Effect of reactor radiation on the thermal conductivity of TREAT fuel

JOURNAL OF NUCLEAR MATERIALS

卷:487

Article

Mo, Kun¹  Miao, Yinbin¹  Kontogeorgakos, Dimitrios C.¹  Connaway, Heather M.¹  Wright, Arthur E.¹  Yacout, Abdellatif M.¹ 

[1] Argonne Natl Lab, Nucl Engn Div, 9700 S Cass Ave, Argonne, IL 60439 USA

关键词: Thermal conductivity;    TREAT;    Uranium oxide;    Fission fragments;    Radiation damage;    Low-enriched uranium (LEU);    Highly-enriched uranium (HEU);   

DOI  :  10.1016/j.jnucmat.2017.02.003

来源: Elsevier

【 摘 要 】

The Transient Reactor Test Facility (TREAT) at the Idaho National Laboratory is resuming operations after more than 20 years in latency in order to produce high-neutron-flux transients for investigating transient-induced behavior of reactor fuels and their interactions with other materials and structures. A parallel program is ongoing to develop a replacement core in which the fuel, historically containing highly-enriched uranium (HEU), is replaced by low-enriched uranium (LEU). Both the HEU and prospective LEU fuels are in the form of UO2 particles dispersed in a graphite matrix, but the LEU fuel will contain a much higher volume of UO2 particles, which may create a larger area of interphase boundaries between the particles and the graphite. This may lead to a higher volume fraction of graphite exposed to the fission fragments escaping from the UO2 particles, and thus may induce a higher volume of fission fragment damage on the fuel graphite. In this work, we analyzed the reactor-radiation induced thermal conductivity degradation of graphite-based dispersion fuel. A semi-empirical method to model the relative thermal conductivity with reactor radiation was proposed and validated based on the available experimental data. Prediction of thermal conductivity degradation of LEU TREAT fuel during a long-term operation was performed, with a focus on the effect of UO2 particle size on fission-fragment damage. The proposed method can be further adjusted to evaluate the degradation of other properties of graphite based dispersion fuel. (C) 2017 Elsevier B.V. All rights reserved.

【 授权许可】

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