Fuel Behaviour — 1-D Radial Thermo-Mechanics

Fuel behaviour under 1-D radial approximation.

Solves coupled radial heat conduction and thermo-elastic-plastic deformation of a single fuel rod over its operational lifetime (default 6 years).

Port of MATLAB Module 08 (fuelBehaviour.m, initializeFuelRod.m, funRHS.m, gapClosureEvent.m).

Key restructuring vs. MATLAB: stresses are NOT carried as DAE state variables. They are computed algebraically at each RHS evaluation by solving the linear stress equilibrium + strain compatibility + boundary condition system. The ODE state vector contains only genuinely time-evolving quantities (temperatures, fission density, swelling, creep strains, and plastic strains).

See also

Fuel Behaviour — 1-D Radial Thermo-Mechanics — Key Facts, gap closure model, MATPRO correlations.

class orpheus.fuel.solver.FuelRodGeometry(h0=3.0, fuel_r_in=0.0, fuel_r_out=0.00412, fuel_nr=30, porosity=0.05, fgr=0.06, q_lhgr=20000.0, clad_r_in=0.00422, clad_r_out=0.00475, clad_nr=5, clad_T_out=600.0, fast_flux=10000000000000.0, roughness=6e-06, T_plenum=600.0, p0=1.0, v_gas_plenum=1e-05, cool_p=16.0, time_end_years=6.0, time_step_days=1.0)[source]

Bases: object

As-fabricated fuel rod geometry and operating parameters.

Parameters:
h0: float = 3.0
fuel_r_in: float = 0.0
fuel_r_out: float = 0.00412
fuel_nr: int = 30
porosity: float = 0.05
fgr: float = 0.06
q_lhgr: float = 20000.0
clad_r_in: float = 0.00422
clad_r_out: float = 0.00475
clad_nr: int = 5
clad_T_out: float = 600.0
fast_flux: float = 10000000000000.0
roughness: float = 6e-06
T_plenum: float = 600.0
p0: float = 1.0
v_gas_plenum: float = 1e-05
cool_p: float = 16.0
time_end_years: float = 6.0
time_step_days: float = 1.0
class orpheus.fuel.solver.FuelBehaviourResult(time, time_years, fuel_r, clad_r, fuel_T, clad_T, fuel_sig_r, fuel_sig_h, fuel_sig_z, fuel_sig_vm, clad_sig_r, clad_sig_h, clad_sig_z, clad_sig_vm, fuel_eps_r, fuel_eps_h, fuel_eps_z, clad_eps_r, clad_eps_h, clad_eps_z, fuel_eps_T, fuel_eps_S, fuel_eps_rE, fuel_eps_hE, fuel_eps_zE, fuel_eps_rC, fuel_eps_hC, fuel_eps_zC, clad_eps_T, clad_eps_rE, clad_eps_hE, clad_eps_zE, clad_eps_rC, clad_eps_hC, clad_eps_zC, clad_eps_rP, clad_eps_hP, clad_eps_zP, gap_dr, gap_open, gap_p_contact, ingas_p, fuel_dz, clad_dz, burnup, geometry)[source]

Bases: object

Complete time-history of the fuel-rod calculation.

Parameters:
time: ndarray
time_years: ndarray
fuel_r: ndarray
clad_r: ndarray
fuel_T: ndarray
clad_T: ndarray
fuel_sig_r: ndarray
fuel_sig_h: ndarray
fuel_sig_z: ndarray
fuel_sig_vm: ndarray
clad_sig_r: ndarray
clad_sig_h: ndarray
clad_sig_z: ndarray
clad_sig_vm: ndarray
fuel_eps_r: ndarray
fuel_eps_h: ndarray
fuel_eps_z: ndarray
clad_eps_r: ndarray
clad_eps_h: ndarray
clad_eps_z: ndarray
fuel_eps_T: ndarray
fuel_eps_S: ndarray
fuel_eps_rE: ndarray
fuel_eps_hE: ndarray
fuel_eps_zE: ndarray
fuel_eps_rC: ndarray
fuel_eps_hC: ndarray
fuel_eps_zC: ndarray
clad_eps_T: ndarray
clad_eps_rE: ndarray
clad_eps_hE: ndarray
clad_eps_zE: ndarray
clad_eps_rC: ndarray
clad_eps_hC: ndarray
clad_eps_zC: ndarray
clad_eps_rP: ndarray
clad_eps_hP: ndarray
clad_eps_zP: ndarray
gap_dr: ndarray
gap_open: ndarray
gap_p_contact: ndarray
ingas_p: ndarray
fuel_dz: ndarray
clad_dz: ndarray
burnup: ndarray
geometry: FuelRodGeometry
orpheus.fuel.solver.solve_fuel_behaviour(geo=None, rtol=1e-06, atol=0.0001, verbose=True)[source]

Simulate fuel behaviour over the rod lifetime.

Parameters:

  • geo (FuelRodGeometry, optional) – Geometry and operating conditions. Uses defaults if None.

  • rtol (float) – Relative and absolute ODE tolerances.

  • atol (float) – Relative and absolute ODE tolerances.

  • verbose (bool) – Print progress messages.

Return type:

FuelBehaviourResult