Laboratory and Field Studies Related to Radionuclide Migration at the Nevada Test Site in Support of the Underground Test Area and Hydrologic Resources Management Projects

Neptunium Transport Behavior in the Vicinity of Underground Nuclear Tests at the Nevada Test Site

“…Regardless of sampling location, all samples except the high concentration Cheshire sample resulted in 237 Np concentrations up to 3 orders of magnitude lower than the previously reported values (Finnegan and Thompson, 2002). The 237 Np data previously reported was obtained from groundwaters sampled at the same locations but on different dates.…”

“…Most of these reported values are near instrument detection limits (Finnegan and Thompson 2002), which can lead to large measurement uncertainties. These large uncertainties limit our ability to interpret Np transport behavior and calibrate or validate reactive transport models.…”

Unclassified Source Term and Radionuclide Data for Corrective Action Unit 98: Frenchman Flat Nevada Test Site, Nevada, Rev. No.: 0

“…Radionuclides were not detected in UE-5n waters until 1989 and are thought to reflect infiltration of water from the CAMBRIC ditch (Rose et al, 2003) 5 pCi/L is obtained. This indicates a slight increase in activity over the period between sampling times (Finnegan and Thompson, 2002 C activity, and very low levels (82 to 84 parts per quadrillion) of 237 Np were detected in UE-5n groundwaters (Finnegan and Thompson, 2002;Tompson et al, 2005b Kr may have partitioned into the atmosphere and soil gases during flow in the ditch (Tompson et al, 2002). The isotopic composition of dissolved uranium in UE-5n groundwaters is consistent with natural abundances (Rose et al, 2003).…”

“…Pumping was necessary to produce an artificial gradient so that water would move to well RNM-2S in a reasonable amount of time. Approximately 1.7 x 10 7 cubic meters (m 3 ) of water were discharged during this RNM experiment (Finnegan and Thompson, 2002) into an unlined discharge ditch that was used to transport the water pumped from Wells RNM-1 and RNM-2S to Frenchman Lake.…”

Phase II Documentation Overview of Corrective Action Unit 98: Frenchman Flat, Nevada Test Site, Nye County, Nevada, Revision 1

“…Groundwater flow from the detonation point to Well RNM-2S was induced by pumping Well RNM-2S from October 1975 to August 1991 (Bryant, 1992). ) of water was discharged during this radionuclide migration experiment (Finnegan and Thompson, 2002). A multiple-well aquifer test (MWAT) was later conducted (April 10 to November 11, 2003) in order to acquire data for use in estimating hydraulic properties of the alluvium in the vicinity of Well RNM-2S (SNJV, 2004a).…”