Abstract: The data obtained from the radioassay of fish collected in vicinity of the Hanford Works between April, 1948 and June, 1950 are presented. Most of the radioactivity in the fish resulted from the concentration of p32 in the scales, bone, and certain visceral organs. The level of activity density in the fish was influenced by size, feeding habits and metabolic rate in addition to the activity density of the water. Changes in operation of nuclear reactors have resulted in progressive increases in activity densities of fish from one year to the next. The levels of radioactivity are not sufficiently high to be hazardous to either the fish or persons eating them.

This development work was undertaken to investigate and standardize scintillation detector and transistorized circuitry techniques in instruments used for detecting and measuring alpha and beta particles, gamma photons, and both slow and fast neutrons. At the present time, the standard radiation detection instrumentation used at Hanford employ vacuum-tube circuitry with typical detectors being ion chambers, G-M tubes, HF3 tubes, etc. The vacuum tubes require excessive battery power, and some of the circuits are adversely affected by humidity and temperature conditions.

In recent months, relatively large quantities of neptunium-237 have been recovered from Hanford irradiated uranium. The over-all recovery process consisted of 1) isolation from Purex plant solutions by solvent extraction, to yield an impure neptunium nitrate solution contaminated principally with uranium, plutonium, and fission products (2) purification by anion exchange 3) precipitation of neptunium (IV) oxalate; and 4) calcination of the oxalate to yield neptunium (IV) oxide, NpO2. This paper describes the oxalate precipitation process investigations and results.

This document authorizes the performance in accordance with the specifications noted, the PRTR Critical Tests described herein. The experiments described have the following objectives: