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A series of experiments on exposure of man and rats to tritium gas (HT) or tritiated water (HTO) are reported. In one human experiment 3 millicuries of HTO was administered in 200 milliliters of water by ingestion. Absorption into the blood stream was linear with time and complete in about 45 minutes. Body water turnover was measured over a period of six days by weighing all food and fluid intake and all excretory output. For four days water turnover was kept near normal (2.7 liters per day). During the last two days water turnover was increased to 12.8 liters per day. Tritium excretion rates was determined on eight other human subjects in which water turnover in which measured less precisely. The biological half-life of HTO in nine human subjects varied from 9 to 14 days on ad libitum and was reduced to 2 1/2 days in one subject on high water intake. The tritium activity in sweat, expired water vapor, septum and urine was found to be essentially the same as that in water from the blood. Rats were continually exposed to various concentrations of tritium in inspired air (0.000001 to 0.03 microcuries per ml) for periods up to 145 …

The disassembly of the `Adams` primary was scheduled for April 28, 29, and 30, 1959. The method of disassembly is provided as a procedure to be accomplished in order and the time and initials of the person accomplishing each step recorded.

In the light of Redox Plant performance since the start-up on 2-3-55, coupled with a review of the technological factors involved in the current flowsheet, a departure from the process program outlined in HW-34882 is herewith presented as an addendum to that document which will also serve to detail the corresponding items in the latest Redox Test Program, HW-35069. The purposes of this document are to: (1) Discuss the need for modifications of the program given in HW-34882, and (2) Present the details of the proposed revisions.

This paper presents the requirements of a nuclear amplifier of short resolving time, designed to accept pulses of widely varying amplitudes. Data are given which show that a proportional ionization chamber loaded with a 1,000-ohm resistor develops pulses of 0.5 microsecond duration and several volts amplitude. Results indicate that seven basic requirements are imposed on the amplifier when counting soft beta and gamma radiation in the presence of alpha particles, without absorbers. It should, (1) have a fast recovery time, (2) have a relatively good low frequency response, (3) accept pulses of widely varying heights without developing spurious pulsed, (4) have a limiting output stage, (5) preserve the inherently short rise time of the chamber, (6) minimize pulse integration, and (7) have sufficient gain to detect the weak pulses well below the chamber voltage at which continuous discharge takes place. The results obtained with an amplifier which meets these requirements is described. A formula is derived which indicates that redesign of the proportional ionization chamber might eliminate the need for an amplifier. This may be possible if the radioactive particles are collimated parallel to the collecting electrode.

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This report addresses the progress report of ANP chemistry for February and March 1956.

This report talks about APPR Meeting Held at Oak Ridge National Laboratory on April 3, 4, and 5.

A considerable number of major improvements have been made in experimental facilities this quarter. These include four targets, three air locks, a deep well, and several thin windows for beam extraction in the target area. Simultaneous operation of up to five experiments has been achieved with a relay-controlled automatic operations selector. A beam-amplitude regulating device has been used to set the beam level on any pulse to within a few percent. The range of this equipment is 1000:1. Experimentation on the accelerator this quarter included measurements of start frequency and frequency-tracking jitter, beam-versus-radial-aperture measurements, empirical study of gas scattering effects, and preliminary testing of an automatic beam-controlled frequency-tracking system. High-energy physics experiments have been performed by ten groups within this laboratory. These groups are using counter techniques for the elastic proton-proton scattering, K-particle half-life determination, and {pi}{sup -}-meson cross-section measurements. A high-pressure hydrogen diffusion chamber is being used to study multiple production of {pi}{sup -} mesons. A strong-focusing pair spectrometer has been used to produce beams of K particles. Emulsion exposures have been made to determine the masses and mean lifetimes of K mesons. The interactions and modes of decay of K{sup {+-}} mesons at rest, as well as in …

The first half of this quarter was in part a continuation of the shutdown of the last period and in part a shutdown recovery period. The second half of the quarter was devoted to high-energy physics and chemistry research and to the extension and improvement in techniques of producing secondary-particle beams. The principal physics research efforts were a continuation of the investigations of interactions of negative particles in hydrogen using the 10- inch liquid hydrogen bubble chamber; counter sludies of the pi /sup 0/ modes of heavy-meson and hyperon decay; and a series of twenty-one nuclear emulsion exposures to K-meson beams. During this period twenty emulsion stacks were exposed for thirteen external groups. Thirteen target bombardments were made for the chemistry group. (For preceding period see UCRJ-8021.) (M. H.R.)

This test project is being carried on for the purpose of testing certain machines which are designed to charge and discharge reactor units with process metal while the unit is in operation. Satisfactory charging of process pieces while the reactor now required for charging operations. These presently required shutdowns are costly in terms of production time, and may cause undesirable thermal stresses in the unit as it changes power level. If charging can be accomplished during operation, reactor shutdowns would only be necessary for maintenance or emergency purposes. During the testing of these metal handling machines, problems have arisen involving the behavior of the process pieces as they are charged. Because these problems directly affect the charging operations, they are being closely investigated also. the machines covered by this report are designated as pressurized machines since they contain the same water pressure as the end of the process tube on ;which they are located. In most of the test work covered by this report, the full scale pressurized charging machine was replaced with a small charging cylinder. The charging operation was simplified by this change.

The pilot charging of I & E fuel elements has been implemented at C-Reactor under Production Test IP-19-A. It was necessary to provide adequate tube protection against flow interruption by establishing proper trip setting on the Panellit pressure gauges. the administration of these Panellit trip settings is done by trip-before- boiling tube outlet temperature limits, which are similar in principle to the current instability limits. Trip-before-boiling limits for C-Reactor I & E fuel elements loadings are presented in this document.

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Resting cells of eleven microorganisms were exposed to radioactive carbon dioxide for 40 minutes. The radioactive compounds formed during this time were separated and identified by paper chromatography. Resting cells of Lactobacillus casei fixed no carbon dioxide and growing cells fixed carbon dioxide primarily in malic and aspartic acids. All of the radioactive compounds formed could have become radioactive by reversal of known decarboxylation reactions.

Uranium is recovered as an aqueous solution of uranyl nitrate and nitric acid in both the tributyl phosphate metal recovery process and the Redox separation process. The streams are designated as RCU and IIIEU in the respective processes. For metal recovery these streams are combined. The purpose of the nitric removal operation is to minimize equipment corrosion and to restrict contamination of the final uranium oxide with corrosion products which might be formed in the elevated temperature reactor employed for the decomposition of uranyl nitrate to the oxide. Because of the large quantities of uranium being processed it is desirable to conduct the concentration of the combined RCU and IIIEU streams in a continuous type process to reduce the operating and fixed charges. Determination of the physical and chemical properties of the dilute aqueous uranyl nitrate -- nitric acid system, as it progresses toward an essentially nitric acid free concentrated state, is necessary to define the optimum operating conditions.

The recent production by Thompson, Ghiorso, and Seaborg of a radioactive isotope of berkelium (atomic number 97) makes it possible to investigate the chemical properties of this transuranium element by means of the tracer technique. This isotope has been prepared through the bombardment of Am{sup 241} with about 35 Mev helium ions in the 60-inch cyclotron of the Crocker Laboratory and is believed to have the mass number 243, or possibly 244. This Bk{sup 243} has a half-life of 4.6 hours and decays by electron capture with about 0.1% branching decay by alpha-particle emission. In the present tracer chemical experiments, the radiations accompanying the electron capture process were used as a means of detection and were counted in two ways. Where the sample deposits on the platinum plates were essentially weightless, as was the case following the evaporation and ignition of the elutriant solutions in the column adsorption experiments, a high efficiency was obtained by using a windowloess proportional counter to count the Auger electrons. The thicker samples from the precipitation experiments in which carrier materials were used were counted close to the thin window (3 mg/cm{sup 2} mica) of a bell type Geiger counter filled with 10 cm. xenon …

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Possible hazards involved in the Mallinckrodt procedures for processing l%-enriched U are analyzed, and necessary precautions are specified. No danger is possible inhandling any amount of nominally l% U in the reduction of UF/sup 4/ to metal, cooling, or remelting. Critical amounts might conceivably be accumulated during the rolling to 3/4'' rod, in which case an''always safe'' amount is indicated. (B.J.H.) 2l92 A neutron burst from an untamped cylindrieal enriched U assembly occurred si ihe Pajarito Remote Control Laboratory ai 1800 hours on 18 April, 1952. The circumstances causing the burst and a description of the assembly involved are given. There was no personnel hazard. Normal operations could have been resumed on other assemblies within two or three hours after the burst. No evidence of damage to the enriched U was observed. Also reported are some results of computations and past-burst tests and a discussion of probable time behavior of power level during the burst. (auth)