Chemical Versus Radiological Hazards - doe-std-1128-98

DOE-STD-1128-98

plutonium facility is probably the most serious threat because the consequences of a

fire could lead to loss of containment and subsequent dispersement of highly mobile

plutonium particulates. In addition, fighting the fire with water to maintain

containment could create the potential for a criticality accident and/or loss of

containment in the immediate vicinity.

The day-to-day hazards for personnel in plutonium facilities involve exposure to

gamma rays, X-rays, and neutrons, as well as possible accumulation of plutonium in

the body. These hazards are described in more detail in Section 3.0, "Radiation

Protection," and Section 7.0, "Nuclear Criticality Safety." The amount of plutonium

needed to present potential hazards to personnel in plutonium-handling facilities is

summarized in Figure 2.4. Hazards related to interim and long term storage of

plutonium will be found in Section 2.7, "Storage and Containment."

2.6.1

Chemical Versus Radiological Hazards

The radiological toxicity of reactor-produced plutonium far exceeds the

chemical toxicity of this heavy element. Furthermore, its low solubility in

near-neutral or basic solutions reduces the uptake through ingestion by a

factor >1000 for any plutonium compounds except certain complexes, such

as the citrate or ethylenediamine tetraacetic acid (EDTA) complex. (Refer

to Sections 2.3, "Radiobiological Properties," and 6.0, "External Dose

Control"). Tipton (1960) summarizes the differences in chemical hazards

between plutonium and uranium: "In contrast to uranium, the chemical

toxicity of plutonium is insignificant in comparison to the hazard arising

from its natural radioactivity." Moreover, "the toxicity of plutonium and

other transuranic elements," according to Voelz et al. (1985), "has only

been studied in animals since acute toxicity has never been observed in

man for these elements and epidemiologic studies have not produced

positive results." However, recent evidence suggests that plutonium can

catalyze reactions including oxidative stress in the absence of significant

radioactive decay. These data presented by Claycamp and Luo (1994)

suggest that plutonium complexes might contribute to long-term oxidative

stress related to tumor promotion.

2.6.2

Associated Chemical Hazards

The main chemical hazard of plutonium is its vulnerability to oxidation and

the pyrophoricity of some of its alloys and compounds (see Section 2.6.3).

The processing of plutonium, including separation from irradiated uranium,

purification, conversion, waste disposal, environmental restoration, and

D&D, necessarily requires the use of chemicals and reagents with varying

degrees of toxicity and hazardous properties. A partial list of chemicals that

are either used or proposed for use at DOE plutonium facilities is provided

in Table 2.9. An abbreviated evaluation of the potential hazards of

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