Hide steam pressure when no steam is present

src/reactor_sim/dashboard.py

@@ -424,7 +424,7 @@ class ReactorDashboard:
             [
                 ("Turbines", " ".join(self._turbine_status_lines())),
                 ("Rated Elec", f"{len(self.reactor.turbines)*self.reactor.turbines[0].rated_output_mw:7.1f} MW"),
-                ("Steam P", f"{state.secondary_loop.pressure:5.2f} MPa"),
+                ("Steam P", f"{self._steam_pressure(state):5.2f} MPa"),
                 ("Unit1 Elec", f"{state.turbines[0].electrical_output_mw:7.1f} MW" if state.turbines else "n/a"),
                 (
                     "Unit2 Elec",
@@ -599,6 +599,12 @@ class ReactorDashboard:
         ]
         return lines
 
+    def _steam_pressure(self, state: PlantState) -> float:
+        # Only report steam pressure if quality/flow indicate steam is present.
+        if state.secondary_loop.steam_quality < 0.05 or state.secondary_loop.mass_flow_rate < 100.0:
+            return 0.0
+        return state.secondary_loop.pressure
+
     def _update_trends(self, state: PlantState) -> None:
         self._trend_history.append((state.time_elapsed, state.core.fuel_temperature, state.core.power_output_mw))