Table 2.7. Common Biokinetic Models for Plutonium and Americum

DOE-STD-1128-98

Table 2.7. Common Biokinetic Models for Plutonium and Americum

Model Parameter

ICRP 30, Part 1

ICRP 48

ICRP 30, Part 4

Metobolic Distribution(a)

Bone Surfaces

0.45

100 y

0.50

50 y

0.45

50y

Liver

0.45

40 y

0.30

20 y

0.45

20 y

Gonads(b)

3.5 x 10-4 α

Male

1.1 x 10-4 α

Female

GI Tract Absorbtion Factor

Ox Oxides

10-5

Pu nitrates

n.a. (c)

10-4

Pu-others

10-4

10-3

Am-(any)

5 x 10-4

10-3

Inhalation Class

Po Oxides

Pu-others

Am-(any)

(a)

F is the fraction of plutonium reaching the bloodstream that is translocated to the organ of concern.

T is the retention (or clearance) half-time in the organ of concern.

(b)

Plutonium is assumed to be uniformly concentrated in male and female gonadal tissue where it is

permanently retained. The deposition fractions are derived, based on the relative mass of the

reference male and female tissues.

(c)

n.a. = not specifically addressed.

2.5

RADIATION EFFECTS ON MATERIALS

The following sections discuss, in order, self-heating and the various effects of radiolysis.

Radioactive decay, particularly alpha decay, can and does affect operations in plutonium

purification processes. The change in emphasis from plutonium production to waste

cleanup, environmental restoration, and the retirement of nuclear weapons will present

favorable circumstances for cumulative radiolytic effects, especially in the stabilization

processes and the final storage form.

Self-heating and helium retention and release are also included in this section since they

too are part of the end result of the alpha decay process. Neutron production from the

alpha-neutron reaction is discussed in Section 6.0. The degree of all these effects depends

on the plutonium isotopic composition and the americium impurity level. Table 2.8 lists

potential hazards or damage to materials from exposure to radiation.

2-20