As directed by a written development plan (BSC 2002 (DIRS 161132)), the primary purpose of this scientific analysis is to identify and document the analyses and resolution of the features, events, and processes (FEPs) affecting the waste package and drip shield performance in the repository. Thirty-three FEPs were identified that are associated with the waste package and drip shield performance. This scientific analysis has been prepared to document the screening methodology used in the process of FEP inclusion and exclusion. The scope of this scientific analysis is to identify the treatment of the FEPs affecting postclosure waste package and drip shield performance. It should be noted that seismic effects are not treated within this report. A full discussion of seismic effects is contained in the Engineered Barrier System Features, Events, and Processes report (BSC 2004 (DIRS 167253)). The FEPs that are deemed potentially important to repository postclosure performance are evaluated, either as components of the total system performance assessment (TSPA) or as a separate discussion in a scientific analysis report. The scope for this activity involves two tasks, namely: Task 1: Identify which FEPs are to be considered explicitly in the TSPA (called included FEPs) and in which scientific analyses these FEPs are addressed. Task 2: Identify FEPs not to be included in the TSPA (called excluded FEPs) and provide justification for why these FEPs do not need to be a part of the TSPA model.