Modularization of Small Modular Reactor Facilities: Physical Protection Recommendations

Technical Report · Mon Sep 01 04:00:00 EDT 2025

DOI:https://doi.org/10.2172/2588286· OSTI ID:2588286

Evans, Alan Scott ^[1]; Sweet, Steve ^[1]; Abell, Doug ^[1]; Stromberg, Ben ^[1]; McCullough, Matt ^[1]

---

1. Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)

U.S. nuclear power facilities face increasing challenges in meeting dynamic security requirements caused by evolving and expanding threats while keeping costs reasonable to make nuclear energy competitive. In consideration of the economic viability of small modular reactor (SMR) facilities, many designers and utilities are considering a modular approach to the construction and operation of these facilities. This modular approach considers building and operating a first unit; once the first reactor is in operation, construction will begin on a second reactor. This process would allow the vendor or utility to ensure production of energy and financial income while the second reactor is under construction. This project evaluates the feasibility of modular construction in terms of physical protection and identifies several recommendations for vendors and utilities considering this approach. To conduct this evaluation, a hypothetical three-unit SMR facility was developed, a physical protection system (PPS) was considered for the design, and a hypothetical design basis threat (DBT) was used to evaluate this PPS. Multiple outsider sabotage scenarios were examined, with adversary team sizes ranging from 4-to-8 to determine security system effectiveness. The results of this work will influence PPS designs and facility designs for U.S. domestic SMRs. This work will also demonstrate how a series of experimental and modeling capabilities across the Department of Energy (DOE) complex can impact the design and completion of security-by-design (SeBD) for SMRs considering modular construction. The conclusions and recommendations in this document may be applicable to all SMR designs.

• Research Organization: Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)
• Sponsoring Organization: USDOE Office of Nuclear Energy (NE), Reactor Fleet and Advanced Reactor Development. Nuclear Reactor Technologies
• DOE Contract Number: NA0003525
• OSTI ID: 2588286
• Report Number(s): SAND--2025-11085R; 1787967
• Country of Publication: United States
• Language: English

Related Subjects

22 GENERAL STUDIES OF NUCLEAR REACTORS
29 ENERGY PLANNING, POLICY, AND ECONOMY
61 RADIATION PROTECTION AND DOSIMETRY