Technological Challenges in Manufacturing of Large Sized Stainless Steel Components of PFBR

摘要

Prototype Fast Breeder Reactor (PFBR) is liquid sodium cooled, pool type nuclear reactor with generating capacity of 1250 MWt / 500MWe. Reactor assembly consists of many large dimensional components made of special grade austenitic stainless steel material. Safety vessel and Main vessel are torispherical dished end vessels with overall height of 12800 mm and 13400/12900 mm diameter with thickness ranging from 20 to 40 mm. Vessels approx. 111 / 135 MT with running weld length of 500 & 540 m. Inner vessel and thermal baffles are the internals of reactor assembly made of SS 316LN. Forming of dished end petals, weld overlay on the inside surface, circumference matching between the cylindrical shells, cylindrical shell to dished portion was achieved within the tolerances specified. Due to limitations of transportation, these large sized components were manufactured at PFBR site. This paper discusses the experiences gained during the manufacturing of such over dimensional components at PFBR site in meeting the stringent tolerances on various dimensions and NDE requirements.