1. NAME AND TITLE

CONDOS-II: Code for Estimating Radiation Doses from Radionuclide-Containing Consumer Products.

This code was developed under sponsorship of the Nuclear Regulatory Commission to serve as a tool for assessing radiation doses that may be associated with consumer products that contain radionuclides. A first version of CONDOS was published during 1975. CONDOS-II is a more flexible and comprehensive version of the original code.

2. CONTRIBUTOR

Oak Ridge National Laboratory, Oak Ridge, Tennessee.

3. CODING LANGUAGE AND COMPUTER

Fortran IV, any main-frame IBM computer.

4. NATURE OF PROBLEM SOLVED.

The code calculates radiation dose equivalents resulting from user-supplied scenarios of exposures to radionuclides contained in or released from sources that contain radionuclides. Dose equivalents may be calculated to total body, skin surface, skeletal bone, testes, ovaries, liver, kidneys, lungs, and maximally exposed segments of the gastrointestinal tract from exposures via (1) direct, external irradiation by photons (including bremsstrahlung) emitted from the source, (2) external irradiation by photons during immersion in air containing photon-emitting radionuclides that have escaped from the source, (3) internal exposures by all radiations emitted by inhaled radionuclides that have escaped from the source, and (4) internal exposures by all radiations emitted by ingested radionuclides that have escaped from the source.

5. METHOD OF SOLUTION

Organ dose equivalents are approximated in two ways, depending on the exposure type. For external exposures, energy specific organ-to-skin-surface dose conversion ratios are used to approximate dose equivalents to specific organs from doses calculated to a point on the skin surface. The organ-to-skin ratios are incorporated in organ- and nuclide-specific dose rate factors, which are used to approximate doses during immersion in contaminated air. For internal exposures, 50 year dose equivalents are calculated using organ- and nuclide-specific, 50 year dose conversion factors.

Doses from direct, external exposures are calculated using the energy-specific dose conversion ratios, user supplied exposure conditions, and photon flux approximations for eleven source geometries. Available source geometries include: point, shielded and unshielded; line, shielded and unshielded; disk, shielded and unshielded; cylindrical surface, unshielded; uniform, semi-infinite volume, shielded and unshielded; uniform, infinite slab, shielded and unshielded; uniform, nonabsorbing cylindrical volume, unshielded; uniform, nonabsorbing spherical volume, unshielded; and uniform, self-absorbing cylindrical volume, shielded and unshielded.

External doses from immersion in contaminated air are calculated using the organ- and nuclide-specific dose rate conversion factors, user supplied exposure conditions, and an infinite to finite air volume correction formula. External doses are calculated using the appropriate inhalation or ingestion, 50 year, organ- and nuclide-specific dose conversion factors and user supplied exposure conditions.

6. RESTRICTIONS OR LIMITATIONS

Variable dimensioning limits: the number of nuclide decay chains to 25, the number of sources in an exposure event to 25, and the number of absorbing materials between the source and dose point to 4 (excluding air).

7. TYPICAL RUNNING TIME

The sample problem required 11.77 cpu seconds on the IBM 3033. Execution time will vary with the size of the input data file, especially with the number of nuclides, sources, and immersion, ingestion, and inhalation events to be considered. The sample problem contains 6 nuclides, 12 sources, and six immersion, ingestion, or inhalation events.

8. COMPUTER HARDWARE REQUIREMENTS

CONDOS-II was designed for use on the IBM 360 or 3033 computers and should run on any machine compatible with IBM Fortran requirements. Modification of format statements to Hollerith fields will enable it to run on most batch computers. The sample problem required 336 K on the IBM 3033. It requires two scratch tapes or temporary system storage devices, one for exposure data and one for nuclide data.

9. SOFTWARE REQUIREMENTS

The sample problem was executed on the Fortran H compiler under MVS.

10. REFERENCES

a. Included in documentation:

F. R. O'Donnell, D. C. Kocher, O. W. Burke, and F. H. Clark, "CONDOS II A Tool for Estimating Radiation Doses from Radionuclide-Containing Consumer Products," NUREG/CR-2068, ORNL/NUREG/TM-454 (November 1981).

b. Background information:

F. R. O'Donnell, et al., "CONDOS A Model and Computer Code to Estimate Population and Individual Radiation Doses to Man from the Distribution, Use, and Disposal of Consumer Products that Contain Radioactive Materials," ORNL/TM-4663 (1975).

11. CONTENTS OF CODE PACKAGE

Included are the referenced document (10.a) and one (1.2MB) DOS diskette which contains the source code plus sample problem input and output.

12. DATE OF ABSTRACT

May 1982.