A turbine arrangement comprising: - a rotor that rotates about a rotor axis (x) and comprises a plurality of rotor blade segments extending radially outward, each rotor blade segment comprises an aerofoil and a radially inner blade platform; - a stator surrounding the rotor so as to form an annular flow path for a pressurised working fluid, the stator comprises a plurality of guide vane segments disposed adjacent the plurality of rotor blades, the plurality of guide vane segments extending radially inward, each guide vane segment comprising an aerofoil and a radially inner vane platform, the stator further comprising a cylindrical stator wall (89, 87) coaxially aligned to the rotor axis (x) and an annular stator wall arranged on a mid section of an outer surface of the cylindrical stator wall (89, 87); - a seal arrangement comprising a trailing edge of the inner blade platform, a leading edge of the inner vane platform and a first annular cavity and a second annular cavity, wherein - the first annular cavity is defined at least by the leading edge of the inner vane platform, a first part of the cylindrical stator wall (89, 87) and the annular stator wall, - the second annular cavity is defined at least by the trailing edge of the inner blade platform, a second part of the cylindrical stator wall (89, 87) and the annular stator wall, - the first annular cavity is in fluid communication with the annular flow path via a first annular seal passage, - the first annular cavity is separated from the second annular cavity via the annular stator wall, - the first annular cavity is in fluid communication with the second annular cavity via a second annular seal passage between a rim of the annular stator wall and the trailing edge of the inner blade platform, - the second annular cavity is in fluid communication with a hollow space for providing sealing fluid via a third annular seal passage. - a rotor that rotates about a rotor axis (x) and comprises a plurality of rotor blade segments extending radially outward, each rotor blade segment comprises an aerofoil and a radially inner blade platform; - a stator surrounding the rotor so as to form an annular flow path for a pressurised working fluid, the stator comprises a plurality of guide vane segments disposed adjacent the plurality of rotor blades, the plurality of guide vane segments extending radially inward, each guide vane segment comprising an aerofoil and a radially inner vane platform, the stator further comprising a cylindrical stator wall (89, 87) coaxially aligned to the rotor axis (x) and an annular stator wall arranged on a mid section of an outer surface of the cylindrical stator wall (89, 87); - a seal arrangement comprising a trailing edge of the inner blade platform, a leading edge of the inner vane platform and a first annular cavity and a second annular cavity, - the first annular cavity is defined at least by the leading edge of the inner vane platform, a first part of the cylindrical stator wall (89, 87) and the annular stator wall, - the second annular cavity is defined at least by the trailing edge of the inner blade platform, a second part of the cylindrical stator wall (89, 87) and the annular stator wall, - the first annular cavity is in fluid communication with the annular flow path via a first annular seal passage, - the first annular cavity is separated from the second annular cavity via the annular stator wall, - the first annular cavity is in fluid communication with the second annular cavity via a second annular seal passage between a rim of the annular stator wall and the trailing edge of the inner blade platform, - the second annular cavity is in fluid communication with a hollow space for providing sealing fluid via a third annular seal passage.