Federal regulations · Through 2026-08-25 · Newer source version available

49 CFR 173.434: Activity-mass relationships for uranium and natural thorium.

The table of activity-mass relationships for uranium and natural thorium are as follows:
Thorium and uranium enrichment 1 (Wt% 235 U present) Specific activity
TBq/gram Grams/Tbq Ci/gram Grams/Ci
0.45 (depleted) 1.9 × 10−8 5.4 × 107 5.0 × 10−7 2.0 × 106
0.72 (natural) 2.6 × 10−8 3.8 × 107 7.1 × 10−7 1.4 × 106
1.0 2.8 × 10−8 3.6 × 107 7.6 × 10−7 1.3 × 106
1.5 3.7 × 10−8 2.7 × 107 1.0 × 10−6 1.0 × 106
5.0 1.0 × 10−7 1.0 × 107 2.7 × 10−6 3.7 × 105
10.0 1.8 × 10−7 5.6 × 106 4.8 × 10−6 2.1 × 105
20.0 3.7 × 10−7 2.7 × 106 1.0 × 10−5 1.0 × 105
35.0 7.4 × 10−7 1.4 × 106 2.0 × 10−5 5.0 × 104
50.0 9.3 × 10−7 1.1 × 106 2.5 × 10−5 4.0 × 104
90.0 2.1 × 10−6 4.7 × 105 5.8 × 10−5 1.7 × 104
93.0 2.6 × 10−6 3.9 × 105 7.0 × 10−5 1.4 × 104
95.0 3.4 × 10−6 3.0 × 105 9.1 × 10−5 1.1 × 104
Natural thorium 8.1 × 10−9 1.2 × 108 2.2 × 10−7 4.6 × 106
1 The figures for uranium include representative values for the activity of uranium-234 which is concentrated during the enrichment process. The activity for thorium includes the equilibrium concentration of thorium-228.

Where this section sits in the code

Title 49—Transportation
Subtitle B—Other Regulations Relating to Transportation
CHAPTER I—PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION
SUBCHAPTER C—HAZARDOUS MATERIALS REGULATIONS
PART 173—SHIPPERS—GENERAL REQUIREMENTS FOR SHIPMENTS AND PACKAGINGS
Subpart I—Class 7 (Radioactive) Materials

The table of activity-mass relationships for uranium and natural thorium are as follows:

Thorium and uranium enrichment 1 (Wt% 235 U present) Specific activity

TBq/gram Grams/Tbq Ci/gram Grams/Ci

0.45 (depleted) 1.9 × 10−8 5.4 × 107 5.0 × 10−7 2.0 × 106

0.72 (natural) 2.6 × 10−8 3.8 × 107 7.1 × 10−7 1.4 × 106

1.0 2.8 × 10−8 3.6 × 107 7.6 × 10−7 1.3 × 106

1.5 3.7 × 10−8 2.7 × 107 1.0 × 10−6 1.0 × 106

5.0 1.0 × 10−7 1.0 × 107 2.7 × 10−6 3.7 × 105

10.0 1.8 × 10−7 5.6 × 106 4.8 × 10−6 2.1 × 105

20.0 3.7 × 10−7 2.7 × 106 1.0 × 10−5 1.0 × 105

35.0 7.4 × 10−7 1.4 × 106 2.0 × 10−5 5.0 × 104

50.0 9.3 × 10−7 1.1 × 106 2.5 × 10−5 4.0 × 104

90.0 2.1 × 10−6 4.7 × 105 5.8 × 10−5 1.7 × 104

93.0 2.6 × 10−6 3.9 × 105 7.0 × 10−5 1.4 × 104

95.0 3.4 × 10−6 3.0 × 105 9.1 × 10−5 1.1 × 104

Natural thorium 8.1 × 10−9 1.2 × 108 2.2 × 10−7 4.6 × 106

1 The figures for uranium include representative values for the activity of uranium-234 which is concentrated during the enrichment process. The activity for thorium includes the equilibrium concentration of thorium-228.

Collected 2026-08-27T02:26:34Z. Source file · JSON

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