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Catalytic Effects of Silver in Iodine Reactors for Dissolved Used Nuclear Fuel
The dissolution of used nuclear fuel generates a variety of off-gasses including flammable hydrogen and other species that are a concern for environmental release. The H-Canyon facility at the Savannah River Site is currently dissolving aluminum-clad research reactor fuel from material test reactors and the High Flux Isotope Reactor (HFIR) using a mercury-catalyzed nitric acid flowsheet. Savannah River National Laboratory recently developed and deployed a Raman spectrometer to monitor the off-gas stream from the dissolution process. Results from these measurements indicated a lack of the expected hydrogen, nitrous oxide, and nitric oxide in the off-gas stream. It was proposed that the silver on the silver nitrate–coated berl saddles present in the reactors for iodine capture were acting as a catalytic hydrogen recombiner. Nitric oxide is readily oxidized to nitrogen dioxide under normal conditions, but it was unclear what happened to the nitrous oxide. A laboratory-scale iodine reactor was assembled and filled with silver nitrate–coated berl saddles to help ascertain the fate of nitrous oxide and hydrogen. Testing with this laboratory-scale reactor observed the recombination of hydrogen when a simulated dissolver off-gas was passed through the reactor containing silver nitrate–coated berl saddles at the approximate temperatures seen in H-Canyon. However, the nitrous oxide concentration was unchanged, suggesting a more complex process occurring within the off-gas stream before it reaches the iodine reactors at H-Canyon.
Complete Metadata
| @type | dcat:Dataset |
|---|---|
| accessLevel | public |
| bureauCode |
[
"000:00"
]
|
| contactPoint |
{
"fn": "Jarrod Gogolski",
"@type": "vcard:Contact",
"hasEmail": "mailto:jarrod.gogolski@srnl.doe.gov"
}
|
| description | The dissolution of used nuclear fuel generates a variety of off-gasses including flammable hydrogen and other species that are a concern for environmental release. The H-Canyon facility at the Savannah River Site is currently dissolving aluminum-clad research reactor fuel from material test reactors and the High Flux Isotope Reactor (HFIR) using a mercury-catalyzed nitric acid flowsheet. Savannah River National Laboratory recently developed and deployed a Raman spectrometer to monitor the off-gas stream from the dissolution process. Results from these measurements indicated a lack of the expected hydrogen, nitrous oxide, and nitric oxide in the off-gas stream. It was proposed that the silver on the silver nitrate–coated berl saddles present in the reactors for iodine capture were acting as a catalytic hydrogen recombiner. Nitric oxide is readily oxidized to nitrogen dioxide under normal conditions, but it was unclear what happened to the nitrous oxide. A laboratory-scale iodine reactor was assembled and filled with silver nitrate–coated berl saddles to help ascertain the fate of nitrous oxide and hydrogen. Testing with this laboratory-scale reactor observed the recombination of hydrogen when a simulated dissolver off-gas was passed through the reactor containing silver nitrate–coated berl saddles at the approximate temperatures seen in H-Canyon. However, the nitrous oxide concentration was unchanged, suggesting a more complex process occurring within the off-gas stream before it reaches the iodine reactors at H-Canyon. |
| distribution |
[
{
"@type": "dcat:Distribution",
"title": "Scaling Trivalent Actinide and Lanthanide Recovery by Diglycolamide Resin from Savannah River Site’s Mark-18A Targets",
"accessURL": "https://figshare.com/articles/journal_contribution/Scaling_Trivalent_Actinide_and_Lanthanide_Recovery_by_Diglycolamide_Resin_from_Savannah_River_Site_s_Mark-18A_Targets/13483425?file=25878177",
"description": "The Savannah River National Laboratory is implementing a separation flowsheet to recover rare isotopes and transplutonium elements from irradiated 242Pu targets known as Mark-18A targets. The Mark-18A targets contain the United States’ supply of nonseparated 244Pu, which has a wide range of applications from nuclear forensics to production of superheavy elements such as flerovium. The targets also contain hundreds of grams of heavy curium (246–248Cm), which is used as a target material for 252Cf production. This work investigates the use of diglycolomide resin (DGA Resin) to recover valuable trivalent actinides from the Mark-18A targets. Batch contact experiments were performed on a representative simulant to determine mass loadings. The resin showed an overall capacity of 11 mg/mL for a mixed metal matrix (Zr and La–Gd). Column experiments showed chromatographic separation with transition-metal breakthroughs occurring first followed by the lanthanide series La–Gd. The experiments showed that lanthanide breakthrough occurred after 11 mg/mL mass loading was reached on the column with the mixed metal matrix. A radiological column experiment with an in-line UV/vis cell was able to detect Nd breakthrough just prior to 241Am breakthrough. Implementing an in-line UV/vis cell into full-scale Mark-18A target processing will be used to limit breakthrough of trivalent actinides recovered from the targets."
}
]
|
| identifier | SRNL-STI-2022-00133 |
| issued | 2020-12-23 |
| keyword |
[
"hydrogen recombination",
"iodine reaction",
"nox gases"
]
|
| landingPage | https://figshare.com/articles/journal_contribution/Scaling_Trivalent_Actinide_and_Lanthanide_Recovery_by_Diglycolamide_Resin_from_Savannah_River_Site_s_Mark-18A_Targets/13483425?file=25878177 |
| language |
[
"en-US"
]
|
| license | https://creativecommons.org/licenses/by/4.0/ |
| modified | 2025-08-13T20:26:51.081Z |
| programCode |
[
"000:000"
]
|
| publisher |
{
"name": "Savannah River National Laboratory (DOE)",
"@type": "org:Organization"
}
|
| references |
[
"https://doi.org/10.1021/acs.iecr.0c03897"
]
|
| rights |
"true"
|
| title | Catalytic Effects of Silver in Iodine Reactors for Dissolved Used Nuclear Fuel |
