Hot Helium Leak Test of ITER blanket shield block

•On February 2018, the Hot Helium Leak Test (HHLT) on the Shield Block full-scale prototype (FSP) had been completed, this is the first HHLT for Shield Block, the first time to have achieved the system sensitivity better than 10−10Pa. m3/s at temperature above 200 °C test conditions and the first time to have monitored the background leak signal with temperature.•The HHLT was completed under the witness of experts from ITER vacuum chamber department, the test process meets the procedure and test result satisfies the current ITER requirements.•The HHLT results provide valuable reference data for further investigating acceptance criteria of ITER Vacuum components. They also provide an important benchmark for developing HHLT standards for the large vacuum components of future tokamaks.