Table 4-7. ARFs From Heating Sm all Pieces Delta-Phase Plutonium M etal Under Specific Conditions

DOE-HDBK-3010-94

4.0 Solids; Metals

aerosol formation under the experimental conditions. The size distribution measured for the

airborne particles under various conditions of atmosphere and temperature are shown in

Figures A.19 and A.20 taken from the reference document. In all cases, the RFs range from

0.05 to 0.5.

Eidson, Yeh, and Kanapilly (1988) reported the airborne release and size distribution from

heating 1-gram or 10-gram pellets or foil to 450 oC in a reducing atmosphere followed in

some cases by heating the powder produced in air. Gas velocities over the reacting materials

ranged from 0.4- to 10-m/s in the 24-mm i.d. quartz reaction tube. The airborne materials

were collected on a glass fiber filter or sized in a 7-stage cascade impactor. Point-to-plane

electrostatic precipitator samples were taken for transmission electron microscopy to

characterize the airborne materials. The pertinent data are shown in Table 4-7 with the data

from the source document reproduced in Table A.27 in Appendix A.

Table 4-7. ARFs From Heating Sm all Pieces Delta-Phase

Plutonium M etal Under Specific Conditions

(Table 1 - Eidson, Yeh and Kanapilly 1988)

Linear Flow Velocity

Pu M ass

Specim en

ARF1

Atm osphere

cm /s

gram s

Shape

3% H2 + Ar then air

500

0.94

pellet

1.1E-4

1000

1.05

pellet

1.1E-3

1000

0.92

pellet

7.4E-4

500

1.08

pellet

3.7E-3

3% H2 + Ar

1000

1.12

pellet

4.6E-3

500

1.05

pellet

3.0E-4

3% H2 + 5% N2 + Ar

1000

1.13

pellet

6.6E-5

1000

1.05

pellet

4.5E-4

1.39

foil

9.2E-5

9.63

pellet

1.2E-5

10.22

foil

8.5E-6

1.40

foil

2.8E-4

3% H2 + Ar

9.62

pellet

1.8E-5

9.64

foil

4.2E-4

All in the respirable fraction defined in this study as particles 5 m AED and less.

The bounding ARF and RF are 5E-3 and 1.0 with median values of 2E-4 and 1.0. There

does appear to be a detectible effect by the atmosphere present or surface to mass ratio. The

MMD of the residual powders ranged from 4 to 350 m Stokes diameter (equivalent sphere).

The Activity Median Aerodynamic Diameter (AMAD, in which half the activity in the

sample is associated with particles less than and half the activity is associated with particles

Page 4-29