Technical know-how of selection process for the Horonobe Underground Research Laboratory area and site

Kunimaru, Takanori; Takeuchi, Ryuji; Matsuzaki, Tatsuji

Proceedings of 14th International Conference on Environmental Remediation and Radioactive Waste Management (ICEM 2011) (CD-ROM), p.1185 - 1194, 2011/09

https://doi.org/10.1115/ICEM2011-59088

This study will be demonstrated the selection process for the URL area and URL site in sequence. Horonobe URL has been declared to be constructed within whole Horonobe Town to be selected early in the fiscal year 2002. The Horonobe URL area/site is required existence of host argillaceous sedimentary formations and saline groundwater. Further fundamental requirements are rock mechanical property and underground flammable (e.g. methane) gas content which meet with safe construction and operation of underground facility. Next, based on surveys of existing information and aerial and ground reconnaissance surveys on a regional scale, and taking into consideration preliminary requirements on the geological environment and safety, as well as social and environmental constraints, an area of 3 km 3 km in the north-central part of Horonobe Town was selected as the main area for the surface-based investigations (URL area). A site for constructing the underground and surface facilities (URL site) was subsequently selected in the URL area, 3 km from the center of Horonobe Town. The selection was based on social conditions and the availability of infrastructure, including roads and land use restrictions, in addition to available geological and hydrogeological information. This study is only fruit of selecting the URL site based on the social and technical requirements in Japan. These stepwise approaches and experiences for selecting the site are applicable when the implementer (e.g. Nuclear Waste Management Organization of Japan) will select the site such as the phase of literature survey, preliminary investigation and detailed investigation in the future.

Technical know-how for the investigation and modelling of topographic evolution for site characterisation

Doke, Ryosuke; Yasue, Kenichi; Niizato, Tadafumi; Nakayasu, Akio

Proceedings of 14th International Conference on Environmental Remediation and Radioactive Waste Management (ICEM 2011) (CD-ROM), p.1467 - 1476, 2011/09

https://doi.org/10.1115/ICEM2011-59171

Palaeo-hydrogeological information based on reconstructing topographical evolution for disposal sites is considered to be available to build a predictive repository safety assessment. However, the construction of the topographical evolution models has a complicated and tacit working process. Additionally, in the investigation and modeling of topographical evolution for site characterization, it is important to make available the technical know-how (e.g., decision-making process) accumulated over decades of research and development and to transfer the knowledge during initiation and implementation phase. The aim of this study is to externalize the technical know-how for the construction of the topographical evolution models. The working process of the model construction is illustrated as a "task-flow" including the tasks of setting of time scale, extraction of information, construction of conceptual model and construction of numerical model. In each task, explanations with the information of input and output data are described in detail. The linkages with other task-flows, such as the investigations and other modeling, were also described in the task-flow. Additionally, the decision-making processes in the investigations are expressed as IF-THEN format in flow-diagrams for each task. Accordingly, IT-based expert systems including the externalized technical know-how are constructed to support planning and implementation of the investigations and modeling for topographical evolution.

Systematic chemical decontamination using IF gas

Hata, Haruhi; Yokoyama, Kaoru; Sugitsue, Noritake

Proceedings of 14th International Conference on Environmental Remediation and Radioactive Waste Management (ICEM 2011) (CD-ROM), p.105 - 110, 2011/09

https://doi.org/10.1115/ICEM2011-59036

IF treatment technique belongs to the system decontamination technology. It has the high performance decontamination technique for the plant that deposits the uranium intermediate fluoride, for example, UF, UF, UF, and UF, which exist in the uranium enrichment plant by the Gas Centrifuge. The characteristics of IF treatment, the secondary waste is just an IF and little adsorbent. In addition, this IF is possible to reuse as a materials for makings new IF gas. According to that IF treatment is the simple method using chemical reaction, we hardly need to care about secondary reaction with the exception of the reaction with IF gas and the uranium intermediate fluoride. This is very important feature when applying to a large-scale plant.

Validation of correlations between Nd isotopes and difficult-to-measure nuclides predicted with burn-up calculation code by post irradiation examination

Asai, Shiho; Okumura, Keisuke; Hanzawa, Yukiko; Suzuki, Hideya; Toshimitsu, Masaaki; Inagawa, Jun; Kimura, Takaumi; Kaneko, Satoru*; Suzuki, Kensuke*

Proceedings of 14th International Conference on Environmental Remediation and Radioactive Waste Management (ICEM 2011) (CD-ROM), p.1437 - 1442, 2011/09

https://doi.org/10.1115/ICEM2011-59086