Synthesis report on the R&D for the Horonobe Underground Research Laboratory; Project carried out during fiscal years 2015-2019

Nakayama, Masashi ; Saiga, Atsushi  ; Kimura, Shun  ; Mochizuki, Akihito  ; Aoyagi, Kazuhei  ; Ono, Hirokazu ; Miyakawa, Kazuya   ; Takeda, Masaki ; Hayano, Akira  ; Matsuoka, Toshiyuki; Sakurai, Akitaka; Miyara, Nobukatsu; Ishii, Eiichi   ; Sugita, Yutaka ; Sasamoto, Hiroshi   ; Tanai, Kenji ; Sato, Toshinori  ; Osawa, Hideaki  ; Kitayama, Ayami  ; Taniguchi, Naoki 

The Horonobe Underground Research Laboratory (URL) Project is being pursued by the Japan Atomic Energy Agency (JAEA) to enhance the reliability of relevant disposal technologies for geological disposal of High-level Radioactive Waste through investigations of the deep geological environment within the host sedimentary rock at Horonobe Town in Hokkaido, north Japan. The investigations will be conducted in three phases, namely "Phase 1: Surface based investigations", "Phase 2: Construction phase" (investigations during construction of the underground facilities) and "Phase 3: Operation phase" (research in the underground facilities). According to the research plan described in the 3rd Mid- and Long- term Plan of JAEA, "Near-field performance study", "Demonstration of repository design option", and "Verification of crustal-movement buffering capacity of sedimentary rocks" are important issues of the Horonobe URL Project, and schedule of future research and backfill plans of the project will be decided by the end of 2019 Fiscal Year. The present report summarizes the research and development activities of these 3 important issues carried out during 3rd Medium to Long-term Research Phase.