Improving Global Quality of Life

9.1.3 Hot topics
Reducing negative impact on the environment e.g. by introducing gas conditioning plants.
Efficient utilisation of refurbished existing assets and life extension of existing plant including
appropriate welding repair specifications, technologies and inspection.
Building new plant with increased efficiency e.g. supercritical or ultra supercritical steam generating
plant.
Changing to cleaner burning fuels, with accompanying asset modification.
Refurbishment rather than replacement of worn components.
Recycling of discarded materials and consumables.
Utilisation of procedures and techniques which put a lower burden on the environment e.g. uptake
of solid state welding processes for fabrication of power plant components.
Improved plant condition monitoring e.g. creep testing.
Retention of skills, and development of personnel to support technologies and welding management.
9.1.4 Power – Nuclear
The challenges in the development of robust welding technology for nuclear reactor materials hold the
key for sustainable development of economic, safe and environmentally friendly nuclear energy. The
development of new as well as improved variants of nuclear reactor materials needs adaptation of the latest
advances in welding technology to ensure cost-competitiveness of nuclear power. The present maturity in
understanding of the science of welding has to be utilised for developing suitable welding consumables for
the advanced/ improved materials as also for evolving appropriate repair welding technologies for existing
nuclear power plants. The innovative welding technologies, like activated TIG welding, friction stir welding,
hybrid welding, have to be harnessed to enable their industrial application for fabrication of nuclear reactor
components. Tools like artificial neural networks would find increasing application in ensuring high quality
welds. Computational, experimental and theoretical are the three pillars to meet the demands of desired
performance and regulatory requirements. On the long-term, development of fusion technology will be
crucially dependent on the development of appropriate welding technologies for materials like low/reduced
activation ferritic-martensitic steels and oxide dispersion strengthened alloys.
Multi-disciplinary intelligent welding approaches are being increasingly adopted for realising high
performance welding technology through synergistic use of sensors, evaluation, modelling and automation.
An intelligent welding system, equipped with sensors, artificial intelligence and actuators to sense and
control welding operations in real time would reduce the occurrence of defects in welds and would also
guide the welder to eliminate errors while providing the adaptability needed to accommodate the variability
found in the welding process. Online monitoring of welding processes is feasible through synergistic use
of sensors and modelling for evaluation of narrow gap welds and resistance welds in high performance
components. The application of artificial intelligence methods in the field of welding is exemplified through
the development of quantitative models using artificial neural networks for predicting ferrite content,
solidification mode and weld-bead geometry in austenitic stainless steel welds. The models for ferrite
content and solidification mode can be effectively used for designing the welding consumables having
chemical compositions that minimise hot-cracking susceptibility in austenitic stainless steel welds, while
the models for weld-bead geometry can be used for optimising welding process parameters for obtaining
high quality welds. Research efforts are continuing worldwide for increasingly applying artificial intelligence
methods in automated welding.
Nuclear power is expected to play a key role in the global energy scenario in the coming years, especially in
the context of the rapid depletion of fossil fuel resources and increasing concerns about climatic changes
90 Improving Global Quality of Life Through Optimum Use and Innovation of Welding and Joining Technologies