The nuclear Waterpik

摘要

What is unique about MHI's water jet peening system is that it can reach, and treat, areas inside the reactor vessel that are inaccessible to other mitigation methods, in particular bottom-mounted instrumentation nozzles (diameter: 10 mm) or the reactor vessel-main coolant pipe weld, underwater, with water. The system directs a jet of high-pressure water to vulnerable or cracked surfaces. Manufacturer Mitsubishi Heavy Industries would not specify the exact pressure, but did say that the jet was 'in the GPa' range, so at least 145,000 psi. Cavitation bubbles are generated at the boundary between the high-pressure water and the surrounding water. The shock pressure caused by the collapse of these bubbles presses against the steel surface underneath. This cold work process tends to compress the surface, which makes it more resistant to crack formation.