CCC-0372 ACT-ARA.

1. NAME OR DESIGNATION OF PROGRAM:  ACT-ARA.

3. DESCRIPTION OF PROGRAM OR FUNCTION

The program calculates the source term activity as a function of time for parent isotopes as well as daughters. Also, at each time, the "probable release" is produced. Finally, the program determines the time integrated probable release for each isotope over the time period of interest.

4. METHOD OF SOLUTION

The ACT-ARA program modifies an initial source  term for changes with time due to decay of parents and production of daughters. The calculated activity for each daughter is based on the activity of the chain's parent. Time steps are distributed uniformly on a base 10 logarithmic scale. Decay constants, half-lives, specific activities, identified daughter products and their rate of  production are maintained in data files IS30, IS50, IS60, IS90, and  IS106. The probable release of the activity is calculated at each time interval based on the fraction released and the probability of  intrusion. The fraction released is a step function which changes from an initial release fraction to a final release fraction at a specified time. The probability of release is non-zero following a period of active control and is modelled by a "Wisconsin Regression" function. The integrated probable release for each isotope is obtained by summation of the probable release over the total time.

5. RESTRICTIONS ON THE COMPLEXITY OF THE PROBLEM

The probability of intrusion is modelled by a "Wisconsin Regression" function that is assumed to be able to fit the projected probability data.

6. TYPICAL RUNNING TIME

Large runs with 500 iterations require approximately 12 s.

NEA-DB compiled the programs and executed the test case on a Cray YMP-EL computer. CPU times were less than one second.

7. UNUSUAL FEATURES OF THE PROGRAM:

8. RELATED AND AUXILIARY PROGRAMS

RACT : Interactive Input Generation Program.
DATA LIBRARIES - IS30; IS50; 1S60; IS90; and IS106: Isotopic decay data for isotopes with atomic numbers 1-30, 31-50, 51-60, 61-90, and 91-106, respectively.

10. REFERENCES:

- S.W. Woolfolk:
  ACT: A Program for calculation of the Changes in Radiological
  Source Terms with Time.
  WIPP/DOE-85-201  (August 12, 1985)

11. MACHINE REQUIREMENTS:  Tested on a CRAY-XMP/2.

13. OPERATING SYSTEM UNDER WHICH PROGRAM IS EXECUTED:  CRAY CTSS operating system, FORTRAN 77 compiler, CFT.

UNICOS rel.6.1.6 with FORTRAN-77 compiler CFT77.

14. OTHER PROGRAMMING OR OPERATING INFORMATION OR RESTRICTIONS:

15. NAME AND ESTABLISHMENT OF AUTHORS

      Developed by:   S.W. Woolfolk
                      Applied Research Associates, Inc.
                      Albuquerque, New Mexico, U. S. A.

      Contributed by: Radiation Safety Information Computational Center
                      Oak Ridge National Laboratory
                      Oak Ridge, Tennessee, U. S. A.

File name	File description	Records
CCC0372_01.001	Information file	44
CCC0372_01.002	JCL	10
CCC0372_01.003	RACT FORTRAN source	71
CCC0372_01.004	CACT FORTRAN source	811
CCC0372_01.005	DACT data file	8
CCC0372_01.006	IS30 input data file	269
CCC0372_01.007	IS50 input data file	156
CCC0372_01.008	IS60 input data file	183
CCC0372_01.009	IS90 input data file	518
CCC0372_01.010	IS106 input data file	233
CCC0372_01.011	CACT output (file TAPE40)	42