Radiochemistry. Concepts and Applications in Environmental Chemistry. Isotopes. Too heavy, too light, rarely just right. Table of Isotopes. 1998 Version, 3000+ isotopes. Properties of , , and . Properties of , , and . ALPHA BETA X-, & GAMMA
Concepts and Applications in Environmental Chemistry
Too heavy, too light, rarely just right.
ALPHABETAX-, & GAMMA
Ionization 1x104 1x1021
Penetrating 1 1x1021x104
Cosmogenic - from the cosmos
3H 7,10Be 14C 18F 22,24Na 26Al 31,32Si 32,33P35,38S 36,38,39Cl 37,39Ar 53Mn 59Ni 80Kr
40K 50V 87Rb 113Cd 115In 123Te 138La144Nd 147Sm 148Sm 152Gd 174Hf 176Lu187Re 190,192Pt 209Bi
232Th+daughters 235U+daughters 238U+daughters
USNRC Occupational Dose Limit50
USNRC Limit for Members of Public20
In 1972 ore deposits were found to contain significantly different isotopic compositions of certain elements than from the mean found in nature.
142Nd normally 27% in nature, at Oklo it was <6%.
99Ru normally ~28% in nature, at Oklo it was 13%.
235U normally 0.72%, at Oklo it was 0.48%.
From 87Rb/87Sr dating, Oklo deposits are 1.7E9 years old, at that time U enrichment was ~3% 235U!
damage to DNA from ionization.
If the cell is exposed to radiation, the probability of the radiation interacting with the DNA is very small since these critical components take up less than 0.5% of the cell volume.
USDOE: Human Genome Project
Indirect Effect on Cells:
decomposition of water.
If the cell is exposed to radiation, the probability of interaction with cellular water is greater since water is 99.5% of the cell volume.
Radiolysis of water produces the following types of sequences:
H2O + ray HOH+ + e- H2O + e- HOH-
HOH+ H+ + OH*HOH- H* + -OH
OH* + OH* H2O2 (hydrogen peroxide)
Net Effect: Free radical formation
• Damaged & Repaired
• Damaged, not Repaired
48 hour time lapsed microscopic photograph of alpha tracks emitted from a radioactive particle of Pu-238 lodged in the lung tissue of an ape.
Field, R.W., Lynch, C.F., Brus, C.P., Woolson, R.F., Fisher, E.F., Platz, C.E., Robinson, R.A., Steck, D.J., Neuberger, J.S. Residential Radon Gas Exposure and Lung Cancer: The Iowa Radon Lung Cancer Study, American Journal of Epidemiology, 151(11);1091-1102, 2000.
Rn is constantly being generated by the uranium in rocks, soil, water, and construction materials derived from rocks and soil.
Uranium is found in small concentrations throughout the earth’s crust. On average, 1 acre down to a 5 ft. depth would contain 50 lbs. of Uranium.
Fuel is inexpensive
Easy to recover (in U.S. and China)
Requires expensive air pollution controls (e.g. mercury, sulfur dioxide)
Significant contributor to acid rain and global warming
Requires extensive transportation system
“Clean Coal” does not yet exist
Fuel is inexpensive
Energy generation is the most concentrated source
Waste is more compact than any source
Extensive scientific basis for the cycle
Easy to transport as new fuel
No greenhouse or acid rain effects
Requires larger capital cost because of emergency, containment, radioactive waste and storage systems
Requires resolution of the long-term high level waste storage issue in most countries
Potential nuclear proliferation issue