Why SMR Cybersecurity Should Start Before the First Reactor Goes Online

AI data centers, net-zero commitments and industrial electrification are creating a new power problem. Demand is rising faster than many organizations can plan for, and interest in the small modular reactor market is growing as organizations look for future sources of reliable power.

According to the International Energy Agency¹, the pipeline of conditional agreements for data center operators to buy future power from small modular reactor (SMR) nuclear projects grew from 25 gigawatts (GW) at the end of 2024 to 45 GW, a scale roughly equivalent to dozens of large power plants.

For the security community, this raises a practical question: Will cybersecurity be built into SMR plans early enough to protect the business case?

The answer depends on decisions being made now. Architecture sets the foundation. Supplier requirements shape long-term risk. Access rules determine who can reach sensitive systems. Monitoring defines what security teams can see once a facility is operating.

SMRs are not just smaller nuclear plants. They can rely on highly digital systems, lean operating teams and new ownership models. That makes cybersecurity a front-end planning issue, not a post-deployment fix.

Why SMR Cybersecurity is Different

Traditional nuclear facilities often have large on-site teams. They may have dedicated security operations resources, full compliance teams and deep internal nuclear expertise.

The SMR business model relies on smaller sites, leaner teams and lower operating costs. If every site copies the staffing model of a large nuclear plant, the economics can quickly become difficult. Centralized or managed security may be part of what makes the SMR model work.

Organizations planning for SMR deployment need to know: who owns cyber risk if a third party runs daily operations? Who sets security requirements? Who monitors the environment? Who is responsible when an incident involves a supplier, operator or remote support pathway?

The answers matter because asset owners may still hold financial and regulatory risk, even when others manage daily operations.

Why Cybersecurity Must Be Built Into SMR Design

SMR cybersecurity should begin during front-end planning and engineering, before key decisions become difficult to change.

That planning includes network architecture, how suppliers connect to systems, how patches are tested, how remote support is controlled and how monitoring data reaches security teams. Physical security should also be planned alongside cybersecurity, not treated as a separate track.

Early planning should define the cybersecurity scope for front-end engineering design and set requirements for segmentation, continuous monitoring, endpoint visibility and secure access.

Regulatory readiness also needs early attention. In the U.S., traditional nuclear cybersecurity programs reference Title 10 of the Code of Federal Regulations, Section 73.54, and Nuclear Energy Institute guidance such as NEI 08-09. Newer SMR approaches are moving toward more performance-based frameworks, including 10 CFR Part 53 and Draft Regulatory Guide 5075.

For now, SMR security expectations are still evolving. Asset owners need a cybersecurity program that can be documented, tested and adapted as requirements mature.

Secure Supply Chain Practices Reduce SMR Risk

SMR supply chain security requires more than choosing trusted suppliers. Operators need to understand how systems will be built, updated and supported. These environments may depend on software, firmware, control systems, cybersecurity tools and long-term vendor support.

That means supplier assurance has to continue after procurement. Operators should expect detailed software bills of materials. They should require clear patch and update processes. They should also look for vendor transparency around vulnerabilities and incidents.

Factory Acceptance Testing can help validate systems before they arrive on site. Clear access rules can also reduce risk when vendors need to support or maintain equipment. SMR operators need confidence in how systems will be changed, tested and maintained over time.

Remote Monitoring and Access Boundaries

Remote support and centralized monitoring may become part of future SMR operating models, but access cannot be routine. Operators need to decide what can be monitored remotely and what requires strict on-site control.

Security teams also need a way to detect abnormal activity, such as unexpected changes to system behavior. This requires a specialized OT SOC that understands the plant well enough to know the difference between a true cyber incident and a routine maintenance cycle or equipment failure.

Vendor access should be approved, logged and reviewed and removable media should be tightly managed through secure, zero trust gatekeepers to detect walk-in threats from contractors before they enter the environment.

The security benefit of a fully air-gapped environment may not be enough when asset owners need visibility across multiple SMR sites. This reality demands a deterministic approach to data transfer, extracting continuous operational telemetry for visibility without creating a bi-directional pathway that exposes the network.

Hardware-based controls, such as embedded data diodes, can help by allowing data to move in one direction. Security teams gain the visibility they need, while critical systems remain tightly protected.

SMR Operators Need Scalable Security Support

Many future SMR operators may not have deep nuclear cybersecurity expertise in-house. Some may be entering the nuclear power sector for the first time.

A scalable support model can help. This may include virtual CISO guidance, centralized OT security operations center services, and managed or co-managed cybersecurity support.

A virtual CISO (vCISO) can be especially important for asset owners. Even when a third party operates the plant, the asset owner may still carry the risk. A vCISO can help define governance and track security performance across multiple SMR sites.

This model can also support day-to-day needs such as monitoring, patching, antivirus, secure remote access, incident response and vulnerability management.

Managed support does not replace operator accountability. Site knowledge, policies and procedures still matter. However, managed support services can help close gaps in expertise, governance and monitoring before they can become operational problems.

How Honeywell Helps Organizations Prepare

Honeywell supports organizations evaluating SMR deployment with OT cybersecurity expertise, network security monitoring, managed OT security services, patch management, antivirus support, and secure remote access.

Organizations evaluating or building SMRs to meet power demands should reach out to Honeywell to assess their OT cybersecurity readiness.

¹ International Energy Agency. “Data centre electricity use surged in 2025, even with tightening bottlenecks driving a scramble for solutions.” Press release, April 16, 2026.