Nuclear Welding: Meeting and Exceeding Critical Industry Standards


In the mid-twentieth century, the world began to advance nuclear technologies for many applications. The first commercial nuclear power plant, commissioned in 1958 in Shippingport, Pennsylvania, initiated the production of nuclear energy for electricity. Today, there are 440 nuclear power reactors throughout the world that fulfill almost 10 percent of the global electricity demand. With nearly 50 new reactors under construction and 220 reactors under research worldwide, the demand for nuclear power continues to rise.

However, harnessing nuclear energy for power generation or defense applications is a challenging task that requires ongoing quality assurance and a fastidious adherence to quality and safety standards. Orbital welding solutions at AMI help manufacturers meet and exceed the strict requirements of the nuclear welding industry. 

Nuclear Industry Welding

Industries harness nuclear energy from the intense heat released during the nuclear fission of certain elements such as uranium. In power generation, this heat energy is used to generate steam that drives the turbine. The process, though, creates extreme pressure and temperature conditions in the reactor and can compromise the physical and chemical properties of welded components.

Welded components at risk of degradation:

  • Vessels
  • Pressurizers
  • Pumps, valves, and nozzles
  • Nuclear piping systems
  • Steam generators

In addition to power generation processes, nuclear fuel storage and waste storage applications also rely on high-quality welds to enhance safety and reduce risks.

Challenges in Nuclear Welding

The extensive welding of pipes, tubes, and vessels in the nuclear industry introduces unique challenges. From material selection to potential weld defect analysis, nuclear welding must meet quality standards through each step of the process.

Proper Material Selection

Given the extreme conditions in nuclear power plants, proper material selection is critical to prevent degradation. Nickel alloys (Inconel®), stainless steel, and copper alloys are generally preferred for their sound mechanical properties, weldability, and corrosion resistance.

Nuclear Plant Component Materials

Nickel alloys Tubes for steam generator and welds in reactor cooling systems
Stainless steel Pipes and welds in the reactor cooling system, heat exchangers, and condenser tubes.
Copper alloys Condenser tubes and heat exchangers
Titanium Condenser tubes in offshore nuclear plants
Zirconium alloys Cladding in fuel rods

Corrosion Prevention

Corrosion threatens the lifespan of nuclear plants and can cause billions of dollars in damages. Materials—especially near the welded joints—are susceptible to corrosion and cracking due to the extreme conditions at the nuclear reactor. The table below discusses the types of corrosion likely to occur in nuclear welding and their potential causes.

Types of Corrosion in Nuclear Welding

Stress-corrosion cracking Mechanical stress in stainless steel due to heating and cooling of weld seams
Pitting corrosion Altercation of chromium content in stainless steel during welding
Microbiologically-induced corrosion Oxidation and break-down of the corrosion-resistance layer of metal during welding

In the nuclear industry, even microscopic defects possess a high level of risk. And while material selection is imperative to maintain vessels, pressurizers, and storage tanks, choosing the right welding technique is just as important.

Adherence to Critical Nuclear Welding Standards

Safety is the top priority in the nuclear industry, and the industry is required to adhere to a strict set of rules and standards for safe operation and quality assurance during the construction and operation of nuclear handling sites. The American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code (BPVC) Section III details the quality requirement for components in nuclear power plants. Other quality-assurance bodies include ISO 3834 which provides welding best practice details for metals and ensures quality adherence for national and international use.

Automated welding processes such as orbital welding have allowed the nuclear industry to overcome these safety challenges while improving weld quality and reducing costs.

Orbital Welding Solutions in the Nuclear Industry

During nuclear welding, the fusion application must perform perfectly without compromising weld quality. Since manual welding introduces the risk of human error, an automated process like orbital welding is recommended. Orbital welding provides high-specification welds that the nuclear industry demands by relying on a mechanized system to rotate an arc 360 degrees around a stationary workpiece. As such, orbital gas tungsten arc welding (GTAW) is suitable for the welding of tubes, pipes, vessels, and other components used in the nuclear power plant.

Since orbital welding accommodates a wide range of materials—such as stainless steel, Inconel®, and titanium—it is well-suited for nuclear welding. With pre-programmable, automated weld heads and remote weld controls that allow operators to remotely monitor the weld parameters, the orbital welding process can keep welders safe from harmful radiation while ensuring consistent, high-quality welds. Additionally, narrow gap orbital welding allows penetration in thicker walls with a controlled heat input that reduces stress-induced corrosion cracking.

Nuclear Welding Solutions from AMI

Since 1976, AMI has provided a wide range of automated welding options. For nuclear welding applications, AMI offers orbital welding solutions for pipe welding, narrow groove welding, tube-to-tube sheet welding, and cladding.

Our advanced orbital welding equipment will help you meet the quality and safety standards for critical nuclear welding applications.

AMI’s orbital welding solution for nuclear application


Arc Machines, Inc. is an industry leader in producing high-quality and high-tech welding equipment. This includes advanced orbital welding machines and weld heads that facilitate your nuclear welding solutions. For inquiries regarding products, contact For service inquiries, contact Arc Machines welcomes the opportunity to discuss your specific needs. Contact us to arrange a meeting.