Estimated airborne release of plutonium from Atomics International's Nuclear Materials Development Facility in the Santa Susana site, California, as a result of postulated damage from severe wind and earthquake hazard

Abstract

The potential mass of airborne releases of plutonium (source term) that could result from wind and seismic damage is estimated for the Atomics International Company's Nuclear Materials Development Facility (NMDF) at the Santa Susana site in California. The postulated source terms will be useful as the basis for estimating the potential dose to the maximum exposed individual by inhalation and to the total population living within a prescribed radius of the site. The respirable fraction of airborne particles is thus the principal concern. The estimated source terms are based on the damage ratio, and the potential airborne releases if all enclosures suffer particular levels of damage. In an attempt to provide a realistic range of potential source terms that include most of the normal processing conditions, a best estimate bounded by upper and lower limits is provided. The range of source terms is calculated by combining a high best estimate and a low damage ratio, based on a fraction of enclosures suffering crush or perforation, with the airborne release from enclosures based upon an upper limit, average, and lower limit inventory of dispersible materials at risk. Two throughput levels are considered. The factors used to evaluate the fractional airborne release of materials and the exchange rates between enclosed and exterior atmospheres are discussed. The postulated damage and source terms are discussed for wind and earthquake hazard scenarios in order of their increasing severity.