Some of the Radioactive Poisons
in Spent Nuclear Fuel
NAME |
HALF-LIFE |
| Hydrogen-3 (tritium) | 12 years |
| Beryllium-10 | 1 million 600 thousand years |
| Carbon-14 | 5 thousand 700 years |
| Silicon-32 | 500 years |
| Phosphorus-32 | 14 days |
| Potassium-40 | 1 thousand million years |
| Calcium-42 | 14 thousand years |
| Iron-55 | 3 years |
| Cobalt-60 | 5 years |
| Nickel-59 | 75 thousand years |
| Nickel-63 | 10 years |
| Selenium-79 | 65 thousand years |
| Krypton-81 | 200 thousand years |
| Krypton-83 | 10 years |
| Rubidium-87 | 47 thousand million years |
| Strontium-90 | 29 years |
| Yttrium-90 | 2 days |
| Zirconium-93 | 1 million 500 thousand years |
| Niobium-93m | 14 years |
| Niobium-94 | 20 thousand years |
| Molybdenum-93 | 3 thousand 500 years |
| Technetium-99 | 200 thousand years |
| Ruthenium-106 | 1 year |
| Palladium-107 | 6 million 500 thousand years |
| Cadmium-113m | 14 years |
| Tin-126 | 100 thousand years |
| Antimony-125 | 3 years |
| Antimony-126 | 12 days |
| Tellurium-125m | 58 days |
| Iodine-129 | 15 million 700 thousand years |
| Cesium-134 | 2 years |
| Cesium-135 | 2 million 300 thousand years |
| Cesium-137 | 30 years |
| Cerium-144 | 3 hundred days |
| Promethium-147 | 3 years |
| Europium-154 | 9 years |
| Europium-155 | 5 years |
| Hafnium-182 | 9 million years |
| Tantalum-182 | 1 hundred days |
| Rhenium-187 | 50 thousand million years |
| Lead-205 | 14 million 300 thousand years |
| Lead-210 | 22 years |
| Bismuth-208 | 400 thousand years |
| Bismuth-210 | 5 days |
| Bismuth-210m | 3 million years |
| Polonium-210 | 138 days |
| Radon-222 | 4 days |
| Radon-223 | 11 days |
| Radium-224 | 37 days |
| Radium-225 | 14 days |
| Radium-226 | 1 thousand 600 years |
| Radium-228 | 6 years |
| Actinium-225 | 10 days |
| Actinium-227 | 22 years |
| Thorium-227 | 19 days |
| Thorium-228 | 2 years |
| Thorium-229 | 7 thousand 300 years |
| Thorium-230 | 77 thousand years |
| Thorium-231 | 1 day |
| Thorium-232 | 14 thousand million years |
| Thorium-234 | 24 days |
| Protactinium-231 | 32 thousand 800 years |
| Protactinium-233 | 27 days |
| Protactinium-234 | 27 days |
| Uranium-232 | 72 years |
| Uranium-233 | 200 thousand years |
| Uranium-234 | 200 thousand years |
| Uranium-235 | 700 million years |
| Uranium-236 | 23 million years |
| Uranium-238 | 4 thousand million years |
| Neptunium-237 | 2 million years |
| Plutonium-238 | 88 years |
| Plutonium-239 | 24 thousand 100 years |
| Plutonium-240 | 6 thousand 500 years |
| Plutonium-241 | 14 years |
| Plutonium-242 | 400 thousand years |
| Americium-241 | 400 years |
| Americium-242m | 100 years |
| Curium-244 | 18 years |
Adapted from APPENDIX F of
ATOMIC ENERGY OF CANADA LIMITED’S
ENVIRONMENTAL IMPACT STATEMENT
ON USED NUCLEAR FUEL