NESC9845 GSM.

1. NAME OR DESIGNATION OF PROGRAM:  GSM.

3. DESCRIPTION OF PROGRAM OR FUNCTION

GSM (Geologic Simulation Model) is a Monte Carlo simulation program for tracking the future evolution of a repository site over periods of up to several million years. Phenomena included in the model that potentially can affect the site over such periods are: climatic changes, glaciation, deformation, geomorphic events, magmatic events, meteorite impact, sea-level fluctuations, shaft seal failure, basement faulting, and undetected features. Interrelationships among phenomena are modeled, and the effects of changes on ground-water flow are followed using a simplified network model of the ground-water system in a two- dimensional cross-section of study area.

4. METHOD OF SOLUTION

The Monte Carlo simulation is based on random sampling from a relatively large number of user-supplied probability density functions. These functions represent phenomena characteristics or probability of occurence and may be derived by a  variety of methods, ranging from statistical analysis to expert opinion. The ground-water portion of the code is two-dimensional and is based on a specific conceptualization of the hydrology in the region surrounding the Pasco Basin. The probabilistic nature of the  model enables it to be used to evaluate whether a potential site meets any probabilistic regulatory standards such as those that have been issued by the Environmental Protection Agency.

5. RESTRICTIONS ON THE COMPLEXITY OF THE PROBLEM:

6. TYPICAL RUNNING TIME:

NEA-DB ran the test case included in this package on a  CDC CYBER 740 compuer in 44 seconds of CPU time.

7. UNUSUAL FEATURES OF THE PROGRAM

The model is specific to a potential repository site in the Pasco Basin area of the Columbia Plateau.

8. RELATED AND AUXILIARY PROGRAMS

GSM was originally developed on a DEC PDP11/70 by Battelle Pacific Northwest Laboratory under the Waste Isolation Safety Assessment Program (WISAP) and the Assessment of Effectiveness of Geologic Isolation Systems (AEGIS) project.
Two auxiliary interactive programs to process input and output, respectively, are included. The Input Module is executed prior to the simultion to 1) generate a set of unformatted data files for first-time simulation access; 2) change any or all input parameter values from the previous simulation; or 3) generate listings of input parameter values. The Output Module is used to examine the three unformatted files (SUMMARY, HISTORY, amd MASTER) produced by GSM. In addition, an auxiliary conversion routine is included to convert the formatted climate data to binary records for use by the  Far Field State Model (FFSM) program (NESC Summary R9844).

10. REFERENCES

- G.M. Petrie, J.T. Zellmer, J.W. Lindberg, and M.G. Foley
  Assessment of Effectiveness of Geologic Isolation Systems,
  PNL-3542, April 1981.
- M.G. Foley, G.M. Petrie, A.J. Baldwin, and R.G. Craig
  Assessment of Effectiveness of Geologic Isolation Systems,
  Geologic-Simulation Model for a Hypothetical Site in the Columbia
  Plateau, Volume 2: Results,
  PNL-3542-2, June 1982.

- INTERA Environmental Consultants, Inc.:
  GSM: Geologic Simulation Model for a Hypothetical Site in the
  Columbia Plateau - Large Computer Version.
  ONWI-447  (April 1983)

11. MACHINE REQUIREMENTS:  25K words.

To run the test case on a CDC CYBER 740, main storage requirements are 125,000 (octal) words.

13. OPERATING SYSTEM UNDER WHICH PROGRAM IS EXECUTED:

NOS2.5.1 664/650 (CDC CYBER 740).

14. OTHER PROGRAMMING OR OPERATING INFORMATION OR RESTRICTIONS:

15. NAME AND ESTABLISHMENT OF AUTHORS

          G.M. Petrie, J.T. Zellmer, J.W. Lindberg
                      and M.G. Foley
           Pacific Northwest Laboratory

          M.J. Golis
          Office of Nuclear Waste Isolation
          Battelle Project Management Division
          505 King Avenue, Columbus, Ohio 43201

File name	File description	Records
NESC9845_01.001	Information file	68
NESC9845_01.002	JCL and input data S.P. for batch run	64
NESC9845_01.003	Input Module FORTRAN source	1787
NESC9845_01.004	GSM FORTRAN source	4300
NESC9845_01.005	Output Module FORTRAN source	737
NESC9845_01.006	Scalar library data	979
NESC9845_01.007	Layer library data, model cross sections	35
NESC9845_01.008	PDF (probab. density function) library	1689
NESC9845_01.009	Polynomial library	347
NESC9845_01.010	Switch library	2
NESC9845_01.011	Climate library	460
NESC9845_01.012	Auxiliary routine to convert climate library	27
NESC9845_01.013	SUMMARY output	40
NESC9845_01.014	HISTORY output	114
NESC9845_01.015	TRACK output	11121