Digital twin-based fault diagnosis technology and application for key equipment in special nuclear isotope production

Special nuclide production lines operate under extreme conditions—including high nuclear criticality risks, intense ionizing radiation, and highly toxic atmospheres—making latent equipment faults difficult to detect, occurred faults hard to resolve, and repair costs prohibitively high. This paper proposes a novel “sensorless-external” status monitoring technology for hot cell equipment. Using key devices such as the master-slave manipulator in special nuclide hot cell production lines as examples, the study demonstrates the integration of digital twin technology with fault diagnosis techniques. A digital twin-based fault prediction and diagnosis system was developed for critical equipment in special nuclide production. The system enables visualized analysis of complex mechanism motion in hot cell devices, and supports coordinated function-performance simulation, and achieves proactive fault tracking. It substantially shortens fault localization and repair times in intense radiation and highly toxic environments, lowers the operational and maintenance difficulty of continuous-trajectory-controlled equipment. The work provides valuable reference for intelligent digital assurance strategies in the operation of international special nuclide production lines.