Bounding - h3010v10093

DOE-HDBK-3010-94

4.0 Solids; Summary

value as designated by the authors is chosen. The measured values were only

for airborne particles <10 m AED. The values for solubility class in

simulated lung fluids are assumed to be >95% "Y" class with remainder in

"D" class, based on the solubilities of sintered oxides recovered from the burn

tests performed as part of the hazard classification tests on armor-defeating

munitions.

The 95% confidence level airborne release value for oxidation of uranium

metal at flow velocities <100 cm/s reported by Carter and Stewart (September

1970) is exceeded by the value reported by Elder and Tinkle (December 1980)

during the oxidation of staballoy penetrators in laboratory experiments. The

ARF x RF values obtained for experiments at temperatures less than 900 oC

were less than 1E-3. ARF and RF values of 1E-3 and 1.0 are assessed to be

bounding for this category with the solubility classification for the oxides

formed given above.

Median

ARF 1E-4/RF 1.0

Bounding

ARF 1E-3/RF 1.0

Airborne release during free-fall of molten metal drops. The median

ARF x RF values for free-fall of molten uranium metal droplets in air are as

given by Carter and Stewart (1970). The ARF x RF value assessed to be

bounding is an arbitrary increase of the 95% confidence level value assigned

by Carter and Stewart (to 1E-2) to be consistent with the comparable value for

plutonium. Since the airborne material is cooled rapidly after formation, the

solubility of the airborne oxides formed from plastic deformation and ignition

of the thin film of metal generated by the impact of penetrators against hard

targets is assessed to be 50% "Y" class and 50% "D" class.

Median

ARF 2E-3/RF 1.0

Bounding

ARF 1E-2/RF 1.0

Airborne release from explosive dispersal of molten uranium. The values for

explosive release of molten uranium indicate that, if the uranium is molten and

subdivided in very small drops (as by the exploding wire technique) and

ejected into air at sonic velocities (as by the electrodynamic thruster technique

described), all the uranium could be made airborne as a very fine particulate

material with all particles or aggregates 10 m AED and less (Rader and

Benson, June 1988). The solubility class of the airborne material is

anticipated to be like the airborne material formed during impact of staballoy

Page 4-3