Manufacturing of segment fuel for irradiation test

As part of high performance fuel development which enables nuclear power plant to operate according to power change, two segment assemblies which include Zr-liner fuel for improvement of resistant to pellet-cladding interaction and hollow pellets for reduction of fuel centerline temperature have been fabricated. The segment assembly is composed of 30 regular length fuel rods and 6 (inner: 3 intermediate: 3) segment fuel rods, and has the same structure as that of ATR demonstration fuel assembly. The production of fuel pellet was started in April, 1986 and the fabrication of the fuel assembly ended in January, 1987. The irradiation of the test assembly was started in April this year and power ramp tests using the segment fuel rods are scheduled to be carried out after the base irradiation in ''FUGEN''. This paper describes the irradiation plan, fuel specification and fuel manufacturing of the segment assemblies. (author)