THE DEVELOPMENT AND TESTING OF UO$sub 2$ FUEL SYSTEMS FOR WATER REACTOR APPLICATIONS. Summary Report, July 1, 1961-June 15, 1962

Technical Report · Sat Oct 31 00:00:00 EST 1964

OSTI ID:4134038

Murtha, B E; Chernock, W P

Vibratory Compaction. Densities of 89 to 90% of theoretical were obtained in 4- to 6-ft long fuel rods, and a pneumatic vibratory compaction process was developed for fuel rod ID of 0.34 to 0.45 inch. A study was made of the variables in the pneumatic compaction process. The problem of low-density regions at the bottom one to two inches of the fuel column was reduced by predensification techniques. Swaged Fuel Elements. The possibility of combining vibratory compaction and small swaging reductions to produce powder packed fuel element densities greater than 90% of theoretical, was studied using stainless steelclad fused UO/sub 2/ fuel rods. The final products had densities of 92 to 93% theoretical and maximum OD variations of plus or minus 0.001 inch. Cost analyses of the process combination show lower fuel cycle costs as compared to vibratory compaction alone. Projection Welding. A multiple-electrode tool capable of simultaneously welding nine fuel rods to a wire spacer is described. An initial study of welding parameters was made using stainless steel tubing. The mechanical problems of stacking and welding of a full-size hexagonal cluster were considered, and a cluster assembly method was evolved which minimizes cluster movement and fabrication time. Development of refined parameters for cluster configurations is in progress. Reduction in Cladding Thickness. Two methods were evaluated for minimizing the cladding thickness in stainless steel- clad fuel elements. One method is the use of higher strength, work hardened cladding. A series of collapse tests were performed on samples with various degrees of cold work hardened wall thicknesses and diameters, and a reasonably accurate criterion was developed for predicting tube collapse of annealed and hardened tubing. The other method is the use of the fuel for internal support of thin cladding. The effects of pellet diameters, defects, and compacted powder density on this method was studied. Several ways of supporting the clad in the fission gas void region above the fuel column were also studied. Rock Riting. An attempt was made to reduce a series of stainless steel tubes containing fused UO/sub 2/ by the Rock Rite process. Buckling problems were encountered due to an axial compression load on the unreduced portion of the rods, but ten rods were processed at reduced feed rates and area reductions of 20 to 39%. Rods initially densified to 75% of theoretical and reduced in area 39% resulted in final gross density of 91.5% of theoretical. Symposium on Powder Packed Uranium Dioxide Fuel Elements. General summaries of each of the five major areas of technology reviewed at this symposium are presented. (D.L.C.)

• Research Organization: Combustion Engineering, Inc. Nuclear Div., Windsor, Conn.
• DOE Contract Number: AT(30-1)-2863
• NSA Number: NSA-18-005750
• OSTI ID: 4134038
• Report Number(s): CEND-157; EURAEC-597
• Resource Relation: Other Information: Work Performed under United States-Euratom Joint Research and Development Program. Orig. Receipt Date: 31-DEC-64
• Country of Publication: United States
• Language: English

Related Subjects

METALS, CERAMICS, AND OTHER MATERIALS
COLD WORKING
COMPACTING
CONFERENCE
CONFIGURATION
DEFECTS
DENSITY
ECONOMICS
EXTRUSION
FABRICATION
FISSION PRODUCTS
FUEL CANS
FUEL ELEMENTS
GASES
MACHINING
MECHANICAL STRUCTURES
PELLETS
PERFORMANCE
PNEUMATICS
POWDERS
REACTORS
REPORT
RODS
STAINLESS STEELS
SWAGING
TESTING
THICKNESS
TUBES
URANIUM DIOXIDE
VIBRATIONS
WATER COOLANT
WELDING
WIRES