Table 6 -5. Neutron Yields from Alpha-Neutron Reactions for Oxides and Fluorides

DOE-STD-1136-2004

Guide of Good Practices for Occupational Radiation Protection in Uranium Facilities

Table 6 -5. Neutron Yields from Alpha-Neutron Reactions for Oxides and Fluorides

Alpha

Average Alpha

alpha, n Yield in

Isotope

Decay

Yield,

Energy,

Oxides,

Fluorides,

Half-Life

alpha/s-g

MeV

n/s-g

232

1.41 x 1010 y

4.1 x 103

2.2 x 10-5

4.00

232

8.0 x 1011

1.49 x 104

2.6 x 106

71.7 y

5.30

233

1.59 x 105 y

3.5 x 108

7.0 x 102

4.82

4.8

234

2.45 x 105 y

2.3 x 108

5.8 x 102

4.76

3.0

235

7.04 x 108 y

7.9 x 104

7.1 x 10-4

4.40

0.08

236

2.34 x 107 y

2.3 x 106

2.4 x 10-2

4.48

2.9

238

4.47 x 109 y

1.2 x 104

8.3 x 10-5

4.19

0.028

Table 6 -6. Neutron Yields for Trace Impurities in Uranium

Neutron Yield

per 106 Alphas

234

at 4.7 MeV ( U)

Element

0.16 0.04

44. 4

12.4 0.6

0.051 0.002

0.040 0.001

3.1 0.3

0.5 0.5

0.42 0.03

0.13 0.01

0.028 0.002

0.01 0.01

6.3 RADIATION DETECTION AND EVALUATION

This section describes the response of portable instruments, personnel dosimeters, and nuclear

accident dosimeters to the radiations emitted by uranium, which are primarily alpha and beta particles

and photons. Neutron emissions may range from negligible to significant. Data are also included on

special spectrometry instruments used to calibrate dosimeters in the field.

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