This report covers work done by the Physical Chemistry Group and the Pile Engineering Groups. Subjects covered are as follows: corrosion laboratory testing details; pile borescopic inspections; slug deformation details; Van Stone flange corrosion details; corrosion rate at elevated temperature; added control ink facility; borescope equipment and repair; water recirculation cooling tests; pile expansion; carbon dioxide experiment; special graphite measurements; graphite core sample; vertical thimble temperature; beta experiment; x-ray diffraction studies; thermal annealing; empty process tube temperatures; oxidation of graphite; thermal annealing -- interferometer measurements.

Some time ago we started work in an attempt to observe alpha-particle decay in isotopes of atomic number less than 83. In the first experiments, thin targets of gold leaf were bombarded with 190-Mev deuterons in the 184-inch cyclotron. Two alpha-decay periods were observed in these targets; one of 0.7 minutes half-life and another of 4.3 minutes half-life. The alpha-particle energies were 5.7 and 5.2 Mev, respectively. Chemical separations proved that the 4.3-minute period is due to a gold isotope and suggested that the 0.7-minute period is due to a mercury isotope. The mass numbers of these new isotopes have not been determined. However, the results of excitation-functions in the production of the gold isotope by bombarding gold and platinum with protons suggest that its mass number lies in the range 185-188. The work on this isotope indicates that the alpha to electron capture branching ratio is of the order of magnitude of 10{sup -4}, and that positron activity accompanies the 4.3-minute alpha-period.

This study was undertaken to determine the maximum temperatures that may be expected in slugs under various operating power levels. Information of this nature is required to properly evaluate the effects on the slug of pile operation at power levels higher than those currently in use.

The redox and pile operations are reported on. Construction in 100 (Pile), 200 (Separation), and 300 (Metal Fabrication) areas is described. General work in the Richland commercial areas and on the Southern Railroad connection is also described. Personnel information is disclosed.

Among the spallation products obtained from the 350-Mev proton bombardment of Th{sup 232} they have identified two gaseous alpha-emitters which apparently do not decay into any presently known alpha-decay chains. The half-lives observed for the decay of the alpha-activities are 23 minutes and 2.1 hours. These half-lives may be principally determined by an unknown amount of orbital electron capture. At least one alpha-emitting daughter (about 4 hours half-life) has been observed to grow from a gaseous parent, but it has not been determined whether it arises from alpha-decay or electron-capture. Since these gaseous atoms emit alpha-particles it is assumed that they are isotopes of element 86 (emanation or radon) rather than a lighter rare gas. if they were heavy isotopes such as Em{sup 221} or Em{sup 223}, both unknown, they would decay into known alpha-decay series, the neptunium and actinium series, respectively, and so would grow known short lived alpha-emitters which would have been detected. It thus appears reasonable that they must be lighter than the known emanation isotopes.

The progress report discusses activities of the P Division for the month of July, 1949. The B and F piles operated at 275 megawatts and the D pile at 305 megawatts throughout the month except for outages listed under Area Activities. A total of 57.5 tons of metal, at an average concentration of 363 megawatt days/ton (MWD/ton) was discharged from the piles during the month. This included 41.9 tons of Class V (alpha-rolled, triple-dipped, completely transformed) metal at an average concentration of 397 MWD/ton which was discharged without difficulty. A portion of this material was inspected and appears to be satisfactory for exposures at this concentration.

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The notes and recommendations contained in this report relate to the design and construction of the Redox Production Plant with its associated Tank Farm at Hanford. All current development work for the Redox Program was to be transferred to the Redox Production Plant. [The Redox plant used a reduction-oxidation process for fuel separation that allowed recovery of uranium as well as plutonium for the first time. It succeeded earlier plants (T and B) that used methods based on the bismuth phosphate process that recovered only plutonium.]

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The study was made in an effort to determine experimentally the relationship between Logac 1,2 counts and the thickness of the slide on which a sample is mounted.