Development and compatibility of magnesium-matrix fuel plates clad with 6061 aluminium alloy

Aluminum is a commonly used matrix for research reactor fuel plates. Reaction at the higher range of reactor fuel operating temperatures between the fuel and its Al matrix may reduce the irradiation stability of the fuel. To further understand the contribution of this reaction to irradiation stability, experiments were performed to develop a nonreacting matrix. The work focused on magnesium, which is an excellent nonreacting matrix candidate with a neutron absorption coefficient similar to that of Al. To avoid the formation of a liquid Al/Mg phase, the roll-bonding process was improved to achieved acceptable bonding at 415 deg C. After these methods were developed, fuel plates were produced with two fuels: uranium-2 wt % molybdenum, and u-10 wt % mo with two matrices (Al and Mg). A reaction between the Mg and the 6061 Al cladding during processing at 415 deg C. To minimize the extend of this reaction, we developed methods to roll-bond the fuel plates at 275 deg C. With this method, fuel plates with an Mg matrix will be fabricated and included in the next irradiation matrix for the RERTR high-density fuel development program. (author)