Modeling Radiation Exposure from Normal Release of 137Cs Radionuclide to Groundwater for Post-Closure Assessment of Serpong Near Surface Disposal Demo Facility

Near-surface disposal (NSD) has been applied in several countries to dispose of low-level radioactive waste. The demo plant of this disposal type is planned to be constructed in Serpong Nuclear Area, Banten. An assessment of radiation exposure is necessary to ensure the safety requirement of the facility in order to support this program. This study aims to estimate radionuclide migration from the proposed NSD demo facility to the environment and the corresponding total human dose using AMBER mathematical modeling. The representative radionuclide,137Cs, was selected because of its high mobility in the environment and the relatively long half-life in the low-level waste inventory. The scenario considered in the modeling was the normal release to the environment through groundwater. Parameters such as initial radionuclide concentration, soil physical parameters of the study site, and disposal design were entered into AMBER software to be calculated using mathematical formulas. The results show that the radionuclide concentration value in the environment is below the safe limit recommended by the Environmental Supervisory Agency. Likewise, the maximum dose received by the community around the facility is 7.40×10-11 mSv/y, 550 years after the post-closure of the facility, which is also below the regulatory limit of 1 mSv/y for the public.

Analysis on radiation control and the impact of land pipeline leakage of offshore nuclear power plant on groundwater

Using the groundwater migration and dispersion analytical model, combined with the topography and groundwater characteristics along the land drainage pipeline of an offshore nuclear power plant, the migration and dispersion of six radionuclides (3H, 14C, 137Cs, 134Cs, 60Co, 90Sr, etc.) in groundwater under the condition of pipeline breach accident are predicted. The scope of impact of radionuclides and the annual effective dose caused by drinking water pathways to the public are analyzed. By summarizing the radionuclide concentration and dose index requirements for groundwater at home and abroad, the corresponding environmental impact assessment is given. The prediction results show that the radionuclide concentration and public effective dose at the same distance first increase and then decrease with time, and the peak radionuclide concentration and maximum public effective dose gradually decrease with distance increasing, in other words, the impact of the breach accident on the distance above 30 m is limited.

Natural radioactivity of coal in the context of radioecological safety and rational use

Introduction. Environmental contamination with natural radioactive elements is an urgent ecological problem of the coal industry. Radiation hazard associated with natural radionuclides in coals and enclosing rock is a poorly studied problem requiring special attention. Radionuclides and their combustion products in coals, i. e. ash and slag waste and gas aerosol emissions, released into the biosphere, become the sources of pollution. Radiation monitoring is required in the course of geological prospecting, deposits development and rational use. The research aims to systematize research and analytical material on specific radioactivity of coal and their combustion products, and update the problem of radioecological safety monitoring. Methodology includes studying data on specific radioactivity of coal at various deposits, studying natural radioactivity of coal, enclosing rock and ash and slag waste, describing ash and slag waste and radon as a source of radioactive contamination, assessing potential radon hazard of mine workings, and analyzing ash composition characteristics for toxicologic estimation of ash dumps and their effect on the environment. Results. Generalized data on radionuclide concentration in coal burned at the CHP facilities, slag and fly ash are presented. Radionuclide specific concentration is much higher in ash and slag waste of coal heat power industry than in initial coal. It is caused by the radionuclide concentration in the products of coal combustion. Potential hazard of radon released from rock is revealed, and ash composition is characterised for toxicologic estimation of ash dumps. Conclusions. Uncontrolled coal combustion exacerbates the problem of radioecological safety due to radioactive aerosol emission and the formation of ash and slag waste with increased concentration of natural radionuclides. System monitoring of radioactivity level in the course of geological prospecting, mining, processing and combustion will allow reducing radionuclides entering the fuel cycle and environment.

Estimation of Radionuclide Concentration in Medical Waste

Almost all hospitals use radioisotopes for different purposes, as their applications grow, so their concentration in the waste of those hospitals does. To address this issue, twenty-nine samples were collected from (9) sites, these samples were collected from the incinerators of medical areas and the waste collection chambers. After collecting the samples, they were prepared for the examination, where a high-purity Germanium detector (HPGe) was used to detect radioactive elements. The lead element (Pb-214) of the uranium chain (U-238) and the actinium element (Ac-228), the lead element (Pb-212) of the thorium chain (Th-246) and the potassium element (K-40) appeared in some medical areas Iodine (I-131). Some regions showed high concentrations of these elements compared to some sites, Iodine (I-131) appeared in high rates in some hospitals specialized in treating cancerous diseases. The equivalent efficacy of radium, the annual equivalent internal and external dose, and the internal and external risk factors were calculated and the results obtained were compared with the global limits.