Security Requirements Should Fit the Reactor, Not the Existing Fleet

As part of its broader effort to modernize the nuclear regulatory framework, the Nuclear Regulatory Commission (NRC) is revisiting how security requirements apply across existing and advanced reactors. The proposed Modernizing Security Requirements rule addresses one part of that larger effort by revising fitness-for-duty programs, physical security requirements, security requirements for independent spent fuel storage installations, and requirements for protecting classified information. The proposed rule would move significant portions of the security framework away from fixed, prescriptive requirements and toward standards based on a facility’s consequences, design features, and demonstrated performance.

The Breakthrough Institute supports that direction. Many existing security requirements were built around the operating characteristics and staffing models of large light-water reactors. As new designs rely more on passive safety features, automation, engineered delay (design features that buy time for responders), and smaller crews, the question should be whether a facility provides adequate protection, not whether it reproduces the security arrangements of the existing fleet. For the same reason, BTI supports replacing the fixed minimum of ten armed responders with a facility-specific approach that allows onsite, offsite, or combined response. What matters is whether the overall protective strategy can reliably provide adequate protection, not where the responders are located. Where a licensee counts on offsite responders to meet its security objective, rather than as backup from local law enforcement, that reliance should rest on a documented, site-specific basis.

One problem is that the rule’s security determinations depend on assumptions that can change. A facility could show that its design leaves an attacker no way to cause unacceptable radiological consequences, which can reduce or remove the security requirements that apply. That conclusion rests on the design-basis threat (the adversary a security program must be able to defeat), which the NRC is reviewing in a separate proceeding. BTI recommends that the final rule or guidance require licensees to reevaluate a determination when a material change affects its basis, such as a revised threat or a plant modification. The final rule should also specify what a determination must document, such as its adversary assumptions, credited mitigation, and timing, and define which protective measures count as passive and which as active, since that distinction decides which requirements apply.

The proposed rule is a substantial improvement over a framework built around prescriptive assumptions for conventional reactors, and the final rule should make its new flexibilities clear and durable. To make the transition work, the final rule should keep existing approved security programs in place until licensees choose to adopt the new flexibilities. The NRC should also reconcile provisions this rule shares with other ongoing rulemakings, so that one final rule does not overwrite another.