IIW White Paper

9 Needs and challenges of major industry sectors for future applications

engineering disciplines due to the need for high priced welding and testing equipment and laboratories that must keep up with industry.

Machine GTAW and Semi-Automatic GMAWwill become important in the coming years and this will require specially trained Welding Technicians to keep the equipment working properly and dialed in for optimal performance. These positions require training found in 2 year associate degree programmes. Certified Senior Welding Inspectors and Non Destructive Testing (NDT) technicians are needed to assure the necessary examinations are performed to provide evidence that welds meet the requisite high quality standards. New phased array ultrasonic techniques and radiography using digital media will be employed. Presently individuals competent in these techniques are as difficult to locate and train as welders. Typically their training is commensurate with an associate degree in engineering technology. The experience levels needed to work independently are of the order of several years. A programmatic method for recording welding data will depend heavily on software designed for the task. The information gathered will provide the utility operators cradle-to-grave traceability. Such data is a great asset for plant engineering staff when they find deficiencies or degradation in the plant equipment once it is placed in operation. The engineering and quality control staff will assure this is accomplished and made available for owner and regulatory review. Generally speaking, GTAWcan be applied for the austenitic stainless steel andNi base alloys against corrosion, heat and extremely low temperature. Since the reactors have the large scale structure, it is necessary to make progress on the welding process with the higher efficiency, the lower heat distortion and the higher quality. This will mean adopting much higher efficiency welding with high deposition rates, such as narrow gap Welding, hot-wire TIG welding, multi-electrode welding and laser-arc hybrid welding at the factory and the local nuclear reactor site. In the case of an International Thermonuclear Energy Reactor (ITER) with large structure and large wall thickness, high power laser and laser arc hybrid welding can be applied for high accuracy and high velocity. Figure 9.9 shows the trend of welding processes for the application to the nuclear equipment.

High Quality High Efficiency

Laser-Arc Hybrid

Super Narrow Gap

Figure 9.9 Trends of welding processes for nuclear power plant (Reproduced courtesy: Satoru Asai)

High Power Laser

Multi-Electrode

Advance MIG

Hot Wire Narrow Gap GTAW

GTAW

Future

Finally, as there are many light-water reactors operating for over 60 years, there will be the need to start the decommissioning of the used reactors. The cutting and recycling technologies of the metal, such as RPV and Core Shroud is utilised for the decrease of the waste volume. Moreover, the waste processing system of used fuel rods, are in operation, and so the components are added to the systems and repaired by remote maintenance technologies of laser welding.

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Through Optimum Use and Innovation of Welding and Joining Technologies

Improving Global Quality of Life