Abstract: A faceplate of a showerhead has a bottom side that faces a plasma generation region and a top side that faces a plenum into which a process gas is supplied during operation of a substrate processing system. The faceplate includes apertures formed through the bottom side and openings formed through the top side. Each of the apertures is formed to extend through a portion of an overall thickness of the faceplate to intersect with at least one of the openings to form a corresponding flow path for process gas through the faceplate. Each of the apertures has a cross-section that has a hollow cathode discharge suppression dimension in at least one direction. Each of the openings has a cross-section that has a smallest cross-sectional dimension that is greater than the hollow cathode discharge suppression dimension.

Abstract: Example embodiments are directed to a method of fuel bundle design, core design, or combined fuel and core design, to ensure Pellet Cladding Interaction (PCI) related fuel failures are mitigated. More specifically, example embodiments provide fuel and/or core designs that may be determined prior to operation of a nuclear power plant, or prior to production of fresh fuel bundles. The PCI optimized fuel/core designs may include some or all of seven PCI Evaluation Methods which may be incorporated into existing nuclear reactor simulation programs. PCI optimized fuel and/or core design enhances fuel reliability, allows faster beginning-of-cycle (BOC) startups and faster middle-of-cycle (MOC) sequence exchanges to maximize plant performance, and minimizes ramping restrictions, thereby maximizing nuclear power plant performance.