TMSR500 is a natural load follower. An increase in load automatically increases the reactor output by decreasing the reactor temperature.
TMSR500 steam cycle is a standard, first-generation, single reheat, super-critical steam cycle, essentially the same steam cycle used in coal-fired power plants today, except that the boiler is replaced by a pollution-free steam generator and reheater. Both have an outlet temperature of 550°C. The outlet pressure of the steam generator is 25.65 MPa.
TMSR500 is a natural load follower. An increase in load automatically increases the reactor output by decreasing the reactor temperature. The reactor flow control system merely speeds this process up. HP and IP attemporators will fine-tune the temperature during rapid load changes and start-up.
TMSR500 does not depend on an outside source of electric power. TMSR500 can be the anchor providing stable, reliable electric power to a developing grid. TMSR500 has a black start capability. They are equipped with a 50 MWt oil-fired auxiliary boiler and a 15 MWe Sentry Turbo-generator. The auxiliary boiler provides steam to heat up and roll the main turbine during a cold start. This boiler also provides steam for the Sentry Turbo-generator, which in turn uses its power to heat up the first power module to be brought online. The boiler allows us to use a turbine-driven main feed pump, which increases cycle efficiency and greatly reduces the need for diesel generator power during start-up. It can also keep the plant warm during an extended shutdown, allowing a quick restart.
The Sentry Turbo-generator helps keep the plant ready to run in a power down. It normally operates in parallel with the main Turbo-generator, taking steam from the cold reheat line. In a power down, decay heat from one 250 MWe module makes steam to feed the Sentry Turbo-generator until the auxiliary boiler fires up to make steam indefinitely. This maintains circulation in the four loops, allowing a warm restart, avoiding a drain and longer restart time.
The TMSR500 steam cycle uses three low-pressure (LP) feed heaters, a deaerator, and four high-pressure (HP) feed heaters. The feed heaters are all arranged horizontally which simplifies level control. The three LP feed heaters are located port side of the generator. The feedwater is piped to LP1 and then works its way up to LP3. The deaerator is located on the main deck above the LP feed heater stack. From the hot side of LP3, the feedwater is piped to the top of the deaerator spray chamber whence almost all the non-condensibles are vented. The deaerator feedwater tank serves as a reserve and buffers to handle changes in feedwater volume in the rest of the loop. From the deaerator tank, the feedwater flows down the outboard of the LP feed heaters to the main feedwater pumps which are located on the inner bottom below the LP feed heaters. The HP feed heaters are located on the port side of the HP/IP turbine. The feed heater tube bundles are extracted into the space between the two stacks. Hatches are provided above this space, served by the turbine hall crane.