Development of Ag/sup 0/Z for bulk /sup 129/I removal from nuclear fuel reprocessing plants and PbX for /sup 129/I storage

Conference · Sat Dec 31 23:00:00 EST 1977

OSTI ID:6942226

Thomas, T R; Staples, B A; Murphy, L P

Tests were conducted to develop Ag-exchanged mordenite (AgZ) for removal of gaseous /sup 129/I from nuclear fuel reprocessing plants. The effects of bed depth and hydrogen pretreatment on the elemental (I/sub 2/) iodine loading of AgZ were examined. The tests indicated that reduced AgZ (Ag/sup 0/Z) had about twice the capacity for iodine as AgZ, and at least 15-cm bed depths should be used for loading tests. The effects of H/sub 2/O(g), NO, NO/sub 2/, and bed temperature on the iodine loading of Ag/sup 0/Z were determined. The highest loadings were obtained with NO in the gas stream. Water vapor and bed temperature appeared to have no effect on the iodine loadings. Tests were conducted to develop a dry method for in situ regeneration of iodine-loaded Ag/sup 0/Z. A test bed of Ag/sup 0/Z was recycled 13 times by loading it with I/sub 2/ and stripping the I/sub 2/ (as HI) with H/sub 2/. A 20 percent loss in iodine capacity was observed by the fourteenth loading. The iodine loadings of lead-exchanged zeolites, which were used to chemisorb HI during the recycle tests, were measured. The iodine vapor pressures at 20/sup 0/C over the substrates were predicted to be 10/sup -6/, 10/sup -8/, and less than 10/sup -16/ atm for Pb-exchanged mordenite, Pb-exchanged faujasite and reduced Pb-exchanged faujasite, respectively. A process-flow diagram was formulated for iodine recovery. Two parallel beds of Ag/sup 0/Z are used to permit continuous iodine recovery. While one is being regenerated the other recovers iodine. The iodine is chemisorbed as AgI, stripped as HI, and chemisorbed on the lead bed as a form of PbI/sub 2/. The Ag beds were sized for a 30-day operation in a fuel reprocessing plant before regeneration. About 5 days would be needed for regeneration. About 2 m/sup 3/ of iodine-loaded Pb-exchanged faujasite would be generated each year. The Pb bed would be contained in canisters to permit transfer in and out of the bed holder and storage in 0.2 m/sup 3/ (55 gal) drums.

• Research Organization: Idaho National Engineering Lab., Idaho Falls (USA)
• DOE Contract Number: EY-76-C-07-1540
• OSTI ID: 6942226
• Report Number(s): CONF-780819-15
• Country of Publication: United States
• Language: English

Related Subjects

050800* -- Nuclear Fuels-- Spent Fuels Reprocessing
052001 -- Nuclear Fuels-- Waste Processing
11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS
12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CHEMICAL REACTIONS
CHEMISORPTION
DESIGN
FUEL REPROCESSING PLANTS
GASEOUS WASTES
INORGANIC ION EXCHANGERS
INTERMEDIATE MASS NUCLEI
INTERNAL CONVERSION RADIOISOTOPES
IODINE 129
IODINE ISOTOPES
ION EXCHANGE MATERIALS
ISOTOPES
MANAGEMENT
MINERALS
NUCLEAR FACILITIES
NUCLEI
ODD-EVEN NUCLEI
OFF-GAS SYSTEMS
PROCESSING
RADIOACTIVE WASTE PROCESSING
RADIOISOTOPES
REGENERATION
SEPARATION PROCESSES
SORPTION
SORPTIVE PROPERTIES
SURFACE PROPERTIES
WASTE MANAGEMENT
WASTE PROCESSING
WASTES
YEARS LIVING RADIOISOTOPES
ZEOLITES