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Title: DEVELOPMENT OF PLUTONIUM-BEARING FUEL MATERIALS. Progress Report for Period January 1 through March 31, 1962

Technical Report ·
DOI:https://doi.org/10.2172/4815636· OSTI ID:4815636

During this reporting period, particular effort was of aced on powder blending and pellet sintering studies prior to irradiation sample fabrication, and, subsequently, the production and characterization of the pellets slated for irradiation. Also, PuO/sub 2/ and UO/sub 2/-PuO/sub 2/ characterization studies were continued, and new techniques are being developed. Specifically, dynamic moisture pickup determinations on PuO/sub 2/ were made in moist air, N, and CO/ sub 2/ atmospheres using a recording thermogravimetric balance; the Sharples Micromerograph was committed to Pu, and powder particle size distributions were measured and compared with previous determinations made with air-permeability equipment; and the suitability and reliability of analytical chemistry assaying procedures such as x-ray-fluorescence and gamma spectrometry are being evaluated. Prototype work on UO/sub 2/ for the direct precipitation of PuO/sub 2/ and PuO/ sub 2/-UO/sub 2/ feed materials for swaging, vibratory compaction, and dispersion fabrication was also continued. In addition, investigation of PuO/sub 2/ spherical particle formation by mechanical buildup and by plasma torch fusion was extended. Associated reactor physics studies were concentrated on the further comparison of Pu and U/sup 235/ in near-thermal converter reactors. In preparation for the fabrication of irradiation test specimens to be prepared by the mechanical blending of individuaI PuO/sub 2/ and UO/sub 2/ powders, bIending studies were initiated to develop methods required for the attainment of desired homogeneity. Sintering studies were carried out on PuOs/sub 2/ to study the effects of compaction pressure, firing temperature, firing time, and firing atmosphere. It was determined that 1400 to 1500 deg C is the best firing temperature to obtain maximum pellet density, and that sintering in air yields higher densities than sintering in a N/sub 2/--H/sub 2/ atmosphere. Further, it was noted that the degree of Pu/sub 2/O/sub 3/ formation while sintering in an N/ sub 2/--H/sub 2/ atm osphere is inversely proportional to compaction pressure, indicating that the degree of formation is determined by the exposed surface area. Two additional Iots of UO/sub 2/-5 wt% PuO/sub 2/ powder were precipitated during this period. Powder characterization data for these and two previously produced lots were obtained. Also, powder characteristics were remeasured following hammermilling in order to allow assessment of the effects of this treatment. In preparation for work with PuO/sub 2/ and UO/sub 2/--PuO/sub 2/, prototype studies are being carried out with UO/sub 2/ to assess the possibility of producing directly high density granular feed for swaging, vibratory compaction, and dispersion fuel fabrication. Effort was continued on the fabrication of spherical PuO/sub 2/ particles by mechanical buildup and by plasma torch fusion. Reactor physics studies were continued to allow assessment of Pu relative to U/ sup 235/ in near-thermal reactor sys tems. Under cost assumptions used previously, it was shown that optimum fuel cycle costs from Pu-natural U fueled systems are well below those attainable with slightly enriched U iueled systems even if it is assumed that radiation damage is not limiting and that an ideal burnable poison (or solution poison) exists to limit the reactivity. (auth)

Research Organization:
Nuclear Materials and Equipment Corp., Apollo, Penna.
DOE Contract Number:
AT(30-1)-2389
NSA Number:
NSA-16-025736
OSTI ID:
4815636
Report Number(s):
NUMEC-P-100
Resource Relation:
Other Information: Orig. Receipt Date: 31-DEC-62
Country of Publication:
United States
Language:
English