Analytical Suite Metadata

Chemex (lake and stream sediment) NADNC ( U – 5**10, He detector, 20s, d.l.=0.5)

Chemex, lake and stream sediment; neutron activation-delayed neutron counting (uranium – 5**10, helium detector, 20 seconds, d.l.= 0.5)

General Methodology:

Uranium was determined using a neutron activation method with delayed neutron counting.  A detailed description of the method is provided by Boulanger et al. (1975).  In brief, a 1 gram sample was weighed into a 7 dram polyethylene vial, capped and sealed.  The irradiation was provided by the Slowpoke reactor with an operating flux of 5** 10 neutrons/  The samples were pneumatically transferred from an automatic loader to the reactor, where each sample was irradiated for 20 seconds.  After irradiation, the sample was again transferred pneumatically to the counting facility where after a 10 second delay the sample was counted for 20 seconds with six helium detector tubes embedded in paraffin.  Following counting, the samples were automatically ejected into a shielded storage container.  Calibration was carried out once a day as a minimum, using natural materials of known uranium concentration.

Instrument: unstated

Sample material: solid

Sample weight: 1000 milligrams

Analytical Technique:

Hierarchical classification

Technique >> Radiochemical methods >> Activation analysis >> Neutron activation >> Fission >> Delayed Neutron Counting



Analytical Decomposition:

Hierarchical classification

Decomposition >> None



Analytical Methods:

IndexMethod OrderMethod IDQuantityDetection Limit
1  2192     U_NADNC  0.5

Associated Analytical Packages:

IndexPackage IDPackage Name
1  416     Chemex (NGR lake sediment) AAS (8+5), CVAAS (Hg), COL(W), LOI, NADNC (U-5**10)
2  417     Chemex (NGR stream sediment)  AAS (8+5), CVAAS (Hg), COL(W), LOI, NADNC (U-5**10)
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