Tritium in ground water at the Idaho National Engineering Laboratory, Idaho

Abstract

From 1952 to 1988, approximately 30,900 curies of tritium were contained in wastewater generated by the ICPP (Idaho Chemical Processing Plant) and the TRA (Test Reactor Area) at the Idaho National Engineering Laboratory. The wastewater at the ICPP was discharged directly to the Snake River Plain aquifer through a disposal well until February 9, 1984, when routine use of the well was discontinued and an unlined infiltration pond was put into use. A second pond was put into use on October 17, 1985. Wastewater disposed at the TRA has been discharged to one to three infiltration ponds since 1952. The average annual concentration of tritium in water from 26 selected wells at the INEL decreased from 250 pCi/mL (picocuries per milliliter) in 1961 to 18 pCi/mL in 1988, a decrease of 93 percent. The maximum tritium concentration was 844±5 pCi/mL in 1961 and 61.6±1.1 pCi/mL in 1988. Four factors are responsible for this decrease in tritium concentration: (1) a decrease in the amount of tritium disposed annually to ponds and wells from 1961 to 1988; (2) the change from the use of a disposal well to infiltration ponds at the ICPP; (3) radioactive decay; and (4) dilution from recharge.

An update of hydrologic conditions and distribution of selected constituents in water, eastern Snake River aquifer and perched groundwater zones, Idaho National Laboratory, Idaho, emphasis 2019–21

“…9). During 1953 Ci of tritium was discharged at the INTEC (Mann and Cecil, 1990;Davis, 2008). Other radionuclides discharged at INTEC included strontium-90, cesium-137, iodine-129, plutonium isotopes, uranium isotopes, neptunium-237, americium-241, and technetium-99 (U.S. Department of Energy, 2021a).…”

2022 Site Environmental Report: Idaho National Laboratory

“…Tritium has previously been detected in three U.S. Geological Survey monitoring wells located on the INL Site along the southern boundary (Mann and Cecil 1990;Bartholomay, Hopkins, and Maimer 2015;Twining et al 2021). These wells, located in an uninhabited area, have shown a historical downward trend in tritium detections.…”

2021 Idaho National Laboratory Site Environmental Report

“…Tritium has previously been detected in three U.S. Geological Survey monitoring wells located on the INL Site along the southern boundary (Mann and Cecil 1990;Bartholomay, Hopkins, and Maimer 2015;Twining et al 2021). These wells, located in an uninhabited area, have shown a historical downward trend in tritium detections.…”