Abstract
Thermal wave signals from nickel ion deposits produced on a heated rod surface in boiling water at atmospheric pressure was measured by two kinds of thermal wave methods, photothermal deflection and photoacoustics. Thickness of the deposits was determined from calibration curves for NiO which was their possible chemical state. It was revealed that the methods served as useful tools for in situ thickness measurement in high temperature water. Nickel ion was deposited in circular patterns (about 1 mmø) at boiling nucleation sites. The deposit thickness (0.1 ∼ 1.1 m) was proportional to time (0 ∼ 20 h) and nickel ion concentration (20 ∼ 50 ppm). This indicated that nickel ion was deposited by the evaporation-dryout mechanism, the same as for iron crud deposition in BWR’s. The deposition rate for nickel ion (2.7 x 10-3) was about 1/6 of that for iron crud. The difference was attributed to dissolution of nickel ion from NiO.
Original language | English (US) |
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Pages (from-to) | 158-164 |
Number of pages | 7 |
Journal | Journal of Nuclear Science and Technology |
Volume | 25 |
Issue number | 2 |
DOIs | |
State | Published - Feb 1988 |
Keywords
- Crud
- Deposition
- Evaporation-dryout model
- High temperature
- Nickel ions
- Photoacoustic method
- Photothermal deflection method
- Thermal wave
- Thickness
- Water
ASJC Scopus subject areas
- Nuclear and High Energy Physics
- Nuclear Energy and Engineering