1. NAME AND TITLE

CDR: A Constant Dose Range Code System, Using the LANL-NWEF Neutron-Gamma-Ray Air Flux Tape.

CDR was developed from the DOSE and SLANT computer programs which are reported by S. A. Dupree in NWEF Report 1040 and NWEF Report 1044.

2. CONTRIBUTORS

Naval Weapons Evaluation Facility, Kirtland Air Force Base, New Mexico.

Los Alamos Scientific Laboratory, Los Alamos, New Mexico.

3. CODING LANGUAGE AND COMPUTER

FORTRAN IV; CDC 6000 (A), IBM 360/75/91 (B).

4. NATURE OF PROBLEM SOLVED

CDR is designed to calculate ranges of constant dose from a point source of radiation in the atmosphere. It scales the results of transport calculations in uniform, sea-level air. CDR combines all the capabilities of earlier versions and is designed to use as input the LANL-NWEF air flux tape or the flux dump from a coupled neutron-gamma-ray transport calculation from a computer program such as CCC-42/DTF-IV. The air flux data consists of complete transport calculations in uniform, sea-level air for one source neutron in each of 30 energy groups and one source photon in each of 12 energy groups. The program uses the air flux tape to produce ranges of constant dose from a point source in the atmosphere.

5. METHOD OF SOLUTION

The LANL-NWEF air flux tape contains complete transport calculations for one source neutron in each of 42 energy groups and one source photon in each of 12 energy groups. CDR folds the user's source spectrum with the air flux data to determine the resulting flux by group and space point to a distance of 5 kilometers in uniform, sea-level air. The appropriate dose conversion factors are applied to this data and the results scaled to provide ranges of constant dose in the atmosphere. The code is designed for user convenience and makes extensive use of free form input.

6. RESTRICTIONS OR LIMITATIONS

Because uniform air results are used in CDR, the results may be in significant error near the air-ground interface or at high altitudes where scaling is performed over more than one atmospheric scale height.

7. TYPICAL RUNNING TIME

Ignoring compile time and the time required to read the air flux tape, the calculations require approximately 0.2 seconds of CPU time on the CDC 6600 computer per constant dose contour. RSIC recorded one minute of running time for the sample problem on the IBM 360/75.

8. COMPUTER HARDWARE REQUIREMENTS

CDR requires approximately 110,000 (octal) central core. It requires the air flux tape in binary form and all output is to a line printer.

9. COMPUTER SOFTWARE REQUIREMENTS

A FORTRAN H compiler is required.

10. REFERENCE

J. E. Campbell and H. A. Sandmeier, "Air Transport Calculations Using the LASL-NWEF Air Flux Tape and the NWEF Computer Program - CDR," NWEF 1090 (April 1972).

11. CONTENTS OF CODE PACKAGE

Included are the referenced document and one (1.2MB) DOS diskette which contains control cards, source codes, sample problem input and output, plus air flux data.

12. DATE OF ABSTRACT

May 1975.