**1. NAME AND TITLE**

SUBDOSA-II: Calculation of External Gamma-Ray and Beta-Ray Doses from Accidental Atmospheric Releases of Radionuclides.

SUBDOSA was derived from RACER (CCC-174). SUBDOSA-II includes improvements which have been made to the original SUBDOSA.

**AUXILIARY ROUTINE**

BIVAR: Gamma-Ray Dose Rate Factors for Bivariate Plumes.

**DATA LIBRARIES**

RMDLIB: Master Data Library.

GISLIG: Gamma-Ray Energy Data Library.

RNDBET: Beta-Ray Energy Data Library.

BIVLIB: Dose Rate Conversion Factor Data Library.

**2. CONTRIBUTOR**

Battelle Memorial Institute, Pacific Northwest Laboratories, Richland, Washington.

**3. CODING LANGUAGE AND COMPUTER**

FORTRAN IV; UNIVAC 1100/44.

**4. NATURE OF PROBLEM SOLVED**

SUBDOSA-II calculates submersion doses from an acute release of radionuclides to the atmosphere, as did SUBDOSA. Doses are calculated as a function of distance from release point, atmospheric stability, and wind speed for a specified radionuclide inventory. Contributions from both beta and gamma radiation are included as a function of tissue depth.

**5. METHOD OF SOLUTION**

The gamma-ray dose calculation uses the finite cloud approach. Numerical integration over the cloud volume is performed using Bode's rule applied to selected intervals to ensure accuracy.

The effective beta-ray energy for each nuclide is calculated from beta-ray end point energy data. Fermi theory is used to determine the effective beta-ray energy by numerical integration (Simpsons 3/8th rule). The method of Loevenger is used to determine the beta-ray depth-dose reduction factor for tissue.

Nuclide decay is considered with branching to and from isomeric states.

SUBDOSA-II will accept the data library RMDLIB as a master library. The beta-ray energy library and gamma-ray energy library used in SUBDOSA were modified in SUBDOSA-II to use the same radionuclide identifications as the master library.

**6. RESTRICTIONS OR LIMITATIONS**

Each case has the following dimensional limitations:

Number of Nuclides 500

Number of Gamma-Ray Energy Groups 12

Number of Downwind Distances 10

Number of Beta-Ray Dose Tissue Depths 4

Number of Gamma-Ray Dose Tissue Depths 3

Number of Release Periods 6

**7. TYPICAL RUNNING TIME**

The running time depends mainly on the number of nuclides in the inventory, the number of release periods and the number of distances. For a typical problem of 10 distances, 1 period, and fewer than 5 nuclides, the running time is 0.3 seconds plus 7 seconds to read the nuclide data libraries plus 2 seconds if a gamma-ray dose rate factor library is read. For 110 nuclides, the dose calculation takes about 7 seconds.

**8. COMPUTER HARDWARE REQUIREMENTS**

SUBDOSA-II was originally designed to run on the CYBER 74; was made operable on the UNIVAC 1100/44.

**9. COMPUTER SOFTWARE REQUIREMENTS**

A FORTRAN IV compiler is required.

**10. REFERENCES**

D. L. Strenge, Informal Note (January 1981).

D. L. Strenge, E. C. Watson, and J. R. Houston, "SUBDOSA: A Computer Program for Calculating External Doses from Accidental Atmospheric Releases of Radionuclides," BNWL-B-351 (June 1975).

**11. CONTENTS OF CODE PACKAGE**

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

**12. DATE OF ABSTRACT**

March 1982; updated January 1983; reviewed January 1985.

**KEYWORDS: ** AIRBORNE; FISSION PRODUCTS; REACTOR ACCIDENT;
ENVIRONMENTAL DOSE; RADIONUCLIDES; GAMMA-RAY; BETA-RAY; KERNEL; GAUSSIAN PLUME MODEL