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Reported are: physics (B Pile, D Pile, F Pile, general physics); and water, corrosion, and engineering (process water control and pressure drop studies, purging studies, corrosion, graphite expansion, downcomer -- B Area).

This report covers work done by the Pile Engineering Groups and work done on special assignments. Topics covered include: slug blistering and corrosion; graphite allocation to DR pile; slug molding; segmental discharge; Van Stone corrosion; flow laboratory modifications; downcomer at B pile; downcomer at D pile; annealing of pile graphite; replacement of pile atmosphere with CO{sub 2}; unit motion; beta experiment; can opening; slug annealing; new technical building, 300 area; and ruptured slugs.

This monthly report details 100 Area technical activities of the Physics Group for the month of August 1949.

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After it had been decided that aluminum was to be used as a corrosion-resistant material with good heat transfer properties, it was desired to determine the operating conditions to be used in the water-cooled Handford plant in order to avoid danger of corrosion penetration of thin aluminum parts. The studies here reported were undertaken with the object of determining these conditions by investigating the effects of all the known variables which might influence the corrosion behavior of aluminum in a water-coolded plant at HEW. The addition of hydrogen peroxide to the testing solutions was the only effort made to simulate special conditions at the plant.

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A portable beta and gamma radiation meter of exceedingly small dimensions and weight has been developed. User acceptance has been more enthusiastic than any previous instrument of its type. The circuit, using one Victoreen V-32 tube, is the simplest electronic circuit possible for radiation work and gives high sensitivity. Stability exceeds anything of comparable sensitivity which has come to our attention. The short term stability is due to a circuit which prevents emission before the cathode reaches operating temperature. Long term stability has been improved by evacuating the tube enclosure and switch. The complete, one unit instrument, weighs four pounds two ounces, and is carried with a pistol grip. Exclusive of chamber and handle, its dimensions are 3'' wide, 6 1/2'' long, and 5'' high. The case is formed of aluminum and is designed to give excellent visibility of the meter. Three ranges of approximately 50, 500 and 5000 mr/hr have been incorporated in the instruments. The instrument has been named ''Cutie Pie'' due to its diminutive size.

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Following the shutdown of the B Pile in March 1946 a method was devised for monitoring the sub-critical reactivity such that any significant change in neutron flux would be detected. This report summarizes the status of the unit until its start up in July 1948.

This report discussed cadmium coated splines which have been developed to supplement the regular control rod systems under emergency shutdown conditions from higher power levels. The objective of this test was to determine the effectiveness of one such spline placed in a tube in the central zone of a pile, and of two splines in the same tube. In addition, the process control group of the P Division asked that probable spline requirements for safe operation at various power levels be estimated, and the details included in this report. The results of the test indicated a reactivity value of 10.5 {plus_minus} 1.0 ih for a single spline, and 19.0 ih {plus_minus} 1.0 ihfor two splines in tube 1674-B under the loading conditions of 4-27-49, the date of the test. The temperature rise of the cooling water for this tube under these conditions was found to be 37.2{degrees}C for 275 MW operation.

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The fourteenth meeting of the Graphite Expansion Committee was held on February 7, 1947. Laboratory studies indicate that either the graphite thermocouples are reading low or that annealing effects at elevated temperatures within the pile are much greater than those encountered In the laboratory. Current difficulties with operation of some of the horizontal and vertical control rods seem to be attributable to graphite expansion, though no complete understanding of the phenomena has been obtained and one is unable to predict the time required for similar difficulties to develop in other rods. Changes in clearance between process tubes and pile graphite in the D Pile have been erratic in nature but have averaged much less than had been anticipated. The negligible decrease in clearance for central tubes indicates that the expanding cross-wise graphite layers are slipping with respect to the graphite layers which contain process tubes.

This report discusses work at the Hanford engineering Works` 100 and 200 areas for August 11th through August 17th, 1944. Topics discussed include canning, slug recovery, testing and miscellaneous items. (JL)

This is a progress report of the production reactors on the Hanford Reservation for the month of March 1949. This report takes each division (e.g. manufacturing, medical, accounting, occupational safety, security, reactor operations, etc.) of the site and summarizes its accomplishments and employee relations for that month. (MB)

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N{sup 12} is shown to have a half life of 12.5 {+-} 1 milliseconds, and a positron upper limit of 16.6 {+-} 0.2 Mev. It is produced by the reaction C{sup 12}(p,n)N{sup 12}, and has a threshold proton energy of 20.0 Mev. This indicates that N{sup 12} is within about 200 Kev of being unstable against proton emission. The mass of N{sup 12} is 12.0228 {+-} 0.00015, and the beta transition is allowed.

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This report contains the calculation of the number and spacing of poison columns required to hold a 105 pile in the following cases: (1) complete failure of horizontal rods, (2) complete failure of all rods. Using 10% Cd 90% Pb poison columns of 1.44 inch diameter, it is found that 17 poison columns are required to hold the pile in case of complete failure of horizontal rods, and 65 poison columns are required to hold the pile in case of complete failure of all rods.