**1. NAME AND TITLE**

DKR: A Radioactivity and Dose Rate Calculation Code System for Fusion Reactors.

**AUXILIARY ROUTINES**

DKRDOSE: Dose rate calculation program

DKRCONVERT: DKR output decay gamma-ray source file conversion program for input to DKRDOSE

**DATA LIBRARY**

ACTLLIB: Cross-section and decay data library for neutron-nucleus transmutations

**RELATED PROGRAMS**

Neutral particle transport codes such as CCC-254/ANISN-ORNL, CCC-428/ONEDANT, and CCC-456/TWODANT

**2. CONTRIBUTOR**

Fusion Technology Institute, University of Wisconsin, Madison, Wisconsin.

**3. CODING LANGUAGE AND COMPUTER**

FORTRAN 77; CRAY XMP/48.

**4. NATURE OF PROBLEM SOLVED**

The radioactivity, afterheat, biological hazard potential (BHP), and biological dose rates are of great concern in the design of fusion reactors. The determination of radioactivity and dose rate play a major role in determining the first wall material, blanket structure, environmental impact and maintenance procedures. The DKR calculation is based on the transmutation of the nuclides in a fusion reactor. The DKR calculation of the pointwise radioactivity of nuclides can be calculated for steady-state and pulsed modes of operation.

This version extends the original DKR with a more realistic pulse sequence scheme to simulate inertial confinement fusion and a capability to treat two-dimensional r-z and x-y geometries.

**5. METHOD OF SOLUTION**

The activation of a nuclide can be represented by linear decay chains which, in turn, can be solved by a recursion coefficient formula. The neutron flux from a transport calculation and the transmutation data from the ACTLLIB library are essential inputs. DKR constructs the linear decay chains by itself with nuclear data from ACTLLIB. The solution of chains is used to compute radioactivity, biological hazard potential (BHP), and afterheat by applying appropriate weighting functions. Decay gamma-ray sources generated by DKR can be used in the DOSE code to calculate either spatially-dependent dose rates at a specific time after shutdown or time-dependent dose rates at a specific position. The CONVERT program can be used to transfer DKR gamma-ray sources to DOSE or another transport code. Forward and adjoint schemes can be utilized in the calculations.

**6. RESTRICTIONS OR LIMITATIONS**

The number of stable nuclides in a decay chain is limited to 4.

A second order decay chain loop treatment is considered but corrections to higher order loops are neglected.

For sequential pulse operation, the burnup of the initial and created isotopes is considered for the initial pulse but ignored for subsequent ones.

Neutron transmutation data and decay gamma-ray sources from DKR are in 46 group and 21 group structure, respectively.

**7. TYPICAL RUNNING TIME**

For one-dimensional problems with about 100 mesh intervals, the CRAY XMP/48 CPU time is 10-20s. For two-dimensional problems with about 3000 mesh intervals, the CPU time is 2-3 m.

**8. COMPUTER HARDWARE REQUIREMENTS**

CRAY XMP/48.

**9. COMPUTER SOFTWARE REQUIREMENTS**

A FORTRAN 77 compiler is required. Several logical units are required, as well as standard I/O.

**10. REFERENCES**

**a. Included in the package:**

D. L. Henderson and O.Yasar, "DKR-ICF: A Radioactivity and Dose-Rate Calculation Code Package," UWFDM-714, Vol. 1 (Revised April 1987) & 2 (November 1986).

**b. Background information:**

T. Y. Sung and W. F. Vogelsang, "DKR: A Radioactivity Calculation Code for Fusion Reactors," UWFDM-170 (September 1976).

T. Y. Sung, "Radioactivity Calculations in Fusion Reactors," Ph.D. Thesis, University of Wisconsin-Madison (1976).

**11. CONTENTS OF CODE PACKAGE**

Included are the documents listed in (10.a) and one (1.2MB) DOS diskette which contains the source codes, data library, and sample problem input and output.

**12. DATE OF ABSTRACT**

January 1982; revised December 1987.

**KEYWORDS: ** ACTIVATION; BETA-RAY; CTR; ENERGY DEPOSITION; GAMMA-RAY;
HEATING; ISOTOPE INVENTORY; MULTIGROUP; NEUTRON; ONE-DIMENSION; RADIOACTIVITY; TIME-DEPENDENT; TWO-DIMENSIONS