Thermal Considerations in a Very Deep Borehole Nuclear Waste Repository for Synroc

2000 ◽  
Vol 663 ◽  
Author(s):  
G.D. Sizgek
Keyword(s):  
Temperature Field ◽  
Radioactive Waste ◽  
High Level Waste ◽  
Nuclear Waste Repository ◽  
Heat Output ◽  
Deep Borehole ◽  
Surface Cooling ◽  
Cooling Period ◽  
Waste Repository ◽  
High Level

ABSTRACTA study of heat propagation in a very deep borehole radioactive waste repository for Synroc is presented. The deep borehole modeled for the high level wastes is hypothetically sited at approximately 4 km below ground level in a granite host rock. The high level waste containers are placed in the lower section of the borehole to within 1.5 km of the surface and backfilled. A geothermal gradient of 0.03°C/m is assumed. Transient temperature field calculations are carried out for both 20 wt% and 10 wt% high level radioactive waste (HLW) bearing Synroc, for cooling periods between reactor discharge and geological disposal varying from 5 years to 50 years. The temperatures in the borehole repository were found to be very sensitive to the surface cooling period as well as the waste loading. The initial heat input of the waste may be controlled by cooling in an interim storage until the total heat output is reduced to a suitably low level. Therefore, surface cooling of at least 15 years for 20 wt% HLW containing Synroc is necessary for the given deep bore hole configuration to avoid the centerline temperatures that might affect durability of Synroc if ground water obtained access to the waste form. On the other hand the corresponding minimum surface cooling period for 10 wt% HLW containing Synroc is predicted to be about 5 years to produce similar temperature profiles in the borehole to those of 20 wt% HLW bearing Synroc with a 15-year cooling period before disposal. A variation in the borehole diameter has also been performed to elucidate the sensitivity of the temperature field of the repository.

scholarly journals Geoscientific Characterization and Interpretation (Geosynthesis) within the Preliminary Safety Assessment in the German Site-Selection Procedure for a High-level Nuclear Waste Repository

2021 ◽  
Vol 1 ◽  
pp. 45-46
Author(s):  
Sönke Reiche ◽  
Reinhard Fink ◽  
Nils-Peter Nilius
Keyword(s):  
Radioactive Waste ◽  
Nuclear Waste ◽  
Site Selection ◽  
Selection Procedure ◽  
Nuclear Waste Repository ◽  
Geological Processes ◽  
Geological Conditions ◽  
Surface Exploration ◽  
Waste Repository ◽  
High Level

Abstract. After implementation of the Repository Site Selection Act (StandAG) in 2017, the Federal Company for Radioactive Waste Disposal (BGE), as the German waste management organization, started the site selection procedure for a nuclear repository for high-level radioactive waste in Germany. On the way towards the repository site with the best possible safety, the site selection procedure is required to be a participatory, transparent, learning and self-questioning process based on scientific expertise. With the Subareas Interim Report published in 2020, first results were presented outlining subareas with favourable geological conditions in preparation for defining the siting regions for surface exploration. Currently, one of the main tasks in the site selection procedure is to establish a detailed geoscientific synthesis (Geosynthesis) for each subarea. The Geosynthesis contains all geological information for the characterization of each subarea and hence serves as the foundation for the subsequent analysis within the representative preliminary safety assessments (rvSU) and the geoscientific consideration criteria. Based on this information, all areas within the subareas will be evaluated to find the siting regions for surface exploration. The Geosynthesis includes a description of the regional geology focusing on the host rock, the overburden and relevant geological processes that may affect the potential nuclear waste repository in the next 1 million years. The data for the Geosynthesis are mostly compiled from state authorities and include 3-D geologic models, regional maps and cross-sections, bore hole data (e.g. geophysical logs) and seismic data. Furthermore, it is necessary to digitize, process, interpret and evaluate the aforementioned data using the available knowledge from the scientific literature in the context of the site selection procedure.

scholarly journals Representing future generations in public participation procedures regarding the siting of a nuclear waste repository

2021 ◽  
Vol 1 ◽  
pp. 219-220
Author(s):  
Lisa P. Hamacher
Keyword(s):  
Radioactive Waste ◽  
Public Participation ◽  
Impact Assessment ◽  
Site Selection ◽  
Constitutional Law ◽  
Future Generations ◽  
Nuclear Waste Repository ◽  
High Level Radioactive Waste ◽  
Waste Repository ◽  
High Level

Abstract. State decisions regarding a repository for high-level radioactive waste have an extraordinary intergenerational significance. The academic legal discussion has increasingly strengthened the status of future generations in constitutional law. In its recent decision on the German Climate Protection Act, the Federal Constitutional Court equally emphasised that state actors have an obligation to protect future generations. Fundamental rights of future generations thus have an anticipated effect in the present. In general, the legislator is free to choose the appropriate means to protect these rights. The interests of future generations may be promoted by substantive or procedural law. The German Site Selection Act (StandAG), however, makes use of procedural protections to a significant extent. Including the interests of future generations in the existing public participation procedures and participation bodies is, therefore, crucial for the effective protection of future generations. The presentation examines to which extent the current legal framework for the site selection for a high-level radioactive waste repository in Germany enables an effective representation of the future generations' interests. Existing publications (Appel, 2005; Rose, 2018; Kloepfer, 1993) name various characteristics of effective “intergenerational institutions”. Accordingly, these institutions should be independent, exist long-term, serve future interests solely or primarily, and have strong rights vis-à-vis decision-makers; however, German constitutional law, namely the principle of democracy, limits the design of such institutions. Not all of the abovementioned characteristics can be combined. Nevertheless, the constitution enables means to include and promote the interests of future generations in decision-making procedures, which are not fully exploited by the German Site Selection Act. The participation procedure includes several groups which could promote intergenerationally just decisions, namely environmental associations, the public and representatives of the “young generation”; however, none of these stakeholders are “intergenerational institutions” in the abovementioned sense. Subsequently, the presentation proposes various reforms: improving the sustainability impact assessment during the legislative procedure, the implementation of an “intergenerational impact assessment” and an ombudsperson for future concerns, who could be affiliated with the National Citizens' Oversight Committee (Nationales Begleitgremium).

Conductivity Behavior of Salt Deposits on the Surface of Engineered Barrier Materials for the Potential High-Level Nuclear Waste Repository at Yucca Mountain, Nevada

2004 ◽  
Vol 824 ◽  
Author(s):  
Lietai Yang ◽  
Miriam R. Juckett ◽  
Roberto T. Pabalan
Keyword(s):  
Electrical Conductance ◽  
Yucca Mountain ◽  
Nuclear Waste Repository ◽  
Conductivity Measurements ◽  
Barrier Materials ◽  
Salt Mixtures ◽  
High Level Nuclear Waste ◽  
Waste Repository ◽  
High Level ◽  
Conductivity Behavior

AbstractThe electrical conductance or conductivity of three salt mixtures, Na-K-Cl-NO3, Ca-K-Cl and Ca-Na-Cl, were measured at 25, 50 and 70°C [77, 122, and 158 °F] as a function of relative humidity (RH). Mutual deliquescence and efflorescence RH (MDRH and MERH) values were determined based on the conductivity measurements. It was found that the conductivity of the three salt mixtures started to increase at RH values that are approximately 40 % of their MDRH and increased by 1to 2 orders of magnitude just before reaching the MDRH. At the MDRH, a significant increase in conductivity was observed. The MDRH and MERH for the Ca-K-Cl and Ca-Na-Cl mixtures were found to be approximately 15 % in the temperature range of 50 to 70 °C [122 to 158 °F]. The MDRH and MERH for the Na-K-Cl-NO3system were found to be approximately 54 % at 50 °C [122 °F] and decreased significantly with an increase in temperature.

Effects of Aging on the Solubility of Palladium

1995 ◽  
Vol 412 ◽  
Author(s):  
C. Oda ◽  
H. Yoshikawa ◽  
M. Yui
Keyword(s):  
Aqueous Solution ◽  
Aging Time ◽  
Room Temperature ◽  
High Level Waste ◽  
Anaerobic Conditions ◽  
Dilute Aqueous Solution ◽  
Waste Repository ◽  
Ph Range ◽  
Effects Of Aging ◽  
High Level

AbstractPalladium solubility was measured in a dilute aqueous solution at room temperature in the pH range from 3 to 13 under anaerobic conditions. Crystalline Pd metal was clearly visible and the concentration of palladium in solution decreased gradually with aging time. The palladium concentrations in solution were less than 9.4×10-10M in the pH range from 4 to 10 and increased to 10-7M in the pH range greater than 10. This study suggests that palladium concentrations in certain high-level waste repository environments may be limited by Pd metal and may be less than 10-9M.

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