Add spool dynamics for pumps and turbines

src/reactor_sim/turbine.py

@@ -26,12 +26,14 @@ class Turbine:
     generator_efficiency: float = constants.GENERATOR_EFFICIENCY
     mechanical_efficiency: float = constants.STEAM_TURBINE_EFFICIENCY
     rated_output_mw: float = 400.0  # cap per unit electrical output
+    spool_time: float = constants.TURBINE_SPOOL_TIME
 
     def step(
         self,
         loop: CoolantLoopState,
         state: TurbineState,
         steam_power_mw: float = 0.0,
+        dt: float = 1.0,
     ) -> None:
         enthalpy = 2_700.0 + loop.steam_quality * 600.0
         mass_flow = loop.mass_flow_rate * 0.6
@@ -43,8 +45,8 @@ class Turbine:
             shaft_power_mw = electrical / max(1e-6, self.generator_efficiency)
         condenser_temp = max(305.0, loop.temperature_in - 20.0)
         state.steam_enthalpy = enthalpy
-        state.shaft_power_mw = shaft_power_mw
-        state.electrical_output_mw = electrical
+        state.shaft_power_mw = _ramp(state.shaft_power_mw, shaft_power_mw, dt, self.spool_time)
+        state.electrical_output_mw = _ramp(state.electrical_output_mw, electrical, dt, self.spool_time)
         state.condenser_temperature = condenser_temp
         LOGGER.debug(
             "Turbine output: shaft=%.1fMW electrical=%.1fMW condenser=%.1fK",
@@ -52,3 +54,10 @@ class Turbine:
             electrical,
             condenser_temp,
         )
+
+
+def _ramp(current: float, target: float, dt: float, time_constant: float) -> float:
+    if time_constant <= 0.0:
+        return target
+    alpha = min(1.0, max(0.0, dt / time_constant))
+    return current + (target - current) * alpha