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BOTTOM-POUR RE-USABLE MELTING CRUCIBLES FOR PLUTONIUM CASTING

Description: 24p. Bottom-pour Ta and CaF/sub 2/-coated steel melt crucibles for Pu and Pu-rich alloys were developed. The controlled pour is effected by melting a Pu plug in the bottom spout of the crucible after the desired temperature and vacuum conditions are obtained. A description is given of the development of the crucibles which have replaced ceramic crucibles for casting work on the kilogram scale. (auth)
Date: October 1, 1960
Creator: Miley, F. & Anderson, J.W.
Partner: UNT Libraries Government Documents Department

THE ETCHING OF PLUTONIUM AND ITS ALLOYS BY CATHODIC BOMBARDMENT

Description: The development of microstructural detail by cathodic bombardment has been used successfully for many metals and alloys which are difficult to etch by conventional methods. An application of this technique to plutonitun and its alloys is presented. A method for preventing the specimen from overheating is included in the description of the equipment. Photomicrographs of a few clean, well defined microstructures obtained by cathodic bombardment of plutonium and some of its alloys are also are included, together with photomicrographs of the same specimens etched by means of conventional techniques. (auth)
Date: January 1, 1959
Creator: Imlah, K.
Partner: UNT Libraries Government Documents Department

U-Pu-Zr Metal Alloy: a Potential Fuel for LMFBR's

Description: This report critically reviews the available information pertinent to the potential use of uranium-plutonium-zirconium alloy fuels clad with stainless steel in LMFBR's. The areas considered include breeding potential, burnup potential, thermal performance, fuel fabricability, fuel reprocessing, and safety considerations. Because information on uranium-plutonium-zirconium alloys is limited, wide use is made of experience with EBR-II metallic driver fuel to infer advantages and limitations of uranium-plutonium-zirconium fuels. It is concluded that sufficient potential exists for the applicability of uranium-plutonium-zirconium fuels to LMBFR's to warrant additional analytical and experimental studies.
Date: November 1975
Creator: Walter, C. M.; Golden, G. H. & Olson, N. J.
Partner: UNT Libraries Government Documents Department

Crystallography of the Delta to Alpha Martensitic Transformation in Plutonium Alloys

Description: A new stress-accommodating crystallographic mechanism of the {delta} {yields} {alpha} martensitic transformation in plutonium alloys is proposed. According to this mechanism, an orientation variant of the {alpha} phase is produced by a combination of a homogeneous strain and shuffling of the alternating close-packed (111){sub {delta}} planes. It is shown that the formation of stable transformation-induced twins whose twin plane orientations and twin shear directions do not depend on the small variations of the crystal lattice parameters is the preferred stress-accommodating mode. Only these stable twins have dislocation-free twin boundaries while the twin boundaries of all others are decorated by ultra-dense distribution of partial dislocations. The theory predicts a crystal lattice rearrangement mechanism involving the (205){sub {alpha}} ((01{bar 1}){sub {delta}}) stable twins. The corresponding Invariant Plane Strain solutions, with special emphasis on two simplest shuffling modes, the single and double elementary modes, are presented and compared with the existing experimental observations. It is shown that the habit plane orientation is highly sensitive to the input values of the crystal lattice parameters and especially to the accuracy of the measured volume change in the {delta}{yields}{alpha} transformation. An analysis of these effects on the habit plane orientation and orientation relations is also presented.
Date: July 15, 2004
Creator: Jin, Y; Wang, Y; Khachaturyan, A; Krenn, C & Schwartz, A
Partner: UNT Libraries Government Documents Department

Probing Radiation Damage in Plutonium Alloys with Multiple Measurement Techniques

Description: A material subjected to radiation damage will usually experience changes in its physical properties. Measuring these changes in the physical properties provides a basis to study radiation damage in a material which is important for a variety of real world applications from reactor materials to semiconducting devices. When investigating radiation damage, the relative sensitivity of any given property can vary considerably based on the concentration and type of damage present as well as external parameters such as the temperature and starting material composition. By measuring multiple physical properties, these differing sensitivities can be leveraged to provide greater insight into the different aspects of radiation damage accumulation, thereby providing a broader understanding of the mechanisms involved. In this report, self-damage from {alpha}-particle decay in Pu is investigated by measuring two different properties: magnetic susceptibility and resistivity. The results suggest that while the first annealing stage obeys second order chemical kinetics, the primary mechanism is not the recombination of vacancy-interstitial close pairs.
Date: April 21, 2010
Creator: McCall, S K; Fluss, M J & Chung, B W
Partner: UNT Libraries Government Documents Department

EFFECTS OF IRRADIATION OF SOME URANIUM-PLUTONIUM ALLOYS. Final Report-- Metallurgy Program 6.5.3 Work Completed: March 1955

Description: Irradiations were made on a number of uranium-plutonium alloy specimens made from both cast and extruded materials. The cast alloys included alloys of uranium with 3.7, 5.6, and 13.0 wt. % plutonium, and the extruded alloys included alloys of uranium with 9.5, 14.1, and 15.7 wt.% plutonium. One-half of the extruded specimens were given a heat treatment consisting of heating to 545 deg C and cooling to and holding at 500 deg C for one hour in an attempt to remove the preferred orientation that was anticipated from extrusion. The specimens were irradiated to burnups ranging up to 0.54 at. % with central temperatures ranging up to 490 deg C. The cast specimens were all found to have developed severe surface roughening as a result of the irradiation they received, presumably because of excessively large grain sizes present before irradiation. Identically fabricated unalloyed uranium specimens showed similar behavior. The as-extruded alloy specimens maintained good surface smoothness under irradiation, but showed elongations which were dependent on plutonium content. For example, in samples with 0.4 at.% burnup, a 14.1 wt.% plutonium alloy specimen elongated 96%, whereas an 18.7 wt. % plutonium alloy specimen elongated only 5.4%. The heat-treated extruded specimens did not elongate anisotropically, indicating that the heat treatment used was effective in randomizing the grain orientation. However, the heat-treated specimens developed excessive surface roughening, apparently because the heat treatment caused an undesirably large grain size. (auth)
Date: January 1, 1958
Creator: Kittel, J.H. & Kelman, L.R.
Partner: UNT Libraries Government Documents Department

Mound Laboratory Progress Report for December 1960

Description: Activities are reported in a program to investigate formulations and procedures which may lead to superior plastics and adhesives. In other work, processes for separating and purifying radioelements are being developed and supply sources are being evaluated. Research was initiated to determine the density, viscosity, thermal capacity, and thermal conductivity of Pu and Pu alloys for use in fast breeder reactors. (J.R.D.)
Date: December 30, 1961
Partner: UNT Libraries Government Documents Department

IRRADIATION OF URANIUM-FISSIUM ALLOYS AND RELATED COMPOSITIONS. Work Performed: 1956

Description: Irradiation results in the range near 1/2% burnup and 500 to 600 deg C are presented for U-fissium amd U-Mo alloys. Under these conditions both classes of alloys show quite low growth coefficients and volume increases, with a few exceptions. Water queaching either alloy from 850 deg C is shown to be unsatisfactory. The effect of an axial hole for relief of fission gases appears to be inconclusive. Surface condition of irradiated U-base alloys appears to be not quite as good as that for U-20 wt.% Pu base alloys. (auth)
Date: September 1, 1957
Creator: Smith, K.F.
Partner: UNT Libraries Government Documents Department

Postirradiation Examination of Ebr-I Core Iv Prototype Fuel Rods. Final Report

Description: BS>Four EBR-I Mark-IV prototype fuel rods containing slugs of plutonium- 1 wt% aluminum alloy were irradiated in the EBR-I reactor at central fuel temperatures from 342 to 386 deg C and at burnups up to 0.1 at.%. No appreciable slumping of the fuel occurred during irradiation, and no significant density nor dimensional changes were observed. Variation of the initial fuel-cladding annulus from 0.004 to 0.019 in. had no significant effect on the slumping behavior, but the larger clearance did allow the fuel pin to bow to a greater extent than that observed in fuel rods with smaller annuli. A niobium restrainer effectively decreased the amount of bowing from that found in a rod with a similar annulus, but did not appear to offer any greater restriction than that provided by a small 0.004-in. annulus. (auth)
Date: September 1, 1963
Creator: Carlander, R.; Kittel, J. H. & Dunworth, R. J.
Partner: UNT Libraries Government Documents Department