Table 6.11. Photon Dose Rates at 2 Meters from Cylinders of Plutonium Containing 1 kg of Plutonium at 5 Years After Chemical Separation

DOE-STD-1128-98

Figure 6.7 shows the reduction in dose equivalent rate for various

shielding materials for plutonium tetrafluoride sources, which have an

average neutron energy of 1.3 MeV. For practical purposes, the shielding

thickness for glove boxes is limited to about 4 in.; it is not possible to

operate machinery through thicker shields. Figure 6.8 shows the

reduction in dose equivalent rate through various slab shields for

plutonium dioxide. These data were obtained from measurements of the

neutron dose using a TEPC.

Table 6.11.1

Photon Dose Rates at 2 Meters from Cylinders of Plutonium Containing 1 kg

of Plutonium at 5 Years After Chemical Separation

Photon Dose Rate, mrad/h

Shield

Thickness

19% 240Pu Source

6% 240Pu Source

Material

Polyvinyl chloride

0.005

19.3

1.74

(PVC)

0.038

8.72

0.570

0.084

6.29

0.391

Lead Glove

0.094

1.85

0.105

Heavy Lead Glove

0.152

0.54

0.0464

Lucite

0.612

7.03

0.447

2.54

3.30

0.190

Steel

0.025

2.69

0.144

0.038

2.41

0.131

0.051

2.19

0.121

0.317

0.42

0.0418

0.635

0.221

0.0299

1.33

0.134

0.0205

2.43

0.0766

0.0119

Lead

0.635

0.0701

0.0103

1.27

0.0380

0.00288

2.57

0.0156

0.000391

5.08

0.00429

0.00023

10.16

0.000467

0.0000001

X-ray Glass

0.645

0.135

0.0251

1.30

0.0841

0.0144

2.60

0.0463

0.00534

Lead Apron

0.16

0.306

0.0346

Safety Glass

1.30

1.94

0.109

2.60

1.50

0.0886

Adapted from NUREG/CR-5550 (Reilly et al., 1991)

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