DEVELOPMENT AND OPERATION OF AN APPARATUS FOR IN-PILE CREEP STUDIES OF LMFBR FUELS Topical Report

摘要

An apparatus for obtaining data on the compressive creep of ceramic fuel materials during irradiation was designed and operated. The specimen was fabricated in the shape of a hollow cylinder to reduce temperature gradients caused by fission heating and to allow placement of creep probes near the ends of the specimen. A compressive load was applied to the specimen through a bellows-sealed, gas-actuated piston. Specimen temperatures were maintained by a resistance-wire heater. Axial creep of the fuel was measured by transmission of the motion through bellows-sealed probes linked to a pneumatic displacement transducer with a variable-area orifice. The apparatus is designed to operate with fuel temperatures in the range from 900 to 1300 C3 stress levels of 1,000 to 12,000 psi, and fission rates ranging up to 2 x 1013 fissions/(cm3) (sec).