This part of the manual applies solely to Unit #2.
An additional Control Room was added specifically for the turbine operations of Unit #2. Please refer to checklists in both the Control Room and the Turbine Control Room for startup procedures. This guide only summarizes the features. There is also interactive turbine startup guide available (right part of the screen under gear icon).
Steam sealing control should be used whenever the turbine is rotating, but it requires condenser vacuum and available steam. Sealing pressure should be maintained at 0.25 bar using supply and leak-off valves. Going beyond these limits will reduce the efficiency of the turbine and may cause steam to leak into the turbine hall.
Oil pumps are provided to supply pressure for both lube and hydraulic oils. Below 1800 RPM, auxiliary pumps should be used; above this threshold, they should be switched off as the shaft pump takes over. In situations where power is lacking, emergency pumps are provided for use below 1800 RPM. Pressures should then self-maintain around the desired levels of 6 bar for lube oil and 12 bar for hydraulic oil.
Oil heating and cooling are achieved through a heat exchanger supplied by either cool or hot water. The temperature should be maintained at all times around 44.8°C. Warm oil should also be distributed to the turbine before startup using the turning gear switch.
Turbine casing heating should be performed while the turbine is on the turning gear before it is started. This process requires hot steam from the reactor. In real life, this process takes 8 hours but has been significantly shortened. The turning gear can be engaged while the turbine is stationary and then turned on to rotate the turbine. To disengage it, the turbine must come to a complete stop. Generator cooling should be provided with outside cool air mixed with exhaust air if needed (refer to humid air operations checklist)
Before starting operations, ensure that the oil valves are open. The startup procedure will require cooperation between both control rooms. Initial oil should be heated and distributed with the turning gear, then the Control Room needs to provide enough steam temperature for casing heating. With steam available and the turbine rotating, steam sealing must be set up properly. Once all lights are green, notify the Control Room that the turbine is ready for run-up. If the turbine can't be started with all green lights, the turbine operator should check the trip bolt at the generator (end of the turbine) and press it if needed.
Lube oil filters can be found in the turbine hall. There are two holders for the filters, one that is in use and the other where the filter can be changed. They can be selected using a lever. This device also displays differential pressure, with typical values ranging from 0.3 to 0.4 bar. If the pressure is higher, it may indicate that a filter is clogged and needs to be changed.
Once the generator is synchronized, it must be provided with cooling air. Air valves are located below the generator (accessible with a ladder from the turbine hall). The cold valve will cool the generator, while the warm valve will mix hot air from the generator with cold outside air to reduce humidity. The efficiency of cooling depends on the outside temperature, the number of valves open, and the generator load. In humid conditions, the warm valve should be set to at least 2/5 of the cold valve.
At higher loads (above 1000 MW), it might not be possible to work continuously in humid conditions because cooling with warm air to raise humidity may not be sufficient. In such cases, if humid conditions persist, it is advisable to lower the generator load below the demand to allow the generator to cool. If no humid conditions are present, the warm air valve should be closed to enable maximum cooling.
Oil valves are located in the turbine hall. These include the Emergency valve, Auxiliary valve, and Main valve, corresponding to their respective pumps. The Main valve is operated by the shaft pump, while the other pumps are for the Auxiliary or Emergency pumps (refer to the pump selector switches in the Turbine Control Room). Additionally, there is a Backflow valve. Closing it will increase pressure. This valve can be used to counteract a random pressure drop (which may occur occasionally) or to temporarily mitigate an oil leak.
Oil leaks can occur whenever malfunctions are enabled. During a leak, oil pressure will constantly drop. Generally, the turbine should be tripped, and a leak check should be called for (using the radio on the desk in the TCR). However, it is possible to bypass the leak in the main valve. To do this, the turbine must be configured to work with the Aux valve while isolating the Shaft pump. The simplest way to achieve this is to work with the Shaft pumps (selectors set to Off), close the Aux valve to about 50%, and then enable the Aux pump by switching both selectors to Aux. The pressure should increase, and it should hopefully stay within limits with the Aux pump valve at 50%. Simultaneously, the Main valve should be completely closed, and the Aux valve should be fully opened. If done quickly, this can be achieved by one user by first closing the Main valve and immediately opening the Aux valve. In the end, the turbine will be operated with only the Aux pump, with the Main pump isolated. The Backflow valve should be used to adjust pressure. This procedure stops the oil leak and allows for normal operation, although with reduced points gained, as it is considered a temporary solution. Eventually, the oil leak will need to be repaired.