Storage and Containment cont'd - doe-std-1128-98

DOE-STD-1128-98

-- Exhibits spontaneous self-sustained ignition (becomes pyrophoric) only if the metal

dimension

- is <0.1 mm and T >150C

- is >0.2 mm and T >500C

-- reacts slowly in air at room temperature (maximum of about 1 m/day)

-- has limiting (T-independent) oxidation rate in air above 500C

-- is not a dispersible form (<10 m geometric size) until oxidation occurs:

- oxide from Pu+Air at ambient T: 100 mass % (ssa = 10-20 m2/g)

- oxide from PuH2+O2: ~25 mass % (ssa ~ 1 m2/g)

- oxide from Pu+O2and Pu+Air at T >500C: < 0.1 mass % (ssa <0.1 m2/g)

-- radiolytically decomposes organic and covalently bound specific species in the

environment

-- reacts with most radiolytically produced gases and with nonequilibrium surface:

- limits pressurization by gases

- forms low-density (pressure-generating) and pyrophoric products

-- retains helium from alpha decay

-- is stabilized by certain storage atmospheres (reactivity decreased by 1012)

-- is stable if isolated from reactive species

-- has good storage history when stored properly.

A similar property summary for plutonium dioxide, the most commonly used form of

plutonium, shows it to be stable and unreactive in air. Storage and containment

recommendations, based on the properties of plutonium metal and dioxide, are shown in

Table 2.10.

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