The present disclosure relates to a decompression apparatus for superheated steam comprising: a temperature raising unit having an inlet connected to an exit side of a boiler for introducing steam discharged from the exit of the boiler, and an outlet for raising the temperature of steam introduced through the inlet and discharging it; a steam utilizing unit connected to the outlet and using the steam discharged from the outlet; and a decompression unit installed at one or all of a section between the exit side of the boiler and the inlet and a section between the outlet and the steam utilizing unit, the decompression unit controlling temperature of steam while decompressing pressure of steam. According to the decompression apparatus for superheated steam, it is possible to control the pressure and temperature of steam more precisely.

The present disclosure relates to a decompression apparatus for superheated steam comprising: a temperature raising unit having an inlet connected to an exit side of a boiler for introducing steam discharged from the exit of the boiler, and an outlet for raising the temperature of steam introduced through the inlet and discharging it; a steam utilizing unit connected to the outlet and using the steam discharged from the outlet; and a decompression unit installed at one or all of a section between the exit side of the boiler and the inlet and a section between the outlet and the steam utilizing unit, the decompression unit controlling temperature of steam while decompressing pressure of steam. According to the decompression apparatus for superheated steam, it is possible to control the pressure and temperature of steam more precisely.

A method for flexibly operating a nuclear power plant with a waste heat steam generator that operates according to the forced-flow principle and that has heating surfaces of different stages of the waste heat steam generator, the heating surfaces being arranged in the flue gas channel, is provided. In order to increase the output, a mass flow of the feedwater flowing through the heating surfaces is increased while almost simultaneously activating a supplementary firing arranged in the flue gas channel of the waste heat steam generator.