Input Preparation ................................................................................. AVAILABILITY OF COMPUTER SOFTWAREElectronic copies of the software described in this publication will be distributed with appropriate restrictions by:Energy Science and Technology Software Center P.O. Box 1020 Oak Ridge, Tennessee 37831-1020 For information regarding requests for software, please call (615) 576-2606. viii NOTATIONThe following is a list of acronyms, initialisms, and abbreviations (including units of measure) used in this document. Some acronyms used in tables only are defined in the respective tables. ACRONYMS, INITIALISMS, AND ABBREVIATIONS ANL ABSTRACTThis report presents the technical details of RISKJND, a computer code designed to estimate potential radiological consequences and health risks to individuals and the collective population from exposures associated with the transportation of spent nuclear fuel. RISKIND is a user-friendly, interactive program that can be run on an IBM or equivalent personal computer under the Windowsw environment. Several models are included in RISKIND that have been tailored to calculate the exposure to individuals under various incidentfree and accident conditions. The incident-free models assess exposures from both gamma and neutron radiation and can account for different cask designs. The accident models include accidental release, atmospheric transport, and the environmental pathways of radionuclides from spent fuels; these models also assess health risks to individuals and the collective population. The models are supported by databases that are specific to spent nuclear fuels and include a radionuclide inventory and dose conversion factors. In addition, the flexibility of the models allows them to be used for assessing any accidental release involving radioactive materials. The RISKJND code allows for userspecified accident scenarios as well as receptor locations under various exposure conditions, thereby facilitating the estimation of radiological consequences and health risks for individuals. Median (50% probability) and typical worst-case (less than 5% probability of being exceeded) doses and health consequences from potential accidental releases can be calculated by constructing a cumulative dose/probability distribution curve for a complete matrix of site joint-wind-frequency data. These consequence results, together with the estimated probability of the entire spectrum of potential accidents, form a comprehensive, probabilistic risk assessment of a spent nuclear fuel transportation accident.