Measurement of scale thickness in geothermal pipeline using gamma transmission method: A preliminary study in Kamojang geothermal power plant

Pipe scale is a common problem in the geothermal power plant. On-stream pipe scaling rate measurement is needed to determine further action to ensure production continuity, occupational safety, and the environment. Kamojang geothermal power plant unit 5 began operating in 2015. There were indications of a decline in performance after five years of operation. The gamma scanning technique was applied to measure the pipe scale thickness in the geothermal power plant while the plant was operating. The Cs-137 gamma radiation source and scintillation detector were positioned flanking the pipe’s cross-section and scanning it. The scanning data profile can represent the inside condition of the pipeline. The results of the inspection indicated that there were deposits in the pipeline to the turbine. The scale thickness varies from 40 mm to 120 mm inside it (D=32 inches). This technique can be developed and applied to study the scaling rate in the geothermal power plant pipeline. Further experimentation is needed to refine the method.