The answer, up front
The nuclear sector has little dedicated post-quantum guidance, and the current reporting is thin and mixed: one preprint models attacks on nuclear plants, one demonstration tests quantum key distribution rather than post-quantum algorithms, and one think-tank piece focuses more on defense and diplomatic systems than civil reactors. The honest read is that researchers are mapping the risk and running early field work, while a sector-wide post-quantum migration plan is not yet visible.
Modeled attack paths
A February 2026 arXiv preprint analyzes quantum attacks on nuclear power plants and reports estimated attack success of 8 to 78 percent under current security postures, falling below 1 percent when full post-quantum migration is combined with a high operational-technology security level 1. These are the authors' modeled estimates in a preprint that is not peer reviewed, so treat the percentages as illustrative of the direction rather than as measured results. The useful point is relative: strong post-quantum migration plus layered OT security sharply reduces the modeled feasibility.
Field work tests a different technology
Field demonstrations so far use quantum key distribution, a physics-based approach distinct from post-quantum algorithms. Purdue University, Oak Ridge National Laboratory and Toshiba announced in June 2025 a demonstration of quantum-secured communications at Purdue's research reactor, described as the first US nuclear reactor to integrate such communications, aimed at data exchange for monitoring, control and safety in advanced reactors, especially remote microreactors 2. Because this is quantum key distribution, it addresses a different part of the problem from the algorithm migration that NIST standards describe, and the two should not be conflated.
The policy view
India offers a regional policy perspective. An Observer Research Foundation piece in April 2025 argued that quantum computers could break the public-key encryption protecting nuclear-related systems, described store-now-decrypt-later collection, and recommended transition to post-quantum standards, dual-layer security and indigenous quantum-resistant infrastructure 3. Parts of that argument concern weapons command systems and apply only loosely to civil reactors, materials and waste, so read it as adjacent rather than directly on point.
What this means for nuclear operators
With guidance thin, the defensible path is the general one applied carefully to safety-critical systems: inventory where public-key cryptography protects monitoring, control and safety communications, treat quantum key distribution demonstrations as complementary research rather than the migration itself, and plan post-quantum work into the long qualification cycles these facilities already run.
How ArcQubit approaches it
ArcQubit treats discovery as the first move where sector guidance is thin and safety margins are tight. QuCode maps where vulnerable cryptography sits across reactor monitoring and control systems, and QuTrust holds the migration plan so changes proceed through the sector's qualification processes in a defensible order.