System for Imaging Leaks from the Primary Water Loop

72829-The primary water loop in a nuclear reactor includes numerous welds which can, over time, develop leaks. Existing methods for leak detection are slow, resulting in costly down-time. A system that could rapidly identify the location of leaks would improve the safety and economics of plant operation. This project will develop technology for illuminating the leaking area with a hand held camera. The camera will include a laser beam that detects the presence of water escaping from the leak. The image of the water will be superimposed on a video image of the weld, so that an operator can instantly identify the leak location. The system also will indicate areas of the weld that have been sufficiently illuminated but do not leak. Phase I determined the best wavelengths for detecting water vapor and heavy water vapor, demonstrated a simple signal recovery method, and showed the proposed approach is accurate and sensitive. In Phase II, a prototype camera will be designed, built, and tested, both in the laboratory and at a research reactor. The effects of radiation on key components will be studied, and the best method for continuous monitoring inside the containment area will be identified. Commercial Applications and Other Benefits as described by awardee: The system should benefit the civilian nuclear power industry and U.S. Navy nuclear powered submarines. By suitably adjusting the laser wavelength, additional products could be developed for monitoring natural gas lines and detecting toxic gas leaks at oil refineries.