USE OF AGGLOMERATED UO2 IN PRESSURE-BONDED STAINLESS STEEL-CLAD FUEL RODS

摘要

In a continuation of the Hanford-Battelle cooperative program reported in BMI-1637, the combined use of the vibrational compaction and gas-pressure-bonding processes for fabricating UO2 fuel elements was studied. Particular emphasis was placed on the use of agglomerated Micronized UO2 to overcome nonunifortuities in the vibrationally compacted pressure-bonded fuels. Inconel X-clad fuel rods were gas-pressure bonded at 2100 F for 3 hr at 10,000 psi to evaluate the use of Micronized UO2 agglomerated by cold high-energy-rate forming methods. Fuel densities from 88 to 93 per cent of theoretical were attained. A limited parallel study was also conducted to evaluate hydrostatic pressing as a method of agglomerating Micronized UO2. Tap density increased from 20 to 25 per cent for the as-received Micronized oxide to 41 per cent for the hydrostatic ally agglomerated plus 200-mesh powder. Studies of the effects of prior cold work and gas-pressure bonding on the mechanical and physical properties of Types 304L and 347 stainless were conducted. Prior cold work in the range of 35 to 50 per cent gave a pressure-bonded structure having a fine grain size.