ANALISIS LAJU DOSIS SERAP MATERIAL NORM DI SEDIMEN DASAR LAUT BANDA, SULAWESI TENGAH

Material radioaktif alam atau NORM (naturally occurring radioactive materials) adalah material yang terkandung di bumi dan umumnya berasal dari beberapa sumber seperti pembakaran batubara, produksi migas, dan penambangan. Daerah pesisir laut banda, khususnya sepanjang Luwuk, Morowali, dan Kendari, Sulawesi Tengah, adalah daerah yang menjadi lokasi untuk beberapa kegiatan, seperti industri pertambangan, migas, dan pembangkit listrik. Tujuan dari penelitian ini adalah untuk mengkaji sebaran laju dosis serap material NORM pada sedimen dasar Laut banda, khususnya sepanjang Luwuk, Morowali, dan Kendari, Sulawesi Tengah, serta menganalisis nilainya terhadap baku mutu yang ada. Pengukuran laju dosis serap dari 226Ra, 232Th, dan 40K yang dilakukan pada 5 stasiun dan didapatkan hasil sebesar 52,53 nGy/jam; 355,75 nGy/jam; 45,88 nGy/jam; 131,86 nGy/jam; dan 35,38 nGy/jam. Hasil kajian yang didapatkan menunjukan bahwa sebaran nilai laju dosis serap dipengaruhi oleh kegiatan industri penghasil NORM yang dekat dengan lokasi stasiun pengukuran. Pola arus dan batimetri sendiri tidak terlalu berpengaruh dalam wilayah kajian ini. Tingkat bahaya laju dosis serap yang didapatkan masih berada <1 sehingga mengindikasikan bahwa risiko terhadap organisme di sekitar perairan tersebut tergolong rendah.

Radiological Dose Assessment of the Landfill Disposal of Consumer Products Containing Naturally Occurring Radioactive Materials in South Korea

Naturally occurring radioactive materials (NORMs) are long-lived radioactive elements such as uranium, thorium, and potassium, and theirdecay products. They are abundant in natural rocks and minerals. In this study, we conducted a radiological dose assessment of the disposal of consumer products (CPs) containing NORMs at landfills and incinerators in South Korea. Household wastes were categorized as combustible and noncombustible on the basis of activity concentrations (ACs) ranging below and above 1 Bq/g, respectively. Analysis data were obtained from previous literature and the Nuclear Safety and Security Commission (NSSC) of South Korea, and statistical analysis was performed using an interval plot and 95% confidence interval of mean for each category as an input. Using RESRAD computer codes for noncombustible CPs with AC below and above 1 Bq/g, we found out that the dose rate was below and above 1 mSv/y, respectively. The RESRAD-OFFSITE results showed that the dose incurred during the study period for both ranges of AC was all below the public dose limit of 1 mSv/y. NORM and LegacY Site Assessment (NORMALYSA) code was used to validate the result of the RESRAD-ONSITE code, and the results showed that the dose was equal to and above 1 mSv/y for ACs below and above 1 Bq/g, respectively. HotSpot code was used for dose evaluation to offsite residents from incineration of combustible CPs, and the resulting dose was below 1 mSv/y. These findings can be used as a guideline for managing public exposure from landfill sites with varying ACs ranges. Therefore, the competent authority should ensure that criteria and protection measures are established for people who live within a distance of 10 km from incinerators and landfill sites that are contaminated with consumer products containing NORMs.

Activity Concentrations of Naturally Occurring Radioactive Materials And Dose Calculation of Soils And Rocks Materials From A Superphosphate Industry

Activity concentration of Naturally Occurring radioactive Materials in samples from superphosphate industry was determined using Neutron Activation Analysis and radiological parameters calculated. Mean Annual Effective-Dose Equivalent(mSv/y), External and Internal Hazard, Annual Gonad Dose Equivalent(mSv/y), Radium Equivalent (Bq/kg), Absorbed Gamma Ray Dose(nGy/h), Potential Toxic Elements, Activity Utilization, and Gamma Representation Index are 87.0, 0.4, 0.5, 517.7, 137.3, 70.9, 20101.3, 9388.9, and 1.1, respectively. Most of the sample had activity concentrations of naturally occurring radioactive materials exceeding world average, indicating that activities of the industry impact on the environment. These results are good baseline data for future follow-up on activities of company.

Radiological Dose Assessment to Members of the Public Using Consumer Products Containing Naturally Occurring Radioactive Materials in Korea

Various products containing a small number of added radionuclides are commonly available for use worldwide. However, frequent use of such products puts the public at risk of radiation exposure. In this study, dose assessments to members of the public using consumer products containing naturally occurring radioactive materials (NORMs) were conducted for various usage scenarios to evaluate the external and internal exposure dose. Data for this study were obtained from previous literature and were statistically analyzed using Boxplot to determine the input data for assessment. A normalized value of activity concentration was used for dose evaluation. In addition to other external and internal dose calculation codes, analytical calculations were used to perform age-dependent. Based on analytical calculations, the highest total effective dose equivalent (TEDE) received from necklace products at the upper whiskers with an activity concentration of 4.21 Bq/g for 238U, 24.4 Bq/g for 232Th, and 0.55 Bq/g for 40K for various age groups is 2.03 mSv/y for 1 year old, 1.24 mSv/y for 10 years old and 1.11 mSv/y for adult, which are above the international commission for radiation protection (ICRP) recommended public dose limit of 1 mSv/y. Results of external and internal exposure dose obtained using Microshield code, IMBA code and Visual Monte Carlo (VMC) code are all below the recommended public dose limit of 1 mSv/y.

Optimization of 210Po determination in soil

In recent years, naturally occurring radioactive materials (NORM) have become an important topic from the perspective of environmental protection. The list of isotopes that should be monitored in the environment is constantly growing as new amendments to international legislation are introduced. One of the often studied NORM elements is 210Po. In this study, a process of elaborating of a new method of 210Po determination in soil was presented. In the proposed method, several analytical aspects, like the influence of silica decomposition or optimization of an electrode material, were revised. The obtained procedure allows performance of complete radiochemical analysis in a single day, with the chemical efficiency of over 85% and great reduction of costs. Further, the influence of the use of phosphate fertilizers on polonium concentration in soil was also confirmed.