A New Radiological Risk Containment Procedure in Potentially Contaminated Areas

A new radiological risk containment procedure, developed to manage the radiological risk in potentially contaminated areas, is presented here. This new methodological approach, systematically employed in sampling and site inspection activities in unknown areas from an environmental point of view, allowed the discovery of eight 226Ra orphan sources buried under the road surface, in a good state of conservation, in an industrial area of the Calabrian territory, southern Italy, and they are reported here as a case study. For workers performing sampling activities in areas for which information regarding the possible presence of contaminated material is missing, an in situ radiometric check is usually carried out as a potential radiological risk prevention, by measuring the levels of environmental radioactivity. Other than this, the procedure described in this article includes, as novelty, a series of progressive operations never carried out before all together for outdoor activities: the assessment of the presence (if any) of hot spots by recording radiometric anomalies, outdoor gamma spectrometry measurements in order to identify the radionuclides generating those anomalies, the sources unearthing activities, the management of the material found and the application of a risk containment protocol.

Review of radiation incidents in the territory of the Voronezh region

The aim of the work was to characterize the radiation incidents that took place in the territory of the Voronezh region. Materials and methods. To prepare this article the stock data of the radiological laboratory of the Center for Hygiene and Epidemiology in the Voronezh Region for 2009-2018 was used. All measurements in the investigation of radiation incidents were carried out with the MKS-AT1117M dosimeter-radiometer which passed the state calibration. The equivalent dose rate of gamma radiation (μSv/h) was determined. Results. For the last 10 years, 8 radiation incidents were registered on the territory of the Voronezh region, which were related to domestic clocks - 4 (measurements according to citizens), the detection of orphan sources of ionizing findings - 2, scrap metal - 1 and a thermometer - 1 (during customs inspection). According to the classification of emergencies, the radiation incidents are local, i.e. do not go beyond the territory of the facility, according to the international scale of nuclear and radiological events, INES refer to the incident (anomalies) with the level 1 “minor problems with the safety of components, a radioactive source of low activity level”. All interactions in the investigation of radioactive incidents involving specialists from the radiological laboratory of the Center for Hygiene and Epidemiology in the Voronezh region with other services showed a good level of rapid response.

Feasibility study of a shielding-independent radiation portal monitor system for revealing 241-Am orphan sources in radiometric surveillance of scrap metal

Orphan radioactive sources inadvertently melted in steel plants are a health and economical hazard. Thus, regulation authorities impose strict control measurements to be performed at these plants. However, a recent series of incidents related to the melting of $${}^{241}\hbox {Am}$$ 241 Am sources demonstrated the inadequacy of even state of the art systems in revealing this low-energy gamma ray emitter up to activities of the order of hundreds GBq. However, $${}^{241}\hbox {Am}$$ 241 Am sources are characterized by a weak neutron emission which can be detected by proper monitor systems. This work provides a feasibility study of a shielding-independent neutron-sensitive portal monitor system to be installed in steel plants. Measurements were performed both with a certified $${}^{241}\hbox {Am}$$ 241 Am shielded source and at the weighing area of a steel plant, to assess both the detector performance and the practical feasibility of the system implementation in work-place fields. A risk evaluation analysis demonstrated that with the current control systems $${}^{241}\hbox {Am}$$ 241 Am sources up to 185 GBq could pass undetected with a potential exposure for workers equal to 1.7 mSv, consistent with recent accidents reports. The proposed technique could reveal $${}^{241}\hbox {Am}$$ 241 Am activities down to 2 GBq, decreasing the worker exposure down to 24 $$\upmu \hbox {Sv}$$ μ Sv , without interfering with the standard plant operations.

The regulatory control over radiation sources: the Brazilian experience and some lessons learned from industrial applications

This study gives an overview of the activities of the National Commission of Nuclear Energy (CNEN), as the Brazilian nuclear regulatory authority. These activities are described, especially those related to management of orphan sources and radioactive material in scrap metal considering the actions already put into place by CNEN during the licensing and controlling of radioactive sources in the industry and other facilities. In Brazil, there is not yet an effective system for controlling the scrap metal and recycling industry, thus a coordinated approach to achieve a harmonized and effective response with the involvement of third parties is needed, especially the metal industries and ores facilities. These practices call for stringent regulatory control, in order to reduce the occurrence of orphan sources, and consequently, radioactive material appearing in scrap metal. Some challenges of managing the national radiation sources register systems will be discussed, in order to cover effectively all the radiation source history (in a ‘from the cradle to the grave’ basis), and the dynamic maintenance and update of these data. The main industrial applications considered in this work are those dealing with constant movement of sources all over the country, with geographical issues to be considered in the managing and controlling actions, such as gammagraphy and well-logging. This study aims to identify and promote good practices to prevent inadvertent diversion of radioactive material, taking into account existing international recommendations and some lessons learned in national level.

ASSESSMENT OF THE ABSORBED DOSES IN THE ORGANS IN CASE OF RADIATION EMERGENCY WITH THE SEALED GAMMA-SOURCES

The majority of the radiation accidents with early acute clinical effects were associated with the orphan sources used in industrial and medical facilities. These accidents involved members of general public, who were entirely unaware of the exposure to the radiation. In such situations, the exposure commonly occurs when the source is in contact with a body of a victim, primarily located in pockets of clothing or in hands. In this research, the average absorbed doses in internal organs, skin and tissues close to the source were assessed using the phantom modeling of contact human exposure by the sealed 192Ir, 137Cs and 60Co gamma sources. The results allow estimating the RBE-weighted absorbed dose values in organs and tissues to assess the possibility and severity of deterministic medical effects caused by the exposure and to compare them with the reference levels established by IAEA for performing the protective and medical actions.

Friends, partners, and orphans

The essay juxtaposes three moments of medical infrastructure and technology aid in Phnom Penh, Cambodia: 1960, 2010, and 2005. The operative terms of these moments are relationship terms: ‘friendship’, ‘partnership’, and ‘orphan’. The 1960 gift of a hospital, equipment, and training made a friend, and reciprocity involved political alignment at the level of the nation-state. The 2010 gift of equipment and training made a partner, and reciprocity involved brand alignment spread across diverse government ministries, public hospitals, private universities, and private businesses. Focusing on the materiality of technology and infrastructure gifts brings us to the orphan. The orphan is a gift that turns toxic. Its toxicity is health-threatening if there is no infrastructure to secure it. The elaborate partnerships required to identify and secure orphan sources of radiation show how gifts of medical technology and infrastructure exist beyond their immediate utility to humans. What technology of partnership will the medical physicist of 2050 unearth, and what ethic of relationality will come to care for, repair, and secure it?

AN ORPHAN SOURCE OF IONIZING RADIATION AS A FACTOR OF BREACH OF RADIATION AND ECOLOGICAL SAFETY

Objective: to estimate the hazard of radiation safety to the population and the environment in the Republic of Belarus analyzing the information about discovered orphan sources of ionizing radiation over 2003-2015. Material and methods. The work describes the method of cluster analysis, which made it possible to systematize and analyze the operative information of the Ministry for Emergency Situations of the Republic of Belarus about orphan sources of ionizing radiation in the territory of the country. Results. It has been found out that 55 % of all the episodes of local radiation pollution of the environment happened in the city of Minsk and Minsk region, out of them 61 % - at economic entities. We have performed the assessment of hazards of point and areal radiation pollution of the environment.

Radioactive Waste Management in Lebanon

The disused sealed radioactive sources including orphan sources in Lebanon, along with the growing industry of sealed radioactive sources in medical, industrial and research fields have posed a serious problem for authorities as well as users due to the lack of a national store for disused radioactive sources. Assistance from the International Atomic Energy Agency (IAEA) was requested to condition and store disused radium needles and tubes present at two facilities. The mission took place on July 25, 2001 and was organized by the IAEA in cooperation with the Lebanese Atomic Energy Commission (LAEC). Other disused radioactive sources were kept in the facilities till a safer and securer solution is provided; however orphan sources, found mainly during export control, were brought and stored temporarily in LAEC. The necessity of a safe and secure store became a must. Prior to October 2005, there was no clear legal basis for establishing such store for disused radioactive sources, until the ministerial decree no 15512 dated October 19, 2005 (related to the implementation of decree-law no 105/83) was issued which clearly stated that “The LAEC shall, in cooperation with the Ministry of Public Health, establish a practical mechanism for safe disposal of radioactive waste”. Following this, the work on inventory of disused sealed sources along with collecting orphan sources and placing them temporarily in LAEC was legally supported. Moreover, several missions were planned to repatriate category I and II sources, one of which was completed specifically in August 2009; other missions are being worked on. In 2008, a national technical cooperation project with the IAEA was launched. Under the Technical Cooperation (TC) project with reference number LEB3002, the project was entitled “Assistance in the establishment of a safe temporary national storage at the LAECfor orphan sources and radioactive waste” which cycle is 2009–2011. Under this project, a national store for radioactive sources in the third basement of LAEC is being established. The area is being reconstructed currently and will be equipped when ready under LEB3002 project. Along with this, a system for sealed disused sources management has been prepared, part of which is applied now and the rest will be applied upon the establishment of the store. This paper will cover the inventory collection process, the study for the establishment of this store, the present and prospective waste management system, and the waste acceptance criteria.