This report follows critical-assembly studies made to provide engineering and physics data to aid in developing the Gas Cooled Reactor Experiments.

Introduction. the colorimetric determination of iron based on the formation of the colored ferrous-1,10-phenanthroline complex has been used successfully by a number of investigators. In this technical report, its adaptation to the routine determination of iron in cerium, thorium, and beryllium metals and their compounds is described.

A series of diffusion length measurements were carried out on graphite stacks of various constructions in an attempt to resolve the discrepancies between the graphite diffusion lengths measured in the Hanford reactors and that value measured in the Hanford Standard Pile. It was found that the diffusion length of the graphite in the Hanford reactors is in good agreement with the value for the Hanford Standard Pile when corrections are made for the absorption and scattering of neutrons by the aluminum process tubes, and for neutrons streaming in the channels of the reactors.

The Zircaloy-a clad, swaged UOa, 19-rod cluster fuel element for the PRTR was designed to use Zircaloy-a wire spirally wrapped around the fuel rods as spacing members. Such use of unbonded, Zircaloy-a spacers introduced the possibility of fretting corrosion. This paper reports preliminary irradiation tests conducted to determine whether or not such corrosions occurs in this fuel element design.

The basic process for fabricating a swaged fuel rod is simple, easy to control and inexpensive. A zircaloy tube is filled with uranium dioxide powder, the ends temporarily plugged and the loaded tube is swaged to compact the UO2 powder to the required density. The swaged rod is then cut to length and counterbored and then end cape are welded into each end. After several tests and inspections, nineteen rods which meet the quality standards are assembled into a single fuel element ready for irradiation.

Technical report. From Abstract : "Paramagnetic susceptibilities of samarium structure alloys in the systems La-Gd, Nd-Y, Nd-Tm, and Ce-Y were measured from 4.2 - 300°K to determine what effect the formation of this structure has on the magnetic properties of the alloys. Susceptibility maxima were observed in the Nd-Y and Nd-Tm alloys, at 34.5 and 28.5°K, respectively. Slope changes were observed in the curve of 1/x versus T for the La-Gd alloy at 155 and 130°K, and the susceptibility of this alloy remained temperature-independent from 130-7°K. A rather poorly defined region of constant susceptibility was also observed or the Ce-Y alloy, from 26-37°K. Above these transition temperatures, the alloys obeyed the Curie-Weiss law, the susceptibilities of the La-Gd and Ce-Y samples indicating the possibility of electron transfer occurring in these cases."

Plankton collected from the Columbia River by the net method and by the centrifuge method were compared. The centrifuged plankton (nannoplankton) exceeded the net plankton in weight, in abundance of organisms and in radioactivity. Similar seasonal trends were present in both types of plankton.

The alternating-gradient proton synchrotrons at CERN and Brookhaven are very similar in size, design and in their experimental use. For this reason, collaboration between the groups at CERN and Brookhaven has been close throughout the history of these two machines. For the most part this has taken the form of exchanges of visits of individual machine designers and of high-energy physicists. By 1962, however, it appeared that the reciprocal flow of information was not adequate and a more formal meeting was arranged. This meeting took place at Brookhaven during the week of September 10, 1962. CERN sent a representative group of machine physicists and high-energy physicists. The meeting was attended also by observers from several American high-energy installations. The discussion covered a wide range of topics, from operating characteristics of the machines themselves to future trends in design of experimental equipment. Plans for beam ejection were presented, techniques were described for better use of secondary beams from internal targets, progress was summarized on dc and rf particle separators. and future trends in neutrino experimentation were predicted.

The ORNL Graphite Reactor operated very well during 1955. The downtime was low, only 8.6%. The fuel in the bonded slugs did not perform as well in 1955 as in 1954. Much of the trouble was undoubtedly due to growth of slugs which were not beta-transformed. It is known that some slugs had grown over 1/2 in. The automatic central system installed in 1954 continued to operate satisfactorily. The cooling system gave minor trouble when one of the 900-hp fan meters had to be replaced because of shorts in the rotor. The high radiation in the canal was the largest source of trouble. Approximately 55 tons of slugs discharged from the reactor in 1952 was sent to the Metal Recovery Plant. Enough slugs had raptured, due to their long exposure in the canal and reactor, to badly contaminate of water. Most of the contamination was removed by the end of the year, but the radioactivity which had soaked into the canal wells was enough to give high radiation fields. A solution to this problem was being sought at the end of the year. A study is under way on the possibility of increasing the flux of the ORNL Graphite Reactor …

Leaching tests were run on two samples from the Grants area in New Mexico. Uranium extractions of 94 per cent were obtained by leaching Sample 6-1 with solutions containing 240 lbs. of Na2CO3 and 60 lbs. of NaHCO3 per ton and by leaching Sample 6-2 with 270 lbs. of Na2CO3 and 180 lbs. of NaHCO3 per ton. Cyclic tests were completed using caustic precipitation of the leach liquor.

"The problem of radiation derange to the walls of two types of vacuum chamber for the 6 Bev Cambridge Electron Accelerator was studied. Radiation damage may arise from the synchrotron radiation and from electrons which are not accepted at injection. The synchrotron radiation produces a large amount of secondary x radiation which is isotropic, and therefore complicates the arrangement of internal shielding. The 20 Mev electrons from the lines cannot be attenuated by shielding. It is concluded that dosages of the order of 10/sup 7/ rad/day near the inflector are unavoidable. This would exceed the allowable dosage for a tube made by cementing a stainless steel liner to supporting ribs, and also exceed the test dosages (so far as we know) for alumina ceramics."