Operational Intervention Levels (OILs) are a part of the emergency preparedness and response program, which must be established during the preparedness stage. OILs are operational criteria that can be used promptly, without further assessment to determine the appropriate protective actions or other response actions based on environmental measurement or laboratory analysis. International Atomic Energy Agency (IAEA) provided a set of spreadsheets to support Member States in determining the default OIL values based on their facilities specific data. In this study, these spreadsheets are utilized to calculate specific time-dependent OIL(t) functions for a 30 MW research reactor RSG-GAS. Time-dependent OIL(t) calculation considers ten elements including generic criteria proposed by IAEA and RSG-GAS source term data for beyond design basis accident (BDBA) computed in previous study. Based on the time-dependent OIL(t) calculation results, facility site condition, limited resources, and any other specific conservative consideration, it can be concluded that some of the IAEA’s default OILs values must be revised before used as operational criteria in case of RSG-GAS accident.

Background: The use of thermoplastic immobilization devices in radiotherapy increases the positional repeatability of irradiation. However, these devices act as boluses and increase surface dose. In this study, we evaluated the increase in surface dose using seven types of thermoplastic immobilization products.
Methods: Seven types of products were cut to a size of 5×5 cm2 and stretched by 5 cm in two directions. The surface dose was measured using Gafchromic EBT3 films placed above a 20 cm stacked water equivalent phantom, and the source surface distance was 100 cm. Subsequently, the shells were placed on a film. The films were then irradiated with 200 MU of 6 MV X-rays. The irradiated films were scanned after 24 h and converted to the absorbed dose using a density-dose conversion table.
Results: The surface dose with no stretch shells was 2.9–fold higher than that without shells. Among the seven products, the maximum and the minimum increase were 3.2– and 2.6–fold, respectively. Meanwhile, the 5 cm stretched shells increased the surface dose by 2.3–fold (max: 2.7–, min: 1.9–fold). The increase in the surface dose decreased with the degree of shell stretch (2.5, 5.0, and 7.5 cm). In addition, the pore size and pore area per cm2 showed a negative correlation with the relative dose increase from without shells (r = -0.66 and -0.69, respectively).
Conclusions: Product dif ferences in dose increase were small, suggesting that pore size and pore area per cm2 are important. Meanwhile, stretch effectively reduce the surface dose increase; however, care must be taken to balance the extent of stretch with the stiffness.

In the radon prone area of the Adamawa region in Cameroon, most of the dwellings are built with locally made mud bricks. The contribution of this building material to the inhalation dose was assessed using the RESRAD Build software. Assuming the indoor occupancy factor of 0.6, the related dose is found to be 0.8 mSv y-1 corresponding to 14% of the total inhalation dose. Thus, the contribution of the used building material to the inhalation dose in this radon prone area is not negligible.

An alternative method to dose estimation in cytogenetic biodosimetry is the cytokinesis-block micronucleus (CBMN) assay. Similar to the dicentric chromosome assay, this method correlates micronuclei formation in binucleated cells with absorbed dose. Instead of colcemid to arrest cells transiting from metaphase to anaphase, cytochalasin B is added to dividing human peripheral blood lymphocytes for cytokinesis inhibition. In this series, the history, applications, and recent developments of the CBMN assay in the context of cytogenetic biodosimetry are discussed. The topics covered include cell culture techniques, harvest and fixation processes, cell staining, imaging methodologies, micronucleus scoring criteria and procedures, and dosimetry applications. This review aims to provide insights into the various aspects of the CBMN assay, highlighting its significance and potential improvements for precise dose estimation in radiation exposure scenarios.