1. NAME AND TITLE

REPRISK-PC 1.02: Repository Risk Assessment Software for Personal Computers.

2. CONTRIBUTOR

EPA, Office of Radiation and Indoor Air, Las Vegas, Nevada.

3. CODING LANGUAGE AND COMPUTER

FORTRAN 77, and C; PC 386.

4. NATURE OF PROBLEM SOLVED

REPRISK-PC is a PC version of the REPRISK model used in the modelling of long-term radionuclide releases and population health effects resulting from disposal of high level radioactive wastes in mined geological repositories. REPRISK is a set of computer programs and databases that models the transport of radionuclides from the repository through the environment to exposed human populations and estimates the resulting health impact. Version 1.02 modifies the carbon-14 risk factor from 5.83E-2 to 1.24E-1 cancer deaths per Curie released.

5. METHOD OF SOLUTION

Various natural processes or human activities could lead to radionuclide releases from a geological repository after it has been closed. These perturbations happen according to some frequency or probability. REPRISK-PC incorporates the characteristics of these perturbations and their associated probability. REPRISK-PC models four release scenarios: (1) direct impact of a waste package releases to air and land surface (volcano, meteorite, drilling/direct hit); (2) direct impact of a waste package releases to an aquifer (faulting, breccia pipes); (3) disruption of the repository releases to land (drilling/no hit); (4) disruption of the repository releases to an aquifer (normal groundwater flow, faulting, breccia pipes, drilling/no hit).

6. RESTRICTIONS OR LIMITATIONS

REPRISK-PC does not model the differences in radionuclide-specific velocities, which may control the travel time from repository to the accessible environment. It is not a good model for time periods greater than 10,000 years when radium daughters become important.

7. TYPICAL RUNNING TIME

REPRISK-PC is interactive, and response time is very fast.

8. COMPUTER HARDWARE REQUIREMENTS

REPRISK-PC requires an IBM PC, PC/XT or PC/AT with 640 K of RAM, parallel communications for printer, math coprocessor, hard disk, EGA or VGA monitor.

9. COMPUTER SOFTWARE REQUIREMENTS

The code was written in FORTRAN 77 and C. The Turbo C++ Version 1.00 compiler and Turbo Link Version 3.0 were used to compile and link the C sources. The Lahey F77L, Version 4.00 and Microsoft 8086 Object Linker were used to compile and link the FORTRAN sources. The code will run under DOS 2.0 or higher.

10. REFERENCES

a. Included in Package:

B. Parks, "Programmer's Maintenance Manual for REPRISK-PC," (September 1992).

b. Background Information:

B. Parks, "Notes on REPRISK-PC Version 1.0 Source Code," Las Vegas EPA Informal Notes (March 6, 1991).

"User's Guide for REPRISK-PC, Version 1.0," U.S. Environmental Protection Agency, Las Vegas, Nevada (March 1991.)

"REPRISK Code Documentation," Arthur D. Little, Inc., Acorn Park, Cambridge, Massachusetts, Volumes 1, 2 (October 1983).

11. CONTENTS OF CODE PACKAGE

Included are the referenced documents and one DS/HD (1.2 MB) 5.25-inch diskette which includes source codes, executables, and data files in compressed format for DOS.

12. DATE OF ABSTRACT

April 1993.