Add generator power model and meltdown handling

tests/test_simulation.py

@@ -42,7 +42,9 @@ def test_health_monitor_flags_core_failure():
     reactor = Reactor.default()
     state = reactor.initial_state()
     state.core.fuel_temperature = constants.MAX_CORE_TEMPERATURE
-    failures = reactor.health_monitor.evaluate(state, True, True, [True, True, True], dt=200.0)
+    failures = reactor.health_monitor.evaluate(
+        state, [True, True], [True, True], [True, True, True], state.generators, dt=200.0
+    )
     assert "core" in failures
     reactor._handle_failure("core")
     assert reactor.shutdown is True
@@ -50,10 +52,10 @@ def test_health_monitor_flags_core_failure():
 
 def test_maintenance_recovers_component_health():
     monitor = HealthMonitor()
-    pump = monitor.component("secondary_pump")
+    pump = monitor.component("secondary_pump_1")
     pump.integrity = 0.3
     pump.fail()
-    restored = monitor.maintain("secondary_pump", amount=0.5)
+    restored = monitor.maintain("secondary_pump_1", amount=0.5)
     assert restored is True
     assert pump.integrity == pytest.approx(0.8)
     assert pump.failed is False
@@ -88,19 +90,20 @@ def test_cold_shutdown_stays_subcritical():
 
 def test_toggle_maintenance_progresses_until_restored():
     reactor = Reactor.default()
+    reactor.primary_pump_units = [False, False]
     reactor.primary_pump_active = False
-    pump = reactor.health_monitor.component("primary_pump")
+    pump = reactor.health_monitor.component("primary_pump_1")
     pump.integrity = 0.2
 
     def provider(t: float, _state):
         if t == 0:
-            return ReactorCommand.maintain("primary_pump")
+            return ReactorCommand.maintain("primary_pump_1")
         return None
 
     sim = ReactorSimulation(reactor, timestep=1.0, duration=50.0, command_provider=provider)
     sim.log()
     assert pump.integrity >= 0.99
-    assert "primary_pump" not in reactor.maintenance_active
+    assert "primary_pump_1" not in reactor.maintenance_active
 
 
 def test_primary_pump_unit_toggle_updates_active_flag():
@@ -134,16 +137,21 @@ def test_secondary_pump_unit_toggle_can_restart_pump():
 def test_primary_pumps_spool_up_over_seconds():
     reactor = Reactor.default()
     state = reactor.initial_state()
+    reactor.secondary_pump_units = [False, False]
     # Enable both pumps and command full flow; spool should take multiple steps.
     target_flow = reactor.primary_pump.flow_rate(1.0) * len(reactor.primary_pump_units)
-    reactor.step(state, dt=1.0, command=ReactorCommand(primary_pump_on=True, coolant_demand=1.0))
+    reactor.step(
+        state,
+        dt=1.0,
+        command=ReactorCommand(primary_pumps={1: True, 2: True}, generator_units={1: True}, coolant_demand=1.0),
+    )
     first_flow = state.primary_loop.mass_flow_rate
     assert 0.0 < first_flow < target_flow
 
     for _ in range(10):
         reactor.step(state, dt=1.0, command=ReactorCommand(coolant_demand=1.0))
 
-    assert state.primary_loop.mass_flow_rate == pytest.approx(target_flow, rel=0.1)
+    assert state.primary_loop.mass_flow_rate == pytest.approx(target_flow, rel=0.15)
 
 
 def test_full_rod_withdrawal_reaches_gigawatt_power():
@@ -178,3 +186,37 @@ def test_partially_inserted_rods_hold_near_three_gw():
 
     assert 2_000.0 < state.core.power_output_mw < 4_000.0
     assert 500.0 < state.core.fuel_temperature < 800.0
+
+
+def test_generator_spools_and_powers_pumps():
+    reactor = Reactor.default()
+    state = reactor.initial_state()
+    reactor.shutdown = False
+    reactor.control.manual_control = True
+    reactor.control.rod_fraction = 0.95  # keep power low; focus on aux power
+    reactor.turbine_unit_active = [False, False, False]
+    reactor.secondary_pump_units = [False, False]
+
+    for step in range(12):
+        cmd = ReactorCommand(generator_units={1: True}, primary_pumps={1: True}) if step == 0 else None
+        reactor.step(state, dt=1.0, command=cmd)
+
+    assert state.generators and state.generators[0].running is True
+    assert state.generators[0].power_output_mw > 0.0
+    assert state.primary_loop.mass_flow_rate > 0.0
+
+
+def test_meltdown_triggers_shutdown():
+    reactor = Reactor.default()
+    state = reactor.initial_state()
+    reactor.shutdown = False
+    reactor.control.manual_control = True
+    reactor.control.rod_fraction = 0.0
+    reactor.primary_pump_active = True
+    reactor.secondary_pump_active = True
+    state.core.fuel_temperature = constants.CORE_MELTDOWN_TEMPERATURE + 50.0
+
+    reactor.step(state, dt=1.0)
+
+    assert reactor.shutdown is True
+    assert reactor.meltdown is True