- The University of Illinois Urbana-Champaign (UIUC), in collaboration with Ultra Safe Nuclear Corporation (USNC), is progressing toward deploying a 15 MW underground small modular reactor (SMR) as a research facility, overcoming regulatory challenges with the Nuclear Regulatory Commission (NRC).
- Underground siting of SMRs, such as the USNC SMR, offers enhanced safety, security, and potential cost-efficiency, with experts highlighting reduced CO2 emissions and resilience against external threats.
- Global interest in underground SMRs is growing, with significant developments in the UK and Singapore, where similar projects emphasize their economic and security advantages for urban and constrained environments.
The University of Illinois is making significant strides in the regulatory process for its proposed underground small modular reactor (SMR), a project reflecting the growing trend toward deploying small modular reactors (SMRs) to meet increasing demand for heat and power. The SMR, designed in collaboration with Ultra Safe Nuclear Corporation (USNC), is planned to be a 15 MW capacity underground research reactor located on the University of Illinois Urbana-Champaign (UIUC) campus. This initiative aligns with the rising electricity demands fueled by advancements in artificial intelligence and the delays in grid connections experienced globally.
In a statement published in November 2024, the University of Illinois outlined its progress with the Nuclear Regulatory Commission (NRC) on this innovative project. The partnership between UIUC and USNC aims to establish the USNC Small Modular Reactor as a pioneering research facility. Pre-application engagement has been underway, with the university submitting several topical reports to the NRC. Once approved, these reports lead to the issuance of Safety Evaluations (SE), facilitating their application in subsequent licensing processes.
The regulatory journey has not been without challenges. Current NRC regulations and design criteria are largely tailored to the existing fleet of large light-water reactors, presenting hurdles for advanced reactor designs. These regulations have often proven either inapplicable or overly complex for emerging reactor technologies. However, USNC’s reactor design, which incorporates Fully Ceramic Micro-encapsulated (FCM) fuel, addresses many safety concerns. This advanced fuel technology is lauded for its inherent safety features, enabling deployment in constrained spaces such as underground facilities.
Since December 2022, UIUC and USNC have worked diligently to mitigate “regulatory uncertainty” with the NRC. A significant milestone was achieved on July 25, 2024, when the NRC issued a Safety Evaluation affirming that the regulatory framework screening conducted by the partnership was acceptable. This milestone provides a well-documented foundation for how existing NRC regulations apply to the USNC SMR, streamlining future applications for high-temperature gas-cooled reactors and accelerating their deployment.
Globally, the development of underground SMRs is garnering attention. In the United Kingdom, Ultra Safe Nuclear Corporation has secured £22.5 million from Great British Nuclear to advance its MMR development. This funding, match-funded by USNC, supports the second phase of work toward building a UK demonstrator. Engineering firm Jacobs has been appointed to aid in the design and development process.
The concept of undergrounding SMRs is receiving widespread endorsement from nuclear experts. King’s College London’s Ross Peel, a research fellow specializing in nuclear security and safeguards, recognizes the potential of below-ground siting for enhanced nuclear security and safety. While acknowledging that no security measure is entirely foolproof, Peel emphasizes that underground siting offers significant protection against external threats, particularly when combined with comprehensive protective systems. He also notes the economic feasibility of underground construction as a critical factor in its adoption.
Further support for underground SMRs comes from the University of Glasgow’s Bjoern Seitz, a senior lecturer with expertise in particle physics and nuclear medicine. Seitz highlights the potential reduction in CO2 emissions associated with underground reactors, as they require less concrete shielding compared to above-ground counterparts.
The benefits of underground siting were also explored in a 2024 paper by Nanyang Technological University in Singapore. Co-authored by Alvin Chew and Zhou Yingxin, the study advocated for underground SMRs in urban centers, citing superior safety and security against military attacks. Additionally, the authors argued that the construction and lifecycle costs of underground reactors could be more economical than traditional ground-level facilities.
The University of Illinois’s proposed underground microreactor represents a convergence of innovative nuclear technology and forward-thinking safety strategies. As regulatory hurdles are addressed and the project advances, it underscores the critical role of SMRs in meeting modern energy demands while ensuring robust safety and security measures.
