Migration behavior of alkali earth ions in compacted bentonite with iron corrosion product using electrochemical method

Kazuya Idemitsu, Daisuke Akiyama, Akira Eto, Yoshihiko Matsuki, Yaohiro Inagaki, Tatsumi Arima

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

Carbon steel overpack will corrode by consuming oxygen introduced during repository construction after closure of repository, that will keep the environment in the vicinity of repository reducing. The iron corrosion products can migrate in bentonite as ferrous cations (Fe2+) through the interlay er of montmorillonite replacing the exchangeable sodium ions in the interlayer. This replacement of sodium may affect the migration behavior in the altered bentonite not only for redox-sensitive elements but also the other ions. Therefore we have carried out electrochemical analysis, of calcium, strontium or barium with the ferrous ion supplied by anodic corrosion of iron coupons in compacted bentonite. Fifteen micro liters of tracer solution containing 8.6 M of CaCl 2 or 3.0 M of SrCl2 or 1.5 M BaCl2 were spiked on the interface between the iron coupon and bentonite, for which the dry density was in the range of 1.4 to 1.5 Mg/m3, before assembling. The iron coupons were connected as working electrodes to the potentiostat and held at a constant supplied potential between - 500 to +300 mV (vs. Ag/AgCl reference electrode) for up to 7 days. Calcium and strontium could migrate faster and deeper into the bentonite than iron in each condition, while barium could migrate slower than iron. A model using dispersion and electromigration can explain the measured profiles in the bentonite specimens. The fitted value of electromigration velocity was a function of applied electrical potential and 10 to 23 nm/s for calcium, 11 to 19 for strontium, around 4 nm/s for barium and 5 to 15 nm/s for iron, respectively. Alternatively, the fitted value of the dispersion coefficient was not a function of applied potential, and the values were 3-8 × 10-12m2/s for calcium, 2-4 × 10-12 m2/s for strontium, 5-10×10 -12m2/s for barium and 3-9×10-12m 2/s for iron, respectively.

Original languageEnglish
Title of host publicationScientific Basis for Nuclear Waste Management XXXIV
Pages227-232
Number of pages6
Volume1265
Publication statusPublished - 2010
Event2010 MRS Spring Meeting - San Francisco, CA, United States
Duration: Apr 5 2010Apr 9 2010

Other

Other2010 MRS Spring Meeting
CountryUnited States
CitySan Francisco, CA
Period4/5/104/9/10

Fingerprint

Bentonite
bentonite
Alkalies
alkalies
corrosion
Iron
Earth (planet)
Ions
Corrosion
iron
Strontium
Barium
products
strontium
barium
calcium
Calcium
ions
Electromigration
electromigration

All Science Journal Classification (ASJC) codes

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanical Engineering
  • Mechanics of Materials

Cite this

Idemitsu, K., Akiyama, D., Eto, A., Matsuki, Y., Inagaki, Y., & Arima, T. (2010). Migration behavior of alkali earth ions in compacted bentonite with iron corrosion product using electrochemical method. In Scientific Basis for Nuclear Waste Management XXXIV (Vol. 1265, pp. 227-232)

Migration behavior of alkali earth ions in compacted bentonite with iron corrosion product using electrochemical method. / Idemitsu, Kazuya; Akiyama, Daisuke; Eto, Akira; Matsuki, Yoshihiko; Inagaki, Yaohiro; Arima, Tatsumi.

Scientific Basis for Nuclear Waste Management XXXIV. Vol. 1265 2010. p. 227-232.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Idemitsu, K, Akiyama, D, Eto, A, Matsuki, Y, Inagaki, Y & Arima, T 2010, Migration behavior of alkali earth ions in compacted bentonite with iron corrosion product using electrochemical method. in Scientific Basis for Nuclear Waste Management XXXIV. vol. 1265, pp. 227-232, 2010 MRS Spring Meeting, San Francisco, CA, United States, 4/5/10.
Idemitsu K, Akiyama D, Eto A, Matsuki Y, Inagaki Y, Arima T. Migration behavior of alkali earth ions in compacted bentonite with iron corrosion product using electrochemical method. In Scientific Basis for Nuclear Waste Management XXXIV. Vol. 1265. 2010. p. 227-232
Idemitsu, Kazuya ; Akiyama, Daisuke ; Eto, Akira ; Matsuki, Yoshihiko ; Inagaki, Yaohiro ; Arima, Tatsumi. / Migration behavior of alkali earth ions in compacted bentonite with iron corrosion product using electrochemical method. Scientific Basis for Nuclear Waste Management XXXIV. Vol. 1265 2010. pp. 227-232
@inproceedings{2f199a04ceef4290aade16cb69251633,
title = "Migration behavior of alkali earth ions in compacted bentonite with iron corrosion product using electrochemical method",
abstract = "Carbon steel overpack will corrode by consuming oxygen introduced during repository construction after closure of repository, that will keep the environment in the vicinity of repository reducing. The iron corrosion products can migrate in bentonite as ferrous cations (Fe2+) through the interlay er of montmorillonite replacing the exchangeable sodium ions in the interlayer. This replacement of sodium may affect the migration behavior in the altered bentonite not only for redox-sensitive elements but also the other ions. Therefore we have carried out electrochemical analysis, of calcium, strontium or barium with the ferrous ion supplied by anodic corrosion of iron coupons in compacted bentonite. Fifteen micro liters of tracer solution containing 8.6 M of CaCl 2 or 3.0 M of SrCl2 or 1.5 M BaCl2 were spiked on the interface between the iron coupon and bentonite, for which the dry density was in the range of 1.4 to 1.5 Mg/m3, before assembling. The iron coupons were connected as working electrodes to the potentiostat and held at a constant supplied potential between - 500 to +300 mV (vs. Ag/AgCl reference electrode) for up to 7 days. Calcium and strontium could migrate faster and deeper into the bentonite than iron in each condition, while barium could migrate slower than iron. A model using dispersion and electromigration can explain the measured profiles in the bentonite specimens. The fitted value of electromigration velocity was a function of applied electrical potential and 10 to 23 nm/s for calcium, 11 to 19 for strontium, around 4 nm/s for barium and 5 to 15 nm/s for iron, respectively. Alternatively, the fitted value of the dispersion coefficient was not a function of applied potential, and the values were 3-8 × 10-12m2/s for calcium, 2-4 × 10-12 m2/s for strontium, 5-10×10 -12m2/s for barium and 3-9×10-12m 2/s for iron, respectively.",
author = "Kazuya Idemitsu and Daisuke Akiyama and Akira Eto and Yoshihiko Matsuki and Yaohiro Inagaki and Tatsumi Arima",
year = "2010",
language = "English",
isbn = "9781605112428",
volume = "1265",
pages = "227--232",
booktitle = "Scientific Basis for Nuclear Waste Management XXXIV",

}

TY - GEN

T1 - Migration behavior of alkali earth ions in compacted bentonite with iron corrosion product using electrochemical method

AU - Idemitsu, Kazuya

AU - Akiyama, Daisuke

AU - Eto, Akira

AU - Matsuki, Yoshihiko

AU - Inagaki, Yaohiro

AU - Arima, Tatsumi

PY - 2010

Y1 - 2010

N2 - Carbon steel overpack will corrode by consuming oxygen introduced during repository construction after closure of repository, that will keep the environment in the vicinity of repository reducing. The iron corrosion products can migrate in bentonite as ferrous cations (Fe2+) through the interlay er of montmorillonite replacing the exchangeable sodium ions in the interlayer. This replacement of sodium may affect the migration behavior in the altered bentonite not only for redox-sensitive elements but also the other ions. Therefore we have carried out electrochemical analysis, of calcium, strontium or barium with the ferrous ion supplied by anodic corrosion of iron coupons in compacted bentonite. Fifteen micro liters of tracer solution containing 8.6 M of CaCl 2 or 3.0 M of SrCl2 or 1.5 M BaCl2 were spiked on the interface between the iron coupon and bentonite, for which the dry density was in the range of 1.4 to 1.5 Mg/m3, before assembling. The iron coupons were connected as working electrodes to the potentiostat and held at a constant supplied potential between - 500 to +300 mV (vs. Ag/AgCl reference electrode) for up to 7 days. Calcium and strontium could migrate faster and deeper into the bentonite than iron in each condition, while barium could migrate slower than iron. A model using dispersion and electromigration can explain the measured profiles in the bentonite specimens. The fitted value of electromigration velocity was a function of applied electrical potential and 10 to 23 nm/s for calcium, 11 to 19 for strontium, around 4 nm/s for barium and 5 to 15 nm/s for iron, respectively. Alternatively, the fitted value of the dispersion coefficient was not a function of applied potential, and the values were 3-8 × 10-12m2/s for calcium, 2-4 × 10-12 m2/s for strontium, 5-10×10 -12m2/s for barium and 3-9×10-12m 2/s for iron, respectively.

AB - Carbon steel overpack will corrode by consuming oxygen introduced during repository construction after closure of repository, that will keep the environment in the vicinity of repository reducing. The iron corrosion products can migrate in bentonite as ferrous cations (Fe2+) through the interlay er of montmorillonite replacing the exchangeable sodium ions in the interlayer. This replacement of sodium may affect the migration behavior in the altered bentonite not only for redox-sensitive elements but also the other ions. Therefore we have carried out electrochemical analysis, of calcium, strontium or barium with the ferrous ion supplied by anodic corrosion of iron coupons in compacted bentonite. Fifteen micro liters of tracer solution containing 8.6 M of CaCl 2 or 3.0 M of SrCl2 or 1.5 M BaCl2 were spiked on the interface between the iron coupon and bentonite, for which the dry density was in the range of 1.4 to 1.5 Mg/m3, before assembling. The iron coupons were connected as working electrodes to the potentiostat and held at a constant supplied potential between - 500 to +300 mV (vs. Ag/AgCl reference electrode) for up to 7 days. Calcium and strontium could migrate faster and deeper into the bentonite than iron in each condition, while barium could migrate slower than iron. A model using dispersion and electromigration can explain the measured profiles in the bentonite specimens. The fitted value of electromigration velocity was a function of applied electrical potential and 10 to 23 nm/s for calcium, 11 to 19 for strontium, around 4 nm/s for barium and 5 to 15 nm/s for iron, respectively. Alternatively, the fitted value of the dispersion coefficient was not a function of applied potential, and the values were 3-8 × 10-12m2/s for calcium, 2-4 × 10-12 m2/s for strontium, 5-10×10 -12m2/s for barium and 3-9×10-12m 2/s for iron, respectively.

UR - http://www.scopus.com/inward/record.url?scp=78650870315&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=78650870315&partnerID=8YFLogxK

M3 - Conference contribution

AN - SCOPUS:78650870315

SN - 9781605112428

VL - 1265

SP - 227

EP - 232

BT - Scientific Basis for Nuclear Waste Management XXXIV

ER -