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

DOE-STD-1128-98

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

Neoprene Glove

Lead-Loaded Glove

Position

330 + 6

Ring Finger

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 + 0.2

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 photons have been shielded out, and the spectrum is

dominated by higher photon energies. Note that plutonium metal buttons

or cans of plutonium oxide prepared for storage are self-shielded, and

high-energy photons from decay progeny such as 237U become

increasingly important.

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