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.
[Amdt. 173-244, 60 FR 50307, Sept. 28, 1995, as amended by 63 FR 52849, Oct. 1, 1998]