Iodine-129 process control monitor for evaporator off-gas streams
Continuous monitoring of gaseous /sup 129/I in evaporator off-gas at nuclear fuel reprocessing facilities is important from both regulatory and process control viewpoints. Accordingly, continuous monitoring of evaporator overheads would supply the necessary information to retain /sup 129/I in the evaporator bottoms should a process control mechanism for the evaporator be developed. Although a continuous /sup 129/I monitor for nuclear fuel reprocessing plant off-gas streams has already been developed, monitoring of evaporator overheads presents unique problems for /sup 129/I monitoring, including /sup 129/I in the form of liquid aerosols, high concentrations of nitric acid mist and organics, and high concentrations of other radionuclides such as /sup 137/Cs. The off-gas is also predominantly water vapor. A two-phase laboratory study was completed. First, the proper configuration to successfully detect /sup 129/I was examined. Second, a 2/sup 4/ factorial design experiment was performed to determine the monitor's response to aerosols, organics, HNO/sub 3/, and /sup 137/Cs. Both response and variability for the monitor were determined. Major conclusions were: the presence of HNO/sub 3/ had no statistically significant effect on the response of the monitor; the presence of TBP significantly increased the response of the monitor; the use of a filter, corresponding to low aerosol conditions, significantly increased the response of the monitor. A filter should be used because the decreased monitor response if the filter is not used (high aerosol conditions); under conditions of the experiments, /sup 137/Cs remained in the evaporator bottoms; and no effect of /sup 137/Cs on the monitor was observed; and the variability of the monitor was not significantly affected by the filter, TBP, HNO/sub 3/, or /sup 137/Cs. The monitor when used with a filter, was considered suitable for use in evaporator off-gas streams.
- Research Organization:
- Westinghouse Idaho Nuclear Co., Inc., Idaho Falls (USA)
- DOE Contract Number:
- AC07-84ID12435
- OSTI ID:
- 5231401
- Report Number(s):
- WINCO-1001; ON: DE84009370
- Country of Publication:
- United States
- Language:
- English
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12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES
AEROSOLS
ALKALI METAL ISOTOPES
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BETA-PLUS DECAY RADIOISOTOPES
BUTYL PHOSPHATES
CESIUM 127
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COLLOIDS
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DISPERSIONS
ELECTRON CAPTURE RADIOISOTOPES
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FUEL REPROCESSING PLANTS
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INTERMEDIATE MASS NUCLEI
INTERNAL CONVERSION RADIOISOTOPES
IODINE 129
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MEASURING INSTRUMENTS
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NITRIC ACID
NUCLEAR FACILITIES
NUCLEI
ODD-EVEN NUCLEI
OFF-GAS SYSTEMS
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PHOSPHORIC ACID ESTERS
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