A method for monitoring components in a nuclear reactor is provided along with related systems and component. In one embodiment, a system is provided that includes a first transducer mechanism disposed within a nuclear reactor, the first transducer being configured to emit a first wireless signal to an identified component of the nuclear reactor. A second transducer mechanism is configured to detect a response signal that is emitted by the identified component in response to the first wireless signal. In one particular embodiment, the first transducer mechanism may include one or more confocal transducers. The confocal transducer may include two or more electrodes configured to emit their respective beams coaxially with focal points that are coincidental. The system may be configured to determine a characteristic of a component being monitored. In one particular embodiment, the component may include a fuel rod.
 This invention was made with government support under Contract Number DE-AC07-05ID14517 awarded by the United States Department of Energy. The government has certain rights in the invention.