Dr. Ashok Kumar Arya

Bhabha Atomic Research Centre, Mumbai 400 085 &

Homi Bhabha National Institute, Mumbai 400 094

Email: aarya@barc.gov.in, ashokarya@gmail.com

 

Dr. Ashok Kumar Arya is working as a senior scientist in Materials Science Divison of Bhabha Atomic Research Centre and as a Professor, Chemical Sciences, HBNI. His major area of research focuses on implementation, development and enhancement of computational tools for materials modeling and design for predicting and understanding thermodynamic, electronic, mechanical and optical properties of alloys and compounds under equilibrium as well as non-equilibrium conditions. His other area of research involves predicting the adhesion strength of ceramic or metal coatings on alloys which operate under conditions of highly corrosive environment and under thermal and mechanical shocks.

 

THERMO-PHYSICAL AND DEFECT PROPERTIES OF THORIA AND THORIA-BASED MOX FUELS

 

The nuclear energy from thorium utilization is being looked into with great interest in recent times to meet the changing global energy scenario and demands with added advantage of long sustainability. Thoria (ThO₂)-based mixed oxide (MOX) fuels have the potential for use in nuclear energy applications with high fuel performance as well as the additional advantages of less radiotoxic nuclear waste generation, with easy management and storage of the long-lived highly radioactive nuclide compared to conventional UO₂ based fuels. ThO₂-based MOX are potential alternative fuels for the current light water reactors (LWR) and upcoming advanced heavy water reactors (AHWR).

The evaluation of fundamental properties, viz., thermodynamic, elastic and defect properties of relatively new fuel materials is important for fuel design, performance modeling and assessment of safety issues. The experimental determination of these properties requires extensive safety precautions and remote handling of samples due to associated radio-toxicity of fuel materials. Hence, experiments can be performed in a limited temperature and/or composition ranges. The experimental limitations can be efficiently overcome by modeling and simulations complementing experimentation.

The talk will focus on evaluation of defect and thermo-physical, viz., thermal expansion, thermal conductivity, melting temperature, superionic transitions, specific heats, density, etc., of ThO₂, (Th,Pu)O₂ and (Th,U)O₂ MOX using DFT and MD simulations. Further, DFT-based evaluation of behavior of fission products (halogens, helium and actindes) in ThO₂ matrix will also be discussed.