IRRADIATION CREEP OF V-TI-CR ALLOY IN BR-10 REACTOR CORE INSTRUMENTEDEXPERIMENTS

A thin wall tubular-type specimen of 4%Ti-4%Cr vanadium alloy was test ed for creep under irradiation in BR-10 reactor at 713-723 K and at 8. 6 x 10(18) n/m(2)s fast neutron flux. A fluence at the end of the expe riment have reached 5.8 x 10(25) n/m(2). Specimen deformation measurem ents were performed by a dynamometric method based on a stress relaxat ion control provided during irradiation under constant load applied. D uring the experiment 13 deformation curves were obtained for different stress levels ranged up to 165 MPa. At the same time the yield stress of the irradiated specimen was periodically determined. The irradiati on creep rate has been found to be proportional to the stress up to 11 0-120 MPa with the module equal to 3.3 x 10(-12) dpa(-1) Pa-1. At high er streses, a creep process essentially accelerates. The results on V- Ti-Cr alloy are discussed in respect to data obtained for stainless st eels in earlier BR-10 reactor experiments.