Arabelle™ steam turbines for nuclear power plants

Our steam turbine technology is used in 30% of power plants worldwide, and forms the basis for all our power conversion solutions  

A modular approach 

Our game-changing Arabelle™ steam turbines channel steam through HP (high pressure), IP (intermediate pressure) and LP (low pressure) sections. The independent architecture of our LP sections means that the vacuum forces onto the LP outer casings are not transmitted to the turbine concrete foundation and the turbine can be centred in a way that’s both precise and stable. 

Streamlined design, efficient output 

Arabelle steam turbines are compact and streamlined, based on a mature 1500 MW design. The outputs range from 900 MW to 1,800 MW. Thanks to the combined HP/IP module of an Arabelle steam turbine, 60% of the steam expansion occurs through highly efficient single flow.

Compatible with your plant 

Both frequencies (60 Hz and 50 Hz) have the same standard footprint, and the highly efficient last stage blade design comes in two sizes for each frequency. You can choose either 2, 3 or 4 LP modules for improved vacuum fit, and they can easily be adjusted thanks to the LP turbine’s independent structure.

Introducing the longest last stage blade of the market!

Alstom’s Arabelle™ steam turbines now come with an additional benefit: our advanced 75” long Last Stage Blade (LSB), the latest evolution in LSB technology. 

The longest of its type on the market, our 75” upgrade is a natural progression from the LSB 69. The LSB 69 is the longest last stage blade in successful operation. It has proved reliable over three years and thousands of operating hours at Oskarshman 3, Sweden, for its 50 Hz version and over seven years at Diablo Canyon, for its 60 Hz version (LSB 56).

Now Alstom has introduced the LSB 75, adding 6 inches to our proven last stage blade to cut exhaust losses by 20% and deliver a typical 10 MW of extra output. The LSB 75 increases the adaptability of the low-pressure modules allowing further backpressure optimisation, more accurate matching to site conditions and increased performance especially in cold climates.


Why Arabelle™ steam turbines? 

  • Easier maintenance thanks to a unique turbine architecture with fewer components
  • Stable setup with reduced loads on the concrete foundation
  • Compatible with all reactor types (PWR, BWR, PHWR, etc)
  • Fewer inspections needed thanks to welded rotors which have excellent resistance to stress corrosion cracking
Clean power: Arabelle