1. NAME AND TITLE
CRAC2: Code System for Calculating Reactor Accident Consequences.
DC: Dose Conversion (Health) Data.
MD-NYC: Meteorological Data for New York City.
IPS: Indian Point Site Data.
Sandia National Laboratories, Albuquerque, New Mexico.
Oak Ridge National Laboratory, Oak Ridge, Tennessee.
3. CODING LANGUAGE AND COMPUTER
Fortran 77 and Assembler language (A), Fortran IV (B); IBM 3033 (A), CDC (B).
4. NATURE OF PROBLEM SOLVED
The CRAC code system was developed in support of the Reactor Safety Study (WASH-1400) to
access the risk from potential accidents at nuclear power plants. CRAC2 was developed to satisfy the
need for more realistic consequence estimation techniques to be used for such purposes as site
evaluation, emergency planning and response, and general risk assessment and to correct errors which
existed in the original CRAC code system. CRAC2 includes modification of the atmospheric
dispersion model and introduction of a new meteorological sampling technique, a new evacuation
model, and new output capabilities.
5. 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.
6. RESTRICTIONS OR LIMITATIONS
The IBM version of CRAC2 may generate incorrect results when temporary modifications are
stacked in a single run. Users are advised to avoid running stacked cases with temporary modifications
using the IBM Fortran 77 version of CRAC2 which was originally released in December 1985.
7. TYPICAL RUNNING TIME
On the IBM 3033, sample problems 1, 2, 3 took about 30 seconds; sample problems 1, 2, 4 took
about 2 minutes and 40 seconds; sample problems 1, 2, and 5 required 3 minutes and 34 seconds.
8. COMPUTER HARDWARE REQUIREMENTS
CRAC2 is operable on the IBM 3033 (A) or CDC (B) computers.
9. COMPUTER SOFTWARE REQUIREMENTS
A Fortran IV compiler is required for the CDC version and a Fortran 77 compiler for the IBM
version. Version A also requires an assembler for function RANF.
L. T. Ritchie, J. D. Johnson, R. 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, D. J. Alpert, R. P. Burke, J. D. Johnson, R. M. Ostmeyer, D. C. Aldrich, R M. Blond, "CRAC2 Model Description," NUREG/CR-2552, SAND82-0342 (March 1984).
Brief explanation of IBM assembler function RANF.
11. CONTENTS OF CODE PACKAGE
Included are the referenced document and one (1.2MB) DOS diskette which contains the source
code and sample problem input and output.
12. DATE OF ABSTRACT
October 1982; revised September 1983, January 1986, October 1986, and September 1989.
KEYWORDS: REACTOR ACCIDENT; AIRBORNE; ENVIRONMENTAL DOSE; INTERNAL DOSE; NUCLIDE TRANSPORT