1980
Creator: Westfall, R.M.; West, J.T.; Whitesides, G.E. & Thomas, J.T.
Partner: UNT Libraries Government Documents Department

TMI-2 criticality analysis: analytical models and methods

Description: The purpose of this paper is to describe the calculational models and analytical methods employed in a comprehensive study of reactivity effects due to hypothetical core disruptive mechanisms associated with the accident at Three Mile Island Unit 2. The TMI core design is described with regard to the heterogeneity arising from various fuel assembly configurations. Then the geometric lattice modeling capabilities of MORSE-SGC/S and KENO-IV are explained. After discussing the calculational difficulties and the analytical tools, the development of the disrupted core models is presented along with the procedure utilized in generating macroscopic cross sections.
Date: January 1, 1980
Creator: West, J.T.; Westfall, R.M.; Whitesides, G.E. & Thomas, J.T.
Partner: UNT Libraries Government Documents Department

Multiprocessing MCNP on an IBM RS/6000 cluster

Description: The advent of high-performance computer systems has brought to maturity programming concepts like vectorization, multiprocessing, and multitasking. While there are many schools of thought as to the most significant factor in obtaining order-of-magnitude increases in performance, such speedup can only be achieved by integrating the computer system and application code. Vectorization leads to faster manipulation of arrays by overlapping instruction CPU cycles. Discrete ordinates codes, which require the solving of large matrices, have proved to be major benefactors of vectorization. Monte Carlo transport, on the other hand, typically contains numerous logic statements and requires extensive redevelopment to benefit from vectorization. Multiprocessing and multitasking provide additional CPU cycles via multiple processors. Such systems are generally designed with either common memory access (multitasking) or distributed memory access. In both cases, theoretical speedup, as a function of the number of processors (P) and the fraction of task time that multiprocesses (f), can be formulated using Amdahl's Law S ((f,P) = 1 f + f/P). However, for most applications this theoretical limit cannot be achieved, due to additional terms not included in Amdahl's Law. Monte Carlo transport is a natural candidate for multiprocessing, since the particle tracks are generally independent and the precision of the result increases as the square root of the number of particles tracked.
Date: January 1, 1993
Creator: McKinney, G.W. (Los Alamos National Lab., NM (United States)) & West, J.T. (IBM Corp., Houston, TX (United States))
Partner: UNT Libraries Government Documents Department

SCALE: A modular code system for performing standardized computer analyses for licensing evaluation. Functional modules F9--F16 -- Volume 2, Part 2, Revision 4

Description: SCALE--a modular code system for Standardized Computer Analyses Licensing Evaluation--has been developed by Oak Ridge National Laboratory at the request of the US Nuclear Regulatory Commission. The SCALE system utilizes well-established computer codes and methods within standard analysis sequences that (1) allow an input format designed for the occasional user and/or novice, (2) automate the data processing and coupling between modules, and (3) provide accurate and reliable results. System development has been directed at problem-dependent cross-section processing and analysis of criticality safety, shielding, heat transfer, and depletion/decay problems. Since the initial release of SCALE in 1980, the code system has been heavily used for evaluation of nuclear fuel facility and package designs. This revision documents Version 4.2 of the system. The manual is divided into three volumes: Volume 1--for the control module documentation, Volume 2--for functional module documentation; and Volume 3--for documentation of the data libraries and subroutine libraries. This volume discusses the following functional modules: MORSE-SGC; HEATING 7.2; KENO V.a; JUNEBUG-II; HEATPLOT-S; REGPLOT 6; PLORIGEN; and OCULAR.
Date: April 1, 1995
Creator: West, J. T.; Hoffman, T. J.; Emmett, M. B.; Childs, K. W.; Petrie, L. M.; Landers, N. F. et al.
Partner: UNT Libraries Government Documents Department