This document is the fifth revision of the Nevada Nuclear Waste Storage Investigations (NNWSI) Project Quality Assurance (QA) Plan (Nvo-196-17). This NNWSI Project QA Plan is a requirements document which was developed from QA requirements imposed on the NNWSI Project by the Office of Civilian Radioactive Waste Management (OCRWM), the U.S. DOE, and the U.S. Nuclear Regulatory Commission (NRC). Accordingly, this document establishes the QA requirements that are applicable to the NNWSI Project participants.