Publications

In support of the Cassini Mission Final Safety Analysis Report (FSAR), Sandia National Laboratories (SNL) was requested by Lockheed Martin Corporation (LMC) to investigate for various scenarios, the distribution of aerosol and particulate mass in a stabilized buoyant plume created as a result of a fireball explosion. The information obtained from these calculations is to provide background information for the radiological consequence analysis of the FSAR. Specifically, the information is used to investigate the mass distribution within the ''cap and stem'' portions of the initial fireball plume, a modeling feature included in the SATRAP module in the LMC SPARRC code. The investigation includes variation of the plume energy and the application of several meteorological conditions for a total of seven sensitivity case studies. For each of the case studies, the calculations were performed for two configurations of particle mass in the plume (total mass and plutonium mass).

Dose calculations were performed using the MELCOR Accident Consequence Code System (MACCS) to support safety analyses for the Los Alamos Neutron Science Center (LANSCE) facility. The LANSCE facility is operated and maintained at Los Alamos National Laboratory (LANL) and will be used to conduct experiments for the U.S. Department of Energy (DOE) to investigate the use of accelerators to produce tritium. This paper focuses on tbe methodology adopted in tbe evaluation of doses from potential accidental releases of radioactive material from the LANSCE facility. Some results of the dose calculations are presented. Also discussed are the important features of an isotope screening process developed for this application to limit the number of consequence calculations.

The joint USNRC/CEC consequence uncertainty study was chartered after the development of two new probabilistic accident consequence codes, MACCS in the U.S. and COSYMA in Europe. Both the USNRC and CEC had a vested interest in expanding the knowledge base of the uncertainty associated with consequence modeling, and teamed up to co-sponsor a consequence uncertainty study. The information acquired from the study was expected to provide understanding of the strengths and weaknesses of current models as well as a basis for direction of future research. This paper looks at the elicitation process implemented in the joint study and discusses some of the uncertainty distributions provided by eight panels of experts from the U.S. and Europe that were convened to provide responses to the elicitation. The phenomenological areas addressed by the expert panels include atmospheric dispersion and deposition, deposited material and external doses, food chain, early health effects, late health effects and internal dosimetry.