**1. NAME AND TITLE**

THIDA-2: Code System for the Calculation of Transmutation, Activation, Decay Heat and Dose
Rate in Fusion Reactors.

**AUXILIARY ROUTINES**

GXC: BCD to Binary Converter GICX40 Data Library.

ACT4: Induced Activity Gamma-Ray Source Calculation.

ANISN: One-Dimensional Discrete Ordinates Transport Calculation.

APPLE-2: Gamma-Ray Flux to Shutdown Dose Rate Converter and Plotter.

MIXE: Mixture-Editing Code.

DOT3.5: Two-Dimensional Discrete Ordinates Transport Calculation.

MORSE-GG: Three-Dimensional Monte Carlo Calculation.

TOPIC: Geometry Preparation and Visualization.

**DATA LIBRARIES**

CHAINLIB: Transmutation and Decay Chain Data Library.

CROSSLIB: 42 Group Transmutation Cross-Section Data Library.

GAMMALIB: Delayed Gamma-Ray Emission Data Library.

GICX40: 42 Group Neutron Cross-Section Library.

GROUPIN: 54 Group Gamma-Ray Cross-Section Library.

GFLXDOSE: Gamma Ray Flux-to-Dose Rate Conversion Factor Data.

**2. CONTRIBUTOR**

Japan Atomic Energy Research Institute (JAERI), Tokai-Mura, Ibaraki-Ken, Japan.

**3. CODING LANGUAGE AND COMPUTER**

Fortran 77; IBM 360. (C00410FM38000)

**4. NATURE OF PROBLEM SOLVED**

THIDA-2 calculates transmutation, radioactivity, decay heat and dose rate for a fusion reactor
using one-, two-, and three-dimensional geometrical models.

**5. METHOD OF SOLUTION**

The neutron flux in and around an operating fusion device is calculated using ANISN, DOT-3.5,
or MORSE-GG. The neutron flux is used as input to ACT4 which calculates the induced activity, the
approximate decay heat and the delayed gamma-ray source after a pulsed operation. The Matrix
Exponential Method is used to solve the decay chain equations to obtain time-dependent nuclide
densities. The delayed gamma-ray source serves as input for the transport calculation of the delayed
gamma-ray flux during shutdown, using the same transport code as was used for the neutron flux
calculation. The gamma-ray flux is converted to shutdown dose rate and the decay heat is calculated
and these quantities are plotted by the APPLE-2 code.

**6. RESTRICTIONS OR LIMITATIONS**

Sequential decay of two short-lived nuclides cannot be calculated accurately, reactions of neutrons
with reaction products are not considered, and neutron flux change caused by transmutation cannot be
treated in a single calculation.

**7. TYPICAL RUNNING TIME**

Problem dependent, with times ranging from 80s to 20m for an iron cylinder problem run in one
dimension and three dimensions, respectively, on an IBM 360.

**8. COMPUTER HARDWARE REQUIREMENTS**

THIDA is operable on the IBM 360 and numerous scratch and permanent storage devices are
required.

**9. COMPUTER SOFTWARE REQUIREMENTS**

A Fortran 77 compiler is required.

**10. REFERENCE**

Y. Seki, H. Iida, H. Kawasaki and K. Yamada, "THIDA-2: An Advanced Code System for
Calculation of Transmutation, Activation, Decay Heat and Dose Rate," JAERI 1301 (March 1986).

**11. CONTENTS OF CODE PACKAGE**

Included are the referenced document and three DS/HD 3.5-in. (1.44 MB) diskettes in self-extracting compressed DOS files which contain the source codes, data libraries, sample problem input
and output.

**12. DATE OF ABSTRACT**

February 1982; revised February 1983; March 1984; April 1987.

**KEYWORDS: ** NEUTRON; GAMMA-RAY SOURCE; ONE-DIMENSION; DISCRETE
ORDINATES; TWO-DIMENSIONS; ACTIVATION; ISOTOPE INVENTORY;
MULTIGROUP; CTR; MONTE CARLO; COMPLEX GEOMETRY