Steam separators and steam dryer services

A steam separator/dryer is part of the reactor vessel. It is an inverted V-shaped structure (aka a chevron) through which water-saturated (“wet”) steam created in the reactor vessel passes. Water droplets collect in the chevron structure and ultimately return to the reactor vessel via a downcomer pipe, where they combine with the feedwater flow.

The separated “dry” steam enters the main steam line which directs it to the power plant’s main turbine. This action causes the turbine to rotate which, in turn, activates the electrical generator, producing electricity.

Analyzed using a highly predictive plant-based load evaluation (PBLE) methodology, GEH’s replacement steam dryer design exceeds ASME’s reduced maximum alternating stress ratio (MASR). This helps ensure that dryer components have the safety margin necessary for operating conditions up to extended power uprate (EPU).

The US Nuclear Regulatory Commission (NRC) has accepted GEH’s PBLE methodology which, to date, has predicted a minimum 2.0 MASR—well below the ASME limit—for each steam dryer component at EPU conditions. GEH steam dryers are currently operating at 10 US plants at EPU power levels.