Steam (H₂O) enters the steam turbine in a nuclear power station at T₁ = 800 K, P₁ = 2 MPa at negligible velocity, and emerges at T₂ = 370 K, P₂ = 0.07 MPa. Assuming steady-state and neglecting heat transfer, and neglecting the potential and kinetic energy of the fluid at the inlet and outlet of the turbine, determine the turbine shaft work per kg of H₂O processed (J/kg) and the mass flow rate Ṁ (kg/s) required to deliver 20 MW of shaft power.