It is now amply clear that nuclear energy can be a sustainable source of clean energy for the whole world if we take into account both the fissile and the fertile material resources availability. If, however, uranium-235 is taken as the only fissionable nuclide from which we can generate nuclear power, the exploitable resources are not adequate to supply fuel for the growing demand of the nuclear power industry beyond a century. The adoption of closed fuel cycle to utilize plutonium-239 which is generated as a transmutation product of uranium-238 in the spent nuclear fuel is, therefore, essential in multiplying the fuel resource base by over 50 times. Thorium-232, the other naturally occurring fertile material can enhance the fissile resources still further several fold. In addition, the use of uranium-233, the fissile product of thorium, offers several advantages in reducing radiotoxic waste burden and in providing a proliferation resistant fuel. Worldwide R&D efforts in establishing the reactor technology with thorium fuel cycle have significantly grown in the recent past mainly because of these factors. India being endowed with a huge reserve of thorium minerals has given the due emphasis on research on thorium fuel cycle and has drawn the roadmap of thorium utilization in her long-term plan for the growth of nuclear energy.

This book gives a comprehensive treatment of various aspects of thoria-based fuels and both the front and the back end of the fuel cycle associated with it. Each chapter is written by experts who have many years of experience in their respective fields. At the same time, the continuity of the theme and coherence among the chapters are maintained. The editors must be complimented for structuring the book very well and make it suitable not only for those who are entering into research in the nuclear fuel cycle area but also for practicing sci­entists. The authors have paid attention to technological details while presenting the scientific basis from a fundamental standpoint. The fact that the authors have direct research and operating experience in the areas which are covered in their respective chapters gets reflected in the clarity of their presentations. There are only a few in the world who have delved into thorium fuel cycle, fabrication of thoria based fuel, reprocessing of high burn up fuels and their waste management
issues. As they have joined hands to prepare this book entitled Thoria-based Nuclear Fuels: Thermophysical and Thermodynamic Properties, Fabrication, Reprocessing and Waste Management, the product that has emerged is not only unique but also extremely valuable.

Mumbai, India, April 2013

Srikumar Banerjee Homi Bhabha Chair Professor Bhabha Atomic Research Centre (Former Chairman, Atomic Energy Commission, & Secretary to the Department of Atomic Energy,

Government of India)