The In-situ experiment for performance confirmation of engineered barrier system at Horonobe Underground Research Laboratory; Installation of engineered barrier system and backfilling the test niche at the 350m gallery

Nakayama, Masashi; Ono, Hirokazu

JAEA-Research 2019-007, 132 Pages, 2019/12

JAEA-Research-2019-007.pdf:11.29MB
JAEA-Research-2019-007-appendix(CD-ROM).zip:39.18MB

The Horonobe Underground Research Laboratory (URL) Project has being pursued by Japan Atomic Energy Agency (JAEA) to enhance the reliability of relevant disposal technologies through investigations of the deep geological environment within the host sedimentary formation at Horonobe, northern Hokkaido. The URL Project consists of two major research areas, "Geoscientific Research" and "Research and Development on Geological Disposal Technologies". The in-situ experiment for performance confirmation of engineered barrier system (EBS experiment) had been prepared from 2013 to 2014 fiscal year at GL-350m gallery, and heating by electric heater in simulated overpack had started in January, 2015. One of objectives of the EBS experiment is acquiring data concerned with Thermal-Hydrological-Mechanical-Chemical (THMC) coupled behavior. These data will be used in order to confirm the performance of engineered barrier system. This report shows following works had carried out at the GL-350 m gallery. Excavation of a test niche and a test pit, Setting buffer material blocks and a simulated overpack into the test pit, Backfilling the niche by compaction backfilling material and setting backfilling material blocks, Casting concrete type plug and contact grouting, Consolidate measurement system and start measuring.

The In-situ experiment for overpack corrosion at Horonobe Underground Research Laboratory; Production and setting simulated overpack, buffer material blocks and heater

Nakayama, Masashi

JAEA-Technology 2018-006, 43 Pages, 2018/08

JAEA-Technology-2018-006.pdf:5.32MB
JAEA-Technology-2018-006-appendix(CD-ROM).zip:29.19MB

The Horonobe URL Project has being pursued by JAEA to enhance the reliability of relevant disposal technologies through investigations of the deep geological environment within the host sedimentary formation at Horonobe, Hokkaido. The URL Project proceeds in 3 overlapping phases, "Phase I: Surface-based investigations", "Phase II: Investigations during tunnel excavation" and "Phase III: Investigations in the underground facilities", over a period of around 20 years. The OP corrosion test was prepared from 2013 FY at Niche No.3, and heating by electric heater in simulated overpack started in November, 2014. The objective of the test is acquiring data concerned with corrosion of carbon steel OP. These data will be used in order to confirm the performance of engineered barrier system. In the OP corrosion test, the diameter of simulated OP and buffer material are 100 mm and 300 mm, respectively. Concrete support using low alkaline cement was used in order to investigate the effect of cementitious materials to OP corrosion behavior. We will measure corrosion potential of carbon steel, natural potential, pH in buffer material for several years. In this report, we describe how to make simulated OP and buffer material blocks, and set sensors, and so on.

Collection of measurement data from in-situ experiment for performance confirmation of engineered barrier system at Horonobe Underground Research Laboratory (FY2015)

Nakayama, Masashi; Ono, Hirokazu; Nakayama, Mariko*; Kobayashi, Masato*

JAEA-Data/Code 2016-005, 55 Pages, 2016/07

JAEA-Data-Code-2016-005.pdf:11.32MB
JAEA-Data-Code-2016-005-appendix(CD-ROM).zip:32.68MB

The Horonobe URL Project has being pursued by JAEA to enhance the reliability of relevant disposal technologies through investigations of the deep geological environment within the host sedimentary formation at Horonobe, northern Hokkaido. The Project consists of two major research areas, "Geoscientific Research" and "Research and Development on Geological Disposal Technologies", and proceeds in three overlapping phases, "Phase I: Surface-based investigations", "Phase II: Investigations during tunnel excavation" and "Phase III: Investigations in the underground facilities". Phase III investigation was started in 2010 fiscal year. The in-situ experiment for performance confirmation of engineered barrier system (EBS experiment) had been prepared from 2013 to 2014 fiscal year at GL-350m gallery, and heating by electric heater in simulated overpack had started in January, 2015. One of objectives of the experiment is acquiring data concerned with Thermal-Hydrological-Mechanical-Chemical (THMC) coupled behavior. These data will be used in order to confirm the performance of engineered barrier system. This report summarizes the measurement data acquired from the EBS experiment from December, 2014 to March, 2016.

Data acquisition on migration of radionuclides under deep geological environments

Iida, Yoshihisa; Taki, Hiroshi; Yamaguchi, Tetsuji; Tanaka, Tadao; Negishi, Kumi; Nakayama, Shinichi

JAERI-Conf 2005-007, p.230 - 235, 2005/08

https://jopss.jaea.go.jp/pdfdata/JAERI-Conf-2005-007.pdf

A variation in data should be quantitatively incorporated in a probabilistic safety assessment of radioactive waste disposal. We focus our experimental efforts on parameters that induce major uncertainties in the radionuclide migration analysis and that have not been quantitatively assessed. Possible sources of uncertainty includes increase in ionic strength of groundwater caused by intrusion of seawater and/or dissolution of sodium nitrate in TRU waste, highly alkaline conditions originating from cementitious materials, and a variation of porewater composition accompanied with corrosion of. This study is a summary of current status of our investigations for solubility and diffusion.