The Role of Engineered Barriers in the Performance Assessment of a Repository for L/ILW

Abstract

ABSTRACTDesigns for repositories for the underground disposal of radioactive waste throughout the world are generally based on the ‘multiple barrier’ concept. This comprises engineered barriers that are the introduced features of the disposal facility, and natural barriers provided by the host geology. In the near field of the repository, the engineered barriers can provide both physical and chemical containment. This paper is mainly concerned with the deep disposal of intermediatelevel and low-level waste. In particular, it reviews current understanding concerning the evolution of the chemical and physical barriers for the disposal concept developed by United Kingdom Nirex Limited. Examples of work from underlying research programmes that support this understanding are discussed. The paper also discusses the representation of the engineered barriers in performance assessment calculations.