From 001d8b7171f920c69877f0bd10f2ba48ab8cc005 Mon Sep 17 00:00:00 2001
From: Codex Agent <codex@example.com>
Date: Sun, 23 Nov 2025 00:28:07 +0100
Subject: [PATCH] Let auto rod control clear shutdown and adjust rods

---
 src/reactor_sim/reactor.py |  8 ++++++++
 tests/test_simulation.py   | 14 ++++++++++++++
 2 files changed, 22 insertions(+)

diff --git a/src/reactor_sim/reactor.py b/src/reactor_sim/reactor.py
index 0107f57..e0e1750 100644
--- a/src/reactor_sim/reactor.py
+++ b/src/reactor_sim/reactor.py
@@ -171,6 +171,8 @@ class Reactor:
         if command:
             overrides = self._apply_command(command, state)
             rod_fraction = overrides.get("rod_fraction", rod_fraction)
+            if not self.shutdown and not self.control.manual_control:
+                rod_fraction = self.control.update_rods(state.core, dt)
 
         decay_power, decay_neutron_source, decay_products, decay_particles = self.fuel.decay_reaction_effects(
             state.core
@@ -476,6 +478,8 @@ class Reactor:
             self.control.set_power_setpoint(command.power_setpoint)
         if command.rod_manual is not None:
             self.control.set_manual_mode(command.rod_manual)
+            if command.rod_manual is False and not self.meltdown:
+                self.shutdown = False
         if command.rod_position is not None:
             self.control.set_manual_mode(True)
             overrides["rod_fraction"] = self.control.set_rods(command.rod_position)
@@ -505,6 +509,10 @@ class Reactor:
             overrides["coolant_demand"] = max(0.0, min(1.0, command.coolant_demand))
         for component in command.maintenance_components:
             self._toggle_maintenance(component)
+        if not self.meltdown and not command.scram:
+            rod_target = overrides.get("rod_fraction", self.control.rod_fraction)
+            if rod_target < 0.95:
+                self.shutdown = False
         return overrides
 
     def _set_primary_pump(self, active: bool) -> None:
diff --git a/tests/test_simulation.py b/tests/test_simulation.py
index 483457e..ff1a17a 100644
--- a/tests/test_simulation.py
+++ b/tests/test_simulation.py
@@ -253,3 +253,17 @@ def test_meltdown_triggers_shutdown():
 
     assert reactor.shutdown is True
     assert reactor.meltdown is True
+
+
+def test_auto_control_resets_shutdown_and_moves_rods():
+    reactor = Reactor.default()
+    state = reactor.initial_state()
+    reactor.shutdown = True
+    reactor.control.manual_control = True
+    reactor.control.rod_fraction = 0.95
+
+    reactor.step(state, dt=1.0, command=ReactorCommand(rod_manual=False))
+
+    assert reactor.shutdown is False
+    assert reactor.control.manual_control is False
+    assert reactor.control.rod_fraction < 0.95