1. NAME AND TITLE

INAP: Improved Neutron Activation Prediction Code Systems.

AUXILIARY ROUTINES

DOT: Discrete Ordinates Neutron Transport ModuleFlux Generation for Engineering System.

NAPK: Activation and Decay Chain ModuleSource Generation for both Systems.

KAPV: Kernel Integration Gamma-Ray Shielding Module for Engineering System.

FASTER: Monte Carlo Neutron Transport and Gamma-Ray Shielding Module for Optional Accurate System.

The NAPK part of this code package originated as CCC-101/NAP which was developed by IIT Research Institute for NASA/MSFC. It was later modified by NASA/LRC and became CCC-164/NAC. CCC-235/INAP contains two code systems: an "Engineering System" which was developed by modifying and integrating into a system CCC-89/DOT, CCC-101/NAP, CCC-94/KAPV to be used for survey and preliminary design; and an "Accurate System" to be used for final design evaluation. The "Accurate System" includes a modified CCC-98/FASTER and NAPK.

2. CONTRIBUTORS

NASA Marshall Space Flight Center, Huntsville, Alabama.

TRW Systems Group, Redondo Beach, California.

3. CODING LANGUAGE AND COMPUTER

FORTRAN IV; UNIVAC 1108.

4. NATURE OF PROBLEM SOLVED

INAP computes the gamma-ray spectrum, cumulative dose, and dose rate at a given detector point generated from a given activation point after transport through complex structural geometry. The activation level at the activation point is computed from a given neutron source distribution after transport through other complex structural geometries. The neutron source may be volume distributed or an incident angular flux. Both the cumulative dose and/or dose rate may be determined at specified detector locations. Neutron and gamma-ray transport is time independent. The time dependence of the dose rate is determined by the NAP program through the power history of the neutron source and the decay rates of the radioactive parents and daughters in the various decay chains produced by neutron activation.

5. METHOD OF SOLUTION

INAP is comprised of three computational modules. The first program module computes the spatial and energy distribution of the neutron flux from an input source and prepares input data for the second program which performs the reaction rate, decay chain and activation gamma-ray source calculations. A third module accepts input prepared by the second program to compute the cumulative gamma-ray doses and/or dose rates at specified detector locations in complex, three-dimensional geometries.

6. RESTRICTIONS OR LIMITATIONS

None noted.

7. TYPICAL RUNNING TIME

No study has been made by RSIC of typical running times for INAP.

8. COMPUTER HARDWARE REQUIREMENTS

INAP is operable on the UNIVAC 1108 computer.

9. COMPUTER SOFTWARE REQUIREMENTS

A FORTRAN IV compiler is required.

10. REFERENCES

R. M. Saqui, R. M. Webb, and D. Richmond, "Improved Neutron Activation Prediction Code System Development: Final Report," NASA CR-1905 (November 1971).

D. A. Klopp, "Prediction of Neutron Induced Activation, Volume INAP Code Manual," IITRI-A6088-21 (January 1966).

D. A. Klopp, "Prediction of Neutron Induced Activation, Volume IINAP: Physical Models and Experimental Validation," IITRI-A6088-22.

D. A. Klopp, "Prediction of Neutron Induced Activation, Volume IIINAP Cross Section Library," IITRI-A6088-23.

D. A. Klopp, "Prediction of Neutron Induced Activation, Volume IVNAP Gamma Radiation Library," IITRI-A6088-24 (January 1966).

11. CONTENTS OF CODE PACKAGE

Included are the referenced documents and one (1.2MB) DOS diskette which contains the source codes, cross sections, and data for sample problems and output.

12. DATE OF ABSTRACT

August 1975.

KEYWORDS: NEUTRON; ACTIVATION; GAMMA-RAY; ISOTOPE INVENTORY; DISCRETE ORDINATES; COMPLEX GEOMETRY; TWO-DIMENSIONS