A steam turbine and a use of the steam turbine, a method of manufacturing or servicing of said steam turbine, a small-modular reactor and a power plant including said steam turbine

A steam turbine including at least one steam turbine section, wherein said at least one steam turbine section comprises at least three blade stages, wherein said blade stages include a row of fixed blades and an accompanying row of moving blades that is downstream of the row of fixed blades, and wherein said blade stages include:

• a single nucleating blade stage,
• at least one downstream blade stage, and
• at least one upstream blade stage,
• wherein said at least one downstream blade stage is located downstream of said nucleating blade stage and said at least one upstream blade stage is located upstream of said nucleating blade stage, and wherein said nucleating blade stage includes the location of the Wilson point,
• wherein
• the stage loading of said at least one upstream blade stage is from 0.5 to 2.0, the stage loading of the nucleating blade stage is from 1.4 to 2.2, and the stage loading of said at least one downstream blade stage is from 0.5 to 1.4, wherein the stage loading of said at least one downstream blade stage is lower than the stage loading of the nucleating blade stage and the stage loading of said at least one upstream blade stage is lower than the stage loading of the nucleating blade stage, but is higher than the stage loading of said at least one downstream blade stage, and the stage reaction for the nucleating blade stage is from 40% to 55% and the stage reaction of said at least one downstream blade stage is higher than for the nucleating blade stage and is from 40% to 60%.

A method of manufacturing or servicing of a steam turbine, wherein the steam turbine includes at least one steam turbine section, wherein said at least one steam turbine section comprises at least three blade stages, wherein said blade stages include a row of fixed blades and an accompanying row of moving blades that is downstream of the row of fixed blades, and wherein the method includes providing a single nucleating blade stage to the steam turbine at the location of the Wilson point, at least one downstream blade stage downstream of said nucleating blade stage and at least one upstream blade stage upstream of said nucleating blade stage, wherein the nucleating blade stage has a value of expansion rate higher than the value of expansion rates of the other blade stages within the steam turbine,

• wherein
• the stage loading of said at least one upstream blade stage is from 0.5 to 2.0, the stage loading of the nucleating blade stage is from 1.4 to 2.2, and the stage loading of said at least one downstream blade stage is from 0.5 to 1.4, wherein the stage loading of said at least one downstream blade stage is lower than the stage loading of the nucleating blade stage and the stage loading of said at least one upstream blade stage is lower than the stage loading of the nucleating blade stage, but is higher than the stage loading of said at least one downstream blade stage, and
• the stage reaction for the nucleating blade stage is from 40% to 55% and the stage reaction of said at least one downstream blade stage is higher than for the nucleating blade stage and is from 40% to 60%.