This technical progress report summarizes work at the Hanford Engineer Works` 100 Areas, 300 Area, 200 Areas for December 15, 1946 through December 21, 1946. (JL)

This document addresses radiation protection concerns for workers in the experimental laboratories and production plants where nuclear fission piles are being used. A broad in-depth discussion is provided based with the experiences gained in the Manhattan Project and being applied to contemporary activities. Discussion is thorough and encompasses control of external irradiations including alpha, beta, gamma, and neutron radiations; and control of radioactivity within the body by control of inhalation, ingestion, and entrance through skin or wounds. General measures for the control of radiation hazards is addressed by provision of clothing and waste disposal. An Appendix 1 is entitled General Rules and Procedures Concerning Activity Hazards.

The chelate process for the extraction and decontamination of plutonium has been investigated. The process is designed as an alternate process for ihe Hanford type operation. The basic chemical factors have been studied and two flowsheeis have been developed and tested for recovery of plutonium. An over-all yield of plutonium in excess of 99% is reported for one flowsheet using benzene as the organic solvent and 98.5% when toluene was substituted for benzene. The general factors involved in establishing all details of the flowsheets are thoroughly discussed and decontamination studies are indicated to complete the study in the present equipment. (auth)

The twelfth meeting of the Graphite Expansion Committee was held on December 6, 1946. A summary of the meeting is as follows. Recent laboratory studies suggest that the rate of graphite expansion decreases with exposure when the samples are exposed in an air atmosphere at ambient pile temperature, through the relative effects of atmosphere and temperature are not known. These observations are in qualitative agreement with the decreased rate of vertical expansion of the piles. The neoprene seal strips at the top of the near and far sides of the F Pile were removed during November. The cork seal in back of the Third Safety Tanks at the F Pile was also removed. Current estimates predict the general rupture of Van Stone flanges after 300,000--350,000 MD of pile operation if the rate of expansion is uniform. The working model of the split gun-barrel has been completed but is being modified to provide a key to prevent the gun-barrel flange from rotating. The proposal to replace a few tubes in operating piles, as discussed last month, has been modified in favor of more extensive work at the B Pile before moving to the D or F Piles.

This report divides the activities for November into three sections: D Pile; F Pile; and general physics. During November the D Pile was down twice for regularly scheduled shutdowns. Two scram occurred during the month, both of short duration. Five Special Request 15 tubes were discharged and recharged with Special Request 15. Some 13 inhour of reactivity were gained during the month. Vertical rod thimbles, 10 through 22, were tested. A Production Test was performed to determine the reactivity power coefficients of the F Pile at low power levels and with practically no xenon poison remaining. Additional experience in the use of temporary poison columns during an extended shutdown of the pile was obtained during the month. Four new bismuth columns were charged during the month and six tubes were charged with LiF. The F Pile had not yet returned to xenon equilibrium following the shutdown of November 27 at the end of the month, but conditions just prior to this shutdown indicate a loss of one inhour since October 31. Two sets of specimens were removed from the ``B`` Test Hole of the F Pile on November 4. Samples were also machined from graphite removed from the No. 9 …

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A table summarizes all the information on blistered slugs from March 1946 to Oct. 12, 1946, as recorded in weekly technical progress letters.

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The D Pile was down five times for scheduled shutdowns. The fifth shutdown was of short duration for the purpose of discharging temporary ``P`` columns. Details of the shutdowns are given. Three new bismuth columns were established, Special Requests were charged into seven tubes and three Special Requests were discharged. Three tubes were charged with four-inch slugs. The power level of the F Pile has been corrected for the discrepancy noted last month. Material for irradiation under the Special Request program was charged into six tubes and the B experimental hole during the month. The effect of poison columns and rods on the temperature distribution of the pile was checked for the overall content of the pile. The F Pile gained two in hours in cold, clean reactivity during the month if allowance is made for xenon poison values corresponding to 190 MW for the beginning of the month and 200 MW at the end of the month. The graphite stringer removed from the ``D`` test hole of the D Pile on 3-12-46 was studied physical radiation effects.

In August 1946 it was discovered that two effluent lines near the Columbia River at Hanford were damaged. The upstream effluent line has broken off 37 fact from the shoreline and the downstream effluent line had been bent and partly broken seventeen feet from shoreline and has swung downstream to a point about 50 feet from shorelines. This study was made to determine how fast and in what fashion the temperature of the effluent water is dissipated in the Columbia River under the present conditions and to compare this to a previous survey made when the effluent lines were believed to be in their original position.

This memorandum provides an estimate of the life of manufacturing piles.

The favorible attention being given graphite as a fuel rod material calls attention to the need for preventing diffusion of fission products from the fuel rods. The methods of prevention include painting the surface of the rod with an impermeable organic synthetic composition, enclosing the rods in metal cans, electroplating the rods with a suitable metal, or covering the surface with some type of inorganic ceranmic glaze. Each of these methods is evaluated as to feasibility. (M.H.R.)

This document details technical activities in the 100, 200, 300 areas as well as activities in the chemical development, statistical studies, and Laboratories Departments for the period of October 6 through October 12, 1946. (FI)

Samples of pile graphite, irradiated in a test-hole at Hanford for 15 months, have been assayed for radioactive C{sup14}, yielding 0.38 ± 0.04 microcuries per gram. At this level of activity, the pile graphite contains very valuable amounts of C{sup14}. The relation between the above assay and the probable average assay of pile graphite is discussed, and it is concluded that the latter is almost certainly above 0.3 uc/ gram. Controlled oxidation of this graphite, either with oxygen at ~ 750°C, or with chromic acid "cleaning solution" at room temperature, yields early fractions which are highly enriched in C{sup14}. Concentrations of 5-fold with oxygen, and 50-fold with CRO{sub3}, have been observed. The relation between the observed enrichment and the Wigner effect is discussed, and a mechanism accounting for the observations put forward. According to this, about 25% of the stable carbon atoms in the lattice have been displaced by Wigner effect, a large fraction of which have healed the migrating to crystal edges. All the C{sup14} atoms have been displaced, and the same fraction of these migrate to the edges. The enrichment then results from surface oxidation, in the oxygen case. Predictions are made on the basis of this hypothesis. …

The Pine unit was down four times during the month. These were all regularly scheduled shutdowns. Times down vary from 16.9 hours to 19.2 hours. A total of 33.4 tons of metal was discharged. The galvano-meter chamber in experimental hole {open_quotes}A{close_quotes} was replaced. One Special Request was discharged and three tubes have been loaded with Special Request samples. A new bismuth column has been established. Some difficulty has been experienced with high temperatures of both tube exit water and graphite following startup. On one occasion the normal operating level was exceeded for a short period of time.

Certain difficulties have been encountered in attempts to substitute a 'one-step' casting process, developed at Iowa State College, for the 'normal' process generally used for the production of extrusion billets. In the 'one-step' process molten metal is delivered from the reduction bomb to the billet mold instead of allowing the metal to solidify in the bomb with subsequent vacuum remelting of the biscuit metal before casting in the billet mold. Routine analyses had failed to establish significant differences in the composition of normal and one-step metal. The one-step billets had been extruded satisfactorily, and finished slugs were prepared and subjected to the usual canning operation. In subsequent tests however, it was found that a large percentage of the canned slugs were badly defective. An investigation was requested to determine the differences in composition or structure of the X-C and normal metal which would account for the failure of the X-C slugs. Samples of the failed slugs and of metal from various stages of both the one-step and normal processes were supplied by Madison Square Area, for comparison on the basis of analyses, microstructure, or such other tests as seemed desirable.

Recent data show that test hole samples out from the center of a bar show greater expansion rates than do samples out from the edge of a bar. The previously noticed irregularities in expansion of test hole samples are attributed to this phenomenon. For unexplained reasons, the expansion of the graphite piles is in close agreement with the smaller expansion rates shown by test hole samples rather than with the larger rates. It is recommended that the neoprene coal on the far side of the F pile be placed before the end of the year. It is recommended that the neoprene seal on the near side of the D Pile be replaced after replacement neoprene is on hand. It is recommended that the compressed cork and about 4 inches of the cement block was in back of the Third Safety Tanks at the D Pile be removed at the time of replacement of the neoprene seal, and that the resulting gap be covered with a flexible air-impermeable membrane such as rubberized canvas. Actual measurement of the length of graphite between the gun barrels of Tube 3671-B confirms the predicted end-wise expansion of the graphite as deduced from jacking tests on …

A revised and expanded version of NNES-DC-1. The liquid thermal diffusion method for the separation of isotopes is described. The discussion includes the experimental aspects of the method, description of equipment, and the theoretical aspects of the process as applied to the design, development, and performance criteria. A short history of the liquid thermal diffusion method from 1940 to 1945 is preserted along; with a survey of relevant literature prior to 1940. The remainder of the report is concerned with theoretical aspects. (J.R.D.)

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Tests made prior to beginning operation of the 100 Areas showed that the cooling water had a tendency to deposit a film upon the slug and tubs surfaces. This film would manifest itself as an increase in the pressure drop through the tubes and its most serious affect would be the resultant decrease in the slug to water host transfer coefficient which would increase the slug surface temperature, causing greatly accelerated corrosion rates. It was thus proposed to study film formation an a production test. This report discusses this test.

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Methods are developed for estimating the effect on a critical assembly of fabricating it as a lattice rather than in the more simply interpreted homogeneous manner. An idealized case is discussed supposing an infinite medium in which fission, elastic scattering and absorption can occur, neutrons of only one velocity present, and the neutron m.f.p. independent of position and equal to unity with the unit of length use. (auth)