Experimental studies on continuous denitration performed in 321 Building resulted in the development of an agitated-through-type calciner. The performance of a paddle-agitated 4-in.-diameter by 44-in.-long reactor was sufficiently promising to warrant construction of a 16-in.-diameter by 8 ft.-long semi-plant scale model. This progress report summarizes the results of studies to date employing the semi-plant scale calciner.

An attempt to apply quantitatively the equation of state of a free electron gas to relatively low temperatures in order to emphasize correlation effects.

Abstract: "The analysis of an immobilized plasma is here extended to the case where the geometry is cylindrical rather than Cartesian. (This report, UCRL-4439 (Rev, 4 constitutes Part II of the report series (UCRL-4466, Parts I, III, and IV) dealing with this general problem.)"

This report discusses details of the release of Xe¹³¹, Xe¹³⁵, Kr⁸⁵m and Kr⁸⁵ into the process water system of the MTR along with the development of high process water radioactivity. It is suggested that this release followed the fissioning of U²³⁵. Equations that produce the rate of release of fission products is given and approximate rate of release is represented in a graph.

Production Test 313-105-13-M authorized the irradiation of a uranium - 0.4 atomic per cent chromium alloy to determine the relative stability of this material during irradiation. Five tubes, each containing six four-inch alloy slugs, were irradiated to exposures ranging from 156 to 834 MWD/T. This report describes the results of the visual examination of the bare uranium alloy slugs and the results of the test to determine slug breaking strength. The breaking strength of both the U-Cr alloy slugs and the normal uranium control slugs was reduced by exposure in the pile. The breaking strength of those U-Cr alloy pieces not cracked or broken in the jackets before examination was consistently greater than the breaking strength of the normal uranium at all exposures.

Equations for the quantity of thorium daughters on an air sampler after various times of collection and decay are derived and evaluated. The most limiting assumption is the constant concentration over the sampling period. Applications of these equations to measurement of decay curves, alpha energy analysis and the simultaneous solution involving measurements at the three decay times are discussed.

During this period a prototype gamma ray detection system was assembled and data was obtained on samples of beryllium salts on filter paper under a variety of conditions. Ordinarily either a scaler-register combination or the CRM-recorder combination would be sufficient for obtaining data. Both units have been used here in order to utilize the particular advantages of each system. The scaler-register unit was employed for obtaining precise data over short intervals while the CRM-recorder was used to maintain a check on stability over longer intervals of time.

Methods for the determination of plutonium and uranium in highly radioactive scrup dissolver solutions have been developed. Plutonium was separated from the dissolver solutions by solvent-extraction and ion-exchange techniques and determined by potentiometric titration. Uranium was separated by ion exchange and determined by potentiometric titration. Solutions that were similar to the actual dissolver solutions and that contained known amounts of plutonium and uranium were analyzed by these methods. Evaluation of the data secured for the determination of plutonium and uranium by the methods given herein indicated that, within the limits of the precision of the methods, there was no bias. The precision of the data obtained for the determination of plutonium, expressed as the relative standard deviation, was better than 2% for plutonium in the concentration range of 0.27 to 0.64 mg/ml. The precision for uranium was estimated to be about 0.2% for uranium concentrations of 425 mg/ml. These methods and the data obtained by then are discussed in this report; the procedures are appended.

Part I. Experimental Reactors: The effect of prompt-neutron lifetime upon reactor safety was investigated for the HRT. It was found that for a given pressure rise the allowable rate of reactivity addition was relatively insensitive to the average prompt-neutron lifetime, although the rate de creased somewhat with decreasing lifetime for the higher pressure rises. With only source neutrons present and the reactor initially subcritical, the allowable rate was practically independent of the initial value of k£. For a core-pressure rise of 400 psi, the corresponding rate of reactivity addition was about 0.8% per second; for a pressure rise of 4000 psi, the rate was 2.5 to 3.0% per second. Part II. Thorium Breeder Reactor: An economic study of one-region thorium breeder reactors was completed. Where possible, the process characteristics and cost factors were the same as those used previously in studies of two-region-type reactors. The mini mum-cost reactor is about 12 ft in diameter, operating with 260 g of thorium per liter on a chemical processing cycle of about 450 days. The ratio of U232 to U233 produced is approximately 2 x 10~4 VIM in the minimum-cost one-region system, compared with 4 x 10 5 in the two-region system. The …

Abstract: The reactor kinetics equations are combined into a single integral equation whose kernel describes the time-dependent characteristics of the reactor including six delayed groups of neutrons. Numerical solutions of the integral equation are given for constant, linear, and ∫sin²kx dx reactivities. An approximate solution of the integral equation is obtained which provides a basis for the formulation and solution of the reactor system control problem using the methods of servomechanisms theory. The reactor frequency response function, a product of the approximate solution, is calculated and plot given.