Migration behavior of plutonium in compacted bentonite under reducing condition using electromigration

Kazuya Idemitsu, Yosuke Yamasaki, Syeda Afsarun Nessa, Yaohiro Inagaki, Tatsumi Arima, Toshiaki Mitsugashira, Mitsuo Hara, Yoshimitsu Suzuki

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

5 Citations (Scopus)

Abstract

Carbon steel is one of the candidate overpack materials for high-level waste disposal and is expected to assure complete containment of vitrified waste glass during an initial period of 1000 years in Japan. Carbon steel overpack will be corroded by consuming oxygen introduced by repository construction after closure of repository and then will keep the reducing environment in the vicinity of repository. The migration of iron corrosion products through the buffer material will affect migration of redox-sensitive radionuclides. Therefore the authors have carried out electromigration experiments with source of iron ions supplied by anode corrosion of iron coupons attached to compacted bentonite. Authors tried to use plutonium in this experimental configuration to obtain the knowledge of migration behavior of actinides. Authors also used cesium as reference. The concentrations of iron and sodium showed nearly complementary distributions. It is expected that iron ion could migrate as ferrous ion through the interlayer of montmorillonite replacing exchangeable sodium ions in the interlayer. Concentration profiles of plutonium in bentonite grew as time supplying electric potential as long as 168 h. Plutonium migrated from the iron anode toward cathode as deeper than 1 mm of the interior of bentonite even in 48 h, though plutonium could not diffuse 1 mm for 2 years. On the other hand, profiles of cesium were reported to be controlled by ordinary diffusion because of large diffusion coefficient of cesium in bentonite as large as 10-12 m2/s. Drift of the cesium profile by electric potential gradient could be observed clearly after 240 h at individual experiment for cesium. Apparent dispersion coefficients of plutonium were calculated from the profiles and were as large as 10-13 m 2/s. Since plutonium migration was accelerated by electric potential, plutonium chemical species would have positive charge and were estimated as PuOH2+ or PuCl2+ by the thermodynamic calculation. Thus this experiment can provide a diffusion field for cations under a reducing condition with ferrous ions in water-saturated bentonite.

Original languageEnglish
Title of host publicationScientific Basis for Nuclear Waste Management XXX
Pages443-448
Number of pages6
Volume985
Publication statusPublished - 2007
Event2006 MRS Fall Meeting - Boston, MA, United States
Duration: Nov 27 2006Dec 1 2006

Other

Other2006 MRS Fall Meeting
CountryUnited States
CityBoston, MA
Period11/27/0612/1/06

Fingerprint

Plutonium
Bentonite
bentonite
Electromigration
electromigration
plutonium
Cesium
cesium
Iron
iron
Ions
carbon steels
profiles
ions
Carbon steel
interlayers
corrosion
Anodes
Electric potential
electric potential

All Science Journal Classification (ASJC) codes

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

Cite this

Idemitsu, K., Yamasaki, Y., Nessa, S. A., Inagaki, Y., Arima, T., Mitsugashira, T., ... Suzuki, Y. (2007). Migration behavior of plutonium in compacted bentonite under reducing condition using electromigration. In Scientific Basis for Nuclear Waste Management XXX (Vol. 985, pp. 443-448)

Migration behavior of plutonium in compacted bentonite under reducing condition using electromigration. / Idemitsu, Kazuya; Yamasaki, Yosuke; Nessa, Syeda Afsarun; Inagaki, Yaohiro; Arima, Tatsumi; Mitsugashira, Toshiaki; Hara, Mitsuo; Suzuki, Yoshimitsu.

Scientific Basis for Nuclear Waste Management XXX. Vol. 985 2007. p. 443-448.

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

Idemitsu, K, Yamasaki, Y, Nessa, SA, Inagaki, Y, Arima, T, Mitsugashira, T, Hara, M & Suzuki, Y 2007, Migration behavior of plutonium in compacted bentonite under reducing condition using electromigration. in Scientific Basis for Nuclear Waste Management XXX. vol. 985, pp. 443-448, 2006 MRS Fall Meeting, Boston, MA, United States, 11/27/06.
Idemitsu K, Yamasaki Y, Nessa SA, Inagaki Y, Arima T, Mitsugashira T et al. Migration behavior of plutonium in compacted bentonite under reducing condition using electromigration. In Scientific Basis for Nuclear Waste Management XXX. Vol. 985. 2007. p. 443-448
Idemitsu, Kazuya ; Yamasaki, Yosuke ; Nessa, Syeda Afsarun ; Inagaki, Yaohiro ; Arima, Tatsumi ; Mitsugashira, Toshiaki ; Hara, Mitsuo ; Suzuki, Yoshimitsu. / Migration behavior of plutonium in compacted bentonite under reducing condition using electromigration. Scientific Basis for Nuclear Waste Management XXX. Vol. 985 2007. pp. 443-448
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AU - Hara, Mitsuo

AU - Suzuki, Yoshimitsu

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