Plant modes (BWR)
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A Plant MODE is the general operation of the plant. The mode corresponds to a few conditions: mode switch position, average reactor coolant temperature, and reactor vessel head closure bolt tensioning.
- There are 5 plant modes for a BWR nuclear power plant.
- Mode 1 - Power operations
- Mode 2 - Startup
- Mode 3 - Hot shutdown
- Mode 4 - Cold shutdown
- Mode 5 - Refueling
| MODE | TITLE | REACTOR MODE SWITCH POSITION | AVERAGE REACTOR COOLANT TEMPERATURE (°F) |
|---|---|---|---|
| 1 | Power Operation | Run | NA |
| 2 | Startup | Refuel[1] or Startup/Hot Standby | NA |
| 3 | Hot Shutdown[1] | Shutdown | > 212 |
| 4 | Cold Shutdown[1] | Shutdown | <=212 |
| 5 | Refueling[2] | Shutdown or Refuel | NA |
No Mode or Mode X
There is a set of circumstances where the plant is not in a Mode. The TS definition is: A MODE shall correspond to any one inclusive combination of mode switch position, average reactor coolant temperature, and reactor vessel head closure bolt tension specified in Table 1.1-1 with fuel In the reactor vessel.
Therefore, in the event that No Fuel is in the reactor than the plant is not in any mode. Note: Some TS applicability does apply even when there isn't a Mode in the applicability.