The guarantee of the performance of the engineered barriers in a geological repository is very important for the long-term safety of disposal as well as the efficient design of the repository. Therefore, the performance of the engineered barriers under repository condition should be demonstrated by in-situ experiments conducted in an underground research laboratory. This article provides a review of the major in-situ experiments that have been carried out over the past several decades at underground research laboratories around the world to validate the performance of engineered barriers of a repository, as well as their results. In-situ experiments to study the coupled thermal-hydraulicmechanical behavior of the engineered barrier system used to simulate the post-closure performance of the repository are analyzed as a priority. In addition, in-situ experiments to investigate the performance of the buffer material under a real repository environment have been reviewed. State-of-the art in-situ validations of the buffer-concrete interaction, and the installation of the buffer, backfill and plug, as well as characterization of the near-field rock and the corrosion of the canister materials are, also performed.

1. Introduction
 2. Underground Research Laboratory
  2.1 Grimsel Test Site
  2.2 Mont Terri Rock Laboratory
  2.3 Aspö Hard Rock Laboratory
  2.4 Exploratory Studies Facility
  2.5 ONKALO Underground Characterizationand Research Facility
  2.6 HADES Underground Research Facility
  2.7 KAERI Underground Research Tunnel
 3. In-Situ Experiments to Validate thePerformance of Engineered Barriers
  3.1 Coupled Thermal-hydraulic-mechanical Behaviorof the Engineered Barrier System
  3.2 Performance of Buffer Material
  3.3 Buffer-Concrete Interaction
  3.4 Installation of Buffer, Backfill and Plug
  3.5 Characterization of the Near-field Rock
  3.6 Corrosion of Canister Material
 4. Conclusions
 REFERENCES

• Won-Jin Cho(Korea Atomic Energy Research Institute) | 조원진 Corresponding Author
• Geon Young Kim(Korea Atomic Energy Research Institute) | 김건영