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Page Title: Stabilize any other potential gas-producing constituents
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by calcination at 950C [Waterbury et al. 1961]. All other nitrates and carbonates
are expected to be decomposed by this procedure. Sulfate is known to be
incorporated into plutonium oxide prepared by peroxide precipitation from
sulfuric acid solutions [Leary et al. 1957]. The report of Moseley and Wing
[Moseley/Wing 1965] shows that 950C calcination is sufficient to destroy this
sulfate constituent. Literature searches indicate that deleterious amounts of
radiolytic gases from residual sulfate and chloride contaminants are unlikely in
the long-term storage conditions anticipated for stabilized materials [Tandon et
al. 1999a, Tandon et al. 1999b and references therein].
The preceding discussion addresses stabilization issues for plutonium oxide materials
that are rooted in safety concerns. An additional issue for these materials, which is
based more in operational than safety concerns, is the behavior of salt impurities in
plutonium oxides that have resulted from pyrochemical operations. The common
impurities NaCl and KCl, which can achieve levels of tens of percent in unstabilized
impure oxides being addressed by this Standard, have moderate volatilities above
800C. The practical impact of moderate volatilities is that materials with these
characteristics have difficulty meeting the 0.5 wt% LOI criterion with reasonable
calcination times. (Corrosion implications of chlorides during storage are addressed
in Section A.6.3 of this Appendix.) A second concern is the maintenance impact of
volatilized salts on furnace and off-gas systems. Salt volatilization is much more
problematic at 950C than at 800C because the vapor pressures of NaCl and KCl are
roughly an order of magnitude greater at the higher temperature. This Standard
retains the 950C calcination criterion of Standard 3013-99 but recommends that
operational complications regarding salt evolution be carefully monitored. Section 5
of the Forward, third bullet states that "Determination that a proposed alternative
criterion or alternative approach to satisfying one or more criteria is technically
equivalent, in terms of safety, to the Standard Criteria" may be submitted, technically
justified, and approved by the DOE. The DOE has approved two submittals as
technically equivalent in the past two years (re Boak et. al. (a and b)). This process
has proved efficient, cost effective, and timely for both Rocky Flats and Richland.
The technical equivalency evaluations were based on well-characterized material,
with no impurities that could cause pressurization, and subsequently stabilized
materials were tested to the same requirements (loss on ignition, etc.) previously

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