• Bhimarao M. Patil

The safe and permanent disposal of high-level radioactive waste (HLW) is one of the most formidable challenges facing the long-term sustainability of nuclear energy. Traditional vitrification in borosilicate glass has served as the baseline approach in several national waste management programs; however, inherent limitations in waste loading, volatility control, and long-term chemical durability under geological repository conditions have motivated the development of advanced ceramic waste forms. Among these, Synroc (Synthetic Rock)—an engineered, multiphase titanate ceramic inspired by naturally durable minerals—has emerged as a leading candidate for the immobilization of HLW. Synroc confines radionuclides within specific crystal lattices such as hollandite for Cs, zirconolite for actinides, and perovskite for rare-earth elements, offering enhanced chemical and radiation stability. This review provides a comprehensive assessment of Synroc’s development, its historical evolution, phase chemistry, synthesis and consolidation routes, and performance under radiation and aqueous environments. The comparative analysis with borosilicate glass highlights Synroc’s superior waste loading capacity (typically 15–30 wt% HLW oxides), extremely low leach rates, and excellent radiation resistance owing to the presence of radiation-tolerant titanate phases that exhibit self-annealing and recrystallization. The key processing techniques—including hot isostatic pressing (HIP), cold pressing with sintering, reactive sintering, sol–gel, and co-precipitation—are discussed in terms of densification, microstructure, and scalability. The remaining challenges such as process cost, industrial scalability, and qualification for diverse waste streams are also evaluated.

High-level radioactive waste (HLW), Synroc, Borosilicate glass, vitrification, Hot isostatic pressing (HIP)

"A REVIEW ON ‘SYNROC: A SUSTAINABLE PATHWAY FOR SAFE IMMOBILIZATION OF HIGH-LEVEL RADIOACTIVE WASTE FOR NEXT-GENERATION NUCLEAR TECHNOLOGIES", International Journal of Emerging Technologies and Innovative Research (www.jetir.org), ISSN:2349-5162, Vol.2, Issue 1, page no.766-773, January 2015, Available :http://www.jetir.org/papers/JETIR1701D60.pdf

"A REVIEW ON ‘SYNROC: A SUSTAINABLE PATHWAY FOR SAFE IMMOBILIZATION OF HIGH-LEVEL RADIOACTIVE WASTE FOR NEXT-GENERATION NUCLEAR TECHNOLOGIES", International Journal of Emerging Technologies and Innovative Research (www.jetir.org | UGC and issn Approved), ISSN:2349-5162, Vol.2, Issue 1, page no. pp766-773, January 2015, Available at : http://www.jetir.org/papers/JETIR1701D60.pdf