Oxides - Continued - std301320000030

DOE-STD-3013-2000

1) Eliminate reactive materials such as finely divided metal or sub-stoichiometric

plutonium oxides

The issue addressed by this requirement is avoidance of energetic events, for

example, when storage containers are opened (see Section A.6.1.1 of this

Appendix regarding metal reactivity). The general plutonium technical literature,

as well as many decades of operating experience, firmly establishes that sub-

stoichiometric plutonium oxide and metal with particle size below the thresholds

defined in this Standard are completely converted to stable plutonium oxide by

calcination in air at 950C in air for two hours [e.g., see ANS 1979, ANS 1980,

Katz et al. 1986].

2) Eliminate organic materials

The primary issue concerning the presence of organic materials (notably plastics)

in stored plutonium materials is the potential for gas generation (particularly

hydrogen) as a result of radiolytic and thermal degradation. The technical

literature conclusively establishes that all plastics less than about one inch in

diameter and any other organic materials likely to accompany unstabilized

plutonium materials are completely oxidized by air in less than five minutes at

800C [ACS 1995; Bockhorn et al. 1996; Panagiotou/Levendis 1996; Wey/Chang

1995; Zevenhoven et al. 1997]. It is presumed that larger pieces will be removed

by visual examination prior to calcination (see Criterion 6.3.3.1), but the

literature indicates that even these will be destroyed by 2hr/950C calcination in

air.

3) Reduce the water content to less than 0.5 wt% and similarly reduce equivalent

quantities of species such as hydrates and hydroxides that might produce water

A key element of the technical basis for both this Standard and DOE-STD-3013-

96 is that water uptake on calcined plutonium oxide is controlled by the oxide

surface area. Measurements show that the surface area of pure plutonium oxide

calcined at 950C is consistently below 5 m /gram [e.g., see Haschke/ Ricketts

1995 and Manchuron-Mandard/Madic 1996]. MIS measurements show this to be

true for impure oxides as well [Mason et al. 1999]. MIS measurements on actual

site materials to be treated under this Standard and other work show that