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in creator/contributor: "Woodruff, S.B."

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Some computational challenges of developing efficient parallel algorithms for data-dependent computations in thermal-hydraulics supercomputer applications

The Transient Reactor Analysis Code (TRAC), which features a two- fluid treatment of thermal-hydraulics, is designed to model transients in water reactors and related facilities. One of the major computational costs associated with TRAC and similar codes is calculating constitutive coefficients. Although the formulations for these coefficients are local the costs are flow-regime- or data-dependent; i.e., the computations needed for a given spatial node often vary widely as a function of time. C… more

Date: January 1, 1992

Creator: Woodruff, S.B.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Faster-than-real-time simulation of nuclear reactor accidents: the TRAC-NPA code

A reactor safety code that provides faster-than-real-time capabilities greatly enhances the effectiveness of an analyst. We have developed a new version of the Transient Reactor Analysis Code, TRAC-NPA, which is capable of running many one- and three-dimensional transients faster than real time on current computers. TRAC is an Eulerian finite-difference code designed to model transient, two-phase, multidimensional, steam-water flow in nuclear reactors. TRAC-NPA is fast running both because it e… more

Date: April 1, 1985

Creator: Woodruff, S.B.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Current algorithms used in reactor safety codes and the impact of future computer development on these algorithms

Computational methods and solution procedures used in the US Nuclear Regulatory Commission's reactor safety systems codes, Transient Reactor Analysis Code (TRAC) and Reactor Leak and Power Safety Excursion Code (RELAP), are reviewed. Methods used in TRAC-PF1/MOD1, including the stability-enhancing two-step (SETS) technique, which permits fast computations by allowing time steps larger than the material Courant stability limit, are described in detail, and the differences from RELAP5/MOD2 are no… more

Date: January 1, 1985

Creator: Mahaffy, J.H.; Liles, D.R. & Woodruff, S.B.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Some strategies for enhancing the performance of the block Lanczos method

The block Lanczos method is used to calculate the eigenfunctions for a generalized eigenvalue problem constructed for a finite element solution to a 2-dimensional Schr/umlt o/dinger equation on the surface of a hypersphere. This equation results from a treatment of the 3-dimensional reactive scattering problem using Adiabatically adjusting. Principal axes Hyperspherical (APH) coordinates. Three stategies are considered with respect to increasing the CPU performance of the block Lanczos (with se… more

Date: January 1, 1988

Creator: Kress, J.D.; Woodruff, S.B.; Parker, G.A. & Pack, R.T.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Unmitigated boron dilution events in a PWR. [During shutdown]

Dissolved boron is required for control of reactivity in a pressurized water reactor that is shut down. TRAC-PF1 calculations for a typical PWR for vessel-closed and vessel-open configurations show that a high-power excursion (approaching 20% of nominal operating power) is possible if dilution of the boron solution occurs. The calculations also show that sufficient heat capacity exists in the primary system to prevent a large temperature increase and that natural circulation flow of high concen… more

Date: March 1, 1982

Creator: Henninger, R.J. & Woodruff, S.B.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Fast numerical methods in 3-D. [PWR; BWR]

During the past decade, various semi-implicit finite-difference schemes such as that used in version PD2 of the Transient Reactor Analysis Code (TRAC-PD2) have been applied to problems in fluid flow. The stability-enhancing two-step (SETS) method was created to improve the running time of the existing TRAC code with inimal impact on the code structure and results. The SETS method eliminates the material Courant stability limit simply by adding a stabilizer step to the basic semi-implicit equati… more

Date: May 1, 1984

Creator: Woodruff, S.B.

Item Type: Article

Partner: UNT Libraries Government Documents Department