Estimated airborne release of plutonium from the Exxon Nuclear Mixed Oxide Fuel Plant at Richland, Washington as a result of postulated damage from severe wind and earthquake hazard

Abstract

The potential airborne releases of plutonium from postulated damage sustained by the Exxon Nuclear Company's Mixed Oxide Fabrication Plant at Richland, Washington, as a result of various levels of wind and earthquake hazard, are estimated. The releases are based on damage scenarios that range up to 250 mph for wind hazard and in excess of 1.0 g ground acceleration for seismic hazard, which were developed by other specialists. The approaches and factors used to estimate the releases (inventories of dispersible materials at risk, damage levels and ratios, fractional airborne releases of dispersible materials under stress, atmosphere exchange rates, and source term ranges) are discussed. Release estimates range from less than 10-7 g to greater than 14 9 of plutonium over a four-day period.

Environmental consequences of postulated plutonium releases from Exxon Nuclear MOFP, Richland, Washington, as a result of severe natural phenomena

“…Figure 1 illustrates the information requirements for such a study and how the data are utilized to estimate dose. The amount and form of plutonium released into the atmosphere was estimated by Mishima et al (1980) for both the present plant throughput of 36 kg plutonium oxide per day and the projected future thoughput of 72 kg/day. The doses presented in the text of this report were calculated using the source terms for a 36 kg/day operation.…”

“…A high, 150-mph straight-line wind condition was considered. The quantities of plutonium released to the atmosphere following a 150-mph severe wind were estimated by Mishima (1980) and are reported in Table 6. (a)Only the quantity released in the respirable particle size range was used to calculate doses.…”

“…Plutonium releases following three tornadoes with maximum total wind speeds of 150 mph, 190 mph, and 250 mph were estimated by Mishima (1980). Releases for four time periods are presented in Table 8.…”