South Korea’s Hyundai Engineering has signed separate non-exclusive MOUs with US nuclear start-ups Nano Nuclear Energy (NNE) and ARC Clean Technology (ARC), aiming to participate in fourth-generation small modular reactor (SMR) demonstration projects and expand its role from design into engineering, procurement & construction (EPC).
NNE is developing a high-temperature gas-cooled reactor (HTGR) based micro-modular reactor. The cooperation centres on the KRONOS MMR project at the University of Illinois Urbana-Champaign (UIUC), a 15 MWe helium-cooled reactor intended to supply heat to the campus and support carbon-neutral goals. Hyundai Engineering is initially expected to contribute to project-execution planning, site-related work, procurement readiness, constructability, modularisation, logistics, supply-chain development and US localisation planning. Future scope could expand to architecture and engineering, full EPC, construction management, equipment fabrication and support for fleet deployment.
ARC is developing the ARC-100, a 100 MWe sodium-cooled fast reactor (SFR). ARC is pursuing a commercial demonstration plant of about 200 MWe at the Idaho National Laboratory (INL) site, with potential expansion to around 600 MWe. Hyundai Engineering plans to cooperate on EPC and explore new business opportunities as the project progresses.
Hyundai Engineering has accumulated extensive nuclear design experience since establishing its nuclear division in 1985, having carried out 254 nuclear-related projects including operating plant designs, fuel facilities, research reactors and SMR technology development. The company frames these MOUs as a stepping stone to strengthen full-cycle capabilities from design to EPC and become a trusted partner in the global SMR market
The regulatory pathways under the US Nuclear Regulatory Commission (NRC) for NNE and ARC are moving at entirely different speeds. One is already navigating a formal review, while the other remains in a strategic pre-application technical phase.
NNE’s KRONOS MMR planned for UIUC is currently on an active, formal licensing track. NRC has locked in a strict public review schedule. UIUC formally submitted the Construction Permit Application (CPA) in March and NRC accepted and docketed the application for review in May. Formal safety, environmental, and technical review activities were initiated in June. Completion of the Draft Environmental Assessment and Draft Safety Evaluation is targeted for February 2027 followed by issuance of the Final Environmental Assessment in May and issuance of the Final Safety Evaluation in September, which would conclude the comprehensive NRC review. Subject to these approvals, NNE plans to break ground on initial on-site construction at the UIUC campus in late 2027, aiming for operation in 2030.
Unlike NNE, ARC has not yet submitted a formal construction application. The company is engaged in Pre-Application Activities (tracked under NRC Project 99902103) to de-risk its design before a formal submission. In April, ARC reaffirmed its intent to formally pursue licensing under the NRC’s newly finalised Part 53 framework, which is designed to streamline next-generation advanced non-light-water reactors.
Throughout 2025 and 2026, ARC has been methodically submitting core technical methodologies to the NRC for safety feedback. The Quality Assurance Program Plan (QAPP) is currently under active NRC review, alongside completed audits on fuel qualification, alternative shutdown systems, and core fluid dynamics. ARC is using a revised Regulatory Engagement Plan to guide monthly technical touchpoints with NRC project managers, establishing a baseline before finalising their application timeline.
