Chromium zirconium copper(CuCrZr)alloy has been selected as the heat sink material for the plasma-facing components in the International Thermonuclear Experimental Reactor(ITER).For the deuterium-tritium(D-T)phase of ITER operation,its highly possible that atomic and ionized T will penetrate through some unshielded CuCrZr heat sink areas and transport into the coolant,which then will raise more complicated T safety and extraction issues.In the present work,experimental and theoretical analysis on hydrogen isotopes permeation through the CuCrZr alloy has been conducted.As a comparison,pure copper and an oxide dispersion strengthened Cu alloy have been studied as well.