Analysis of Different Requirements of Dissimilar Metal Joint Welding Procedure Qualification Between RCC-M and ASME BPVC

Abstract In order to enhance the comprehension of the welding procedure qualification standards, RCC-M (Design and Construction Rules for Mechanical Components of PWR Nuclear Islands) and ASME BPVC (American Society of Mechanical Engineers Boiler and Pressure Vessel Code), used by the components fabrication for nuclear power industry in the People’s Republic of China, this paper takes the qualification of dissimilar metal joint between inlet-nozzle and safe end of steam generator in Generation III nuclear power unit as an example, taking a comparative approach, compares the requirements of different welding variables one by one between two standards and then lists the differences and analyzes the differences. It shows that RCC-M has more strict requirements than ASME BPVC on the qualification of dissimilar metal joint with buttering, the type of test couple qualified by RCC-M is more similar to product than that by ASME BPVC, and qualification by RCC-M may need more test couples than that by ASME BPVC, if choosing same value of variables which have overlap between these two standards, test coupon qualified by RCC-M can used for that qualified by ASME BPVC, but not vice versa. At last, the paper gives some implementation advises and guidance of subsequent qualification works during design and fabrication.