Combined effects of radiation damage and He accumulation on bubble nucleation in Gd2Ti2O7

JOURNAL OF NUCLEAR MATERIALS

卷:479

Article

Taylor, Caitlin A.¹  Patel, Maulik K.¹  Aguiar, Jeffery A.^2,3  Zhang, Yanwen^1,4  Crespillo, Miguel L.¹  Wen, Juan^5,6  Xue, Haizhou¹  Wang, Yongqiang⁶  Weber, William J.^1,4 

[1] Univ Tennessee, Dept Mat Sci & Engn, Knoxville, TN 37996 USA

[2] Idaho Natl Lab, Fuel Performance & Design Dept, Idaho Falls, ID 83415 USA

[3] Natl Renewable Energy Lab, Ctr Mat Sci, Golden, CO 80220 USA

[4] Oak Ridge Natl Lab, Mat Sci & Technol Div, Oak Ridge, TN 37831 USA

[5] Lanzhou Univ, Sch Nucl Sci & Technol, Lanzhou 730000, Gansu, Peoples R China

[6] Los Alamos Natl Lab, Mat Sci & Technol Div, Los Alamos, NM 87545 USA

关键词: Pyrochlore;    Helium bubble;    Radiation damage;    Nuclear waste;   

DOI  :  10.1016/j.jnucmat.2016.07.043

来源: Elsevier

【 摘 要 】

Pyrochlores have long been considered as host phases for long-term immobilization of radioactive waste nuclides that would undergo a-decay for hundreds of thousands of years. This work utilizes ion-beam irradiations to examine the combined effects of radiation damage and He accumulation on bubble formation in Gd2Ti2O7 over relevant waste-form timescales. Helium bubbles are not observed in pre-damaged Gd2Ti2O7 implanted with 2 x 10(16) He/cm(2), even after post-implantation irradiations with 7 MeV Au3+ at 300, 500, and 700 K. However, He bubbles with average diameters of 1.5 nm and 2.1 nm are observed in pre-damaged (amorphous) Gd2Ti2O7 and pristine Gd2Ti2O7, respectively, after implantation of 2 x 10(17) He/cm(2). The critical He concentration for bubble nucleation in Gd2Ti2O7 is estimated to be 6 at.% He. (C) 2016 Elsevier B. V. All rights reserved.

【 授权许可】

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