Nanoscopic structure of borosilicate glass with additives for nuclear waste vitrification

Ryuhei Motokawa, Koji Kaneko, Yojiro Oba, Takayuki Nagai, Yoshihiro Okamoto, Taishi Kobayashi, Takayuki Kumada, William T. Heller

Research output: Contribution to journalArticlepeer-review

4 Scopus citations

Abstract

We investigated the nanoscopic structure of borosilicate glasses as a host for high-level radioactive liquid waste (HLLW) in the presence of the additives Na2O and CaO/ZnO with and without Li2O. These additives have been used to lower the glass melting point, suppress the macroscopic phase separation, and increase the chemical durability of glasses. Small-angle neutron scattering was used to elucidate the effect of the additives on the nanoscopic structure along with macro- and atomic-scale observations obtained using neutron imaging and X-ray diffraction, respectively. The borosilicate glass made without Na2O formed a microphase-separated structure of SiO2- and B2O3-rich domains approximately 100 nm in size, and the material was homogeneous at length scales up to millimeters. With the addition of increasing amounts of Na2O, the domain spacing decreased. Introducing CaO/ZnO additives induced inhomogeneities in the glass, such as void structures several nanometers in size, although the inhomogeneity was suppressed by the coaddition of Li2O. These results provide insights into the performance of host glasses for HLLW vitrification. Incorporating HLLW into glasses is likely to cause changes in the nanoscopic structure of host glasses similar to those revealed here.

Original languageEnglish
Article number121352
JournalJournal of Non-Crystalline Solids
Volume578
DOIs
StatePublished - Feb 15 2022

Funding

This work was supported in part by the Agency for Natural Resources and Energy, Ministry of Economy, Trade and Industry of Japan (Basic Research Programs of Vitrification Technology for Waste Volume Reduction; Grant No. JPJ010599) and the Ministry of Education, Culture, Sports, Science and Technology of Japan (Grant-in-Aid for Scientific Research B, 2018–2022, No. 18H0192). The authors thank the staff at RADEN (BL22), MLF, and J-PARC for operating the accelerators and the neutron production target. The neutron imaging experiments at BL22 were performed under the program for project use (2018B0009, 2019A0061, and 2019B0161). Access to the experiment at the SANS-J (C3–2) was provided by the Japan Research Reactor-3 (JRR-3) with the approval of Japan Atomic Energy Agency (JAEA; Proposal 2021-D420). A portion of this research used resources at the Spallation Neutron Source, a DOE Office of Science User Facility operated by Oak Ridge National Laboratory. This work was supported in part by the Agency for Natural Resources and Energy, Ministry of Economy, Trade and Industry of Japan (Basic Research Programs of Vitrification Technology for Waste Volume Reduction; Grant No. JPJ010599) and the Ministry of Education, Culture, Sports, Science and Technology of Japan (Grant-in-Aid for Scientific Research B, 2018–2022, No. 18H0192). The authors thank the staff at RADEN (BL22), MLF, and J-PARC for operating the accelerators and the neutron production target. The neutron imaging experiments at BL22 were performed under the program for project use (2018B0009, 2019A0061, and 2019B0161). Access to the experiment at the SANS-J (C3–2) was provided by the Japan Research Reactor-3 (JRR-3) with the approval of Japan Atomic Energy Agency (JAEA; Proposal 2021-D420). A portion of this research used resources at the Spallation Neutron Source, a DOE Office of Science User Facility operated by Oak Ridge National Laboratory.

Keywords

  • Borosilicate glass
  • Nanoscopic structure
  • Nuclear waste vitrification
  • Small-angle neutron scattering

Fingerprint

Dive into the research topics of 'Nanoscopic structure of borosilicate glass with additives for nuclear waste vitrification'. Together they form a unique fingerprint.

Cite this