Measurement of Radioactivity in Some Commercial Porcelain Samples by Using HPGe Detector

Estimations of specific activity concentrations in eight commercial porcelain tiles made in different countries were performed by the use of HPGe detector. We have found that the highest specific activity concentrations for 238U, 40K were equal to (21.120 Bq/kg) and (283.862 Bq/kg) respectively, Iranian origin, while the highest specific activity concentration for 232Th was found to be equal to (29.292 Bq/kg), Iraqi origin; all of which were less than their corresponding recommended values given by (UNSCEAR, 2000). The radiation hazard indices [Iɣ , Hin ,Hex , Raeq ,DƔ , (AEDE) in and (AEDE) out] were also studied and their values were less than the allowed values determined by (UNSCEAR, 2000). Therefore, all the studied tiles of commercial porcelain are safe when used, for example, in floor constructions. Keyword: Radiation hazard indices, porcelain samples, HPGe detector.

Information about natural radioactivity to decide the amount of public exposure in flooring materials [5]. We use HPGe detector to determine the specific activity concentrations and radiation hazard indices for some commercial porcelain tiles, which is the aim of this paper.

Materials and Method
Eight commercial porcelain tiles were gathered from various different markets and industrial facilities. The tiles were picked from most regular Iraqi markets, see Figure 1. Each tile was pounded into small pieces, then into fine powder by utilizing jaw crusher. The tiles were dried at 100 °C for one hour to guarantee that any moisture was expelled from the tests. In order to acquire uniform molecular sizes, a (500 μm) mesh was utilized, and then, the tiles were weighted (one kg) and transferred to a Marinelli beaker. The HPGe system which was used in the present work was a (3×3) inch, see Figure 2. A fundamental prerequisite to estimate a gamma producer was the character of photo peaks showed in the spectrum made by the detector system. Calibration   The equation which was used to obtain the specific activity concentrations in porcelain tiles is [6]. (1) Where: A: represents the specific activity of radioactive elements.
N: area of the photo peak at energy (Eγ). T: duration of measuring procedure (7200 s).
Where ATh, Ak and AU are the specific activity concentrations of 238 U, 232 Th and 40 K, respectively in (Bq/kg) units.

5-Activity Concentration Index (Iɣ) [10]
. Table 1. Contains the results of the present work. It can be noticed that the specific activity of ( 238 U) was found to be varied from (14.830 Bq/kg) (Syrian origin) to (21.120 Bq/kg) (Iranian origin), with a mean value of (17.968±2.248 Bq/kg), see Figure 3. Which do not reach the preferred value (35 Bq/kg) for the specific activity of 238 U specified by (UNSCEAR, 2000).

Results and Discussions
Specific activity of ( 232 Th) was found to be ranged from (19.564 Bq/kg) (Spanish origin) to (29.292 Bq/kg) (Iraqi origin), with a mean value of (24.282±3.168 Bq/kg), see Figure 3. Which do not reach the preferred value (30 Bq/kg) for the specific activity of 232 Th specified by (UNSCEAR, 2000).
Specific activity of ( 40 K) was found to be ranged from (154.070 Bq/kg) (Vietnamese origin) to (283.862 Bq/kg) (Iranian origin), with an average value of (222.715±47.09 Bq/kg), see Figure 3. Which do not reach the preferred value (400 Bq/kg) for the specific activity of 40 K specified by (UNSCEAR, 2000).

Conclusion
All results concerning values of the specific activity for ( 238 U, 232 Th and 40 K) and radiation hazard indices [Iɣ , Hin ,Hex , Raeq ,DƔ , (AEDE) in and (AEDE) out] were found to be less than their permitted limits and it will not pose relatively serious health risk when used, for example, in floor contractions.