1. NAME AND TITLE

TDT: Generalized One-Dimensional Multigroup Time-Dependent Transport and Diffusion Kinetic Code System.

TDT is based on CCC-184/TASK.

2. CONTRIBUTORS

Nuclear Engineering Department, University of Tennessee, Knoxville, Tennessee.

Neutron Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee.

3. CODING LANGUAGE AND COMPUTER

FORTRAN IV; IBM 360/370.

4. NATURE OF PROBLEM SOLVED

TDT solves the one-dimensional multigroup form of the time-dependent reactor kinetics equations, allowing an arbitrary number of delayed neutron groups. It can also solve standard static problems such as eigenvalue problems (transport only), distributed source problems, and boundary source problems using either diffusion theory or transport theory. Convergence problems associated with highly multiplicative media are circumvented, and such problems are readily calculable.

5. METHOD OF SOLUTION

TDT employs a combination scattering and transfer matrix method to solve the transport equation in the spatial domain and a predictor-corrector method to obtain solutions in the temporal domain.

6. RESTRICTIONS OR LIMITATIONS

The principal restrictions are available storage and computational time. Since the code is flexibly dimensioned, there are no internal restrictions on group structure, quadrature, and number of coordinates. The code contains an option whereby it will calculate the most efficient time mesh. The cylindrical geometry option is not operational in this version.

7. TYPICAL RUNNING TIME

A 10-second rod-drop transient in a 7-region, 5-group, S4 problem requires 5 minutes on the IBM 360/91 computer. The packaged sample problem ran in 1.6 minutes. A point kinetics approximation is available which significantly reduces the computational time.

8. COMPUTER HARDWARE REQUIREMENTS

TDT runs on the IBM 360/370 computers, requiring 178 K of storage plus data block storage, a total of 244 K. One tape is required to utilize the flux tape option.

9. COMPUTER SOFTWARE REQUIREMENTS

A FORTRAN IV compiler is required.

10. REFERENCE

E. T. Tomlinson, H. L. Dodds, R. A. Lillie, and J. C. Robinson, "A User's Manual for TDT (Time Dependent Task)," ORNL-TM-4869 (June 1975).

11. CONTENTS OF CODE PACKAGE

Included are the referenced document and one (1.2MB) DOS diskette which contains the source code and sample problem input and output.

12. DATE OF ABSTRACT

September 1975; revised January 1983.