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T.M. Beasley

Publications and source records attributed to T.M. Beasley.

3 recordsLinked to original sources

Chlorine-36 in the Snake River Plain Aquifer at the Idaho National Engineering Laboratory; origin and implications

Between 1952 and 1984, low-level radioactive waste was introduced directly into the Snake River Plain aquifer at the Idaho National Engineering Laboratory (INEL), Idaho Falls, Idaho. These wastes were generated, principally, at the nuclear fuel reprocessing facility on the site. Our measurements of 36C1 in monitoring and production well waters, downgradient from disposal wells and seepage ponds, found easily detectable, nonhazardous concentrations of this radionuclide from the point of injection to the INEL southern site boundary. Comparisons are made between 3 H and 36 Cl concentrations in aquifer water and the advantages of 36 C1 as a tracer of subsurface-water dynamics at the site are discussed.

Idaho

Iodine-129 in the Snake River Plain aquifer at and near the Idaho National Engineering Laboratory, Idaho, 1990-91

From 1953 to 1990, an estimated 0.56 to 1.18 curies of iodine-129 were contained in wastewater generated by the Idaho Chemical Processing Plant (ICPP) at the Idaho National Engineering Laboratory. The waste- water was discharged directly to the Snake River Plain aquifer through a deep disposal well prior to February 1984 and through unlined disposal ponds in 1984-90. The wastewater did not contain measurable concentrations of iodine-129 in 1989-90. Samples were collected from 51 wells that obtain water from the Snake River Plain aquifer and 1 well that obtains water from a perched ground-water zone. The samples were analyzed for iodine-129 using an accelerator mass spectrometer which is two to six orders of magnitude more sensitive than neutron- activation methods. Therefore, iodine-129 was detectable in samples from a larger number of wells distributed over a larger area than previously was possible. Ground-water flow velocities calculated using iodine-129 data are estimated to be at least 6 feet per day. These velocities compare favorably with those of 4 to 10 feet per day calculated from tritium data and tracer studies at wells down- gradient from the ICPP. In 1990-91, concentrations of iodine-129 in water samples from wells that obtain water from the Snake River Plain aquifer ranged from less than 0.0000006+0.0000002 to 3.82.+0.19 picocuries per liter (pCi/L). The mean concentration in water from 18 wells was 0.81+0.19 pCi/L as compared with 1.30+0.26 pCi/L in 1986. The decrease in the iodine-l29 concentrations from 1986 to 1990-91 chiefly was the result of a decrease in the amount of iodine-129 disposed of annually, and changes in disposal techniques.

Water-Resources Investigations Report