FUNCTIONALIZED SILICA AEROGELS: ADVANCED MATERIALS TO CAPTURE AND IMMOBILIZE RADIOACTIVE IODINE
To support the future expansion of nuclear energy, an effective method is needed to capture and safely store radiological iodine-129 released during reprocessing of spent nuclear fuel. Various materials have been investigated to capture and immobilize iodine. In most cases, however, the materials that are effective for capturing iodine cannot subsequently be sintered/densified to create a stable composite that could be a viable waste form. We have developed chemically modified, highly porous, silica aerogels that show sorption capacities higher than 440 mg of I2 per gram at 150 C. An iodine uptake test in dry air containing 4.2 ppm of iodine demonstrated no breakthrough after 3.5 h and indicated a decontamination factor in excess of 310. Preliminary densification tests showed that the I2-loaded aerogels retained more than 92 wt% of I2 after thermal sintering with pressure assistance at 1200 C for 30 min. These high capture and retention efficiencies for I2 can be further improved by optimizing the functionalization process and the chemistry as well as the sintering conditions.
- Research Organization:
- Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC05-76RL01830
- OSTI ID:
- 1030878
- Report Number(s):
- PNNL-SA-77216; AF5805000; TRN: US1106054
- Resource Relation:
- Conference: Ceramic Materials for Energy Applications: Papers from The American Ceramic Society's 35th International Conference on Advanced Ceramics and Composites, January 23-28, 2011, Daytona Beach, Florida. Ceramic Engineering and Science Proceedings, 32(9):23-33
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
12 MANAGEMENT OF RADIOACTIVE WASTES, AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES
AIR
CERAMICS
CHEMISTRY
DECONTAMINATION
EFFICIENCY
IODINE
IODINE 129
NUCLEAR ENERGY
NUCLEAR FUELS
REPROCESSING
RETENTION
SILICA
SINTERING
SORPTION
WASTE FORMS
Functionallized silica aerogel
Gaseous radioiodine
Capture
Immobilization