Management of radioactive waste from application of radioactive materials and small reactors in non-nuclear industries in Canada and the implications for their new application in the future

<abstract> <p>A large number of artificial-origin radionuclides from irradiation in small reactors and/or nuclear reactions in accelerators are currently used in non-nuclear industries such as education, oil and gas, consumer merchandise, research, and medicine. Radioactive wastes from the use of these radionuclides in non-nuclear industries include expired sealed radioactive sources, biological materials, radionuclide-containing chemicals, contaminated equipment, and very small quantities of used nuclear fuel. Although being less challenging and complex than nuclear energy production and research waste streams, these wastes are subject to the common nuclear regulations by the Canadian Nuclear Safety Commission, and are managed following domestic and international standards and guidelines made by the Canadian Standards Association, International Atomic Energy Agency, and International Organization for Standardization. Management practices used in the nuclear industry in Canada are commonly applied to the non-nuclear industry radioactive waste streams, such as waste handling, treatment, packaging, storage, transportation, clearance and exemptions, and disposal. The half-lives of radionuclides in non‑nuclear applications range from hours to thousands of years, and their activities in non-nuclear industrial applications can be as low as their clearance level or as high as the upper limits for intermediate level radioactive waste. Waste containing only short half-life radionuclides is placed in temporary storage to allow decay, and then is cleared and disposed of through non-radioactive waste routes. Non‑clearable waste materials are treated, consolidated, and managed along with radioactive waste generated from the nuclear industries at designated radioactive waste management sites.</p> </abstract>

Health Physics Calculation Framework for Environmental Impact Assessment of Radiological Contamination

<abstract><p>A fundamental step for safety assessment is the study and modeling of the radionuclide transfer through the environment up to reach and expose population to risk. In this vein we are working to provide a reliable and flexible computational framework which can be used for both retrospective and prospective calculations of radiation doses and human health effects, resulting from both routine and uncontrolled releases of radionuclides to the environment and from pre-existing environment contamination. The goal is to provide a multipurpose computational tool to be used for siting facilities, environmental impact statements, and safety analysis reports. The code can handle: external exposure from finite or infinite atmospheric plumes; external exposure from contaminated soil, sediments, and water; external exposure from special geometries; and internal exposures from inhalation, inadvertent intake of soil, consumption of terrestrial foods, aquatic foods, drinking water, and animal products.</p></abstract>

Management of hospital radioactive liquid waste: treatment proposal for radioimmunoassay wastes

<abstract> <p>Radioactive liquid wastes are produced at hospitals from diagnostic and therapeutic applications of radionuclides. The most usual management of these wastes is temporary storage at the hospital for radioactivity decay and, then, discharge into sewage if not other pollutants are present in waste, always after authorization of the corresponding institution. In some cases, radioactive wastes have other hazards, such as chemical or biological ones, which can be more dangerous than radiological hazard, and do not allow direct discharge into sewage in spite of decaying activity below the clearance level. Therefore, these wastes have to be treated and condition before discharge in spite of activity decay below discharge limit. This is the case of liquid wastes from radioimmunoassay (RIA), a laboratory technique that allows to determine human substances in very low concentrations (below 10^-12 g/mL), like hormones, using ¹²⁵I as radionuclide. This study summarizes the usual management of radioactive liquid wastes from hospitals, including conventional and recent treatments applied. Furthermore, based on experimental results obtained with real RIA wastes, this work exposes a proposal of treatment with ultrafiltration and reverse osmosis membranes, and determines the most suitable application of this treatment according to radiological and operational considerations.</p> </abstract>

A case study of management and disposal of TENORMs: radiological risk estimation by TSD Dose and RESRAD-ONSITE

<abstract> <p>Naturally Occurring Radioactive Materials (NORMs) and Technologically Enhanced NORMs (TENORMs) are among the principal sources of radiation exposure for humans and for the environment. Therefore, the assessment of the impact of NORMs and TENORMs waste on human health is a key issue for their management and for acceptance of disposal sites. The radiological doses to workers and public due to TENORMs disposal depend on the waste inventory, on the usage of the site during operational activities and post closure phase and on the presence of dwelling areas in the vicinity of the disposal site. In the present study it is presented a methodology to preliminary assess the feasibility of a disposal of TENORMs, mainly constituted by phosphate sludges, originated from phosphoric acid industry activities. The hypothetical case study here presented is inspired by a real case study. Different possible scenarios have been considered. The potential doses to workers and to the public on-site have been estimated by the use of the TSD Dose and the RESRAD on-site codes both during the production life cycle of the site and once it ended. Sensitivity analyses were conducted to evaluate the impact of some key parameters, such the coverage thickness and wind velocity, on potential risk for workers and public.</p> </abstract>

Analysis of short-term air quality monitoring data in a coastal area

<abstract> <p>Short-term air quality monitoring in a coastal area, Naklua Subdistrict, Pattaya, Thailand is an activity to support the designated area under Thailand's sustainable tourism development. This study provided a short-term monitoring data analysis on time series and Bivariate Polar Plot (BVP) to provide the status of air quality and to determine the potential source area of air pollution. The result showed that NO₂, SO₂, CO and PM₁₀ were not higher than the national air quality standards, while the 24-hour average of PM_2.5 and the 8-hour average of O₃ were slightly higher than the World Health Organization (WHO) air quality guideline values. The nighttime PM_2.5 concentration was higher than the daytime concentration, and its potential source area is urban areas in the south. However, the daytime O₃ concentration is higher than the nighttime concentration. Its potential source area is from the northwest, where Sichang island is located. This result could be used to support air pollution management by controlling and reducing emissions in the potential source areas as the first priority. Also, the study revealed that the BVP technique could be used to determine the source area of air pollution in the coastal area, where wind circulation is more complex than that over the land.</p> </abstract>