Effectiveness of A{sup 3}MCNP for a purely absorbing medium with void region
One of the most widely used approaches to solve three-dimensional steady-state shielding problems is the Monte Carlo method. It offers several advantages, including accurate representation of problem geometry and physics, and ease of utilization. However, its disadvantages include large computational time and, as a result, a limited amount of information. For deep-penetration shielding calculations, the analog Monte Carlo method is ineffective and/or impractical because of the low probability of particle transmission/survival. For this type of application, nonanalog Monte Carlo methods are used. There are several effective variance reduction techniques, but their use for large or complex problems is not straightforward because of the need for space, energy, and sometimes angular-dependent parameters. In recent years, several researchers have devoted their efforts in developing methods and codes that can facilitate the determination of the variance reduction parameters. Automatic Adjoint Accelerated MCNP (A{sup 3}MCNP) is a version of the MCNP code that generates and utilizes variance reduction parameters to perform nonanalog Monte Carlo simulation. A{sup 3}MCNP uses the deterministic adjoint function to determine the parameters for source biasing and the weight-window technique. It automatically prepares the necessary inputs to determine the adjoint functions. This includes an input file for the GIP code (used to prepare mixture cross sections) and an input file for the TORT code (a three-dimensional discrete ordinates transport code). A{sup 3}MCNP has been used to calculate displacements per atom at a boiling water reactor core shroud and to simulate a shipping cask. Here, the authors demonstrate the effectiveness of A{sup 3}MCNP for a deep-penetration test problem.
- Research Organization:
- Pennsylvania State Univ., University Park, PA (US)
- OSTI ID:
- 20005821
- Journal Information:
- Transactions of the American Nuclear Society, Vol. 81; Conference: American Nuclear Society 1999 Winter Meeting, Long Beach, CA (US), 11/14/1999--11/18/1999; Other Information: PBD: 1999; ISSN 0003-018X
- Country of Publication:
- United States
- Language:
- English
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