fix: keep dashboard logging inside curses UI

AGENTS.md

@@ -9,7 +9,7 @@ All source code lives under `src/reactor_sim`. Submodules map to plant systems:
 - `python -m pip install -e .[dev]` — install editable package with optional tooling when dev dependencies are defined.
 
 ## Operations & Control Hooks
-Manual commands live in `reactor_sim.commands.ReactorCommand`. Pass a `command_provider` callable to `ReactorSimulation` to adjust rods, pumps, turbine, coolant demand, or the attached `ElectricalConsumer`. Use `ReactorCommand.scram_all()` for full shutdown, `ReactorCommand(consumer_online=True, consumer_demand=600)` to hook the grid, or toggle pumps (`primary_pump_on=False`) to simulate faults. Control helpers in `control.py` expose `set_rods`, `increment_rods`, and `scram`.
+Manual commands live in `reactor_sim.commands.ReactorCommand`. Pass a `command_provider` callable to `ReactorSimulation` to adjust rods, pumps, turbine, coolant demand, or the attached `ElectricalConsumer`. Use `ReactorCommand.scram_all()` for full shutdown, `ReactorCommand(consumer_online=True, consumer_demand=600)` to hook the grid, or toggle pumps (`primary_pump_on=False`) to simulate faults. Control helpers in `control.py` expose `set_rods`, `increment_rods`, and `scram`, and you can switch `set_manual_mode(True)` to pause the automatic rod controller. For hands-on runs, launch the curses dashboard (`FISSION_DASHBOARD=1 FISSION_REALTIME=1 python run_simulation.py`) and use the on-screen shortcuts (q quit/save, space SCRAM, p/o pumps, t turbine, +/- rods in 0.05 steps, [/ ] consumer demand, s/d setpoint, `a` toggles auto/manual rods). Recommended startup: enable manual rods (`a`), withdraw to ~0.3 before ramping the turbine/consumer, then re-enable auto control when you want closed-loop operation.
 The plant now boots cold (ambient core temperature, idle pumps); scripts must sequence startup: enable pumps, gradually withdraw rods, connect the consumer after turbine spin-up, and use `ControlSystem.set_power_setpoint` to chase desired output. Set `FISSION_REALTIME=1` to run continuously with real-time pacing; optionally set `FISSION_SIM_DURATION=infinite` for indefinite runs and send SIGINT/Ctrl+C to stop. Use `FISSION_SIM_DURATION=600` (default) for bounded offline batches.
 
 ## Coding Style & Naming Conventions

src/reactor_sim/__init__.py

@@ -5,6 +5,7 @@ from __future__ import annotations
 from .atomic import Atom, AtomicPhysics, FissionEvent
 from .commands import ReactorCommand
 from .consumer import ElectricalConsumer
+from .dashboard import ReactorDashboard
 from .failures import HealthMonitor
 from .logging_utils import configure_logging
 from .state import CoreState, CoolantLoopState, TurbineState, PlantState
@@ -24,5 +25,6 @@ __all__ = [
     "ReactorCommand",
     "ElectricalConsumer",
     "HealthMonitor",
+    "ReactorDashboard",
     "configure_logging",
 ]

src/reactor_sim/commands.py

@@ -19,6 +19,7 @@ class ReactorCommand:
     power_setpoint: float | None = None
     consumer_online: bool | None = None
     consumer_demand: float | None = None
+    rod_manual: bool | None = None
 
     @classmethod
     def scram_all(cls) -> "ReactorCommand":

src/reactor_sim/constants.py

@@ -16,4 +16,4 @@ GENERATOR_EFFICIENCY = 0.96
 ENVIRONMENT_TEMPERATURE = 295.0  # K
 AMU_TO_KG = 1.660_539_066_60e-27
 MEV_TO_J = 1.602_176_634e-13
-ELECTRON_FISSION_CROSS_SECTION = 5e-23  # cm^2, tuned for simulation scale
+ELECTRON_FISSION_CROSS_SECTION = 5e-16  # cm^2, tuned for simulation scale

src/reactor_sim/consumer.py

@@ -14,6 +14,7 @@ class ElectricalConsumer:
     demand_mw: float
     online: bool = False
     power_received_mw: float = 0.0
+    _under_supply_logged: bool = False
 
     def request_power(self) -> float:
         return self.demand_mw if self.online else 0.0
@@ -30,11 +31,16 @@ class ElectricalConsumer:
 
     def update_power_received(self, supplied_mw: float) -> None:
         self.power_received_mw = supplied_mw
-        if supplied_mw < self.request_power():
-            LOGGER.warning(
-                "%s under-supplied: %.1f/%.1f MW",
-                self.name,
-                supplied_mw,
-                self.request_power(),
-            )
-
+        if supplied_mw + 1e-6 < self.request_power():
+            if not self._under_supply_logged:
+                LOGGER.warning(
+                    "%s under-supplied: %.1f/%.1f MW",
+                    self.name,
+                    supplied_mw,
+                    self.request_power(),
+                )
+                self._under_supply_logged = True
+        else:
+            if self._under_supply_logged:
+                LOGGER.info("%s demand satisfied", self.name)
+            self._under_supply_logged = False

src/reactor_sim/control.py

@@ -21,8 +21,11 @@ def clamp(value: float, lo: float, hi: float) -> float:
 class ControlSystem:
     setpoint_mw: float = 3_000.0
     rod_fraction: float = 0.5
+    manual_control: bool = False
 
     def update_rods(self, state: CoreState, dt: float) -> float:
+        if self.manual_control:
+            return self.rod_fraction
         error = (state.power_output_mw - self.setpoint_mw) / self.setpoint_mw
         adjustment = -error * 0.3
         adjustment = clamp(adjustment, -constants.CONTROL_ROD_SPEED * dt, constants.CONTROL_ROD_SPEED * dt)
@@ -50,6 +53,11 @@ class ControlSystem:
         self.setpoint_mw = clamp(megawatts, 100.0, 4_000.0)
         LOGGER.info("Power setpoint %.0f -> %.0f MW", previous, self.setpoint_mw)
 
+    def set_manual_mode(self, manual: bool) -> None:
+        if self.manual_control != manual:
+            self.manual_control = manual
+            LOGGER.info("Rod control %s", "manual" if manual else "automatic")
+
     def coolant_demand(self, primary: CoolantLoopState) -> float:
         desired_temp = 580.0
         error = (primary.temperature_out - desired_temp) / 100.0

src/reactor_sim/dashboard.py

@@ -0,0 +1,367 @@
+"""Interactive curses dashboard for real-time reactor operation."""
+
+from __future__ import annotations
+
+import curses
+import logging
+from collections import deque
+from dataclasses import dataclass
+from typing import Optional
+
+from .commands import ReactorCommand
+from .reactor import Reactor
+from .simulation import ReactorSimulation
+from .state import PlantState
+
+
+@dataclass
+class DashboardKey:
+    key: str
+    description: str
+
+
+class ReactorDashboard:
+    """Minimal TUI dashboard allowing user control in real-time."""
+
+    def __init__(
+        self,
+        reactor: Reactor,
+        start_state: Optional[PlantState],
+        timestep: float = 1.0,
+        save_path: Optional[str] = None,
+    ) -> None:
+        self.reactor = reactor
+        self.start_state = start_state
+        self.timestep = timestep
+        self.save_path = save_path
+        self.pending_command: Optional[ReactorCommand] = None
+        self.sim: Optional[ReactorSimulation] = None
+        self.quit_requested = False
+        self.log_buffer: deque[str] = deque(maxlen=4)
+        self._log_handler: Optional[logging.Handler] = None
+        self._previous_handlers: list[logging.Handler] = []
+        self._logger = logging.getLogger("reactor_sim")
+        self.keys = [
+            DashboardKey("q", "Quit & save"),
+            DashboardKey("space", "SCRAM"),
+            DashboardKey("p", "Toggle primary pump"),
+            DashboardKey("o", "Toggle secondary pump"),
+            DashboardKey("t", "Toggle turbine"),
+            DashboardKey("c", "Toggle consumer"),
+            DashboardKey("+/-", "Withdraw/insert rods"),
+            DashboardKey("[/]", "Adjust consumer demand −/+50 MW"),
+            DashboardKey("s", "Setpoint −250 MW"),
+            DashboardKey("d", "Setpoint +250 MW"),
+            DashboardKey("a", "Toggle auto rod control"),
+        ]
+
+    def run(self) -> None:
+        curses.wrapper(self._main)
+
+    def _main(self, stdscr: "curses._CursesWindow") -> None:  # type: ignore[name-defined]
+        curses.curs_set(0)
+        curses.start_color()
+        curses.use_default_colors()
+        curses.init_pair(1, curses.COLOR_CYAN, -1)
+        curses.init_pair(2, curses.COLOR_YELLOW, -1)
+        curses.init_pair(3, curses.COLOR_GREEN, -1)
+        curses.init_pair(4, curses.COLOR_RED, -1)
+        stdscr.nodelay(True)
+        self._install_log_capture()
+        self.sim = ReactorSimulation(
+            self.reactor,
+            timestep=self.timestep,
+            duration=None,
+            realtime=True,
+            command_provider=self._next_command,
+        )
+        self.sim.start_state = self.start_state
+        try:
+            for state in self.sim.run():
+                self._draw(stdscr, state)
+                self._handle_input(stdscr)
+                if self.quit_requested:
+                    self.sim.stop()
+                    break
+        finally:
+            if self.save_path and self.sim and self.sim.last_state:
+                self.reactor.save_state(self.save_path, self.sim.last_state)
+            self._restore_logging()
+
+    def _handle_input(self, stdscr: "curses._CursesWindow") -> None:
+        while True:
+            ch = stdscr.getch()
+            if ch == -1:
+                break
+            if ch in (ord("q"), ord("Q")):
+                self.quit_requested = True
+                return
+            if ch == ord(" "):
+                self._queue_command(ReactorCommand.scram_all())
+            elif ch in (ord("p"), ord("P")):
+                self._queue_command(ReactorCommand(primary_pump_on=not self.reactor.primary_pump_active))
+            elif ch in (ord("o"), ord("O")):
+                self._queue_command(ReactorCommand(secondary_pump_on=not self.reactor.secondary_pump_active))
+            elif ch in (ord("t"), ord("T")):
+                self._queue_command(ReactorCommand(turbine_on=not self.reactor.turbine_active))
+            elif ch in (ord("+"), ord("=")):
+                self._queue_command(ReactorCommand(rod_position=self._clamped_rod(-0.05)))
+            elif ch == ord("-"):
+                self._queue_command(ReactorCommand(rod_position=self._clamped_rod(0.05)))
+            elif ch == ord("["):
+                demand = self._current_demand() - 50.0
+                self._queue_command(ReactorCommand(consumer_demand=max(0.0, demand)))
+            elif ch == ord("]"):
+                demand = self._current_demand() + 50.0
+                self._queue_command(ReactorCommand(consumer_demand=demand))
+            elif ch in (ord("c"), ord("C")):
+                online = not (self.reactor.consumer.online if self.reactor.consumer else False)
+                self._queue_command(ReactorCommand(consumer_online=online))
+            elif ch in (ord("s"), ord("S")):
+                self._queue_command(ReactorCommand(power_setpoint=self.reactor.control.setpoint_mw - 250.0))
+            elif ch in (ord("d"), ord("D")):
+                self._queue_command(ReactorCommand(power_setpoint=self.reactor.control.setpoint_mw + 250.0))
+            elif ch in (ord("a"), ord("A")):
+                self._queue_command(ReactorCommand(rod_manual=not self.reactor.control.manual_control))
+
+    def _queue_command(self, command: ReactorCommand) -> None:
+        if self.pending_command is None:
+            self.pending_command = command
+        else:
+            for field in command.__dataclass_fields__:  # type: ignore[attr-defined]
+                value = getattr(command, field)
+                if value is None or value is False:
+                    continue
+                if field == "rod_step" and getattr(self.pending_command, field) is not None:
+                    setattr(
+                        self.pending_command,
+                        field,
+                        getattr(self.pending_command, field) + value,
+                    )
+                else:
+                    setattr(self.pending_command, field, value)
+        if self.pending_command.rod_position is not None and self.pending_command.rod_manual is None:
+            self.pending_command.rod_manual = True
+
+
+    def _next_command(self, _: float, __: PlantState) -> Optional[ReactorCommand]:
+        cmd = self.pending_command
+        self.pending_command = None
+        return cmd
+
+    def _draw(self, stdscr: "curses._CursesWindow", state: PlantState) -> None:
+        stdscr.erase()
+        height, width = stdscr.getmaxyx()
+        if height < 24 or width < 90:
+            stdscr.addstr(
+                0,
+                0,
+                "Terminal window too small. Resize to at least 90x24.".ljust(width),
+                curses.color_pair(4),
+            )
+            stdscr.refresh()
+            return
+
+        data_height = height - 6
+        right_width = max(32, width // 3)
+        left_width = width - right_width
+        if left_width < 60:
+            left_width = min(60, width - 20)
+            right_width = width - left_width
+
+        data_win = stdscr.derwin(data_height, left_width, 0, 0)
+        help_win = stdscr.derwin(data_height, right_width, 0, left_width)
+        status_win = stdscr.derwin(6, width, data_height, 0)
+
+        self._draw_data_panel(data_win, state)
+        self._draw_help_panel(help_win)
+        self._draw_status_panel(status_win, state)
+        stdscr.refresh()
+
+    def _draw_data_panel(self, win: "curses._CursesWindow", state: PlantState) -> None:
+        win.erase()
+        win.box()
+        win.addstr(0, 2, " Plant Overview ", curses.color_pair(1) | curses.A_BOLD)
+        y = 2
+        y = self._draw_section(
+            win,
+            y,
+            "Core",
+            [
+                ("Fuel Temp", f"{state.core.fuel_temperature:8.1f} K"),
+                ("Core Power", f"{state.core.power_output_mw:8.1f} MW"),
+                ("Neutron Flux", f"{state.core.neutron_flux:10.2e}"),
+                ("Rods", f"{self.reactor.control.rod_fraction:.3f}"),
+                ("Setpoint", f"{self.reactor.control.setpoint_mw:7.0f} MW"),
+                ("Reactivity", f"{state.core.reactivity_margin:+.4f}"),
+            ],
+        )
+        y = self._draw_section(
+            win,
+            y,
+            "Primary Loop",
+            [
+                ("Pump", "ON" if self.reactor.primary_pump_active else "OFF"),
+                ("Flow", f"{state.primary_loop.mass_flow_rate:7.0f} kg/s"),
+                ("Inlet Temp", f"{state.primary_loop.temperature_in:7.1f} K"),
+                ("Outlet Temp", f"{state.primary_loop.temperature_out:7.1f} K"),
+                ("Pressure", f"{state.primary_loop.pressure:5.2f} MPa"),
+            ],
+        )
+        y = self._draw_section(
+            win,
+            y,
+            "Secondary Loop",
+            [
+                ("Pump", "ON" if self.reactor.secondary_pump_active else "OFF"),
+                ("Flow", f"{state.secondary_loop.mass_flow_rate:7.0f} kg/s"),
+                ("Inlet Temp", f"{state.secondary_loop.temperature_in:7.1f} K"),
+                ("Pressure", f"{state.secondary_loop.pressure:5.2f} MPa"),
+                ("Steam Quality", f"{state.secondary_loop.steam_quality:5.2f}"),
+            ],
+        )
+        consumer_status = "n/a"
+        consumer_demand = 0.0
+        if self.reactor.consumer:
+            consumer_status = "ONLINE" if self.reactor.consumer.online else "OFF"
+            consumer_demand = self.reactor.consumer.demand_mw
+        y = self._draw_section(
+            win,
+            y,
+            "Turbine / Grid",
+            [
+                ("Turbine", "ON" if self.reactor.turbine_active else "OFF"),
+                ("Electrical", f"{state.turbine.electrical_output_mw:7.1f} MW"),
+                ("Load", f"{state.turbine.load_supplied_mw:7.1f}/{state.turbine.load_demand_mw:7.1f} MW"),
+                ("Consumer", f"{consumer_status}"),
+                ("Demand", f"{consumer_demand:7.1f} MW"),
+            ],
+        )
+        self._draw_health_bar(win, y + 1)
+
+    def _draw_help_panel(self, win: "curses._CursesWindow") -> None:
+        win.erase()
+        win.box()
+        win.addstr(0, 2, " Controls ", curses.color_pair(1) | curses.A_BOLD)
+        y = 2
+        for entry in self.keys:
+            win.addstr(y, 2, f"{entry.key:<8} {entry.description}")
+            y += 1
+        win.addstr(y + 1, 2, "Tips:", curses.color_pair(2) | curses.A_BOLD)
+        tips = [
+            "Start pumps before withdrawing rods.",
+            "Bring turbine and consumer online after thermal stabilization.",
+            "Watch component health to avoid automatic trips.",
+        ]
+        for idx, tip in enumerate(tips, start=y + 2):
+            win.addstr(idx, 4, f"- {tip}")
+
+    def _draw_status_panel(self, win: "curses._CursesWindow", state: PlantState) -> None:
+        win.erase()
+        win.hline(0, 0, curses.ACS_HLINE, win.getmaxyx()[1])
+        msg = (
+            f"Time {state.time_elapsed:7.1f}s | Rods {self.reactor.control.rod_fraction:.3f} | "
+            f"Primary {'ON' if self.reactor.primary_pump_active else 'OFF'} | "
+            f"Secondary {'ON' if self.reactor.secondary_pump_active else 'OFF'} | "
+            f"Turbine {'ON' if self.reactor.turbine_active else 'OFF'}"
+        )
+        win.addstr(1, 1, msg, curses.color_pair(3))
+        if self.reactor.health_monitor.failure_log:
+            win.addstr(
+                3,
+                1,
+                f"Failures: {', '.join(self.reactor.health_monitor.failure_log)}",
+                curses.color_pair(4) | curses.A_BOLD,
+            )
+        log_y = 3
+        for record in list(self.log_buffer):
+            if log_y >= win.getmaxyx()[0] - 1:
+                break
+            win.addstr(log_y, 1, record[: win.getmaxyx()[1] - 2], curses.color_pair(2))
+            log_y += 1
+        win.addstr(log_y, 1, "Press 'q' to exit and persist the current snapshot.", curses.color_pair(2))
+
+    def _draw_section(
+        self,
+        win: "curses._CursesWindow",
+        start_y: int,
+        title: str,
+        lines: list[tuple[str, str] | str],
+    ) -> int:
+        height, width = win.getmaxyx()
+        inner_width = width - 4
+        if start_y >= height - 2:
+            return height - 2
+        win.addstr(start_y, 2, title[:inner_width], curses.A_BOLD | curses.color_pair(1))
+        row = start_y + 1
+        for line in lines:
+            if row >= height - 1:
+                break
+            if isinstance(line, tuple):
+                label, value = line
+                text = f"{label:<18}: {value}"
+            else:
+                text = line
+            win.addstr(row, 4, text[:inner_width])
+            row += 1
+        return row + 1
+
+    def _draw_health_bar(self, win: "curses._CursesWindow", start_y: int) -> None:
+        height, width = win.getmaxyx()
+        if start_y >= height - 2:
+            return
+        win.addstr(start_y, 2, "Component Health", curses.A_BOLD | curses.color_pair(1))
+        bar_width = max(10, min(width - 28, 40))
+        for idx, (name, comp) in enumerate(self.reactor.health_monitor.components.items(), start=1):
+            filled = int(bar_width * comp.integrity)
+            bar = "█" * filled + "-" * (bar_width - filled)
+            color = 3 if comp.integrity > 0.5 else 2 if comp.integrity > 0.2 else 4
+            row = start_y + idx
+            if row >= height - 1:
+                break
+            label = f"{name:<12}:"
+            win.addstr(row, 4, label[:14], curses.A_BOLD)
+            bar_start = 4 + max(len(label), 14) + 1
+            win.addstr(row, bar_start, bar[:bar_width], curses.color_pair(color))
+            percent_col = min(width - 8, bar_start + bar_width + 2)
+            win.addstr(row, percent_col, f"{comp.integrity*100:5.1f}%", curses.color_pair(color))
+
+    def _current_demand(self) -> float:
+        if self.reactor.consumer:
+            return self.reactor.consumer.demand_mw
+        return 0.0
+
+    def _clamped_rod(self, delta: float) -> float:
+        new_fraction = self.reactor.control.rod_fraction + delta
+        return max(0.0, min(0.95, new_fraction))
+
+    def _install_log_capture(self) -> None:
+        if self._log_handler:
+            return
+        self._previous_handlers = list(self._logger.handlers)
+        for handler in self._previous_handlers:
+            self._logger.removeHandler(handler)
+        handler = _DashboardLogHandler(self.log_buffer)
+        handler.setFormatter(logging.Formatter("%(levelname)s | %(message)s"))
+        self._logger.addHandler(handler)
+        self._logger.propagate = False
+        self._log_handler = handler
+
+    def _restore_logging(self) -> None:
+        if not self._log_handler:
+            return
+        self._logger.removeHandler(self._log_handler)
+        for handler in self._previous_handlers:
+            self._logger.addHandler(handler)
+        self._log_handler = None
+        self._previous_handlers = []
+
+
+class _DashboardLogHandler(logging.Handler):
+    def __init__(self, buffer: deque[str]) -> None:
+        super().__init__()
+        self.buffer = buffer
+
+    def emit(self, record: logging.LogRecord) -> None:
+        msg = self.format(record)
+        self.buffer.append(msg)

src/reactor_sim/fuel.py

@@ -42,7 +42,10 @@ class FuelAssembly:
         event = self.simulate_electron_hit()
         effective_flux = max(0.0, flux * max(0.0, 1.0 - control_fraction))
         atoms = self.mass_kg / self.fissile_atom.atomic_mass_kg
-        event_rate = effective_flux * constants.ELECTRON_FISSION_CROSS_SECTION * atoms * self.enrichment
+        event_rate = max(
+            0.0,
+            effective_flux * constants.ELECTRON_FISSION_CROSS_SECTION * atoms * self.enrichment,
+        )
         power_watts = event_rate * event.energy_mev * constants.MEV_TO_J
         power_mw = power_watts / constants.MEGAWATT
         LOGGER.debug(
@@ -53,4 +56,4 @@ class FuelAssembly:
             event.products[1].mass_number,
             power_mw,
         )
-        return max(0.0, power_mw), event
+        return max(0.0, power_mw), event_rate, event

src/reactor_sim/reactor.py

@@ -102,7 +102,9 @@ class Reactor:
 
         self.neutronics.step(state.core, rod_fraction, dt)
 
-        prompt_power, fission_event = self.fuel.prompt_energy_rate(state.core.neutron_flux, rod_fraction)
+        prompt_power, fission_rate, fission_event = self.fuel.prompt_energy_rate(
+            state.core.neutron_flux, rod_fraction
+        )
         decay_power = decay_heat_fraction(state.core.burnup) * state.core.power_output_mw
         total_power = prompt_power + decay_power
         state.core.power_output_mw = total_power
@@ -125,7 +127,7 @@ class Reactor:
         self.thermal.step_secondary(state.secondary_loop, transferred)
 
         if self.turbine_active:
-            self.turbine.step(state.secondary_loop, state.turbine, self.consumer)
+            self.turbine.step(state.secondary_loop, state.turbine, self.consumer, steam_power_mw=transferred)
         else:
             state.turbine.shaft_power_mw = 0.0
             state.turbine.electrical_output_mw = 0.0
@@ -147,16 +149,13 @@ class Reactor:
         LOGGER.info(
             (
                 "t=%5.1fs rods=%.2f core_power=%.1fMW prompt=%.1fMW :: "
-                "%s-%d + %s-%d, outlet %.1fK, electrical %.1fMW load %.1f/%.1fMW"
+                "fissions %.2e/s, outlet %.1fK, electrical %.1fMW load %.1f/%.1fMW"
             ),
             state.time_elapsed,
             rod_fraction,
             total_power,
             prompt_power,
-            fission_event.products[0].symbol,
-            fission_event.products[0].mass_number,
-            fission_event.products[1].symbol,
-            fission_event.products[1].mass_number,
+            fission_rate,
             state.primary_loop.temperature_out,
             state.turbine.electrical_output_mw,
             state.turbine.load_supplied_mw,
@@ -183,7 +182,10 @@ class Reactor:
             self._set_turbine_state(False)
         if command.power_setpoint is not None:
             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_position is not None:
+            self.control.set_manual_mode(True)
             overrides["rod_fraction"] = self.control.set_rods(command.rod_position)
             self.shutdown = self.shutdown or command.rod_position >= 0.95
         elif command.rod_step is not None:

src/reactor_sim/simulation.py

@@ -72,11 +72,29 @@ def main() -> None:
     else:
         duration = None if realtime else 600.0
     reactor = Reactor.default()
-    sim = ReactorSimulation(reactor, timestep=5.0, duration=duration, realtime=realtime)
+    dashboard_mode = os.getenv("FISSION_DASHBOARD", "0") == "1"
+    timestep_env = os.getenv("FISSION_TIMESTEP")
+    if timestep_env:
+        timestep = float(timestep_env)
+    else:
+        timestep = 1.0 if dashboard_mode or realtime else 5.0
+
+    sim = ReactorSimulation(reactor, timestep=timestep, duration=duration, realtime=realtime)
     load_path = os.getenv("FISSION_LOAD_STATE")
     save_path = os.getenv("FISSION_SAVE_STATE")
     if load_path:
         sim.start_state = reactor.load_state(load_path)
+    if dashboard_mode:
+        from .dashboard import ReactorDashboard
+
+        dashboard = ReactorDashboard(
+            reactor,
+            start_state=sim.start_state,
+            timestep=sim.timestep,
+            save_path=save_path,
+        )
+        dashboard.run()
+        return
     try:
         if realtime:
             LOGGER.info("Running in real-time mode (Ctrl+C to stop)...")

src/reactor_sim/thermal.py

@@ -5,6 +5,8 @@ from __future__ import annotations
 from dataclasses import dataclass
 import logging
 
+import math
+
 from . import constants
 from .state import CoolantLoopState, CoreState
 
@@ -14,8 +16,9 @@ LOGGER = logging.getLogger(__name__)
 def heat_transfer(primary: CoolantLoopState, secondary: CoolantLoopState, core_power_mw: float) -> float:
     """Return MW transferred to the secondary loop."""
     delta_t = max(0.0, primary.temperature_out - secondary.temperature_in)
-    conductance = 0.05  # steam generator effectiveness
-    transferred = min(core_power_mw, conductance * delta_t)
+    conductance = 0.15  # steam generator effectiveness
+    efficiency = 1.0 - math.exp(-conductance * delta_t)
+    transferred = min(core_power_mw, core_power_mw * efficiency)
     LOGGER.debug("Heat transfer %.2f MW with ΔT=%.1fK", transferred, delta_t)
     return transferred
 

src/reactor_sim/turbine.py

@@ -34,10 +34,12 @@ class Turbine:
         loop: CoolantLoopState,
         state: TurbineState,
         consumer: Optional[ElectricalConsumer] = None,
+        steam_power_mw: float = 0.0,
     ) -> None:
         enthalpy = 2_700.0 + loop.steam_quality * 600.0
         mass_flow = loop.mass_flow_rate * 0.6
-        shaft_power_mw = (enthalpy * mass_flow / 1_000.0) * self.mechanical_efficiency / 1_000.0
+        available_power = max(steam_power_mw, (enthalpy * mass_flow / 1_000.0) / 1_000.0)
+        shaft_power_mw = available_power * self.mechanical_efficiency
         electrical = shaft_power_mw * self.generator_efficiency
         if consumer:
             load_demand = consumer.request_power()