d2997c2861
Fill out the DRC mode set with ctrl_shutdown (u = -5*beta), ctrl_scram (u = -8*beta), and ctrl_heatup (feedback-linearizing P on ramped T_avg reference, saturated u, no integrator). Add ctrl_operation_lqr as a full-state-feedback counterpart to ctrl_operation — K cached, closed-loop essentially perfect under the 100%->80% Q_sg step where plain P has ~5F overshoot. Add pke_linearize for numerical (A, B, B_w) Jacobians at any operating point; test_linearize confirms ~4e-4 rel err vs nonlinear sim for a 5% Q_sg step. Extend pke_solver with an optional x0 argument so each mode can start from a plausible IC. main_mode_sweep.m exercises all five modes back-to-back and saves the 4-panel plots. CLAUDE.md updated with model-validity-range note (trust region is ~+/-50C around operating point; true cold shutdown is out of scope for the linear feedback coefficients). Hacker-Split: build out control layer end-to-end for reachability. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
plant-model
PWR plant model (point kinetics + lumped thermal-hydraulics) and mode-specific continuous controllers for the HAHACS preliminary example.
Overview
A 10-state coupled neutronics + thermal-hydraulics model in MATLAB:
- 6 delayed neutron precursor groups (U-235 thermal fission, Keepin)
- Lumped fuel, core coolant, and SG/cold-leg thermal nodes
- Steam generator heat removal
Q_sg(t)as the bounded disturbance input - Doppler and moderator temperature reactivity feedback
- External rod reactivity
uas the controllable input
State vector: x = [n; C1..C6; T_f; T_c; T_cold] (10 states). See
CLAUDE.md for the naming convention.
Quick Start
Open MATLAB in this directory and run:
main
The default scenario runs two simulations of a 100% → 80% SG demand step:
once with ctrl_null (plant feedback only) and once with ctrl_operation
(proportional rod reactivity on T_avg error), and plots the comparison.
Files
| File | Role |
|---|---|
main.m |
Entry point — scenario config and run |
pke_params.m |
Plant parameters and steady-state derivation |
pke_th_rhs.m |
Dynamics ẋ = f(t, x, plant, Q_sg, u) |
pke_initial_conditions.m |
Analytic steady-state x0 |
pke_solver.m |
Closed-loop driver — takes a controller function handle |
plot_pke_results.m |
4-panel results plot |
load_profile.m |
SG heat demand shapes |
controllers/ctrl_null.m |
u = 0 baseline |
controllers/ctrl_operation.m |
Stabilizing mode: P on T_avg |
Controllers
Controllers share a single signature:
u = ctrl_<mode>(t, x, plant, ref)
Returns scalar u (external rod reactivity in dk/k). The solver swaps
controllers via function handle:
[t, X, U] = pke_solver(plant, Q_sg, @ctrl_operation, ref, tspan);
Additional modes (ctrl_heatup, ctrl_scram, ctrl_shutdown) will land in
controllers/ following the same signature.
Running Different Scenarios
Swap Q_sg in main.m:
% Step down to 90% at t = 10s
Q_sg = @(t) plant.P0 * (1.0 - 0.1 * (t >= 10));
% Interpolated time series
t_data = [0, 100, 200, 300];
q_data = [1.0, 0.85, 0.9, 1.0] * plant.P0;
Q_sg = @(t) interp1(t_data, q_data, t, 'linear', 'extrap');
Swap the controller:
[t, X, U] = pke_solver(plant, Q_sg, @ctrl_null, [], tspan);
Change the reference (for modes that use one):
ref.T_avg = plant.T_c0 + 5; % track 5 C above nominal
Requirements
MATLAB (R2020b or newer, tested on R2025b). Uses ode15s from base MATLAB
— no toolboxes required.