diff --git a/doc/content/source/scalar_kernels/FuelCycleSystemScalarKernel.md b/doc/content/source/scalar_kernels/FuelCycleSystemScalarKernel.md
new file mode 100644
index 000000000..7d4430b90
--- /dev/null
+++ b/doc/content/source/scalar_kernels/FuelCycleSystemScalarKernel.md
@@ -0,0 +1,29 @@
+# FuelCycleSystemScalarKernel
+
+!syntax description /ScalarKernels/FuelCycleSystemScalarKernel
+
+## Overview
+
+This object implements the time-dependent mass-transport equations for a
+single variable given an arbitrary number of coupled inputs/outputs (coupled [ScalarVariables](/syntax/Variables))
+and/or sources and sinks. Also tracks tritium decay. All parameters are defined as functors,
+which should allow versatility in accepting a variety of input arguments. An example of using this
+kernel for a system is available, following the [Abdou fuel cycle](/examples/fuel_cycle_Abdou) model.
+
+Rather than using [`ParsedODEKernel`](/syntax/ScalarKernels/ParsedODEKernel) and [`ODETimeDerivative`](/syntax/Scalarkernels/ODETimeDerivative) kernels, the scalar kernels block can be simplified.
+
+!listing test/tests/fuel_cycle_Abdou/fuel_cycle_abdou_generic.i link=false block=ScalarKernels
+
+There is still a need to define appropriate [`Postprocessors`](/syntax/Postprocessors) to inform the scalar kernels, as these cannot be assumed for the general case.
+
+!listing test/tests/fuel_cycle_Abdou/fuel_cycle_abdou_generic.i link=false block=Postprocessors
+
+As a reminder, the system of variables should be defined with the [!param](/Variables/family) attribute set to `SCALAR` for each variable.
+
+!listing test/tests/fuel_cycle_Abdou/fuel_cycle_abdou_generic.i link=false block=Variables/T_01_BZ
+
+!syntax parameters /ScalarKernels/FuelCycleSystemScalarKernel
+
+!syntax inputs /ScalarKernels/FuelCycleSystemScalarKernel
+
+!syntax children /ScalarKernels/FuelCycleSystemScalarKernel
diff --git a/include/scalar_kernels/FuelCycleSystemScalarKernel.h b/include/scalar_kernels/FuelCycleSystemScalarKernel.h
new file mode 100644
index 000000000..d3c148bba
--- /dev/null
+++ b/include/scalar_kernels/FuelCycleSystemScalarKernel.h
@@ -0,0 +1,49 @@
+/************************************************************/
+/*                DO NOT MODIFY THIS HEADER                 */
+/*   TMAP8: Tritium Migration Analysis Program, Version 8   */
+/*                                                          */
+/*   Copyright 2021 - 2025 Battelle Energy Alliance, LLC    */
+/*                   ALL RIGHTS RESERVED                    */
+/************************************************************/
+
+#pragma once
+
+#include "ODETimeDerivative.h"
+#include "ADScalarTimeDerivative.h"
+#include "FunctorInterface.h"
+#include "MooseTypes.h"
+
+template <bool is_ad>
+class FuelCycleSystemScalarKernelTempl
+  : public std::conditional<is_ad, ADScalarTimeDerivative, ODETimeDerivative>::type,
+    public FunctorInterface
+{
+  using Base = typename std::conditional<is_ad, ADScalarTimeDerivative, ODETimeDerivative>::type;
+
+public:
+  FuelCycleSystemScalarKernelTempl(const InputParameters & parameters);
+  virtual bool isADObject() const override { return is_ad; };
+  static InputParameters validParams();
+
+protected:
+  virtual GenericReal<is_ad> computeQpResidual() override;
+  virtual Real computeQpJacobian();
+  size_t _n_inputs;
+  size_t _n_other_sources;
+  size_t _n_other_sinks;
+  std::vector<const VariableValue *> _input_vals;
+  std::vector<const Moose::Functor<GenericReal<is_ad>> *> _input_fractions;
+  const Moose::Functor<GenericReal<is_ad>> & _decay_constant;
+  const Moose::Functor<GenericReal<is_ad>> & _residence_time;
+  const Moose::Functor<GenericReal<is_ad>> & _leakage_rate;
+  bool _pseudo_steady_state;
+  bool _disable_residence_time;
+  bool _is_implicit;
+  const Moose::Functor<GenericReal<is_ad>> & _TBR;
+  std::vector<const Moose::Functor<GenericReal<is_ad>> *> _other_sources;
+  std::vector<const Moose::Functor<GenericReal<is_ad>> *> _other_sinks;
+  const Moose::Functor<GenericReal<is_ad>> & _burn_rate;
+};
+
+typedef FuelCycleSystemScalarKernelTempl<false> FuelCycleSystemScalarKernel;
+typedef FuelCycleSystemScalarKernelTempl<true> ADFuelCycleSystemScalarKernel;
diff --git a/src/scalar_kernels/FuelCycleSystemScalarKernel.C b/src/scalar_kernels/FuelCycleSystemScalarKernel.C
new file mode 100644
index 000000000..ad49a5033
--- /dev/null
+++ b/src/scalar_kernels/FuelCycleSystemScalarKernel.C
@@ -0,0 +1,184 @@
+/************************************************************/
+/*                DO NOT MODIFY THIS HEADER                 */
+/*   TMAP8: Tritium Migration Analysis Program, Version 8   */
+/*                                                          */
+/*   Copyright 2021 - 2025 Battelle Energy Alliance, LLC    */
+/*                   ALL RIGHTS RESERVED                    */
+/************************************************************/
+#include "FuelCycleSystemScalarKernel.h"
+
+// MOOSE includes
+#include "Assembly.h"
+#include "MooseVariableScalar.h"
+#include "FunctorInterface.h"
+#include "TMAP8PhysicalConstants.h"
+#include "ScalarCoupleable.h"
+
+registerMooseObject("TMAP8App", FuelCycleSystemScalarKernel);
+registerMooseObject("TMAP8App", ADFuelCycleSystemScalarKernel);
+
+template <bool is_ad>
+InputParameters
+FuelCycleSystemScalarKernelTempl<is_ad>::validParams()
+{
+  InputParameters params =
+      is_ad ? ADScalarTimeDerivative::validParams() : ODETimeDerivative::validParams();
+  params += FunctorInterface::validParams();
+  params.addClassDescription("Implements a generic system component.");
+  params.addCoupledVar(
+      "inputs", {}, "Variables which feed into this system. Takes a list of scalar variable names");
+  params.addParam<std::vector<MooseFunctorName>>(
+      "input_fractions",
+      std::vector<MooseFunctorName>({}),
+      "Fraction of upstream variable coming into this system. Must be the same length as 'inputs'");
+  params.addParam<MooseFunctorName>("decay_constant",
+                                    PhysicalConstants::tritium_decay_const,
+                                    "The decay constant of tritium (ln(2)/half-life)");
+  params.addParam<MooseFunctorName>(
+      "residence_time", 1, "The residence time for tritium in this system");
+  params.addParam<MooseFunctorName>(
+      "leakage_rate", 0, "The fractional loss rate for tritium in this system");
+  params.addParam<bool>("steady_state",
+                        false,
+                        "Whether to apply a psuedo steady-state approximation (ignore dt term)");
+  params.addParam<bool>(
+      "is_implicit",
+      false,
+      "Whether an explicit (previous value calculation) or implicit (current value) is used");
+  params.addParam<MooseFunctorName>("TBR", 0.0, "Tritium breeding ratio");
+  params.addParam<std::vector<MooseFunctorName>>(
+      "other_sources",
+      std::vector<MooseFunctorName>({}),
+      "Other tritium sources - terms not dependent on any scalar variables");
+  params.addParam<std::vector<MooseFunctorName>>(
+      "other_sinks",
+      std::vector<MooseFunctorName>({}),
+      "Other tritium sinks - terms not dependent on any scalar variables");
+  params.addParam<MooseFunctorName>("burn_rate", 0.0, "Burn rate of tritium within this system");
+  params.addParam<bool>("disable_residence_time",
+                        false,
+                        "Assume an infinite residence time. (no leakage from this system).");
+  return params;
+}
+
+template <bool is_ad>
+FuelCycleSystemScalarKernelTempl<is_ad>::FuelCycleSystemScalarKernelTempl(
+    const InputParameters & parameters)
+  : Base(parameters),
+    FunctorInterface(this),
+    _n_inputs(ScalarCoupleable::isCoupledScalar("inputs")
+                  ? ScalarCoupleable::coupledScalarComponents("inputs")
+                  : 0),
+    _n_other_sources(
+        this->template getParam<std::vector<MooseFunctorName>>("other_sources").size()),
+    _n_other_sinks(this->template getParam<std::vector<MooseFunctorName>>("other_sinks").size()),
+    _input_vals(_n_inputs),
+    _input_fractions(
+        this->template getParam<std::vector<MooseFunctorName>>("input_fractions").size()),
+    _decay_constant(this->template getFunctor<GenericReal<is_ad>>("decay_constant")),
+    _residence_time(this->template getFunctor<GenericReal<is_ad>>("residence_time")),
+    _leakage_rate(this->template getFunctor<GenericReal<is_ad>>("leakage_rate")),
+    _pseudo_steady_state(this->template getParam<bool>("steady_state")),
+    _disable_residence_time(this->template getParam<bool>("disable_residence_time")),
+    _is_implicit(this->template getParam<bool>("is_implicit")),
+    _TBR(this->template getFunctor<GenericReal<is_ad>>("TBR")),
+    _other_sources(this->template getParam<std::vector<MooseFunctorName>>("other_sources").size()),
+    _other_sinks(this->template getParam<std::vector<MooseFunctorName>>("other_sinks").size()),
+    _burn_rate(this->template getFunctor<GenericReal<is_ad>>("burn_rate"))
+{
+  if (_n_inputs != _input_fractions.size())
+  {
+    mooseError("\"input_fractions\" must be defined with the same length as \"inputs\".");
+  }
+  auto & input_functor_names =
+      MooseBase::getParam<std::vector<MooseFunctorName>>("input_fractions");
+  for (size_t i = 0; i < _n_inputs; ++i)
+  {
+    if ((ScalarCoupleable::coupledScalar("inputs", i)) == (Base::_var).number())
+    {
+      mooseError("Primary variable cannot be listed as a coupled variable.");
+    }
+    _input_vals[i] = &(ScalarCoupleable::coupledScalarValue("inputs", i));
+    _input_fractions[i] = &(this->template getFunctor<GenericReal<is_ad>>(input_functor_names[i]));
+  }
+  auto & other_source_names = MooseBase::getParam<std::vector<MooseFunctorName>>("other_sources");
+  for (size_t i = 0; i < _n_other_sources; ++i)
+  {
+    _other_sources[i] = &(this->template getFunctor<GenericReal<is_ad>>(other_source_names[i]));
+  }
+  auto & other_sink_names = MooseBase::getParam<std::vector<MooseFunctorName>>("other_sinks");
+  for (size_t i = 0; i < _n_other_sinks; ++i)
+  {
+    _other_sinks[i] = &(this->template getFunctor<GenericReal<is_ad>>(other_sink_names[i]));
+  }
+}
+
+template <bool is_ad>
+GenericReal<is_ad>
+FuelCycleSystemScalarKernelTempl<is_ad>::computeQpResidual()
+{
+  GenericReal<is_ad> partial_residual = 0;
+  const Moose::ElemArg _qp = Moose::ElemArg();
+  const int _i = 0;
+  const auto _state = _is_implicit ? Moose::currentState() : Moose::oldState();
+  for (unsigned int i = 0; i < _n_inputs; ++i)
+  {
+    partial_residual += -(*(_input_vals[i]))[_i] * (*(_input_fractions[i]))(_qp, _state);
+  }
+  for (unsigned int i = 0; i < _n_other_sources; ++i)
+  {
+    partial_residual += -(*(_other_sources[i]))(_qp, _state);
+  }
+  for (unsigned int i = 0; i < _n_other_sinks; ++i)
+  {
+    partial_residual += (*(_other_sinks[i]))(_qp, _state);
+  }
+  partial_residual += -_TBR(_qp, _state) * _burn_rate(_qp, _state);
+  if (!_disable_residence_time)
+  {
+    partial_residual += _leakage_rate(_qp, _state) / _residence_time(_qp, _state) * Base::_u[_i];
+    partial_residual += Base::_u[_i] / _residence_time(_qp, _state);
+  }
+  partial_residual += _decay_constant(_qp, _state) * Base::_u[_i];
+  if (!_pseudo_steady_state)
+    partial_residual += Base::_u_dot[_i];
+  return partial_residual;
+}
+
+template <bool is_ad>
+Real
+FuelCycleSystemScalarKernelTempl<is_ad>::computeQpJacobian()
+{
+  if constexpr (!is_ad)
+  {
+    Real partial_residual = 0;
+    const Moose::ElemArg _qp = Moose::ElemArg();
+    const int _i = 0;
+    const auto _state = _is_implicit ? Moose::currentState() : Moose::oldState();
+    if (!_disable_residence_time)
+    {
+      partial_residual += _leakage_rate(_qp, _state) / _residence_time(_qp, _state);
+      partial_residual += 1 / _residence_time(_qp, _state);
+    }
+    partial_residual += _decay_constant(_qp, _state);
+    if (!_pseudo_steady_state)
+      partial_residual += Base::_du_dot_du[_i];
+    return partial_residual;
+  }
+  else
+  {
+    mooseError("computeQpJacobian() should not be called in AD mode");
+    return 0;
+  }
+}
+
+template <>
+Real
+FuelCycleSystemScalarKernelTempl<true>::computeQpJacobian()
+{
+  mooseError("Internal error, calling computeQpJacobian in AD class.");
+  return 0.0;
+}
+
+template class FuelCycleSystemScalarKernelTempl<false>;
+template class FuelCycleSystemScalarKernelTempl<true>;
diff --git a/test/tests/fuel_cycle_Abdou/fuel_cycle.i b/test/tests/fuel_cycle_Abdou/fuel_cycle.i
index 23af444d0..7b4fcb888 100644
--- a/test/tests/fuel_cycle_Abdou/fuel_cycle.i
+++ b/test/tests/fuel_cycle_Abdou/fuel_cycle.i
@@ -79,7 +79,6 @@
 # on the ParsedODEKernels due to moving the terms to the
 # left hand side.
 
-
 [ScalarKernels]
   [I1t]
     type = ODETimeDerivative
@@ -296,7 +295,7 @@
     value = 0.95
   []
   [TBR] #According to the PhD Thesis referenced in the paper,
-        # this is the required Tritium Breeding Ratio (TBR)
+    # this is the required Tritium Breeding Ratio (TBR)
     type = ConstantPostprocessor
     execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
     value = 1.9247
@@ -339,7 +338,7 @@
   [epsilon8] #FCU
     type = ConstantPostprocessor
     execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
-    value =  1e-4
+    value = 1e-4
   []
   [epsilon9] #ISS
     type = ConstantPostprocessor
@@ -419,7 +418,7 @@
   [tdecay]
     type = ConstantPostprocessor
     execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
-    value = ${fparse log(2)/388800000.0}
+    value = '${fparse log(2)/388800000.0}'
   []
   [tritium_burn_fraction]
     type = ConstantPostprocessor
diff --git a/test/tests/fuel_cycle_Abdou/fuel_cycle_abdou_generic.i b/test/tests/fuel_cycle_Abdou/fuel_cycle_abdou_generic.i
new file mode 100644
index 000000000..860247282
--- /dev/null
+++ b/test/tests/fuel_cycle_Abdou/fuel_cycle_abdou_generic.i
@@ -0,0 +1,643 @@
+# This input file re-creates the deuterium-tritium fuel cycle model
+# described by Abdou et al (2021).
+# "Physics and technology considerations for the deuterium-tritium fuel cycle
+#   and conditions for tritium fuel self sufficiency" M Abdou & M Riva & A Ying
+#   & C Day & A Loarte & L R Baylor & P Humrickhouse & T F Fuerst & S Cho
+#   Nucl. Fusion 61 (2021) https://doi.org/10.1088/1741-4326/abbf35
+
+# Since this is a 0D simulation, the mesh is only a single point. If high-fidelity
+# models of specific components are required, the scalar variables can be coupled to
+# "Field" variables which can vary spatially across the mesh, or could be co-ordinated
+# with sub-apps.
+
+[Mesh]
+  type = GeneratedMesh
+  dim = 1
+  xmin = 0
+  xmax = 1
+  nx = 1
+[]
+
+# One variable for each inventory of tritium is generated. All variables
+# are defined as "SCALAR", meaning that they are a single value and are
+# disconnected from any specific geometry
+
+[Variables]
+  [T_01_BZ]
+    family = SCALAR
+  []
+  [T_02_TES]
+    family = SCALAR
+  []
+  [T_03_FW]
+    family = SCALAR
+  []
+  [T_04_DIV]
+    family = SCALAR
+  []
+  [T_05_HX]
+    family = SCALAR
+  []
+  [T_06_CPS]
+    family = SCALAR
+  []
+  [T_07_vacuum]
+    family = SCALAR
+  []
+  [T_08_FCU]
+    family = SCALAR
+  []
+  [T_09_ISS]
+    family = SCALAR
+  []
+  [T_10_exhaust]
+    family = SCALAR
+  []
+  [T_11_storage]
+    family = SCALAR
+    initial_condition = 225.4215
+  []
+[]
+
+# Tritium burn fraction is going to be small. Much
+# will be lost to the scrape-off-layer (SOL) and
+# recycled.
+
+# TES - tritium extraction system pulls tritium from
+# the blanket
+
+# CPS - Coolant purification system pulls tritium from
+# the coolant
+
+# An ODE is defined in TMAP8 such that all of the terms must
+# be on the left hand side. The terms can be split
+# across multiple "ScalarKernels", which are additive,
+# so that we have one ODETimeDerivative for each tritium
+# inventory and a ParsedODEKernel for the rest of the
+# terms. These equations should reflect those described
+# in Appendix A of the paper (A.1-A.13), with negation
+# on the ParsedODEKernels due to moving the terms to the
+# left hand side.
+
+[ScalarKernels]
+  [I1] # Breeding Zone
+    type = FuelCycleSystemScalarKernel
+    TBR = TBR
+    burn_rate = tritium_burn_rate
+    inputs = 'T_02_TES '
+    input_fractions = TES_frac # expression = '(1 - TES_efficiency)/residence2'
+    residence_time = residence1
+    leakage_rate = epsilon1
+    variable = 'T_01_BZ'
+  []
+  [I2] #Tritium Extraction System
+    type = FuelCycleSystemScalarKernel
+    inputs = 'T_01_BZ'
+    input_fractions = BZ_TES_frac
+    residence_time = residence2
+    leakage_rate = epsilon2
+    variable = 'T_02_TES'
+  []
+  [I3] #First Wall
+    type = FuelCycleSystemScalarKernel
+    variable = 'T_03_FW'
+    other_sources = 'plasma_FW_flux'
+    inputs = 'T_05_HX T_06_CPS'
+    input_fractions = 'HX_FW_flux HX_CPS_flux'
+    residence_time = residence3
+    leakage_rate = epsilon3
+  []
+  [I4] #Divertor
+    type = FuelCycleSystemScalarKernel
+    other_sources = 'plasma_div_flux'
+    inputs = 'T_05_HX T_06_CPS'
+    input_fractions = 'HX_div_flux CPS_div_flux'
+    residence_time = residence4
+    leakage_rate = epsilon4
+    variable = 'T_04_DIV'
+  []
+  [I5] #Heat eXchanger
+    type = FuelCycleSystemScalarKernel
+    inputs = 'T_01_BZ T_03_FW T_04_DIV'
+    input_fractions = 'BZ_HX_flux FW_HX_flux div_HX_flux'
+    variable = 'T_05_HX'
+    residence_time = 'residence5'
+    leakage_rate = epsilon5
+  []
+  [I6] #Coolant Purification System
+    type = FuelCycleSystemScalarKernel
+    inputs = 'T_05_HX'
+    input_fractions = 'CPS_HX_flux'
+    leakage_rate = epsilon6
+    residence_time = residence6
+    variable = 'T_06_CPS'
+  []
+  [I7] #Vacuum Pump
+    type = FuelCycleSystemScalarKernel
+    other_sources = Vacuum_pump_breeding
+    variable = 'T_07_vacuum'
+    leakage_rate = epsilon7
+    residence_time = residence7
+  []
+  [I8] #Fuel clean-up
+    type = FuelCycleSystemScalarKernel
+    inputs = 'T_07_vacuum'
+    input_fractions = 'VAC_FCX_flux'
+    leakage_rate = epsilon8
+    residence_time = residence8
+    variable = 'T_08_FCU'
+  []
+  [I9] #Isotope Separation System
+    type = FuelCycleSystemScalarKernel
+    inputs = 'T_02_TES T_06_CPS T_08_FCU T_10_exhaust'
+    input_fractions = 'TES_ISS_flux CPS_ISS_flux FCU_ISS_flux EXH_ISS_flux'
+    leakage_rate = epsilon9
+    residence_time = residence9
+    variable = 'T_09_ISS'
+  []
+  [I10] #Exhaust and Water Detritiation System (EXO)
+    type = FuelCycleSystemScalarKernel
+    inputs = 'T_05_HX T_09_ISS'
+    input_fractions = 'HX_EXO_flux ISS_EXO_flux'
+    variable = 'T_10_exhaust'
+    leakage_rate = epsilon10
+    residence_time = residence10
+  []
+  [I11] #Storage and Management (STO)
+    type = FuelCycleSystemScalarKernel
+    inputs = 'T_08_FCU T_09_ISS'
+    input_fractions = 'FCU_STO_flux ISS_STO_flux'
+    other_sinks = 'device_T_consumption'
+    variable = 'T_11_storage'
+    disable_residence_time = true
+  []
+[]
+
+# These postprocessors define the constants referenced in
+# the equations above. The value of any of these constants
+# could be informed by more detailed models (using sub-apps
+# and transfers), but it is important that the postprocessor
+# is evaluated before the executioner attempts to solve the
+# ODE, which is not the default behavior.
+[Postprocessors]
+  [BZ_HX_leak_fraction] #f_{1-5}
+    type = ConstantPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    value = 1e-2
+  []
+  [CPS_FW_leak_fraction] #f_{6-3}
+    type = ConstantPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    value = 0.6
+  []
+  [CPS_efficiency] #eta_6
+    type = ConstantPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    value = 0.95
+  []
+  [FCU_STO_fraction] #f_{8-11}
+    type = ConstantPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    value = 0
+  []
+  [HX_CPS_leak_fraction] #f_{5-6}
+    type = ConstantPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    value = 1e-2
+  []
+  [HX_EXO_leak_fraction] #f_{5-10}
+    type = ConstantPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    value = 1e-4
+  []
+  [HX_FW_leak_fraction] #f_{5-3}
+    type = ConstantPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    value = 0.6
+  []
+  [ISS_EXO_leak_fraction] #f_{9-10}
+    type = ConstantPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    value = 1e-1
+  []
+  [P_DIV_leak_fraction] #f_{P-4}
+    type = ConstantPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    value = 1e-4
+  []
+  [P_FW_leak_fraction] #f_{P_3}
+    type = ConstantPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    value = 1e-4
+  []
+  [TES_efficiency] #eta_2
+    type = ConstantPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    value = 0.95
+  []
+  [TBR] #According to the PhD Thesis referenced in the paper,
+    # this is the required Tritium Breeding Ratio (TBR)
+    type = ConstantPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    value = 1.9247
+  []
+  [epsilon1] #BZ
+    type = ConstantPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    value = 0
+  []
+  [epsilon2] #TES
+    type = ConstantPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    value = 1e-4
+  []
+  [epsilon3] #FW
+    type = ConstantPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    value = 0
+  []
+  [epsilon4] #DIV
+    type = ConstantPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    value = 0
+  []
+  [epsilon5] #HX
+    type = ConstantPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    value = 1e-4
+  []
+  [epsilon6] #CPS
+    type = ConstantPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    value = 1e-4
+  []
+  [epsilon7] #Vac
+    type = ConstantPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    value = 1e-4
+  []
+  [epsilon8] #FCU
+    type = ConstantPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    value = 1e-4
+  []
+  [epsilon9] #ISS
+    type = ConstantPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    value = 1e-4
+  []
+  [epsilon10] #EXO
+    type = ConstantPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    value = 1e-4
+  []
+  [epsilon11] #STO
+    type = ConstantPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    value = 0
+  []
+  [residence1] #BZ
+    type = ConstantPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    value = 86400 #1 day, Abdou
+    #value = 8640-86400 EXOTIC-6-7-8
+  []
+  [residence2] #TES
+    type = ConstantPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    value = 86400 # Abdou
+    #value = 86400-432000 Riva
+  []
+  [TES_frac]
+    type = ParsedPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    pp_names = 'TES_efficiency residence2'
+    expression = '(1 - TES_efficiency)/residence2'
+  []
+  [BZ_TES_frac]
+    type = ParsedPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    pp_names = 'BZ_HX_leak_fraction residence2'
+    expression = '(1 - BZ_HX_leak_fraction)/residence2'
+  []
+  [plasma_FW_flux]
+    type = ParsedPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    expression = 'P_FW_leak_fraction*tritium_burn_rate /tritium_burn_fraction / tritium_fueling_efficiency'
+    pp_names = 'P_FW_leak_fraction tritium_burn_rate tritium_burn_fraction tritium_fueling_efficiency'
+  []
+  [HX_FW_flux]
+    type = ParsedPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    expression = 'HX_FW_leak_fraction * (1 - HX_CPS_leak_fraction) * (1 - HX_EXO_leak_fraction)/residence5'
+    pp_names = 'HX_FW_leak_fraction HX_CPS_leak_fraction HX_EXO_leak_fraction residence5'
+  []
+  [HX_CPS_flux]
+    type = ParsedPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    expression = 'CPS_FW_leak_fraction * (1 - CPS_efficiency) /residence6'
+    pp_names = 'CPS_FW_leak_fraction CPS_efficiency residence6'
+  []
+  [CPS_HX_flux]
+    type = ParsedPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    expression = 'HX_CPS_leak_fraction * (1 - HX_EXO_leak_fraction)/residence5'
+    pp_names = 'HX_CPS_leak_fraction HX_EXO_leak_fraction residence5'
+  []
+  [plasma_div_flux]
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    type = ParsedPostprocessor
+    expression = 'P_DIV_leak_fraction * tritium_burn_rate/tritium_burn_fraction / tritium_fueling_efficiency'
+    pp_names = 'P_DIV_leak_fraction tritium_burn_rate tritium_burn_fraction tritium_fueling_efficiency'
+  []
+  [HX_div_flux]
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    type = ParsedPostprocessor
+    expression = '(1-HX_FW_leak_fraction)* (1-HX_CPS_leak_fraction)*(1-HX_EXO_leak_fraction)/residence5'
+    pp_names = 'HX_FW_leak_fraction HX_CPS_leak_fraction HX_EXO_leak_fraction residence5'
+  []
+  [CPS_div_flux]
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    type = ParsedPostprocessor
+    expression = '(1-CPS_FW_leak_fraction)*(1 - CPS_efficiency) /residence6'
+    pp_names = 'CPS_FW_leak_fraction CPS_efficiency residence6'
+  []
+  [BZ_HX_flux]
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    type = ParsedPostprocessor
+    expression = 'BZ_HX_leak_fraction/residence1'
+    pp_names = 'BZ_HX_leak_fraction residence1'
+  []
+  [FW_HX_flux]
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    type = ParsedPostprocessor
+    expression = '1/residence3'
+    pp_names = 'residence3'
+  []
+  [div_HX_flux]
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    type = ParsedPostprocessor
+    expression = '1/residence4'
+    pp_names = 'residence4'
+  []
+  [Vacuum_pump_breeding]
+    type = ParsedPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    expression = '(1-tritium_burn_fraction*tritium_fueling_efficiency - P_FW_leak_fraction
+                    - P_DIV_leak_fraction) * tritium_burn_rate/(tritium_burn_fraction
+                    * tritium_fueling_efficiency)'
+    pp_names = 'tritium_burn_fraction tritium_fueling_efficiency P_FW_leak_fraction
+     P_DIV_leak_fraction tritium_burn_rate'
+  []
+  [VAC_FCX_flux]
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    type = ParsedPostprocessor
+    expression = '1/residence7'
+    pp_names = 'residence7'
+  []
+  [TES_ISS_flux]
+    type = ParsedPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    expression = 'TES_efficiency/residence2 '
+    pp_names = 'TES_efficiency residence2'
+  []
+  [FCU_ISS_flux]
+    type = ParsedPostprocessor
+    pp_names = 'FCU_STO_fraction residence8'
+    expression = '(1-FCU_STO_fraction)/residence8'
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+  []
+  [CPS_ISS_flux]
+    type = ParsedPostprocessor
+    expression = 'CPS_efficiency/residence6'
+    pp_names = 'CPS_efficiency residence6'
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+  []
+  [EXH_ISS_flux]
+    type = ParsedPostprocessor
+    expression = '1/residence10'
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    pp_names = 'residence10'
+  []
+  [HX_EXO_flux]
+    type = ParsedPostprocessor
+    expression = 'HX_EXO_leak_fraction/residence5'
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    pp_names = 'HX_EXO_leak_fraction residence5'
+  []
+  [ISS_EXO_flux]
+    type = ParsedPostprocessor
+    expression = 'ISS_EXO_leak_fraction/residence9'
+    pp_names = 'ISS_EXO_leak_fraction residence9'
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+  []
+  [FCU_STO_flux]
+    type = ParsedPostprocessor
+    expression = 'FCU_STO_fraction /residence8'
+    pp_names = 'FCU_STO_fraction residence8'
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+  []
+  [ISS_STO_flux]
+    type = ParsedPostprocessor
+    expression = '(1-ISS_EXO_leak_fraction)/residence9'
+    pp_names = 'ISS_EXO_leak_fraction residence9'
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+  []
+  [device_T_consumption]
+    type = ParsedPostprocessor
+    expression = 'tritium_burn_rate/tritium_burn_fraction/tritium_fueling_efficiency'
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    pp_names = 'tritium_burn_rate tritium_burn_fraction tritium_fueling_efficiency'
+  []
+
+  [residence3] #FW
+    type = ConstantPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    value = 1000 #Riva
+  []
+  [residence4] #DIV
+    type = ConstantPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    value = 1000 #Riva
+  []
+  [residence5] #HX
+    type = ConstantPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    value = 1000 # Abdou 2021 paper chosen for analysis
+  []
+  [residence6] #CPS
+    type = ConstantPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    value = 864000 #Abdou analysis case
+    #value 8640000 Abdou 1,4
+  []
+  [residence7] #Vac
+    type = ConstantPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    value = 1
+    #value = 1800 # 30 minutes (20-30 minutes)
+  []
+  [residence8] #FCU
+    type = ConstantPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    value = 1
+    #value = 4680 # 1.3 h as per Day
+    #value = 5 h Coleman
+    #value = 8640 Abdou
+    #value = 86400 Abdou
+  []
+  [residence9] #ISS
+    type = ConstantPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    value = 14400
+    #value = 7920 #(for four hour overall residence time in inner loop)
+  []
+  [residence10] #EXO
+    type = ConstantPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    value = 3600 # Day et al
+    #value = 72000 #Coleman et al
+  []
+  [tdecay]
+    type = ConstantPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    value = '${fparse log(2)/388800000.0}'
+  []
+  [tritium_burn_fraction]
+    type = ConstantPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    value = 0.0036
+  []
+  [tritium_burn_rate]
+    type = ConstantPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    value = 5.3125e-6 # 0.459 kg/day
+  []
+  [tritium_fueling_efficiency]
+    type = ConstantPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    value = 0.25
+  []
+  # These postprocessors exist to sum up the tritium inventory
+  #  across the entirety of the system
+  [T_BZ]
+    type = ScalarVariable
+    variable = T_01_BZ
+    execute_on = TIMESTEP_END
+  []
+  [T_TES]
+    type = ScalarVariable
+    variable = T_02_TES
+    execute_on = TIMESTEP_END
+  []
+  [T_FW]
+    type = ScalarVariable
+    variable = T_03_FW
+    execute_on = TIMESTEP_END
+  []
+  [T_DIV]
+    type = ScalarVariable
+    variable = T_04_DIV
+    execute_on = TIMESTEP_END
+  []
+  [T_HX]
+    type = ScalarVariable
+    variable = T_05_HX
+    execute_on = TIMESTEP_END
+  []
+  [T_CPS]
+    type = ScalarVariable
+    variable = T_06_CPS
+    execute_on = TIMESTEP_END
+  []
+  [T_VAC]
+    type = ScalarVariable
+    variable = T_07_vacuum
+    execute_on = TIMESTEP_END
+  []
+  [T_FCU]
+    type = ScalarVariable
+    variable = T_08_FCU
+    execute_on = TIMESTEP_END
+  []
+  [T_ISS]
+    type = ScalarVariable
+    variable = T_09_ISS
+    execute_on = TIMESTEP_END
+  []
+  [T_EXO]
+    type = ScalarVariable
+    variable = T_10_exhaust
+    execute_on = TIMESTEP_END
+  []
+  [T_STO]
+    type = ScalarVariable
+    variable = T_11_storage
+    execute_on = TIMESTEP_END
+  []
+  [total_tritium]
+    type = SumPostprocessor
+    values = 'T_BZ T_TES T_FW T_DIV T_HX T_CPS T_VAC T_FCU T_ISS T_EXO T_STO'
+  []
+[]
+[UserObjects]
+  [terminator]
+    type = Terminator
+    expression = 'T_STO < 0'
+    fail_mode = 'HARD'
+    message = 'Tritium in storage has been depleted'
+  []
+  [terminator2]
+    type = Terminator
+    expression = 'total_tritium < 0'
+    fail_mode = 'HARD'
+    message = 'Tritium in system has been depleted'
+  []
+[]
+# The tritium breeding ratio is not directly given in the paper,
+# but is specified as a "five year" doubling time from the initial
+# inventory. As such, it may be necessary to force the simulation to
+# record a timestep at exactly five years, or whatever doubling time
+# is wanted, to dial in the tritium breeding ratio. This can be done
+# using the IterationAdaptiveDT settings commented out below along
+# with this function.
+#
+#[Functions]
+#  [catch_five_year]
+#    type = PiecewiseLinear
+#    x = '0 157680000 157680100 864000000.0'
+#    y = '0 0 1 1'
+#  []
+#[]
+
+[Executioner]
+  type = Transient
+  start_time = 0
+  dtmin = 1
+  end_time = 946080000.0
+  [TimeStepper]
+    type = IterationAdaptiveDT
+    growth_factor = 1.4
+    dt = 5
+    #timestep_limiting_function = 'catch_five_year'
+    #max_function_change = 0.5
+    #force_step_every_function_point = true
+  []
+  solve_type = 'PJFNK'
+  nl_rel_tol = 1e-08
+  nl_abs_tol = 1e-14
+[]
+[Outputs]
+  hide = "BZ_HX_leak_fraction CPS_FW_leak_fraction CPS_efficiency FCU_STO_fraction
+          HX_CPS_leak_fraction HX_EXO_leak_fraction HX_FW_leak_fraction ISS_EXO_leak_fraction
+          P_DIV_leak_fraction P_FW_leak_fraction TBR TES_efficiency T_BZ T_CPS T_DIV T_EXO
+          T_FCU T_FW T_HX T_ISS T_STO T_TES T_VAC epsilon1 epsilon10 epsilon11 epsilon2 epsilon3
+          epsilon4 epsilon5 epsilon6 epsilon7 epsilon8 epsilon9 residence1 residence10 residence2
+          residence3 residence4 residence5 residence6 residence7 residence8 residence9 tdecay
+          tritium_burn_fraction tritium_burn_rate tritium_fueling_efficiency BZ_TES_frac CPS_HX_flux
+          CPS_ISS_flux CPS_div_flux EXH_ISS_flux FCU_ISS_flux FCU_STO_flux FW_HX_flux HX_CPS_flux
+          HX_EXO_flux HX_FW_flux HX_div_flux ISS_EXO_flux ISS_STO_flux TES_ISS_flux TES_frac VAC_FCX_flux
+          Vacuum_pump_breeding device_T_consumption div_HX_flux plasma_FW_flux plasma_div_flux BZ_HX_flux"
+  csv = true
+  console = false
+[]
diff --git a/test/tests/fuel_cycle_Abdou/fuel_cycle_abdou_generic_AD.i b/test/tests/fuel_cycle_Abdou/fuel_cycle_abdou_generic_AD.i
new file mode 100644
index 000000000..faf067cdc
--- /dev/null
+++ b/test/tests/fuel_cycle_Abdou/fuel_cycle_abdou_generic_AD.i
@@ -0,0 +1,643 @@
+# This input file re-creates the deuterium-tritium fuel cycle model
+# described by Abdou et al (2021).
+# "Physics and technology considerations for the deuterium-tritium fuel cycle
+#   and conditions for tritium fuel self sufficiency" M Abdou & M Riva & A Ying
+#   & C Day & A Loarte & L R Baylor & P Humrickhouse & T F Fuerst & S Cho
+#   Nucl. Fusion 61 (2021) https://doi.org/10.1088/1741-4326/abbf35
+
+# Since this is a 0D simulation, the mesh is only a single point. If high-fidelity
+# models of specific components are required, the scalar variables can be coupled to
+# "Field" variables which can vary spatially across the mesh, or could be co-ordinated
+# with sub-apps.
+
+[Mesh]
+  type = GeneratedMesh
+  dim = 1
+  xmin = 0
+  xmax = 1
+  nx = 1
+[]
+
+# One variable for each inventory of tritium is generated. All variables
+# are defined as "SCALAR", meaning that they are a single value and are
+# disconnected from any specific geometry
+
+[Variables]
+  [T_01_BZ]
+    family = SCALAR
+  []
+  [T_02_TES]
+    family = SCALAR
+  []
+  [T_03_FW]
+    family = SCALAR
+  []
+  [T_04_DIV]
+    family = SCALAR
+  []
+  [T_05_HX]
+    family = SCALAR
+  []
+  [T_06_CPS]
+    family = SCALAR
+  []
+  [T_07_vacuum]
+    family = SCALAR
+  []
+  [T_08_FCU]
+    family = SCALAR
+  []
+  [T_09_ISS]
+    family = SCALAR
+  []
+  [T_10_exhaust]
+    family = SCALAR
+  []
+  [T_11_storage]
+    family = SCALAR
+    initial_condition = 225.4215
+  []
+[]
+
+# Tritium burn fraction is going to be small. Much
+# will be lost to the scrape-off-layer (SOL) and
+# recycled.
+
+# TES - tritium extraction system pulls tritium from
+# the blanket
+
+# CPS - Coolant purification system pulls tritium from
+# the coolant
+
+# An ODE is defined in TMAP8 such that all of the terms must
+# be on the left hand side. The terms can be split
+# across multiple "ScalarKernels", which are additive,
+# so that we have one ODETimeDerivative for each tritium
+# inventory and a ParsedODEKernel for the rest of the
+# terms. These equations should reflect those described
+# in Appendix A of the paper (A.1-A.13), with negation
+# on the ParsedODEKernels due to moving the terms to the
+# left hand side.
+
+[ScalarKernels]
+  [I1] # Breeding Zone
+    type = ADFuelCycleSystemScalarKernel
+    TBR = TBR
+    burn_rate = tritium_burn_rate
+    inputs = 'T_02_TES '
+    input_fractions = TES_frac # expression = '(1 - TES_efficiency)/residence2'
+    residence_time = residence1
+    leakage_rate = epsilon1
+    variable = 'T_01_BZ'
+  []
+  [I2] #Tritium Extraction System
+    type = ADFuelCycleSystemScalarKernel
+    inputs = 'T_01_BZ'
+    input_fractions = BZ_TES_frac
+    residence_time = residence2
+    leakage_rate = epsilon2
+    variable = 'T_02_TES'
+  []
+  [I3] #First Wall
+    type = ADFuelCycleSystemScalarKernel
+    variable = 'T_03_FW'
+    other_sources = 'plasma_FW_flux'
+    inputs = 'T_05_HX T_06_CPS'
+    input_fractions = 'HX_FW_flux HX_CPS_flux'
+    residence_time = residence3
+    leakage_rate = epsilon3
+  []
+  [I4] #Divertor
+    type = ADFuelCycleSystemScalarKernel
+    other_sources = 'plasma_div_flux'
+    inputs = 'T_05_HX T_06_CPS'
+    input_fractions = 'HX_div_flux CPS_div_flux'
+    residence_time = residence4
+    leakage_rate = epsilon4
+    variable = 'T_04_DIV'
+  []
+  [I5] #Heat eXchanger
+    type = ADFuelCycleSystemScalarKernel
+    inputs = 'T_01_BZ T_03_FW T_04_DIV'
+    input_fractions = 'BZ_HX_flux FW_HX_flux div_HX_flux'
+    variable = 'T_05_HX'
+    residence_time = 'residence5'
+    leakage_rate = epsilon5
+  []
+  [I6] #Coolant Purification System
+    type = ADFuelCycleSystemScalarKernel
+    inputs = 'T_05_HX'
+    input_fractions = 'CPS_HX_flux'
+    leakage_rate = epsilon6
+    residence_time = residence6
+    variable = 'T_06_CPS'
+  []
+  [I7] #Vacuum Pump
+    type = ADFuelCycleSystemScalarKernel
+    other_sources = Vacuum_pump_breeding
+    variable = 'T_07_vacuum'
+    leakage_rate = epsilon7
+    residence_time = residence7
+  []
+  [I8] #Fuel clean-up
+    type = ADFuelCycleSystemScalarKernel
+    inputs = 'T_07_vacuum'
+    input_fractions = 'VAC_FCX_flux'
+    leakage_rate = epsilon8
+    residence_time = residence8
+    variable = 'T_08_FCU'
+  []
+  [I9] #Isotope Separation System
+    type = ADFuelCycleSystemScalarKernel
+    inputs = 'T_02_TES T_06_CPS T_08_FCU T_10_exhaust'
+    input_fractions = 'TES_ISS_flux CPS_ISS_flux FCU_ISS_flux EXH_ISS_flux'
+    leakage_rate = epsilon9
+    residence_time = residence9
+    variable = 'T_09_ISS'
+  []
+  [I10] #Exhaust and Water Detritiation System (EXO)
+    type = ADFuelCycleSystemScalarKernel
+    inputs = 'T_05_HX T_09_ISS'
+    input_fractions = 'HX_EXO_flux ISS_EXO_flux'
+    variable = 'T_10_exhaust'
+    leakage_rate = epsilon10
+    residence_time = residence10
+  []
+  [I11] #Storage and Management (STO)
+    type = ADFuelCycleSystemScalarKernel
+    inputs = 'T_08_FCU T_09_ISS'
+    input_fractions = 'FCU_STO_flux ISS_STO_flux'
+    other_sinks = 'device_T_consumption'
+    variable = 'T_11_storage'
+    disable_residence_time = true
+  []
+[]
+
+# These postprocessors define the constants referenced in
+# the equations above. The value of any of these constants
+# could be informed by more detailed models (using sub-apps
+# and transfers), but it is important that the postprocessor
+# is evaluated before the executioner attempts to solve the
+# ODE, which is not the default behavior.
+[Postprocessors]
+  [BZ_HX_leak_fraction] #f_{1-5}
+    type = ConstantPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    value = 1e-2
+  []
+  [CPS_FW_leak_fraction] #f_{6-3}
+    type = ConstantPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    value = 0.6
+  []
+  [CPS_efficiency] #eta_6
+    type = ConstantPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    value = 0.95
+  []
+  [FCU_STO_fraction] #f_{8-11}
+    type = ConstantPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    value = 0
+  []
+  [HX_CPS_leak_fraction] #f_{5-6}
+    type = ConstantPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    value = 1e-2
+  []
+  [HX_EXO_leak_fraction] #f_{5-10}
+    type = ConstantPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    value = 1e-4
+  []
+  [HX_FW_leak_fraction] #f_{5-3}
+    type = ConstantPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    value = 0.6
+  []
+  [ISS_EXO_leak_fraction] #f_{9-10}
+    type = ConstantPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    value = 1e-1
+  []
+  [P_DIV_leak_fraction] #f_{P-4}
+    type = ConstantPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    value = 1e-4
+  []
+  [P_FW_leak_fraction] #f_{P_3}
+    type = ConstantPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    value = 1e-4
+  []
+  [TES_efficiency] #eta_2
+    type = ConstantPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    value = 0.95
+  []
+  [TBR] #According to the PhD Thesis referenced in the paper,
+    # this is the required Tritium Breeding Ratio (TBR)
+    type = ConstantPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    value = 1.9247
+  []
+  [epsilon1] #BZ
+    type = ConstantPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    value = 0
+  []
+  [epsilon2] #TES
+    type = ConstantPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    value = 1e-4
+  []
+  [epsilon3] #FW
+    type = ConstantPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    value = 0
+  []
+  [epsilon4] #DIV
+    type = ConstantPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    value = 0
+  []
+  [epsilon5] #HX
+    type = ConstantPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    value = 1e-4
+  []
+  [epsilon6] #CPS
+    type = ConstantPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    value = 1e-4
+  []
+  [epsilon7] #Vac
+    type = ConstantPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    value = 1e-4
+  []
+  [epsilon8] #FCU
+    type = ConstantPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    value = 1e-4
+  []
+  [epsilon9] #ISS
+    type = ConstantPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    value = 1e-4
+  []
+  [epsilon10] #EXO
+    type = ConstantPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    value = 1e-4
+  []
+  [epsilon11] #STO
+    type = ConstantPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    value = 0
+  []
+  [residence1] #BZ
+    type = ConstantPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    value = 86400 #1 day, Abdou
+    #value = 8640-86400 EXOTIC-6-7-8
+  []
+  [residence2] #TES
+    type = ConstantPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    value = 86400 # Abdou
+    #value = 86400-432000 Riva
+  []
+  [TES_frac]
+    type = ParsedPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    pp_names = 'TES_efficiency residence2'
+    expression = '(1 - TES_efficiency)/residence2'
+  []
+  [BZ_TES_frac]
+    type = ParsedPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    pp_names = 'BZ_HX_leak_fraction residence2'
+    expression = '(1 - BZ_HX_leak_fraction)/residence2'
+  []
+  [plasma_FW_flux]
+    type = ParsedPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    expression = 'P_FW_leak_fraction*tritium_burn_rate /tritium_burn_fraction / tritium_fueling_efficiency'
+    pp_names = 'P_FW_leak_fraction tritium_burn_rate tritium_burn_fraction tritium_fueling_efficiency'
+  []
+  [HX_FW_flux]
+    type = ParsedPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    expression = 'HX_FW_leak_fraction * (1 - HX_CPS_leak_fraction) * (1 - HX_EXO_leak_fraction)/residence5'
+    pp_names = 'HX_FW_leak_fraction HX_CPS_leak_fraction HX_EXO_leak_fraction residence5'
+  []
+  [HX_CPS_flux]
+    type = ParsedPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    expression = 'CPS_FW_leak_fraction * (1 - CPS_efficiency) /residence6'
+    pp_names = 'CPS_FW_leak_fraction CPS_efficiency residence6'
+  []
+  [CPS_HX_flux]
+    type = ParsedPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    expression = 'HX_CPS_leak_fraction * (1 - HX_EXO_leak_fraction)/residence5'
+    pp_names = 'HX_CPS_leak_fraction HX_EXO_leak_fraction residence5'
+  []
+  [plasma_div_flux]
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    type = ParsedPostprocessor
+    expression = 'P_DIV_leak_fraction * tritium_burn_rate/tritium_burn_fraction / tritium_fueling_efficiency'
+    pp_names = 'P_DIV_leak_fraction tritium_burn_rate tritium_burn_fraction tritium_fueling_efficiency'
+  []
+  [HX_div_flux]
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    type = ParsedPostprocessor
+    expression = '(1-HX_FW_leak_fraction)* (1-HX_CPS_leak_fraction)*(1-HX_EXO_leak_fraction)/residence5'
+    pp_names = 'HX_FW_leak_fraction HX_CPS_leak_fraction HX_EXO_leak_fraction residence5'
+  []
+  [CPS_div_flux]
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    type = ParsedPostprocessor
+    expression = '(1-CPS_FW_leak_fraction)*(1 - CPS_efficiency) /residence6'
+    pp_names = 'CPS_FW_leak_fraction CPS_efficiency residence6'
+  []
+  [BZ_HX_flux]
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    type = ParsedPostprocessor
+    expression = 'BZ_HX_leak_fraction/residence1'
+    pp_names = 'BZ_HX_leak_fraction residence1'
+  []
+  [FW_HX_flux]
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    type = ParsedPostprocessor
+    expression = '1/residence3'
+    pp_names = 'residence3'
+  []
+  [div_HX_flux]
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    type = ParsedPostprocessor
+    expression = '1/residence4'
+    pp_names = 'residence4'
+  []
+  [Vacuum_pump_breeding]
+    type = ParsedPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    expression = '(1-tritium_burn_fraction*tritium_fueling_efficiency - P_FW_leak_fraction
+                    - P_DIV_leak_fraction) * tritium_burn_rate/(tritium_burn_fraction
+                    * tritium_fueling_efficiency)'
+    pp_names = 'tritium_burn_fraction tritium_fueling_efficiency P_FW_leak_fraction
+     P_DIV_leak_fraction tritium_burn_rate'
+  []
+  [VAC_FCX_flux]
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    type = ParsedPostprocessor
+    expression = '1/residence7'
+    pp_names = 'residence7'
+  []
+  [TES_ISS_flux]
+    type = ParsedPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    expression = 'TES_efficiency/residence2 '
+    pp_names = 'TES_efficiency residence2'
+  []
+  [FCU_ISS_flux]
+    type = ParsedPostprocessor
+    pp_names = 'FCU_STO_fraction residence8'
+    expression = '(1-FCU_STO_fraction)/residence8'
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+  []
+  [CPS_ISS_flux]
+    type = ParsedPostprocessor
+    expression = 'CPS_efficiency/residence6'
+    pp_names = 'CPS_efficiency residence6'
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+  []
+  [EXH_ISS_flux]
+    type = ParsedPostprocessor
+    expression = '1/residence10'
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    pp_names = 'residence10'
+  []
+  [HX_EXO_flux]
+    type = ParsedPostprocessor
+    expression = 'HX_EXO_leak_fraction/residence5'
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    pp_names = 'HX_EXO_leak_fraction residence5'
+  []
+  [ISS_EXO_flux]
+    type = ParsedPostprocessor
+    expression = 'ISS_EXO_leak_fraction/residence9'
+    pp_names = 'ISS_EXO_leak_fraction residence9'
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+  []
+  [FCU_STO_flux]
+    type = ParsedPostprocessor
+    expression = 'FCU_STO_fraction /residence8'
+    pp_names = 'FCU_STO_fraction residence8'
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+  []
+  [ISS_STO_flux]
+    type = ParsedPostprocessor
+    expression = '(1-ISS_EXO_leak_fraction)/residence9'
+    pp_names = 'ISS_EXO_leak_fraction residence9'
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+  []
+  [device_T_consumption]
+    type = ParsedPostprocessor
+    expression = 'tritium_burn_rate/tritium_burn_fraction/tritium_fueling_efficiency'
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    pp_names = 'tritium_burn_rate tritium_burn_fraction tritium_fueling_efficiency'
+  []
+
+  [residence3] #FW
+    type = ConstantPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    value = 1000 #Riva
+  []
+  [residence4] #DIV
+    type = ConstantPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    value = 1000 #Riva
+  []
+  [residence5] #HX
+    type = ConstantPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    value = 1000 # Abdou 2021 paper chosen for analysis
+  []
+  [residence6] #CPS
+    type = ConstantPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    value = 864000 #Abdou analysis case
+    #value 8640000 Abdou 1,4
+  []
+  [residence7] #Vac
+    type = ConstantPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    value = 1
+    #value = 1800 # 30 minutes (20-30 minutes)
+  []
+  [residence8] #FCU
+    type = ConstantPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    value = 1
+    #value = 4680 # 1.3 h as per Day
+    #value = 5 h Coleman
+    #value = 8640 Abdou
+    #value = 86400 Abdou
+  []
+  [residence9] #ISS
+    type = ConstantPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    value = 14400
+    #value = 7920 #(for four hour overall residence time in inner loop)
+  []
+  [residence10] #EXO
+    type = ConstantPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    value = 3600 # Day et al
+    #value = 72000 #Coleman et al
+  []
+  [tdecay]
+    type = ConstantPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    value = '${fparse log(2)/388800000.0}'
+  []
+  [tritium_burn_fraction]
+    type = ConstantPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    value = 0.0036
+  []
+  [tritium_burn_rate]
+    type = ConstantPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    value = 5.3125e-6 # 0.459 kg/day
+  []
+  [tritium_fueling_efficiency]
+    type = ConstantPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    value = 0.25
+  []
+  # These postprocessors exist to sum up the tritium inventory
+  #  across the entirety of the system
+  [T_BZ]
+    type = ScalarVariable
+    variable = T_01_BZ
+    execute_on = TIMESTEP_END
+  []
+  [T_TES]
+    type = ScalarVariable
+    variable = T_02_TES
+    execute_on = TIMESTEP_END
+  []
+  [T_FW]
+    type = ScalarVariable
+    variable = T_03_FW
+    execute_on = TIMESTEP_END
+  []
+  [T_DIV]
+    type = ScalarVariable
+    variable = T_04_DIV
+    execute_on = TIMESTEP_END
+  []
+  [T_HX]
+    type = ScalarVariable
+    variable = T_05_HX
+    execute_on = TIMESTEP_END
+  []
+  [T_CPS]
+    type = ScalarVariable
+    variable = T_06_CPS
+    execute_on = TIMESTEP_END
+  []
+  [T_VAC]
+    type = ScalarVariable
+    variable = T_07_vacuum
+    execute_on = TIMESTEP_END
+  []
+  [T_FCU]
+    type = ScalarVariable
+    variable = T_08_FCU
+    execute_on = TIMESTEP_END
+  []
+  [T_ISS]
+    type = ScalarVariable
+    variable = T_09_ISS
+    execute_on = TIMESTEP_END
+  []
+  [T_EXO]
+    type = ScalarVariable
+    variable = T_10_exhaust
+    execute_on = TIMESTEP_END
+  []
+  [T_STO]
+    type = ScalarVariable
+    variable = T_11_storage
+    execute_on = TIMESTEP_END
+  []
+  [total_tritium]
+    type = SumPostprocessor
+    values = 'T_BZ T_TES T_FW T_DIV T_HX T_CPS T_VAC T_FCU T_ISS T_EXO T_STO'
+  []
+[]
+[UserObjects]
+  [terminator]
+    type = Terminator
+    expression = 'T_STO < 0'
+    fail_mode = 'HARD'
+    message = 'Tritium in storage has been depleted'
+  []
+  [terminator2]
+    type = Terminator
+    expression = 'total_tritium < 0'
+    fail_mode = 'HARD'
+    message = 'Tritium in system has been depleted'
+  []
+[]
+# The tritium breeding ratio is not directly given in the paper,
+# but is specified as a "five year" doubling time from the initial
+# inventory. As such, it may be necessary to force the simulation to
+# record a timestep at exactly five years, or whatever doubling time
+# is wanted, to dial in the tritium breeding ratio. This can be done
+# using the IterationAdaptiveDT settings commented out below along
+# with this function.
+#
+#[Functions]
+#  [catch_five_year]
+#    type = PiecewiseLinear
+#    x = '0 157680000 157680100 864000000.0'
+#    y = '0 0 1 1'
+#  []
+#[]
+
+[Executioner]
+  type = Transient
+  start_time = 0
+  dtmin = 1
+  end_time = 946080000.0
+  [TimeStepper]
+    type = IterationAdaptiveDT
+    growth_factor = 1.4
+    dt = 5
+    #timestep_limiting_function = 'catch_five_year'
+    #max_function_change = 0.5
+    #force_step_every_function_point = true
+  []
+  solve_type = 'PJFNK'
+  nl_rel_tol = 1e-08
+  nl_abs_tol = 1e-14
+[]
+[Outputs]
+  hide = "BZ_HX_leak_fraction CPS_FW_leak_fraction CPS_efficiency FCU_STO_fraction
+          HX_CPS_leak_fraction HX_EXO_leak_fraction HX_FW_leak_fraction ISS_EXO_leak_fraction
+          P_DIV_leak_fraction P_FW_leak_fraction TBR TES_efficiency T_BZ T_CPS T_DIV T_EXO
+          T_FCU T_FW T_HX T_ISS T_STO T_TES T_VAC epsilon1 epsilon10 epsilon11 epsilon2 epsilon3
+          epsilon4 epsilon5 epsilon6 epsilon7 epsilon8 epsilon9 residence1 residence10 residence2
+          residence3 residence4 residence5 residence6 residence7 residence8 residence9 tdecay
+          tritium_burn_fraction tritium_burn_rate tritium_fueling_efficiency BZ_TES_frac CPS_HX_flux
+          CPS_ISS_flux CPS_div_flux EXH_ISS_flux FCU_ISS_flux FCU_STO_flux FW_HX_flux HX_CPS_flux
+          HX_EXO_flux HX_FW_flux HX_div_flux ISS_EXO_flux ISS_STO_flux TES_ISS_flux TES_frac VAC_FCX_flux
+          Vacuum_pump_breeding device_T_consumption div_HX_flux plasma_FW_flux plasma_div_flux BZ_HX_flux"
+  csv = true
+  console = false
+[]
diff --git a/test/tests/fuel_cycle_Abdou/gold/implicit_out.csv b/test/tests/fuel_cycle_Abdou/gold/implicit_out.csv
new file mode 100644
index 000000000..987d55894
--- /dev/null
+++ b/test/tests/fuel_cycle_Abdou/gold/implicit_out.csv
@@ -0,0 +1,4 @@
+time,TBR,T_BZ,device_T_consumption,epsilon1,residence1,tritium_burn_fraction,tritium_burn_rate,tritium_fueling_efficiency,T_01_BZ
+0,1.9247,0,0.0059027777777778,0,86400,0.0036,5.3125e-06,0.25,42
+5,1.9247,41.968108151891,0.0059027777777778,0,86400,0.0036,5.3125e-06,0.25,41.968108151891
+10,1.9247,41.936218149552,0.0059027777777778,0,86400,0.0036,5.3125e-06,0.25,41.936218149552
diff --git a/test/tests/fuel_cycle_Abdou/gold/ss_kernel_out.csv b/test/tests/fuel_cycle_Abdou/gold/ss_kernel_out.csv
new file mode 100644
index 000000000..907107f1c
--- /dev/null
+++ b/test/tests/fuel_cycle_Abdou/gold/ss_kernel_out.csv
@@ -0,0 +1,4 @@
+time,TBR,T_BZ,device_T_consumption,epsilon1,residence1,tritium_burn_fraction,tritium_burn_rate,tritium_fueling_efficiency,T_01_BZ
+0,1.9247,0,0.0059027777777778,0,86400,0.0036,5.3125e-06,0.25,42
+5,1.9247,-509.03815399751,0.0059027777777778,0,86400,0.0036,5.3125e-06,0.25,-509.03815399751
+10,1.9247,-509.03815399751,0.0059027777777778,0,86400,0.0036,5.3125e-06,0.25,-509.03815399751
diff --git a/test/tests/fuel_cycle_Abdou/ss_kernel.i b/test/tests/fuel_cycle_Abdou/ss_kernel.i
new file mode 100644
index 000000000..d5f089f4c
--- /dev/null
+++ b/test/tests/fuel_cycle_Abdou/ss_kernel.i
@@ -0,0 +1,114 @@
+# This input file re-creates the deuterium-tritium fuel cycle model
+# described by Abdou et al (2021).
+# "Physics and technology considerations for the deuterium-tritium fuel cycle
+#   and conditions for tritium fuel self sufficiency" M Abdou & M Riva & A Ying
+#   & C Day & A Loarte & L R Baylor & P Humrickhouse & T F Fuerst & S Cho
+#   Nucl. Fusion 61 (2021) https://doi.org/10.1088/1741-4326/abbf35
+
+# Since this is a 0D simulation, the mesh is only a single point. If high-fidelity
+# models of specific components are required, the scalar variables can be coupled to
+# "Field" variables which can vary spatially across the mesh, or could be co-ordinated
+# with sub-apps.
+
+[Mesh]
+  type = GeneratedMesh
+  dim = 1
+  xmin = 0
+  xmax = 1
+  nx = 1
+[]
+
+[Variables]
+  [T_01_BZ]
+    family = SCALAR
+    initial_condition = 42
+  []
+[]
+[ScalarKernels]
+  [I1] # Breeding Zone
+    type = FuelCycleSystemScalarKernel
+    TBR = TBR
+    burn_rate = tritium_burn_rate
+    residence_time = residence1
+    leakage_rate = epsilon1
+    variable = 'T_01_BZ'
+    steady_state = true
+    other_sinks = 'device_T_consumption'
+  []
+[]
+
+# These postprocessors define the constants referenced in
+# the equations above. The value of any of these constants
+# could be informed by more detailed models (using sub-apps
+# and transfers), but it is important that the postprocessor
+# is evaluated before the executioner attempts to solve the
+# ODE, which is not the default behavior.
+[Postprocessors]
+  [TBR] #According to the PhD Thesis referenced in the paper,
+    # this is the required Tritium Breeding Ratio (TBR)
+    type = ConstantPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    value = 1.9247
+  []
+  [epsilon1] #BZ
+    type = ConstantPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    value = 0
+  []
+  [residence1] #BZ
+    type = ConstantPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    value = 86400 #1 day, Abdou
+    #value = 8640-86400 EXOTIC-6-7-8
+  []
+  [device_T_consumption]
+    type = ParsedPostprocessor
+    expression = 'tritium_burn_rate/tritium_burn_fraction/tritium_fueling_efficiency'
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    pp_names = 'tritium_burn_rate tritium_burn_fraction tritium_fueling_efficiency'
+  []
+  [tritium_burn_fraction]
+    type = ConstantPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    value = 0.0036
+  []
+  [tritium_burn_rate]
+    type = ConstantPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    value = 5.3125e-6 # 0.459 kg/day
+  []
+  [tritium_fueling_efficiency]
+    type = ConstantPostprocessor
+    execute_on = 'TIMESTEP_BEGIN INITIAL LINEAR NONLINEAR'
+    value = 0.25
+  []
+  # This postprocessor exists to sum up the tritium inventory
+  #  across the entirety of the system
+  [T_BZ]
+    type = ScalarVariable
+    variable = T_01_BZ
+    execute_on = TIMESTEP_END
+  []
+[]
+
+[Executioner]
+  type = Transient
+  start_time = 0
+  dtmin = 1
+  end_time = 10
+  [TimeStepper]
+    type = IterationAdaptiveDT
+    growth_factor = 1.4
+    dt = 5
+    #timestep_limiting_function = 'catch_five_year'
+    #max_function_change = 0.5
+    #force_step_every_function_point = true
+  []
+  solve_type = 'PJFNK'
+  nl_rel_tol = 1e-08
+  nl_abs_tol = 1e-14
+[]
+[Outputs]
+  csv = true
+  console = true
+[]
diff --git a/test/tests/fuel_cycle_Abdou/tests b/test/tests/fuel_cycle_Abdou/tests
index 4779e2c8e..11ed89bc3 100644
--- a/test/tests/fuel_cycle_Abdou/tests
+++ b/test/tests/fuel_cycle_Abdou/tests
@@ -7,6 +7,61 @@
     csvdiff = 'fuel_cycle_out.csv'
     requirement = 'The system shall reproduce a consistent solution to an ODE system of equations modeling the tritium fuel cycle.'
   []
+  [fuel_cycle_kernel]
+    type = CSVDiff
+    input = 'fuel_cycle_abdou_generic.i'
+    issues = '#329'
+    design = 'FuelCycleSystemScalarKernel.md'
+    csvdiff = 'fuel_cycle_out.csv'
+    cli_args = 'Outputs/file_base=fuel_cycle_out'
+    rel_err = 1.6e-6
+    requirement = 'The system shall reproduce a consistent solution to an ODE system of equations modeling the tritium fuel cycle with a built-in kernel.'
+  []
+  [fuel_cycle_kernel_ss]
+    type = CSVDiff
+    input = 'ss_kernel.i'
+    issues = '#329'
+    design = 'FuelCycleSystemScalarKernel.md'
+    csvdiff = 'ss_kernel_out.csv'
+    requirement = 'The fuel cycle system kernel shall have a steady-state flag that will allow the kernel to neglect time-dependent contributions.'
+  []
+  [fuel_cycle_kernel_implicit]
+    type = CSVDiff
+    input = 'ss_kernel.i'
+    issues = '#329'
+    design = 'FuelCycleSystemScalarKernel.md'
+    cli_args = 'ScalarKernels/I1/steady_state=false ScalarKernels/I1/is_implicit=true Outputs/file_base=implicit_out'
+    csvdiff = 'implicit_out.csv'
+    requirement = 'The fuel cycle system kernel shall run with either current or old state inputs.'
+  []
+  [fuel_cycle_kernel_inputs_mismatch]
+    type = RunException
+    input = 'ss_kernel.i'
+    issues = '#329'
+    design = 'FuelCycleSystemScalarKernel.md'
+    cli_args = 'ScalarKernels/I1/input_fractions=0.2'
+    expect_err = '"input_fractions" must be defined with the same length as "inputs".'
+    requirement = 'The fuel cycle system kernel shall not run with inconsistent inputs.'
+  []
+  [fuel_cycle_kernel_invalid_coupling]
+    type = RunException
+    input = 'ss_kernel.i'
+    issues = '#329'
+    design = 'FuelCycleSystemScalarKernel.md'
+    cli_args = 'ScalarKernels/I1/input_fractions=0.2 ScalarKernels/I1/inputs=T_01_BZ'
+    expect_err = 'Primary variable cannot be listed as a coupled variable'
+    requirement = 'The fuel cycle system kernel shall not run with the primary variable listed in inputs.'
+  []
+  [fuel_cycle_kernel_AD]
+    type = CSVDiff
+    input = 'fuel_cycle_abdou_generic_AD.i'
+    issues = '#329'
+    design = 'FuelCycleSystemScalarKernel.md'
+    csvdiff = 'fuel_cycle_out.csv'
+    cli_args = 'Outputs/file_base=fuel_cycle_out'
+    rel_err = 1.6e-6
+    requirement = 'The system shall reproduce a consistent solution to an ODE system of equations modeling the tritium fuel cycle with a built-in AD kernel.'
+  []
   [fuel_cycle_Abdou_comparison]
     type = RunCommand
     command = 'python3 plot_comparison.py'