4.1.2 Wet Chemistry Laboratory
The Wet Chemistry Laboratory provided a facility for the quantitative and qualitative wet chemistry
separation and purification of radioelements in the soil samples. The ashed and aliquoted soil
samples from the Sample Preparation Laboratory, after separation and purification, were
electrodeposited on stainless steel] dises for subsequent alpha spectrometry counting by the Counting
Laboratory.
Although the Wet Chemistry Laboratory was established primarily for the analytical
determination of plutonium, some chemical separations were performed on a limited number of
samples for americium, strontium, and uranium.
The Wet Chemistry Laboratory was a 12-foot by 53-foot modular mobile office unit bought in the
United States. EIC assembled the basic laboratory environment in Albuquerque, New Mexico, and
shipped it to Enewetak prior to personnel arrival. Cabinets, benches, plumbing, electrical wiring and
air conditioning were constructed in the United States with exhaust outlets prepared for immediate
hood installation on the island. An air conditioner was installed on each end of the trailer and
connected through a common duet system to provide a backup system in case one unit failed. The
Wet Chemistry Laboratory is shown in Figure 4-3.
Wet chemistry procedures involved the dissolution of sample aliquots, chemical separation and
purification of the desired nuclides, tracer yielding and quantification.
For these purposes the
laboratory contained two 59-ineh hoods, a 72-inch hood, air intake and exhaust stacks for each,
benches, cabinets, work table, centrifuge, Burrell shaker, sinks, dishwasher, and the essential
chemicals, tools and small equipment required for wet chemistry procedures.
One 59-inch hood was used mainly for wet-ashing the sample aliquots brought over from the Sample
Preparation Laboratory. The wet ashing process oxidized ali organic matter to a white residue, thus
facilitating the sample dissolution prior to chemical processing. The large 72-inch hood contained 25
ion exchange columns used for the purification process of the sample, a step that functioned to
isolate plutonium and americium and separate them from interfering elements. The second 59-inch
hood was used to draw off toxic fumes during solvent extractions. All three hoods were standard
Labeconeo add-air hoods and had intake and exhaust stacks installed through the roof. Fresh outside
air was supplied to the hood through the short air intake units, then exhausted while simultaneously
pulling air from the trailer. Since the fumes exhausted to the atmosphere were free of radioactivity,
no HEPA filters were required on the hoods.
Base cabinets with acid resistant table tops were installed under each hood for supply storage and
work counters.
A radioactive solution storage with 2-inch lead shielding was located under the
72-inch hood. Standard Equipto benches were placed between the two hoods and installed away from
the wall, approximately 4 to 6 inches, to allow space for a laboratory pipe chase.
The chase and
benches were covered with a stainless steel sheet for protection from corrosion and for ease of
decontamination. The benches were also painted with green epoxy paint to inhibit rust and
deterioration.
A Burrell shaker, designed to accommodate twelve separatory funnels, was set up over the center
table. A special flat plate was installed into the trailer ceiling, and a three-inch pipe column was
dropped from the ceiling to secure the top of the shaker.
increase mass and cut down the amplitude of vibration.
Lead weights were added to the column to
4.1.3 Counting Laboratory
The Counting Laboratory was used to assess the radiological content of soil samples, nose swipes, air
filter papers, and other samples as required in support of DOE operations on Enewetak. The
capabilities of the laboratory included alpha and gamma spectrometry, gross alpha and beta, and gas
flow proportional alpha and beta counting. These facilities provided the basis for determining the
TRU to 44lAmratio of soil samples to be used with the in-situ IMP results.
Although the majority
of samples counted by the laboratory were for Pu and Am analysis by alpha and gamma
spectrometry, a small number of samples was processed for Sr and U.
shown in Figure 4-4.
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The Counting Laboratory is