کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4435597 1620224 2016 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Reactive transport modelling of the long-term interactions of corrosion products and compacted bentonite in a HLW repository in granite: Uncertainties and relevance for performance assessment
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات ژئوشیمی و پترولوژی
پیش نمایش صفحه اول مقاله
Reactive transport modelling of the long-term interactions of corrosion products and compacted bentonite in a HLW repository in granite: Uncertainties and relevance for performance assessment
چکیده انگلیسی


• Magnetite precipitation reduces significantly the porosity of the bentonite near the canister.
• The thickness of the zone of reduced porosity is 7 cm at t = 1 Ma.
• This thickness increases significantly when the dependence of the corrosion rate on the chemical conditions is considered.
• Model results are not significantly sensitive to the thermal transient and the effect of temperature on the corrosion rate.
• The conclusions of our simulations are consistent with those reported by others.

Here we present a long-term nonisothermal reactive transport model for the interactions of the corrosion products of a carbon-steel canister and the compacted bentonite of the engineered barrier of a high-level radioactive waste repository in granite. Canister corrosion causes an increase in the pH and the concentration of dissolved Fe2+ of the bentonite porewater. Iron precipitates as magnetite and siderite and sorbs via cation exchange and surface complexation on weak sites. Magnetite precipitation reduces significantly the porosity of the bentonite near the canister. The thickness of the zone of reduced porosity is 7 cm at t = 1 Ma. This thickness increases significantly when the dependence of the corrosion rate on the chemical conditions is considered and decreases 3 cm when smectite dissolution and analcime precipitation are taken into account. Model results are not significantly sensitive to the thermal transient and the effect of temperature on the corrosion rate. The conclusions of our simulations are consistent for the most part with those reported by others for engineered barrier systems at similar chemical conditions.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Applied Geochemistry - Volume 67, April 2016, Pages 42–51
نویسندگان
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