CCC-0419 CRAC2.

1. NAME OR DESIGNATION OF PROGRAM:  CRAC2.

3. DESCRIPTION OF PROBLEM OR FUNCTION

CRAC2 is a revision of the CRAC (Calculation of Reactor Accident Consequences) program developed in  support of the Reactor Safety Study, WASH-1400, to assess the risk from potential accidents at nuclear power plants. The need for more  realistic consequence estimation techniques for purposes such as site evaluation, emergency planning and response, and general risk assessment guided the development of CRAC2. Errors were corrected and changes including modification of the atmospheric dispersion model and introduction of a new meteorological sampling technique, a new evacuation model, and additional output capabilities were made.  CRAC2 retains the organization, structure, and analytical capabilities of CRAC.

4. METHOD OF SOLUTION

The assessment of accident risk entails the coupling of a series of mathematical and statistical models. CRAC2 requires as input an inventory of radioisotopes released from the reactor containment to the environment and a description of the accident conditions. It (1) models the meteorological dispersion of  the cloud of radioactive material; (2) determines the health effects of the material upon the surrounding population; and (3) estimates the costs to the public from the accident. CRAC2 samples specific meteorological conditions from a set of representative reactor locations and probabilistically combines the results to form frequency distributions of consequence from a reactor accident. It requires detailed meteorological, population, economic, and health data. In addition, CRAC2 models emergency planning procedures, such  as evacuation. Detailed parametric and sensitivity studies can be simply accomplished in one computer run.
Data utilized by some of the models have been upgraded: (1) latent cancer fatality risk factors have been changed to reflect the lifetime risk of latent cancer from radiation exposure and (2) economic data have been upgraded to reflect 1980 economic statistics for the United States.

5. RESTRICTIONS ON THE COMPLEXITY OF THE PROBLEM

Because of possible  system dependencies for the IBM version, CRAC2 may not execute all 5 sample problems in one computer run. Should this happen, sample problem 5 must be run separately, making sure the permanent changes  in sample problems 1 and 2 are included.

6. TYPICAL RUNNING TIME

On the IBM 3033, sample problems 1, 2, 3, and 4, run at the same time, required about 4 minutes and 17 seconds of  CPU time; sample problems 1,2, and 5, run at the same time, required 3 minutes and 34 seconds.

NEA-DB executed the test case included in the package on a CDC CYBER 830 computer in 1288 seconds of CPU time.

NEA-DB executed the test cases included in the package  on IBM 3090. CPU times required were: 45 seconds for test cases 1,2,3, and 4; 61 seconds for test cases 1,2, and 5.

7. UNUSUAL FEATURES OF THE PROGRAM:

8. RELATED AND AUXILIARY PROGRAMS

Data Libraries:
     DC:     Dose Conversion (Health) Data;
     MD-NYC: Meteorological Data for New York City;
     IPS:    indian Point Site Data.

10. REFERENCES:

- Lynn T. Ritchie, Jay D. Johnson, and Roger M. Blond:
  Calculations of Reactor Accident Consequences Version 2 CRAC2:
  Computer Code User's Guide
  NUREG/CR-2326, SAND81-1994 (February 1983)
- L.T. Ritchie et al.:
  CRAC2 Model Description.
  NUREG/CR-2552, SAND82-0342  (March 1984)
- J.E. White, R.W. Roussin, H. Gilpin:
  Guide for Licensing Evaluations Using CRAC2
  A Computer Program for Calculating Reactor Accident Consequences
  NUREG/CR-5264, ORNL/TDMC-3 (December 1988)
- Lynn T. Ritchie, Jay D. Johnson, and Roger M. Blond,
  Calculations of Reactor Accident Consequences Version 2 CRAC2:
  Computer Code User's Guide
  NUREG/CR-2326, SAND81-1994 (February 1983)
- L.T. Ritchie et al.:
  CRAC2 Model Description.
  NUREG/CR-2552, SAND82-0342  (March 1984)
- NEA-DB Note (January 20, 1989)
- J.E. White, R.W. Roussin, H. Gilpin:
  Guide for Licensing Evaluations Using CRAC2
  A Computer Program for Calculating Reactor Accident Consequences
  NUREG/CR-5264, ORNL/TDMC-3 (December 1988)

11. MACHINE REQUIREMENTS:

To run the test case on a CDC CYBER 830 computer, storage requirements are: 261,151 (octal) words CM and 150,420 (octal) words ECS.

To run the test cases of this package, 984K bytes of main storage were required on an IBM 3090 computer.

13. OPERATING SYSTEM UNDER WHICH PROGRAM IS EXECUTED:

NOS2.5.1 (CDC CYBER 830).

MVS/XA with compiler VS FORTRAN Level 2.2.0 and assembler ASMH V 02 17.10.

14. OTHER PROGRAMMING OR OPERATING INFORMATION OR RESTRICTIONS

Memory
should be preset to zero for execution on CDC systems. CRAC2 uses the local RANF system routine to generate random numbers. In different computing environments where different sequences of random numbers are produced the sample output may vary. The 12 pages of sample output, titled "Accident Sequence BMR1, Evacuation Scheme Summary" will vary depending on the random numbers used.

15. NAME AND ESTABLISHMENT OF AUTHOR

             L.T. Ritchie* and J.D. Johnson
             Sandia National Laboratories
             P.O. Box 5800
             Albuquerque, New Mexico 87145

             R.M. Blond
             Office of Nuclear Regulatory Research
             U.S. Nuclear Regulatory Commission
             Washington, D.C. 20555
* Contact

File name	File description	Records
CCC0419_09.001	Information file	50
CCC0419_09.002	JCL and control information	13
CCC0419_09.003	CRAC 2 source program	8048
CCC0419_09.004	CRAC 2 sample problem input	618
CCC0419_09.005	SITE data file	135
CCC0419_09.006	HEALTH data file	1423
CCC0419_09.007	METEOROLOGICAL data file	8762
CCC0419_09.008	Sample Problem Output	6804

File name	File description	Records
CCC0419_10.001	Information file	82
CCC0419_10.002	JCL used at NEA Data Bank	135
CCC0419_10.003	FORTRAN source	8220
CCC0419_10.004	ASSEMBLER source	22
CCC0419_10.005	Data of sample problems 1,2,3 and 4	614
CCC0419_10.006	Data of sample problems 1,2 and 5	585
CCC0419_10.007	Output of sample problems 1,2,3 and 4	5067
CCC0419_10.008	Output of sample problems 1,2 and 5	5659
CCC0419_10.009	Data file 1 (site data)	135
CCC0419_10.010	Data file 2 (dose conversion)	1423
CCC0419_10.011	Data file 3 (meteorological data)	8762