Evaluation of irradiation technique to improve dose uniformity in semi-industrial irradiator (IRKA)

• Main Authors: Fitriana, Rizka, Putri, Marrisa Arlinkha Ega, Kusuma, Adam Tirta, Yunus, Muhammad Yasin
• Format: Conference Proceeding
• Language: English
• Subjects: Natural rubber; Racks; Radiation dosage
• ISSN: 0094-243X; 1551-7616
• DOI: 10.1063/5.0192853

Natural Rubber Irradiator (IRKA) is a category IV irradiator that has now been shifted into a semi-industrial irradiator. IRKA is currently still operating to irradiate some herbals and health products. The IRKA irradiation room consists of 2 racks, the west rack and the east rack which can contain 6 products for each rack. In carrying out its operations, IRKA still relies on operators (humans) to move boxes in its radiation racks. This box movement is an irradiation technique to get a good DUR (Dose Uniformity Ratio). As a comparison, different product densities were applied to see the effect. Irradiation was carried out using a dummy product (containing husk and sand) in 2 densities, namely 0.1 g/cm3 and 0.3 g/cm3 with the same irradiation time of 4 hours. The irradiation technique is applied through 4 steps of movement: initial position, zz’ 180° reversed position, exchange level + row position, and zz’ 180° reversed position again. Based on the results obtained, the box movement of the irradiation technique applied still has drawbacks because there is a large difference between the maximum and minimum doses in each box was around 40.2% - 60.8% with a DUR ranging from 1.50 to 1.90. Meanwhile, the global DUR for each rack and the density difference is between 1.77 – 2.00 with a percentage difference of 55.5% - 67.1%. Therefore, the irradiation technique in IRKA at the full position of the product in one batch is evaluated to achieve good dose uniformity between each box so that there is not too much DUR inequality.