An Experimental Investigation of the Interaction of Primary and Secondary Stresses in Fuel Plates

Abstract

If the load is not relieved as a structure starts to yield, the induced stress is defined as primary stress. If the load relaxes, as a structure begins to yield the induced stress is defined as secondary stress. In design, it is not uncommon to give more weight to primary stresses than to secondary stresses. However, knowing when this is good design practice and when it is not good design practice represents a problem. In particular, the fuel plates in operating reactors contain both primary stresses and secondary stresses, and to properly assess a design there is a need to assign design weights to the stresses. Tests were conducted on reactor fuel plates intended for the advanced neutron source (ANS) to determine the potential of giving different design weights to the primary and secondary stresses. The results of these tests and the conclusion that the stresses should be weighted the same are given in this paper.