Hazards Created by Oxidation and Pyrophoricity

DOE-STD-1128-98

these substances is also provided. Table 2.9 is not meant to replace the

Material Safety Data Sheet (MSDS) available from chemical

manufacturers; rather, it is intended to help readers recognize the toxicity

of these chemicals and identify any possible side effects from their use that

could jeopardize radiation safety or plutonium containment.

2.6.3

Hazards Created by Oxidation and Pyrophoricity

This section describes the oxidation and burning characteristics of

plutonium, summarizes the storage properties of the metal and oxides, and

presents recommendations for their storage conditions. Waste remediation

plans for TRU materials and the necessity for dealing with ton quantities of

plutonium metal from the retirement of weapons require the identifying of

long-term and intermediate-term waste forms with appropriate stability.

Economic considerations make clear the importance of generating few, if

any, new wastes in accomplishing this task.

2.6.3.1 Oxidation of Plutonium

The problems of oxidation of metallic plutonium were recognized

shortly after the discovery of plutonium, and extensive studies of

the low-temperature corrosion of plutonium and its alloys have

been performed. Oxidation can produce fine loose plutonium

oxide, which disperses easily in glovebox systems, complicating

housekeeping chores. If not controlled, loss of accountability and

increased radiation exposure to personnel is certain. The reactivity

of plutonium metal is discussed in Section 2.3.1. The tendency for

enhanced oxidation is promoted by the self-heating properties of

plutonium isotopes (discussed in Section 2.5.1). A kilogram of

239Pu can easily reach an equilibrium temperature of 80C in a

glove-box environment (Raynor and Sackman, 1967). Thermally

isolated 238Pu metal can easily melt from its own decay heat. The

heat generated by oxidation may be sufficient to ignite nearby

combustible materials. Metal turnings and scrap should be

reprocessed or converted to stable alternatives as soon as

practicable. Plutonium metal, its alloys, and its reactive

compounds need to be excluded from both oxygen and water

vapor, but especially the latter since it catalyzes and accelerates

oxidation.

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