"A series of thermal neutron diffusion length measurements has been made on non-multiplying lattice of lead-cadmium alloy rods in D2O. One-inch diameter rods in square lattice spacing of 4, 9, 6, 9, and 12 inches were used. Excellent agreement was found between theoretical and experimental values of the diffusion length. The analysis o the diffusion length measurement required a correction for the epithermal neutrons entering the exponential tank. These epithermal neutrons provided a distributed source of thermal neutrons upon slowing down in the lattice."

"Work has continued on high temperature methods for processing irradiated uranium fuel. Additional results have been obtained with fused halide treatment, solid scavengers and direct Pu distillation. With fussed fluorides about 95 per cent of the Pu was removed from a uranium sample, while treatment of uranium with HC1 gas removed almost all the Pu and many fission products. treatment of molten uranium with uranium oxide removed a substantial fraction of the fission products without removing Pu. Uranium carbide treatment results were similar to the oxide but not as effective. A small scale distillation of Pu from uranium showed that Raoult's law is obeyed."

None

"A design study is presented for a sodium cooked, graphite moderated power reactor utilizing low enrichment uranium fuel. The design is characterized by dependence on existing technology and the use of standard, or nearly standard, components. The reactor has a nominal rating of 167 thermal megawatts, and a plant comprising three such reactors for a total output of 500 thermal megawatts is described. Sodium in a secondary, non-radioactive, circulation system carries the heat to a steam generator at 910 degrees F and is returned at 420 degrees F. Steam conditions at the turbine throttle are 600 psig and 825 degrees F. Cost of the complete reactor power plant, consisting of the three reactors, and on 150-megawatt turbogenerator, is estimated to be approximately $43,165,000."

"An investigation of the chemical effects of 1-Mev electrons on BrF3 at 25 degrees C has been carried out. Pressure measurements taken during the irradiation suggest the presence of Br2 and BrF5 as decomposition products and a fractional distillation of the irradiated liquid confirmed their presence. The extent of decomposition was determined both by fraction distillation and spectrophotometric methods. The radiation effect seemed to reach saturation when approximately 10 per cent of the BrF3 was destroyed. The exposure necessary for the decomposition products to reach a concentration of half the saturated value was calculated to be 2.7 microampere hours/cc BrF3 while the "G" value was found to be 1.5. A qualitative comparison of irradiation dosages from the Statiltron with that expected from spent fuels revealed that little decomposition of BrF3 reagent is to be expected from 1-say cooled Hanford fuel (in pile for 100 days) while in the case of 1-day cooled MTR type fuel (in pile for 12 days) a saturated effect might be realized in 1-3 hours. Since at most only 10 per cent of the BrF3 is destroyed it is concluded that BrF3, from a radiation resistance standpoint, is a suitable standpoint, is a suitable reagent for …

"The Atomic energy Commission has undertaken a development program to provide the technology needed for the evaluation and economic design of nuclear power plants. This program is to be carried out during the next five years at several national laboratories and industrial organizations. The Sodium Graphite Reactor (the SGR) is one of those to be investigated and experimentally tested as part of this 5-year effort. The program on the SGR is intended to expand our area of information covering sodium-graphite technology, experimentally demonstrate the feasibility of this reactor complex and extend its performance limits, and apply in information developed to designs suitable for the full-scale nuclear power plant. As a principal part of this program, a Sodium Reactor Experiment (the SRE) is to be constructed and operated; it will be the major experimental facility in which the performance of this reactor will be studied and new technological advances tested. This report continues an earlier series 2-7 in which previous work on the SGR and the SRE has been described. In this report, the progress on the program is described in two main sections. Section A is devoted to work relating to the general technology of Sodium Graphite Reactors, and to …

"General Chemistry investigations reported herein includes: (1) the Organic Coolant-Moderator Program, (2) investigations on zirconium hydride, and (3) analytical chemistry."

From abstract: This paper presents temperature-entropy and Mollier charts for sodium, and describes briefly the method used for their construction, based upon data from the literature.

From conclusions: There is a close enough correlation for most metals to give the chart some utility in estimating vapor pressure of metals.

From abstract: A conceptual design study has been performed for a sodium cooled, graphite moderated, thermal power-breeder reactor utilizing the Thorium-Uranium 233 breeding cycle. Several aspects of the design of the system are considered but no attempt has been made to supply all the details. It appears that the design presented is feasible and will allow the production of economic power as well as full utilization of thorium resources.

Abstract: The fast and thermal neutron leakage from the 30 megawatt SGR-P4 reactor has been studied by three independent methods.

Report describing reactor components, operational characteristics, and operating instructions for the Model L-3 research reactor.

Introduction: The purpose of this experiment was to demonstrate that a liquid metal heat transfer system could be built and operated at very high temperatures.

Introduction: This memo gives a general description of the components and equipment affecting the control of the SRE, and the equipment associated with all reactor services.

Design and operational techniques are described for a freeze seal type centifugal pump for use in the Sodium Reactor Experiment.

Abstract: Presented herein is the preliminary design of a natural uranium, graphite moderated, CO2-cooled reactor and power plant similar to, but larger than, the British Calder Hall plant, with a net electrical output of 130 MWE.

Abstract: This report presents a reference design of an organic moderated and cooled reactor for the propulsion of a 38,000-dwt tanker.

Abstract: This report presents the results of plant optimization studies and cost estimates of the reference design for a natural uranium, graphite moderated, gas-cooled reactor and power plant which was described in NAA-SR-1833.

Abstract: The data presented herein, in the form of graphs, can be used to obtain the value of this energy.

Report describing technical progress on the design and construction of an Organic Moderated Reactor Experiment (OMRE), to be operated at the National Reactor Testing Station in Arco, Idaho. "This is the second report of the series, and covers the period from August 1, 1956 through October 31, 1956" (p. 3).

"Measurements of the intra-cell neutron flux distributing for a proposed Uranium Production Reactor have been made using a mock-up of a portion of the reactor core. Thermal neutron and thorium resonance neutron flux-distributions were investigated. As a result of the experimental measurements on the first mock-up, a decrease in thorium content appeared necessary in the reactor design studies. Experiments are now in progress on a second mock-up in which this change has been made."

"Continued progress has been made with the high temperature decontamination processes for irradiated uranium fuel. The fused salt treatment of molten uranium has been extended to UCl3. Plutonium and rare earths were extracted into the UCl3 phase. Direct plutonium distillation from molten irradiated uranium has been scaled up to the hundred gram scale. Solid scavenging experiments using uranium oxide, uranium carbide, and uranium nitride in contact with molten uranium have indicated fission product removal. A scaled-up investigation of the separation and recover of uranium from an SIR type ceramic fuel using the volatile fluoride process has indicated the feasibility of this separation method. The effect of irradiation on the decomposition of BrF3 has been further studies in experiments using the NAA statitron.'

"A thorough analysis of the data obtained on depleted, natural, and enriched uranium lattices has been made. Consideration of the possible sources of discrepancies between theory and experiment has led to a suspicion of the calculated thermal neutron diffusion lengths. A series of diffusion length measurements in non-multiplying lattices of lead-cadmium alloy has been initiated. An analysis of some early exponential experiments on lattices proposed for a neutron production reactor has been carried out in order to determine whether experimental results on these more complicated structures are consistent with the analysis carried out for the "clean" lattices."

"A study has been made of methods to prepare a fluid containing 1 gram of thorium per milliliter. The methods considered were solutions of thorium salts, suspensions of dry solids in water, and collodial suspensions. Thorium oxide, oxalate, and fluoride were tried in conjunction with one or more surface actants, but it was not possible to attain the required thorium concentration. Thorium hydrosol, produced by peptization of thorium hydroxide and subsequent electrodialysis, gave the necessary concentration of 1 gram per milliliter. A solution of 0.5 gram per milliliter was found to be stable to electron irradiation and did not flocculate upon shaking or standing. Selected surface actans which might be used as protective colloids were found to be unstable to electron irradiation.