[2M08-12] Reactor Pressure Vessel

[2M08] In-situ transmission electron microscopy study of evolution of dislocation loops in irradiated reactor pressure vessel model alloys

*Liang Chen¹, Kenta Murakami², Dongyue Chen¹, Hiroaki Abe¹, Zhengcao Li³, Naoto Sekimura¹ (1. Univ. of Tokyo, 2. Nagaoka Univ. of Tech., 3. Tsinghua Univ.)

Keywords:Reactor pressure vessel, Dislocation loops, Model alloy, In-situ transmission electron microscopy

Dislocation loop is a principal feature of radiation damage which causes hardening and accompanying embrittlement in nuclear reactor pressure vessel steel. The objective of this work is to investigate the mechanism of loop evolution under irradiation, particularly loop growth which can be a dominant phenomenon at high dose region. For this purpose, reactor pressure vessel model alloys are selected, and in-situ irradiation following bulk irradiation is performed. To be specific, first, bulk of the model alloy is irradiated to 1 dpa at 400 ^oC to produce well visible loops, and then subsequent in-situ irradiation with accelerator-TEM linked facility is conducted to observe the evolution of loops. The growth kinetics of loops is investigated, and the effect of one-dimensional migration of loops is analysed.