Sensitivity and uncertainty studies of the CRAC2 computer code
The authors have studied the sensitivity of health impacts from nuclear reactor accidents, as predicted by the CRAC2 computer code, to the following sources of uncertainty: (1) the model for plume rise, (2) the model for wet deposition, (3) the meteorological bin-sampling procedure for selecting weather sequences with rain, (4) the dose conversion factors for inhalation as affected by uncertainties in the particle size of the carrier aerosol and the clearance rates of radionuclides from the respiratory tract, (5) the weathering half-time for external ground-surface exposure, and (6) the transfer coefficients for terrestrial foodchain pathways. Predicted health impacts usually showed little sensitivity to use of an alternative plume-rise model or a modified rain-bin structure in bin-sampling. Health impacts often were quite sensitive to use of an alternative wet-deposition model in single-trial runs with rain during plume passage, but were less sensitive to the model in bin-sampling runs. Uncertainties in the inhalation dose conversion factors had important effects on early injuries in single-trial runs. Latent cancer fatalities were moderately sensitive to uncertainties in the weathering half-time for ground-surface exposures, but showed little sensitivity to the transfer coefficients for terrestrial foodchain pathways. Sensitivities of CRAC2 predictions to uncertainties in the models and parameters also depended on the magnitude of the source term, and some of the effects on early health effects were comparable to those that were due only to selection of different sets of weather sequences in bin-sampling.
- Research Organization:
- Oak Ridge National Lab., TN
- DOE Contract Number:
- AC05-84OR21400
- OSTI ID:
- 5283473
- Journal Information:
- Risk Anal.; (United States), Journal Name: Risk Anal.; (United States) Vol. 7:4; ISSN RIAND
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
220900* -- Nuclear Reactor Technology-- Reactor Safety
500300 -- Environment
Atmospheric-- Radioactive Materials Monitoring & Transport-- (-1989)
54 ENVIRONMENTAL SCIENCES
ACCIDENTS
AIR POLLUTION MONITORING
ATMOSPHERIC PRECIPITATIONS
BIOLOGICAL EFFECTS
BIOLOGICAL RADIATION EFFECTS
C CODES
CARCINOGENS
COMPUTER CODES
COMPUTERIZED SIMULATION
DATA COVARIANCES
DOSE-RESPONSE RELATIONSHIPS
ENVIRONMENTAL EFFECTS
ENVIRONMENTAL EXPOSURE PATHWAY
ENVIRONMENTAL TRANSPORT
FOOD CHAINS
HAZARDS
HEALTH HAZARDS
HUMAN POPULATIONS
INHALATION
INTAKE
MASS TRANSFER
MATERIALS
METEOROLOGY
MONITORING
PLUMES
POPULATIONS
RADIATION EFFECTS
RADIATION HAZARDS
RADIATION MONITORING
RADIOACTIVE MATERIALS
RADIOACTIVE WASTES
RADIONUCLIDE MIGRATION
RAIN
REACTOR ACCIDENTS
SENSITIVITY ANALYSIS
SIMULATION
WASTES
WEATHER