scholarly journals Impact of Updated OECD/NEA Thermodynamic Database on the Safety Assessment of Radioactive Waste Repository Studied Using RESRAD-OFFSITE Code

2021 ◽  
Vol 11 (16) ◽  
pp. 7269
Author(s):  
Jun-Yeop Lee ◽  
Sang June Park ◽  
Seokyoung Ahn
Keyword(s):  
Radioactive Waste ◽  
Distribution Coefficient ◽  
Thermodynamic Data ◽  
Safety Assessment ◽  
Exposure Dose ◽  
Thermodynamic Database ◽  
Assessment Model ◽  
Chemical Thermodynamic ◽  
Thermodynamic Databases ◽  
Waste Repository

A RESRAD-OFFISTE computational code for the safety assessment model of a radioactive waste repository was utilized to evaluate the influence of the updated OECD/NEA thermodynamic database on the safety assessment model in terms of exposure dose. The solubility data as the input parameter for the RESRAD-OFFSITE code obtained with two different sets of chemical thermodynamic databases such as JAEA-TDB and amended JAEA-TDB reflecting the updates of the OECD/NEA thermodynamic database were calculated and compared with each other. As a result, almost identical exposure doses were obtained due to the remarkable similarity between the solubility data of various radionuclides for both chemical thermodynamic databases. In contrast, dramatic changes in exposure dose were observed with varying distribution coefficients. Thermodynamic calculations indicated that the aqueous species distribution can be significantly changed by the selection of a chemical thermodynamic database and thus the relevant distribution coefficient can also be influenced as a consequence. Accordingly, the result obtained in the present work indicated that (i) the impact of the updated chemical thermodynamic data was somewhat minor from the viewpoint of the solubility and (ii) the distribution coefficient, which can be sensitively influenced by the predominant chemical species, produced a remarkable change in the exposure dose. This work provided an insight into the precise exposure dose calculation in terms of the reliable estimation of the distribution coefficient by means of a surface complexation model, which can predict the distribution coefficient as a function of groundwater composition coupled with a chemical speciation calculation based on up to date chemical thermodynamic data.

scholarly journals The thermodynamic database COST MP0602 for materials for high-temperature lead-free soldering

2012 ◽  
Vol 48 (3) ◽  
pp. 339-346 ◽  
Author(s):  
A. Kroupa ◽  
A. Dinsdale ◽  
A. Watson ◽  
J. Vrestal ◽  
A. Zemanova ◽  
...  
Keyword(s):  
High Temperature ◽  
Thermodynamic Data ◽  
Ternary Systems ◽  
Thermodynamic Modelling ◽  
Thermodynamic Database ◽  
Lead Free ◽  
Commercial Software ◽  
Current State ◽  
Software Packages ◽  
Thermodynamic Databases

The current state of thermodynamic modelling in the field of high-temperature lead-free soldering is presented. A consistent thermodynamic database, containing 18 elements (Ag, Al, Au, Bi, Co, Cu, Ga, Ge, Mg, Ni, P, Pb, Pd, Sb, Sn, Ti and Zn) has been created. The thermodynamic data for the most of the important binary and selected ternary systems were checked and included into the database. The database was tested using major commercial software packages. Such reliable and sophisticated software coupled to reliable thermodynamic databases are necessary prerequisites for application of thermodynamics in advanced alloys design.

Long-Term Safety Assessment of a (Near-Surface) Short-Lived Radioactive Waste Repository in Lithuania

2008 ◽  
Vol 161 (2) ◽  
pp. 156-168 ◽  
Author(s):  
J. Mazeika ◽  
R. Petrosius ◽  
V. Jakimaviciute-Maseliene ◽  
D. Baltrunas ◽  
K. Mazeika ◽  
...  
Keyword(s):  
Radioactive Waste ◽  
Safety Assessment ◽  
Near Surface ◽  
Radioactive Waste Repository ◽  
Waste Repository

scholarly journals Nagra/PSI Chemical Thermodynamic Data Base 01/01

2002 ◽  
Vol 90 (9-11) ◽  
Author(s):  
W. Hummel ◽  
U. Berner ◽  
E. Curti ◽  
F. J. Pearson ◽  
T. Thoenen
Keyword(s):  
Radioactive Waste ◽  
Data Base ◽  
Thermodynamic Data ◽  
Critical Appraisal ◽  
Fission Products ◽  
Performance Assessments ◽  
The Other ◽  
Chemical Thermodynamic ◽  
Carbonate Complexes

SummaryThe Nagra/PSI Chemical Thermodynamic Data Base has been updated to support performance assessments of the planned Swiss repositories for radioactive waste. The update from version 05/92 to 01/01 involved major revisions for most of the actinides and fission products. Altogether, more than 70% of the database contents have been revised. Data for U, Np, Pu, Am and Tc recommended by the NEA TDB project were considered in the update. Thermodynamic data for Th, Sn, Eu, Pd, Al, and solubility and metal complexation of sulphides and silicates were extensively reviewed. Data for Zr, Ni and Se were examined less rigorously as these elements are currently being reviewed in phase II of the NEA TDB project. Our experiences from this two year team effort can be summarised as follows. Detailed in-house reviews and critical appraisal of NEA recommendations greatly improved the chemical consistency and quality of the selected data. On the other hand, we could discern major gaps in the data, especially missing carbonate complexes. In some systems,

The Compilation of Geochemical Data Bases for Performance Assessment of a Planned Repository in the Opalinus Clay in Northern Switzerland

2003 ◽  
Vol 807 ◽  
Author(s):  
Bernhard Schwyn ◽  
Paul Wersin
Keyword(s):  
Radioactive Waste ◽  
Safety Assessment ◽  
Near Field ◽  
Opalinus Clay ◽  
Geochemical Data ◽  
Data Bases ◽  
Northern Switzerland ◽  
Compacted Bentonite ◽  
Waste Repository ◽  
Chemical Retention

ABSTRACTChemical retention of radionuclides in the near field and in the host rock is an important safety pillar within the Swiss concept for a radioactive waste repository. Geochemical databases for solubility limits in cement and bentonite porewater and sorption / diffusion in cement, compacted bentonite and Opalinus Clay were compiled for use in safety assessment calculations. The databases are presented for selected safety-relevant radioelements. In contrast to earlier safety assessment studies Kd values were not truncated at 5 m3 kg−1 and values well above 10 m3 kg−1 (e.g. for actinides) are reported.

Evaluated and Estimated Solubility of Some Elements for Performance Assessment of Geological Disposal of High-Level Radioactive Waste Using Updated Version of Thermodynamic Database

2010 ◽  
Author(s):  
Akira Kitamura ◽  
Reisuke Doi ◽  
Yasushi Yoshida
Keyword(s):  
Radioactive Waste ◽  
Performance Assessment ◽  
Safety Assessment ◽  
Thermodynamic Database ◽  
Energy Agency ◽  
Geological Disposal ◽  
High Level Radioactive Waste ◽  
Five Elements ◽  
High Level ◽  
Aqueous Species

Japan Atomic Energy Agency (JAEA) established the thermodynamic database (JAEA-TDB) for performance assessment of geological disposal of high-level radioactive waste (HLW) and TRU waste. Twenty-five elements which were important for the performance assessment of geological disposal were selected for the database. JAEA-TDB enhanced reliability of evaluation and estimation of their solubility through selecting the latest and the most reliable thermodynamic data at present. We evaluated and estimated solubility of the 25 elements in the simulated porewaters established in the “Second Progress Report for Safety Assessment of Geological Disposal of HLW in Japan” using the JAEA-TDB and compared with those using the previous thermodynamic database (JNC-TDB). It was found that most of the evaluated and estimated solubility values were not changed drastically, but the solubility and speciation of dominant aqueous species for some elements using the JAEA-TDB were different from those using the JNC-TDB. We discussed about how to provide reliable solubility values for the performance assessment.

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