Fix units and unit-conversion factors (#2891)

* Removed redundant units

* Removed all 'years' variable and YR_TO_S variables. Found two possible errors.

* Made units more understandable

* Undid all the raw_uc conversions in tools.py as they are not compatible with numba.jit's optimization. Using the constants YR_TO_S and S_TO_YR.

* Removed as many S_TO_YR and YR_TO_S as possible.

* Fixed the problem of missing elementary charge (e) constant in base.constants

* Undid all S_TO_YR/YR_TO_S changes

* Minor fixes to the YR_TO_S

* Added back in C_LIGHT

* Made sure all of the units used in neutronics matches the units used in plasma_physics

bluemira/codes/openmc/solver.py

@@ -353,7 +353,7 @@ def run(
         """Run stage for Teardown task"""
         result = OpenMCResult.from_run(
             universe,
-            n_DT_reactions(source_params.plasma_physics_units.reactor_power),
+            n_DT_reactions(source_params.reactor_power),
             statepoint_file,
         )
         if delete_files:

bluemira/fuel_cycle/tools.py

@@ -482,7 +482,7 @@ def legal_limit(
         mb = None
 
     if mb is None:
-        mb = raw_uc(r_T_burn(p_fus), "kg/s", "g/s")
+        mb = r_T_burn(p_fus)
 
     m_plasma = (
         (mb * ((1 / fb - 1) + (1 - eta_fuel_pump) * (1 - eta_f) / (eta_f * fb)) + m_gas)