Most radiotoxic isotopes in spent fuel, after ten years' storage



For all isotopes of the element For isotope(s) with greatest radiotoxicity




Mass
Mole Radiotoxicity Sv
Refiner


Z Sym A Mass (gm) Fraction Moles Fraction Sv Fraction Sv/gm Dest. Half Life Parent Daughters
38 Sr 90 1135 2.180E-02 12.76 2.877E-02 8.70E+007 5.303E-01 1.018E-05 E 28.79y
Y-90 Zr-90*

39 Cs 137 3680 7.067E-02 27.3 6.156E-02 6.75E+007 4.119E-01 7.909E-06 E 30.04y
Ba-137* Ba-137m Ba-137*

40 Y 90 676.2 1.298E-02 7.605 1.715E-02 8.39E+006 5.116E-02 9.823E-07 E 2.671d Sr-90 Zr-90*


41 Eu 152 154 233.4 4.482E-03 1.535 3.461E-03 6.24E+005 3.806E-03 7.308E-08 E 13.52y
Gd-152 Gd-154* Sm-154* Sm-148 Nd-144 Ce-140*
42 Ru 106 3465 6.654E-02 33.99 7.664E-02 2.01E+005 1.224E-03 2.351E-08 A 1.020y
Rh-106 Pd-106*

43 Pm 147 11.02 2.116E-04 7.50E-002 1.692E-04 9.84E+004 5.997E-04 1.152E-08 E 2.623d
Sm-147 Nd-143*

44 Sb 125 29.06 5.580E-04 0.2379 5.364E-04 6.77E+004 4.128E-04 7.927E-09 E 2.759y
Te-125*


45 Cd 113m 198 3.802E-03 1.776 4.005E-03 5.10E+004 3.109E-04 5.971E-09 A 14.10y
Cd-113 In-113* In-113*

46 Ce 144 3607 6.926E-02 25.61 5.775E-02 33900 2.067E-04 3.970E-09 E 285.9d
Pr-144 Nd-144 Ce-140*
47 Te 125m 749.1 1.438E-02 5.797 1.307E-02 13070 7.970E-05 1.530E-09 E 57.40d Sb-125 Te-125*


48 Sm 151 1284 2.466E-02 8.6 1.939E-02 2017 1.230E-05 2.362E-10 E 90.00y
Eu-151*


49 Tc 99 1136 2.181E-02 11.49 2.591E-02 456.1 2.781E-06 5.341E-11 A 214.0ky
Ru-99*


50 Pr 144 1689 3.243E-02 11.99 2.704E-02 326 1.988E-06 3.817E-11 E 17.28m Ce-144 Nd-144 Ce-140*

51 Sn 126 139.9 2.686E-03 1.125 2.537E-03 213.8 1.304E-06 2.504E-11 E 230.0ky
Sb-126 Te-126*

52 I 129 257.6 4.947E-03 2.784 6.278E-03 196.5 1.198E-06 2.301E-11 E 16.10My Te-129m Xe-129*


53 Zr 93 5449 1.046E-01 58.51 1.319E-01 109.8 6.695E-07 1.286E-11 A 1.530My
Nb-93*


54 Se 79 84.68 1.626E-03 1.048 2.363E-03 66.32 4.044E-07 7.766E-12 E 377.0ky
Br-79*


55 Ag 110m 115.4 2.216E-03 1.06 2.390E-03 30.36 1.851E-07 3.555E-12 E 249.8d
Cd-110*


56 Rh 102 611.3 1.174E-02 5.94 1.339E-02 7.574 4.619E-08 8.869E-13 A 2.902y
Ru-102* Pd-102*


57 Nb 93m 7.06E-003 1.356E-07 7.59E-005 1.710E-07 5.227 3.187E-08 6.121E-13 A 16.13y
Nb-93*


58 Ho 166m 2.89E-001 5.553E-06 1.75E-003 3.953E-06 4.57E-001 2.784E-09 5.347E-14 E 1200y
Er-166*


59 Pd 107 2359 4.530E-02 22.31 5.031E-02 2.54E-001 1.551E-09 2.979E-14 A 6.500My
Ag-107*


60 Gd 153 223.6 4.294E-03 1.435 3.236E-03 6.82E-003 4.158E-11 7.984E-16 E 240.4d
Eu-153*


61 Rb 87 524.5 1.007E-02 6.079 1.371E-02 1.76E-003 1.072E-11 2.059E-16 E 48.10Gy
Sr-87*


62 Tm 171 9.54E-005 1.831E-09 5.64E-007 1.273E-09 2.17E-004 1.325E-12 2.545E-17 E 1.917y
Yb-171*


63 Be 10 2.29E-004 4.392E-09 2.32E-005 5.225E-08 1.81E-004 1.103E-12 2.118E-17 E 1.600My
B-10*


64 In 115 2.892 5.553E-05 2.52E-008 5.682E-11 1.99E-008 1.212E-16 2.328E-21 E 441.0Ty Cd-115m Sn-115*


65 La 138 1849 3.551E-02 13.31 3.001E-02 5.97E-009 3.638E-17 6.986E-22 E 102.0Gy
Ba-138*


66 Tb 160 4.337 8.328E-05 2.73E-002 6.154E-05 6.68E-011 4.072E-19 7.820E-24 E 72.3d
Dy-160*


67 Li
2.57E-001 4.943E-06 4.24E-005 9.565E-08


E Stable




68 Zn
9.72E-003 1.866E-07 1.40E-004 3.152E-07


E Stable




69 Ga
7.93E-006 1.522E-10 1.14E-007 2.573E-10


E Stable




70 Ge
0.9951 1.911E-05 1.32E-002 2.981E-05


E Stable




71 As
0.2982 5.726E-06 3.98E-003 8.974E-06


E Stable




72 Br
31.96 6.137E-04 0.395 8.907E-04


E Stable




73 Kr
533 1.024E-02 6.28 1.416E-02


G 10.75y




74 Mo
5059 9.715E-02 51.89 1.170E-01


E Stable




75 Xe
8024 1.541E-01 59.85 1.350E-01


G 11.00Py




76 Ba 137m 2766 5.312E-02 20.23 4.562E-02


E 2.552m Cs 137 Ba-137


77 Nd
6143 1.180E-01 42.41 9.563E-02


E 2.290Py




78 Dy
2.568 4.931E-05 1.59E-002 3.587E-05


E Stable




79 Er
0.1055 2.026E-06 6.35E-004 1.432E-06


E Stable




80 Yb
4.30E-005 8.250E-10 2.53E-007 5.698E-10


E Stable






















Total
5.21E+004
4.43E+002
1.640E+008
































ICRP 119 provides no radiotoxicity Refiner destinations









factor for half lives < 10 m or > 1 Py E = Electrolyte, A = Anode, G = Gas









or for gas ingestion