CCC-0858 TMAP7.

TMAP7

The Tritium Migration Analysis Program (TMAP) code was written as a tool for safety analysis of systems involving tritium. TMAP and TMAP4 had the capacity to deal with only a single trap for diffusing gaseous species in solid structures. TMAP7 includes up to three separate traps and up to 10 diffusing species. TMAP7 resolved the difficulty of the previous codes when dealing with heteronuclear molecule formation such as HD and DT under solution law–dependent diffusion boundary conditions.

TMAP7 automatically generates heteronuclear molecular partial pressures when solubilities and partial pressures of the homonuclear molecular species are provided for law-dependent diffusion boundary conditions. A further sophistication is the addition of non-diffusing surface species. Atoms such as oxygen or nitrogen, formation and decay, or combination of hydroxyl radicals on metal surfaces are sometimes important in reactions with diffusing hydrogen isotopes but do not themselves diffuse appreciably in the material. TMAP7 will accommodate up to 30 such surface species, allowing the user to specify relationships between those surface concentrations and partial pressures of gaseous species above the surfaces or to form them dynamically by combining diffusion species or other surface species.

Additionally, TMAP7 allows the user to include a surface binding energy and an adsorption barrier energy. The code includes asymmetrical diffusion between the surface sites and regular diffusion sites in the bulk. All the previously existing features for heat transfer, flows between enclosures, and chemical reactions within the enclosures have been retained, but the allowed problem size and complexity have been increased to take advantage of the greater memory and speed available on modern computers. One additional feature unique to TMAP7 is the addition of radioactive decay for both trapped and mobile species. Whereas earlier versions required a separate FORTRAN compiler to operate, TMAP7 is based on a public license compiler, which is distributed with the code.

At the time of its original development, TMAP was unique in its ability to model diffusion through a significant number of structures and enclosures. It incorporated unique physical models applicable to tritium transport and retention, such as recombination boundary conditions and trapping. TMAP7 includes a number of additional models (e.g., surface-only species), features (e.g., larger problem sizes), and fixes to TMAP4.

None noted.

Dependent on input file parameters. Typical problems can run in less than five minutes.

Windows, Linux, Mac OS X.

Fortran-77 compiler.

Contributed by: Radiation Safety Information Computational Center

                Oak Ridge National Laboratory, Oak Ridge, TN, USA

Developed by:   Idaho National Engineering and Environmental Laboratory, Idaho, USA