Uncertainty Chains in the Geological and Geotechnical Barriers of a HAW-disposal site

Author(s):  
Volker Mintzlaff ◽  
Joachim Stahlmann

<p>When projecting and planning a final high-level radioactive waste disposal site various uncertainties need to be addressed. A geological model is an abstraction of one possibility to interpret the exposed outcrops, drilling results and geophysical data. In numerical modelling the geological model is further simplified due to computational limitations. The behaviour of rocks is modelled with more or less complex constitutive models which are based upon laboratory experiments. Complex constitutive models have a huge range of input parameters, which rarely can be obtained completely by these experiments. The samples, which will be used in the laboratory experiments, are, as the data of the geological model, always a selection of drilling cores. For example, in a mechanical laboratory, harder rocks will be overrepresented in comparison to softer parts of the core.</p><p>Since the mentioned uncertainties are not avoidable many authors suggest that an open communication of these uncertainties can support the confidence of the public in the work of the professionals and as well as the projected development of the final disposal site. This contribution will present an overview of these uncertainties in the geological and geotechnical barriers of an final disposal site to discuss the relevance of these.</p>

Author(s):  
Kazumi Kitayama

In the year 2000, the Japanese geological disposal program for high-level radioactive waste (HLW) moved from the phase of generic research and development into the phase of implementation. Following legislation entitled the “Specified Radioactive Waste Final Disposal Act” (hereafter “the Act”), the Nuclear Waste Management Organization of Japan (NUMO) was established as the implementing organization in October 2000. The assigned activities of NUMO include repository site selection, developing relevant license applications and construction, operation and closure of the repository. To initiate the first stage, NUMO has chosen an “open solicitation” approach for finding candidate sites in the belief that the support of local communities is essential to the success of this highly public, long-term project extending over more than a century. Based on this concept, NUMO announced the start of open solication for volunteer municipalities for selection of Preliminary Investigation Areas to the public on December 19, 2002. This paper describes NUMO’s open solicitation of volunteer municipalities for a potential disposal site.


2013 ◽  
Vol 726-731 ◽  
pp. 869-876
Author(s):  
Guo Hua Qiu

On the basis of field environmental investigation and monitoring, the environmental radioactivity background of Xinchang and Jijicao rock in Beishan preselected region has been preliminary investigated and studied, and the public dose from local natural background radiation is estimated which can provide basic data and information for environmental impact assessment and safety assessment of HLW(the high level radioactive waste) disposal repository in the future. From the result of investigation and study, the environmental radioactivity of Xinchang and Jijicao rock is generally within normal natural background. The effective dose to local resident from natural background radiation is 2.110 mSv/a by internal and external exposure.


2021 ◽  
Vol 6 (2) ◽  
pp. 82
Author(s):  
Bayhaqqi Bayhaqqi ◽  
Saiful Bukhori ◽  
Gayatri Dwi Santika

Temporary Waste Disposal Site (TPSS) is a place to collect waste from various community activities which will later be transported to the final disposal site by garbage trucks. There are many considerations in choosing a TPSS location, so the selection of a TPSS location is very important in supporting the collection of waste that will be transported to final disposal. The Jember Regency Environmental Service is an agency in charge of waste management, including the selection of TPSS locations. Choosing the location of TPSS so far is still manual, where manual selection cannot be separated from human error, so that choosing the location of TPSS is not accurate can cause new problems in the community. In addition, there is no standardized assessment system in the TPSS selection process, so a decision support system is needed that can be used to assist the process of selecting the best TPSS location recommendations. In making this research system, we implemented the hybrid method of AHP and TOPSIS. Where the AHP method is used to determine the weight of the criteria while the TOPSIS method is used for the selection process for TPSS candidates.


Geophysics ◽  
2000 ◽  
Vol 65 (4) ◽  
pp. 1070-1079 ◽  
Author(s):  
Martyn J. Unsworth ◽  
Xinyou Lu ◽  
M. Don Watts

The long term disposal of radioactive waste in an underground repository requires the detailed geological evaluation of a potential site. Owing to their inherent sensitivity to the presence of fluids in rocks, electromagnetic (EM) methods have an important role in this assessment. Controlled‐source EM techniques are especially useful in strong anthropogenic noise environments such as industrial locations. However the complexity of modeling and inversion can limit the quantitative interpretation of controlled‐source EM data. A potential radioactive waste disposal site at Sellafield in Great Britain has been investigated using a variety of EM exploration techniques. Controlled‐source audio‐frequency magnetotelluric (CSAMT) data have given the best subsurface information in an environment that has a high level of cultural noise. One‐dimensional inversions of the Sellafield CSAMT data were found to be inadequate; 2.5-D forward modeling and inversion were used to interpret the data. The resulting resistivity models show good agreement with well log data collected at the site. These resistivity models show the presence of a large zone of hypersaline groundwater extending 1 km inland towards the potential repository and indicate the effect of faults on the hydrogeology.


2021 ◽  
pp. 104490
Author(s):  
Ervin Hrabovszki ◽  
Emese Tóth ◽  
Tivadar M. Tóth ◽  
István Garaguly ◽  
István Futó ◽  
...  

2021 ◽  
Vol 1 ◽  
pp. 99-100
Author(s):  
Ute Maurer-Rurack ◽  
Guido Bracke ◽  
Eva Hartwig-Thurat ◽  
Artur Meleshyn ◽  
Torben Weyand

Abstract. The Site Selection Act stipulates a precautionary temperature limit of 100 ∘C on the outer surface of the containers with high-level radioactive waste (HLRW) in the final disposal site. This precautionary temperature limit should be applied in preliminary safety analyses provided that the maximum physically possible temperatures in the respective host rocks have not yet been determined due to pending research. Increasing temperatures in the deep geological underground, caused by the heat generation of the HLRW, can trigger thermal, hydraulic, mechanical, chemical and biological processes (THMCB) in the respective host rocks of a final disposal site and thus endanger safety. Furthermore, high temperatures may hamper the feasibility to retrieve and recover HLRW from a final disposal site. Such processes are described in detail in databases for features, events and processes (FEP) databases. Single components or barriers of a final disposal facility may require specific design temperatures for the preservation of their features once a concept for long-term safety of a final disposal site is established; however, the interactions of all relevant processes of a concept for a final disposal site must be considered when a specific temperature limit for the outer surface of the containers is derived. This temperature limit may vary for particular safety and final disposal concepts in the host rock: salt, clay and crystalline rock. The conclusion is that temperature limits regarding the outer surface of the containers should be derived specifically for each safety and disposal concept and should be supported by a solid safety analysis. Temperature limits without reference to specific safety concepts or the particular design of the final disposal site likely narrow down the possibilities for optimisation and could adversely affect the site selection process in finding the best suitable site.


Water ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 200
Author(s):  
Viktor Goliáš ◽  
Lenka Hájková ◽  
Tomáš Lipanský ◽  
Tomáš Černík ◽  
Pavel Kohn ◽  
...  

Radioactive (radon) groundwaters are highly valued among mineral waters for their healing effects. Between 2005 and 2015, a large exploratory event for prospecting and documenting radon water springs took place in the crystalline area of Lugicum (Bohemian Massif) under Czech–Polish cooperation. For these purposes, an exploration method was developed as a combination of GIS (ArcMap 9.1–10.2) area preparation followed by field radiohydrogeochemical mapping at a scale of 1:10,000. The gamma indication method was optimized and used for the selection of water samples. A total of 2354 water sources were examined. Radon activity concentrations were measured at 660 sources found throughout the territory. Of those, 111 sources exhibited 222Rn activity above 1500 Bq/L and, thus, were categorized as sources of mineral radioactive waters according to Czech legislation. The highest 222Rn activity was found in the Michael spring near Nové Město pod Smrkem (up to 6237 Bq/L 222Rn). Many discovered sources with high balneological potential are significant and, therefore, are quickly becoming popular among the public.


2020 ◽  
Vol 49 (3) ◽  
pp. 13-18
Author(s):  
Dimitar Antonov ◽  
Madlena Tsvetkova ◽  
Doncho Karastanev

In Bulgaria, from the preliminary analyses performed for site selection of deep geological disposal of high-level waste (HLW) and spent fuel (SF), it was concluded that the most promising host rocks are the argillaceous sediments of the Sumer Formation (Lower Cretaceous), situated in the Western Fore-Balkan Mts. The present paper aims to compare the transport of three major radionuclides from a hypothetical radioactive waste disposal facility, which incorporates an engineering barrier of bentonite into the argillaceous (marl) medium. The simulations were performed by using HYDRUS-1D computer programme. The results are used for a preliminary estimation of argillaceous sediments as a host rock for geological disposal of HLW.


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