The single rod ultrasonic leak detection tool will be used to detect leaking fuel rods by evaluation if there is water inside the rod. The test will be performed by moving one fuel rod between two ultrasonic transducer oriented in a pitch/catch configuration. The detection tool uses ultrasonic transducers as the primary method to detect leaking fuel rods. Two probes are preferably positioned near the fuel rod in a pitch/catch or transmitting/receiving configuration. One probe 36 sends the signal into the rod and the other probe of a set of probes receives the signal. An evaluation of the received signal is performed in various embodiments, to determine leak tightness of the fuel rod. In various aspects, two sets of probes may be utilized so that measurements can be taken on both sides of the fuel rod.