Report discussing a study on neutron detection schemes and the effect of neutron scattering on neutron image formation quality.

Introduction: "This report is an expanded version of the regular monthly letter report and is prepared in this form with the intention of reviewing work on the subject program for Euratom technical personnel. Work performed during the month of September, which normally constitutes the entire letter report, has been condensed under one heading."

Abstract: A definitive investigation of the boron-carbon equilibrium system is being made by X-ray diffraction, metallographic, and thermal analytical techniques. Alloys are being produced by sintering pressed powder aggregates with subsequent arc melting. Alloys have been made at two atomic percent intervals up to thirty atomic per cent carbon. In the future, higher carbon compositions are to be investigated. Techniques have been worked out for the metallographic preparation of the extremely hard and friable alloys.

From abstract: The principal efforts during the fourth project quarter were the near-completion of the final design and preparation of specifications for plant components. Reactor development work included final preparations for the flexible zero-power test (PMZ-1) program and revised fuel element irradiation test program, continuation of reactor flow test, further work on heat transfer test program, and final design and fabrication of the prototype magnetic jack-type control rod actuators.

From abstract: Reactor development work includes: initiation of the flexible zero-power test (PMZ-1) experimental program, fabrication and delivery of a PM-1 type fuel element, continuation of reactor flow and heat transfer tests, development work on rare earth control rods, and testing and redesign of the prototype magnetic jack-type control rod actuator.

This document reports the circumstances surrounding the failure of sheathed thermocouples during a test being conducted in the KAPL-120 Loop. The report is prepared to provide a record of these events and to acquaint those who use these thermocouples for testing of other applications with the difficulties that are sometimes encountered.

Although the corrosion of resistance of Zircaloy--2 clad fuel elements in high temperature water is excellent, some concern has been expressed in regard to the resistance against fretting corrosion. Since this form of corrosion can proceed quite rapidly it could induce fuel element failure through penetration of the cladding. Fretting corrosion if it occurred, would take place either where the fuel element contacted the process tube or where portions of the fuel element contacted each other, e. g. wire-wrapping around a cluster of cylindrical fuel rods. This form of corrosion is defined as corrosion occurring at contact areas and as such, fretting of Zircaloy-2 could take place in many reactor concepts. This report details the results of testing performed to induce fretting corrosion of Zircaloy-2 and the direction of the future tests.

From Abstract: "The data for gummed film fallout measurements through December 1959 are reported. The bulk of the report consists of summary tables for each gummed film station listing the monthly estimates of strontium 90 deposition and infinity gamma dose."

Abstract: An analysis of SM-1 Core II and SM-1A Core I zero power experiments was made by comparing these cores to each other and to AM-1 Core I on the basis of critical bank positions, bank calibrations and available chemical analyses of the fuel plate compositions. The effects of replacing boron absorbers by europium absorbers upon rod worth and stuck rod conditions were studied. Comparisons of measured and calculated power distributions were made. It was concluded that both SM-1 Core II and SM-1A Core I contain nearly identical B-10 loading of 17.79 grams, compared to the best estimate of 15.75 grams for SM-1 Core I. The available data indicates that all three cores possess similar nuclear characteristics.

aluminum has been considered as a material for cladding fuel elements to be used in reactors cooled by high-temperature recirculating water. Aluminum is abundant, chap, has a relatively low cross section for thermal neutrons, and is readily fabricated into complex shapes. For these reasons, it appears that the use of aluminum rather than steel, Zircaloy or other candidate materials for fuel element cladding, would result in considerable savings in operating expense. The actual economics will of course depend on specific factors such as core materials and design of the reactor/. Aluminum appears particularly attractive for cladding the cores of aluminum-plutonium alloy proposed for the Plutonium Recycle Test Reactor since, in this case, the physical characteristics of the core and cladding would be practically identical.

This is the third of a series of reports describing the phases of a study of the wear and galling of autoclavedZircaloy-2 by various bearing surface materials. The first report (1) showed that increasing contact area between the autoclaved Zircaloy-2 surfaces will not prevent scratching. It also showed that metals softer than Zircaloy-2 in general do not scratch it. The second report (2) described how eight metals and alloys were wear-tested on autoclaved Zircaloy-2 as prospects for fuel element support-bearing surface materials.

Four naturally occurring materials, namely, vermiculite, variscite, Tennessee rock phosphate, and Florida pebble phosphate, were studied to determine the feasibility of their use in columns for the sorption of strontium from high pH, intermediate-level wastes produced at ORNL. Excepting vermiculite, all materials were found to be effective in strontium removal.

An estimate was made of the beam hole currents to be expected from both the radial and tangential beam holes in the present HFIR design. The angular fluxes required for these calculation were determined by an 18-group, S8 transport calculation (SNG reactor code). Both type beam holes produced thermal neutron currents of 7.5 x 10^10 neutrons/cm^2 sec. at a power level of 100 Mw. The nonthermal component of the beam current was 7.0 x 10^10 and 4.5 x 10^10 neutrons/cm^2 -sec for the radial and tangential holes, respectively.