Determination of 226Ra Contamination Depth Around Phosphogypsum Pit Using In-Situ Gamma Spectrometer

The feasibility of applying multiple photopeak method (MPM) and peak to valley ratio (PVRM) method to determine Radium-226 contamination depth (²²⁶Ra h_c) has been investigated. Gamma spectra in eight positions around phosphogypsum disposal pit has been measured using portable NaI(Tl) gamma spectrometer. MPM was investigated by calculating the ratio [Formula: see text] of 609 keV gamma line net counts to the corresponding value of 352 keV. PVRM was investigated by calculating the ratio [Formula: see text] of net counts of 609 keV gamma line to the corresponding valley counts. ²²⁶Ra h_c in the positions has been determined using traditional soil coring. It was found that, [Formula: see text] and [Formula: see text] have good linear correlations with ²²⁶Ra h_cTherefore, ²²⁶Ra h_c can be determined by MPM and PVRM. These methods save a lot of time, costs and efforts in comparison with the traditional one.

Assessment of soil contamination by (210)Po and (210)Pb around heavy oil and natural gas fired power plants

Soil contamination by (210)Pb and (210)Po around heavy oil and natural gas power plants has been investigated; fly and bottom ash containing enhanced levels of (210)Pb and (210)Po were found to be the main source of surface soil contamination. The results showed that (210)Pb and (210)Po in fly-ash (economizer, superheater) is highly enriched with (210)Pb and (210)Po, while bottom-ash (boiler) is depleted. The highest (210)Pb and (210)Po activity concentrations were found to be in economizer ash, whereas the lowest activity concentration was in the recirculator ash. On the other hand, (210)Pb and (210)Po activity concentrations in soil samples were found to be higher inside the plant site area than those samples collected from surrounding areas. The highest levels were found in the vicinity of Mhardeh and Tishreen power plants; both plants are operated by heavy oil and natural fuels, while the lowest values were found to be in those samples collected from Nasrieh power plant, which is only operated by one type of fuel, viz. natural gas. In addition, the levels of surface soil contamination have decreased as the distance from the power plant site center increased.