A nuclear power plant (101) having a protective superstructure (203) is shown. The superstructure comprises a first end region (204) configured to cover a nuclear reactor in a containment structure, a second end region (206) opposite the first end region and configured to cover a cooling water pump house, and a central region (205) between the first and second end regions and configured to cover a turbine hall. The superstructure has an oval-shaped plan profile, the oval having a greater degree of curvature at the first end region than at the second end region.