21. A large containment is filled with steam, air, and nitrogen. The containment also has a pool of water, which is sprayed in the containment atmosphere. Heat is added to the con- tainment at a specified rate. Use the given data to find a) the initial containment pressure and b) the time it takes for the containment pressure to reach the pressure limit of 145 psia (1 MPa). Total mass of water (water in the pool and steam) m,, = 3.42E6 lbm (1.55E6 kg) Water-steam quality x = 0.03 Air mass m, = 0.132E6 lbm (6E4 kg) Nitrogen mass m, = 2200 lbm (998 kg) Containment initial temperature T; = 688 R (109 C) Initial relative humidity ø = 100% Rate of heat addition to containment atmosphere Q = 1.02E8 Btu/h (30 MW) [Ans.: 7.66 h].

21. A large containment is filled with steam, air, and nitrogen. The containment also has a pool of water, which is sprayed in the containment atmosphere. Heat is added to the con- tainment at a specified rate. Use the given data to find a) the initial containment pressure and b) the time it takes for the containment pressure to reach the pressure limit of 145 psia (1 MPa). Total mass of water (water in the pool and steam) m,, = 3.42E6 lbm (1.55E6 kg) Water-steam quality x = 0.03 Air mass m, = 0.132E6 lbm (6E4 kg) Nitrogen mass m, = 2200 lbm (998 kg) Containment initial temperature T; = 688 R (109 C) Initial relative humidity ø = 100% Rate of heat addition to containment atmosphere Q = 1.02E8 Btu/h (30 MW) [Ans.: 7.66 h].