Excellent contribuition dear friend! May I suggest a description? Main Steam System Power Plant The function of the main steam supply system is to supply steam from the steam generators to the turbine elements over a range of flows and pressures covering the entire operating range from system warmup to maximum calculated turbine conditions. The system also provides steam to the moisture separator/reheaters and the gland seal system for the main turbine. The system dissipates heat generated by the nuclear steam supply system (NSSS) by means of steam dump valves to the condenser when the turbine-generator is unavailable, or to the atmosphere through power-operated atmospheric relief valves or spring-loaded main steam safety valves when neither the turbine-generator nor the condenser is available. The main steam supply system includes the following major components: • Main steam piping from the steam generator outlet steam nozzles to the main turbine stop valves, • One main steam isolation valve and one main steam isolation valve bypass valve per main steam line, • Main steam safety valves, and • Power-operated atmospheric relief valves and associated upstream isolation valves.