1. NAME AND TITLE

CLOUD: Gamma-Ray Dose Rate from a Radioactive CloudKernel Integration Code.

The above-named code is listed in the ANL NESC collection as Reactor Code Abstract 47. It is early technology and is retained by RSIC as one of a series of similar codes. Between 19661981, it was distributed eleven times by RSIC.

2. CONTRIBUTOR

Atomics International, Canoga Park, California.

CLOUD was placed in the RSIC collection through the services of the former Argonne Code Center, now NESC.

3. CODING LANGUAGE AND COMPUTER

FORTRAN; IBM 360/370.

4. NATURE OF PROBLEM SOLVED

CLOUD was designed to calculate the external gamma-ray dose rate and total integrated dose resulting from the accidental release of radioactive materials to the atmosphere. Meteorological parameters such as wind velocity, lateral and vertical diffusion coefficients, stability parameters and the presence of physical boundaries such as a ground surface and a temperature inversion layer, are considered. Depletion of the cloud due to wash-out and fall-out has also been included.

The degree of hazard is estimated both from the standpoint of internal as well as external exposure.

5. METHOD OF SOLUTION

A Legendre-Gauss quadrature technique is used to perform the numerical integrations of the attenuation kernel over the source regions.

A two compartment continuous release model is assumed to simulate holdup of the source material. Decay of the source material is described either by the use of a simple parent-daughter decay scheme or by a Way-Wigner type relationship. Provisions have been made to permit the use of either empirical or calculated fission product decay data.

6. RESTRICTIONS OR LIMITATIONS

No information on restrictions or limitations is available at this time.

7. TYPICAL RUNNING TIME

Formulas are given in the referenced report by which time may be estimated. The sample problems described took 6.32 and 1.38 minutes, respectively.

8. COMPUTER HARDWARE REQUIREMENTS

The code, designed for the IBM 7090 and 7094, is operable on the IBM 360/370. A 32,768 core memory and three tape units are required.

9. COMPUTER SOFTWARE REQUIREMENTS

The code was designed to compile and execute in the IBM FORTRAN II Monitor System and is compatible with other FORTRAN systems. Input, output, and system tape assignments are made. BCD output on punched cards is controlled by an input parameter. When using this option an assignment must by made for an auxout tape.

10. REFERENCE

D. S. Cuncan, A. B. Speir, G. H. Anno, D. C. Kolesar, CLOUDAn IBM 709 Program for Computing Gamma-Ray Dose Rate from a Radioactive Cloud, NAA-SR- Memo-4822 (April 1959).

11. CONTENTS OF CODE PACKAGE

The package contains the referenced document and a reel of magnetic tape on which is writtenin separate filesthe source card deck, a library of permanent data and input for a sample problem, BCD punched card output, and output from the sample problem; total records 10,975.

12. DATE OF ABSTRACT

January 1966; updated July 1981, February 1985.

KEYWORDS: GAMMA-RAY; ENVIRONMENTAL DOSE; KERNEL; AIR TRANSPORT; FALLOUT