Nuclear steam generator tubing

Tube, pipe, fittings and flanges

Are you retrofitting an older boiling water or pressurized water nuclear reactor (BWR or PWR)? Or maybe designing a new plant fitted with several pressurized water reactors (PWRs)? Either way, we offer steam generators tubing (SGT) of such high quality it has an Eddy Current signal-to-noise ratio of 15:1 or better.

Nuclear steam generator tubing

Since 1964, we’ve collaborated with leading utilities and other organizations to drive a safe and reliable road to clean energy production for all of society. As an independent partner, we can effectively navigate geopolitical challenges and nationalistic barriers, allowing us to solve problems quickly for a wide range of reactor types. To date, we have successfully delivered tube bundles to more than 400 steam generators in over 20 countries.

More than 400 tube bundles (approx. 2,600,000 tubes) supplied to nuclear steam generators in 20 countries.

Integrated, precision manufacturing

To meet your high requirements, we operate one of the world’s largest and most advanced dedicated nuclear tube lines in Sandviken, Sweden. The mill is roughly 340 meters long, and covers 12,000 square meters, or the equivalent of two soccer pitches. Our focus is on premium seamless stainless steel and high nickel alloy steam generator tubing for the world’s toughest industry requirements.

Signal-to-noise ratio of 15:1 or better

The tubes produced at our mill in in Sandviken fulfill the most stringent Eddy Current multifrequency demands and have a signal-to-noise ratio of 15:1 or better. This ensures the absence of any surface or sub-surface flaws and guards against corrosion, deposits or the risk of nickel release.

Key material challenges of SGT

  • Stress corrosion cracking (SCC) in high-temperature corrosive environments.
  • Corrosion and deposits on the tube, affecting heat transfer and leading to localized corrosion
  • Nickel release of ions in the reactor coolant impacting water chemistry controls

Alloy 690 and Alloy 800

Thanks to our fully integrated manufacturing setup, we can maintain very tight quality control – from melt to final tube. Production is focused on steam generator tubing in outer diameters of 10 – 25.4 mm (0.3937 – 1.000"). The main materials are Alloy 690 (Sanicro® 69, UNS: N06690) and Alloy 800 (Sanicro® 30, UNS: N08800), all produced in accordance with ASME and RCC-M standards.

Quality and Sustainable manufacturing

From melt to individual tube, our fully integrated controlled manufacturing process guarantees the highest quality. Beyond meeting all relevant quality standards in nuclear, we are committed to sustainable manufacturing practices. For example, our production in Sweden utlizes 100% fossil-free electricity in, and 83% of our steel is made from recycled materials, embracing a circular approach.

Size range and alloys

The Alleima portfolio includes steam generator tubes in two alloys in size range OD 10-25.4 mm (0.394-1 in.):

Grade UNS RCCM
Sanicro® 69 N06690 (Alloy 690) NC 30FE
Sanicro® 30 N08800 (Alloy 800) -

Sanicro® 69

Sanicro® 69 (Alloy 690) is primarily used in nuclear power plants of the pressurized water reactor (PWR) type. For this application Sanicro 69 is used in the 'thermally treated' condition, and is characterized by:

  • Extremely high resistance to stress corrosion cracking in PWR primary side water conditions
  • Good corrosion resistance in caustic environments
  • Good structural stability
  • Good weldability

Product standards

  • Seamless condenser tubes and heat exchanger tubes: ASTM B 163

Approvals

  • ASME Boiler and Pressure Vessel section II ASME SB 163, AFCEN RCCM M4105

Get an overview of our nuclear solution here

From melt to final tube

Our quality control process starts from the melt stage with a material content analysis and continues through each stage of production, including extrusion, pilgering, and inspection, testing and marking – and all documentation.

Featured articles

Press release (non-regulatory) 22 December, 2023

Alleima receives a major order for steam generator tubes in the Nuclear segment

Alleima has received a major order for steam generator tubes, to a total value of approximately SEK 220 million. The receipt of this order is a clear proof of Alleima’s strong position in the Nuclear segment.

Feature story 19 June, 2023

The next big thing in nuclear

Small-scale nuclear reactors are starting to be developed around the world. Designed to introduce more flexibility in the nuclear energy industry, they are set to open up new opportunities.

Feature story 30 April, 2023

How nuclear became a fuel for the future – again

As the world seeks to solve an increasingly complex energy puzzle, nuclear has once again made its way to the top of the political agenda.

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