This review article explores the integration of blockchain and IoT technologies to enhance data security and privacy in energy applications, particularly in nuclear energy. The study analyzes the challenges, scope, and potential solutions of integrating blockchain with IoT, emphasizing their roles in ensuring data security, privacy, and integrity. A secure data management framework is developed, incorporating encryption, integrity verification, and integrated communication networks, along with a robust data flow architecture. The study investigates secure transaction processes, focusing on cryptographic, mathematical, and algorithmic perspectives. It demonstrates the use of blockchain in the nuclear energy sector using flow charts, addressing associated security and privacy concerns. The study acknowledges limitations such as the need for practical validation, challenges with resource-constrained IoT environments, increasing cyber threats, and limited real-time data availability. The future scope includes standardization, scalable blockchain, post-quantum cryptography, privacy, regulations, real-world testbeds, and deep learning for nuclear sector security. The findings highlight that the integration of blockchain and IoT can significantly enhance the security and privacy of nuclear energy applications, although practical validation and optimization are necessary. The article also discusses the potential of blockchain and IoT in various domains, including healthcare, supply chain, and smart cities, and highlights the importance of data preprocessing, encryption, and privacy-preserving techniques in ensuring secure and reliable data management. The study presents a comprehensive framework for secure data management in IoT applications, emphasizing the need for robust security measures, privacy considerations, and the integration of blockchain technology to address the challenges of data security and privacy in energy applications.This review article explores the integration of blockchain and IoT technologies to enhance data security and privacy in energy applications, particularly in nuclear energy. The study analyzes the challenges, scope, and potential solutions of integrating blockchain with IoT, emphasizing their roles in ensuring data security, privacy, and integrity. A secure data management framework is developed, incorporating encryption, integrity verification, and integrated communication networks, along with a robust data flow architecture. The study investigates secure transaction processes, focusing on cryptographic, mathematical, and algorithmic perspectives. It demonstrates the use of blockchain in the nuclear energy sector using flow charts, addressing associated security and privacy concerns. The study acknowledges limitations such as the need for practical validation, challenges with resource-constrained IoT environments, increasing cyber threats, and limited real-time data availability. The future scope includes standardization, scalable blockchain, post-quantum cryptography, privacy, regulations, real-world testbeds, and deep learning for nuclear sector security. The findings highlight that the integration of blockchain and IoT can significantly enhance the security and privacy of nuclear energy applications, although practical validation and optimization are necessary. The article also discusses the potential of blockchain and IoT in various domains, including healthcare, supply chain, and smart cities, and highlights the importance of data preprocessing, encryption, and privacy-preserving techniques in ensuring secure and reliable data management. The study presents a comprehensive framework for secure data management in IoT applications, emphasizing the need for robust security measures, privacy considerations, and the integration of blockchain technology to address the challenges of data security and privacy in energy applications.