Performance of alloy M5~R cladding and structure at burn-ups beyond the current licensing limit in US reactors

摘要

Achieving PWR fuel assembly burn-ups beyond currently licensed limits requires improved corrosion resistance as well as improvements in irradiation-induced growth and creep. The excellent performance of alloy M5 fuel rods and structural components in a wide variety of fuel assembly designs and PWR operating environments world-wide has been widely reported. This paper examines the performance of the alloy in burn-ups in US reactors beyond the currently licensed limit. The results of examinations performed to date confirm the excellent in-reactor behaviour of alloy M5 observed in European reactors with similar burn-ups but varying (lower and higher) duty indices.