RESRAD-ONSITE
RESRAD-ONSITE is used to assess radiation exposures of a human receptor located on top of soils contaminated with radioactive materials.
Objectives
RESRAD-ONSITE (formerly just RESRAD) is a computer code designed at Argonne National Laboratory for estimating radiation doses and cancer risks to an individual located on top of radioactively contaminated soils and to derive radionuclide soil guideline levels corresponding to a specific dose criterion.
Modeling Approach
The calculation of dose and cancer risk by the RESRAD-ONSITE code is scenario driven, with the use of parameter values specified by the user. Nine exposure pathways are provided which can be selected or suppressed to reflect the land use and receptor scenario under consideration. These nine exposure pathways are: (1) direct external radiation from radionuclides in soil, (2) inhalation of airborne radionuclides resuspended or volatilizing (H-3 and C-14) from soil, (3) incidental ingestion of soil, (4) ingestion of plant foods grown in contaminated soil and irrigated with contaminated water, (5) ingestion of meat and (6) ingestion of milk produced by livestock fed with contaminated fodder and water, (7) ingestion of drinking water from a well or pond adjacent to the contaminated area, (8) ingestion of aquatic foods from the pond, and (9) inhalation of radon emitted from contaminated soil. Input information needed for the calculation include characteristics of the contamination, properties of surface, sub-surface, and saturated soil strata, site-specific meteorological, hydraulic, and hydrogeological data, as well as exposure pattern of the receptor.
The modeling of RESRAD-ONSITE considers radiological decay and ingrowth and environmental transport, partitioning, and dilution, governed by the principle of mass conservation over time. Essentially all the input parameters used for the calculation can be specified by the user; therefore, the user can control the level of conservatism of each calculation, and apply the RESRAD-ONSITE code for screening, site-specific screening, or site-specific evaluation purposes.
Features
The RESRAD-ONSITE code is equipped with a user-friendly interface to facilitate data entry, performing calculations, displaying calculation results, and accessing general and context-specific help. The user has the option of choosing either ICRP-38 or ICRP-107 radionuclide transformation database, and a compatible dose conversion factors and cancer risk slope factors library for his analysis. Depending on the cut-off half-life specified, the code automatically assembles the branching and decay chains of the initially present radionuclides in soil, and calculates the effective DCFs for each principle nuclide in the decay chains, assuming secular equilibrium for short-lived associated progenies. Deterministic and probabilistic sensitivity analysis can be easily conducted on selected input parameters, which can be applied to prioritize efforts for input data collection.
Use and Applications
RESRAD-ONSITE is the only code designated by DOE in Order 458.1 for the evaluation of radioactively contaminated sites. It is also approved by NRC for use by licensees to evaluate radiation dose and demonstrate compliance concerning decommissioning of a licensed facility and by NRC staff to review license termination plans. The EPA Science Advisory Board reviewed the RESRAD model and used it in their rulemaking on radiation site cleanup regulations.
RESRAD-ONSITE has been used widely in the risk assessment community, including in the IAEA's VAMP and BIOMOVS II projects to compare environmental transport models. It has been applied to more than 300 sites in the U.S. and other countries. More than 1,000 people have been trained to use the code through its training workshops, which are held twice a year at Argonne National Laboratory.
Learn more about the use and applications of RESRAD-ONSITE at a training workshop at Argonne National Laboratory.