The relative stopping powers for 300 Mev protons of H, Li, Be, C, Al, Fe, Cu, Ag, Sn, W, Pb, and U have been measured. The results are shown in Table I. The energy spent per ion-pair production in the gases H{sub 2}, He, N{sub 2}, O{sub 2}, and A at 340 Mev proton energy has also been measured. The results are shown in Table II.

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The operation of a Priest Rapids dam is stated to necessitate river flow manipulation varying from 25,000 cfs to 120,000 cfs in the winter months of a critical water year. The low flow may persist for periods of six hours daily, and the expected daily average low flow is 61,000 cfs. The possible effects of this on reactor operation and waste disposal to the Columbia River which are of the interest to the Radiological Sciences Department were reviewed by J.F. Honstead, R.E. Rostenbach, and R.F. Foster. These include radiation hazards in reactor area water treatment plants, reactor area drinking water contamination; increased river temperature; chromium pollution problems; effects on downstream river usage, and effects on aquatic life.

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The recent modernization program for the 300 area metal preparation process has included installation of automatic spray pickling machines. Operative problems have accompanied start-up of the new machine including too rapid reoxidation of slugs leaving the pickle operation. Numerous slugs have had to be repickled with consequent interruption to canning operations. Investigations were conducted in cooperation with Coatings and Corrosion Unit, Fuel Technology Sub-Section and Process Improvement Unit, Metal Preparation Section, to obtain basis information about slug oxide removal and reoxidation. Findings and conclusions from the investigation are presented in this document.

This is the monthly 100 areas technical activities report for the physics group for the month of July 1951. This group was concerned with pile related studies. Work discussed includes neutron attenuation measurements in pile shielding test facilities, studies of physical properties of shielding materials (concrete), work on a xenon generator and separation facility, further development and shielding work for a neutron spectrometer, continued work on a magnetic spectrometer, and counting equipment. Studies of neutron fluxes from exponential piles, and criticality studies are also discussed.