Benchmarking of Mechanical Test Facilities Related to ITER CICC Steel Jackets

The International Thermonuclear Experimental Reactor (ITER) cable-in-conduit conductor used in the superconducting magnet system consists of a cable made of 300 to 1440 strands housed in a stainless steel tube (called as jacket or conduit). There are circular, square, as well as circle-in-square jackets, made of either a very low carbon AISI 316LN and AISI 316L grade stainless steels, or a high Mn austenitic stainless steel developed for ITER called JK2LB. Selected mechanical properties of the base material and weld joint were tested at room temperature and/or cryogenic temperatures (<; 7 K) at predefined mechanical deformation and heat treatment condition. The domestic agencies´ reference laboratories and the ITER-IO appointed reference laboratories, CERN and Karlsruhe Institute of Technology performed mechanical tests such as tensile strength, fracture toughness, and fatigue crack growth rate. This paper will compare the test results (e.g., elongation to failure) from different laboratories, present the statistics, and identify any systematic differences.