Effects of Neutron Dose, Dose Rate, and Irradiation Temperature on the Irradiation Embrittlement of a Low-Copper Reactor Pressure Vessel Steel

Kasada, R
Institute of Advanced Energy, Kyoto University, Gokasho, Uji, Japan

Kudo, T
Graduate School of Energy Science, Kyoto University, Gokasho, Uji, Japan

Kimura, A
Institute of Advanced Energy, Kyoto University, Gokasho, Uji, Japan

Matsui, H
Institute for Materials Research, Tohoku University, Aoba-ku, Uji, Japan

Narui, M
Institute for Materials Research, Tohoku University, Aoba-ku, Uji, Japan

(Received 5 June 2004; accepted 26 October 2004)
JOURNAL JAI
Abstract
A series of irradiation experiments to investigate the effects of neutron fluence and flux on reactor pressure vessel (RPV) steels has been performed using the Japan Material Testing Reactor (JMTR). The irradiation temperature has been precisely controlled at 290°C within an error of ±2°C during reactor operation. The neutron fluence and flux ranged from 9.3×10¹⁷ to 1.1×10²⁰ n/cm² and from 1.4×10¹¹ to 6.3×10¹³ n/cm²/s, respectively. The material used in the present study was an A533B RPV steel in which the copper and phosphorous concentrations are 0.03 and 0.002 wt%, respectively. Charpy impact test results with one-third sized specimens showed no dose-rate dependence. Microstructural observation revealed that a higher irradiation temperature at around 340°C resulted in formation of rather large dislocation loops and smaller microvoids.

Keywords:
Charpy impact test, dose rate effects, irradiation, irradiation embrittlement, irradiation hardening, Reactor pressure vessel steel

Paper ID: JAI12399
DOI: 10.1520/JAI12399

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Author Kasada, R Affiliation Institute of Advanced Energy, Kyoto University, Gokasho, Uji, Japan Author Kudo, T Affiliation Graduate School of Energy Science, Kyoto University, Gokasho, Uji, Japan Author Kimura, A Affiliation Institute of Advanced Energy, Kyoto University, Gokasho, Uji, Japan Author Matsui, H Affiliation Institute for Materials Research, Tohoku University, Aoba-ku, Uji, Japan Author Narui, M Affiliation Institute for Materials Research, Tohoku University, Aoba-ku, Uji, Japan Title: Effects of Neutron Dose, Dose Rate, and Irradiation Temperature on the Irradiation Embrittlement of a Low-Copper Reactor Pressure Vessel Steel Symposium: Effects of Radiation on Materials: 22nd International Symposium, 2004-6-10
Committee: E10 on Nuclear Technology and Applications