Table 6.5. Gamma Dose Rates Along an Arm Phantom in Contact with a Steel Can Containing 1 kg

DOE-STD-1128-98

Guide of Good Practices for Occupational Radiological Protection in Plutonium Facilities

75% normal UO2 showed that dose rates increased as dust loadings increased with

use; the dose rates on the hand and forearm increased to levels of about 30 mrem/h

to 20 mrem/h, respectively.

Table 6.5.

Gamma Dose Rates Along an Arm Phantom in Contact with a Steel Can Containing 1 kg of

Plutonium Dioxide in an Uncontaminated Glove Box

Gamma Dose Rates, mrad/h

Position

Neoprene Glove

Lead-Loaded Glove

Ring finger

330 6

272 25

Palm

292 9

220 16

Back of hand

72 2

65 1

Wrist

Inside

84 6

56 5

Outside

31 1

24 1

Forearm

Inside

22 0.4

12 1

Outside

4.4 0.1

3.8 0.4

Elbow

Inside

4.8 0.1

2.6 0.2

Outside

1.4 0.1

1.8 0.4

Front

2.9 0.2

2.1 0.1

Bottom of humerus

2.2 0.1

2.5 0.5

Lower mid-arm

7.1 0.1

3.9 0.3

Lower mid-humerus

3.8 0.1

2.3 0.2

Upper mid-arm

2.4 0.1

2.5 0.2

Upper mid-humerus

1.8 0.1

1.8 0.2

Top of arm

0.9 0.03

2.2 0.8

Top of humerus

1.1 0.02

1.3 0.1

The gamma energy spectra from plutonium sources are highly variable, depending

on the amount of shielding present, including self-shielding. Small lightly shielded

sources, such as dust layers on the interior of glove boxes, are dominated by L X-

rays and the 60-keV photons from 241Am, the decay progeny of 241Pu.

But the gamma energy spectra are quite different in storage vaults and other

facilities where the plutonium is encapsulated. In those cases, the low-energy

6-9