IAEA Project Research Articles

Environmental Modeling for Radiation Safety

The newly launched IAEA project MEREIA (MEthods for Radiological and Environmental Impact Assessment; 2021- 2025), MEREIA continues some activities of previous IAEA exercises in the field of radioecological modelling and focuses on areas where the probabilistic approach determines the predictive capability of environmental models. The program offered the opportunity to set up well-designed and verified scenarios to collect and compare exposures predicted by particular models based on this scenario and then perform a validation study of contributing models. It consists of the comparison of model prediction with observed data or in the case where there is a lack of measurement data to perform a comparison within model prognoses. The previous international works have brought significant improvement in environmental modeling in terms of better understanding and mathematical description of complex physical and chemical phenomena that occur in various environmental media and also have promoted new areas for experimental investigations. The new experimental results yielded updated handbooks of a large number of environmental parameters for less-known elements. Moreover, the principal objective of the activities in environmental modelling was an integrated risk assessment of the reference group of population and biota associated with radionuclides releases from various kinds of nuclear facilities as from different types and power nuclear reactors, radioactive waste disposal and more complex nuclear research facility. This reflects recent international recommendations to extend protection against radiation hazards of humans to wildlife flora and fauna. However, the statistics supported knowledge on some essential environmental parameters still remain small. Therefore, one could be aware of some limitations of the probabilistic approach that required advanced methods of probabilistic prognosis Monte Carlo.

Bulgarian public opinion survey for risk perception including radon and suggestions for communication

The paper reviews and analyses the results of STEAM survey of the Bulgarian population. A Survey and the preparation of a questionnaire were initiated within the framework of the IAEA Project RER9153 “Enhancing the Regional Capacity to Control Long-Term Risks to the Public due to radon in Dwellings and Workplaces”. The survey includes 1003 respondents from the Bulgarian adult population 18+. The main conclusions are:The health of the Bulgarian people is mostly assessed as satisfactory (38.7%) and all respondent considers a person's health better than the people's health as a whole. The main risk factors that can affect the health of Bulgarians are: Stress; Unhealthy nutrition; Smoking; Polluted air/dust; Health system - difficult access, improper treatment; Economic situation - low income; Alcohol; Lack of physical activity. Risks such as Environment; Working place and Lifestyle (harmful habits) are below 10%. The general awareness of radon and associated risks with it is very low among the Bulgarian adult population: 78% know nothing or very little about the health risks of radon. Almost half of the population doesn't know if home radon testing is a priority for them. About 30% of Bulgarians think that there is no point in testing the home they live in since they always maintain good ventilation. The population does not recognize the National Radiation Protection and Public Health Authorities as a trusted source of health risk information. The internet and social media are the main sources of information regarding health risks. The most important result that should be taken into account when building a new communication strategy is the fact that nearly 40% of the respondents declare that they are informed about health risks by general practitioners (GP), and the trust in them is over 50%.

Large differences in education and training of radiographers in Europe and Central Asia: Results from an IAEA coordinated study

IntroductionEducation and training of radiographers is known to be diverse between countries and regions. Under an IAEA project, this work collected data on radiographer education for the Europe and Central Asia region with a particular focus on radiation protection gaps and potential actions. MethodsFollowing piloting, an electronic questionnaire was distributed to all national counterparts for the IAEA Technial Coopearation (TC) Europe region (n = 33 countries) and nominated national representatives. Contacts were additionally invited to a virtual workshop to discuss and rank common problems in education and training of radiographers and to propose potential solutions. ResultsResponses were received from 31 countries, including 14 from the European Union. Just over half of countries reported radiographer education being in higher education with 71% having program durations more than 3 years (range: 1 month-4 years). Programs included a spectrum of both clinical training and radiation protection hours with ten-fold variations noted across the region. Inclusion of core radiation protection topics within curricula varied similarly, as did radiographers’ clinical involvement in both justification and optimisation between countries. Workshop participants identified five common training problems, namely education availability, lack of standardisation, radiation protection course quality, teamwork problems and lack of equipment. ConclusionRadiographer education in the IAEA Europe region is heterogeneous with substantial differences in duration and quality of training programs between countries, which likely impact on quality of patient care delivered. Common problems have been identified and potential solutions proposed to focus quality improvement initiatives. Implications for practiceRadiographer education and training is diverse throughout the IAEA TC Europe region, with likely impacts on radiation protection practices applied. Clinical involvement of radiographers in justification and optimisation differs, potentially limiting adherence to radiation protection principles.

Integrated nuclear techniques for sedimentation assessment in Latin American region

The paper shows the novel techniques introduction in the region of Latin America and the Caribbean in order to strengthen the surveillance and monitoring of the sedimentation phenomenon in the surface water reservoirs. The integrated use of the nuclear techniques allows a more complete assessment of water and land sustainability. With the development of a regional project, supported by the International Agency of Atomic Energy, Cuba participates as technical leader for 15 countries, to encourage and implement the integrated application of 3 nuclear techniques (Fallout Radionuclides (137Cs, 7Be, 210Pb), Compound Specific Stable Isotopes (fatty acids of the ∂13C) and the Isotopic Hydrology (18O, 2H, 3H). The methodology used in the last studies referred to RLA 5076 Project is to apply the integration of these three techniques allows evaluating, in the hydraulic facilities and surface water reservoirs, the negative sedimentation impacts in natural and anthropic process as environmental and social risk. These techniques evaluate the sedimentation process and its synergy, obtaining since the soil quantification in the landscape, definition the soil origin deposited until the dynamic characterization of the water body as soil receptor. The integrated application of these nuclear techniques in the Project RLA-5076 confirms it as a useful tool to support the decisions makers in the definition of the national strategies and programs related to the land and the water resources sustainability. With the support of the IAEA projects in the Latin American and Caribbean region, has been evidenced an important increment in the use of these novel techniques.

Verification of radioecological models to the instrumental data of the specific activity <sup>131</sup>I in a grass in Mazovia and Bohemia after the Chernobyl accident (from “Prague” and “Warsaw” scenarios of the IAEA project EMRAS

The analysis of instrumental data of “Prague” and “Warsaw” scenarios on the dynamics of 131I specific activities in the grass is carried out. Reconstruction of the 131I the specific activities dynamics in the grass in the Mazovia and Bohemia localities is performed in three models: direct calculation the input data of the “Prague” and “Warsaw” scenarios, homogeneous cloud, heterogeneous rain and heterogeneous cloudhomogeneousrain. The actual 137Cs fallout densities in the grass sampling sites in average more than 2.9 times for Prague and 2 times for Warsaw. Effective rain during the main fallout at the grass sampling sites, reconstructed on the model of a homogeneous cloud is 3–4 times more than at the nearest weather stations during this time. A realistic scenario of the input data leading to the optimal agreement of the calculated and instrumental data is revealed. It is shown that direct calculations and the homogeneous cloud model give almost identical results and lead to a significantly better agreement with the instrumental data than the an inhomogeneous cloud model. The calculated and instrumental data show a significant decrease in the 131I specific activity in the grass after the end of the main fallout due to its flushing from the grass surface by strong prolonged rain 13 and 19 days after the accident in Mazovia and 30 and 35 days in Bohemia. Uncertainties in the results of reconstruction of the dynamics of 131I and 137Cs activities in vegetation are estimated. The meangeometric values and standard mean-geometric deviations of the calculation/ 8instrumental data ratios are: 0.8–1.1 and 1.8–1.9 for grass.

Long-Term Storage and Radioactive Waste Retrieval from Historical Radon-Type Storage Facility

ABSTRACTWithin the framework of the IAEA project “CRAFT” (2011-2014), specialists of JSC “VO “Safety” participated in working group “Safety assessment of the Radon-type facilities”. The IAEA GSG-3 methodology was used in order to address the issue of safety assessment of radioactive waste removal from historical near-surface storage facility of the Radon type. SAFRAN tool (Sweden) was used for safety assessment of a historical Radon type storage facility. Practical experience of SAFRAN application has shown that it can play a significant role in managing records and knowledge on radioactive waste, nuclear facility site, characteristics of geological environment and safety barriers. It can provide reliable long-term storage and effective management of safety related records for the purposes of safety reassessments, review and supervision.

I182] Dosimetry in radiopharmaceutical therapy

Purpose EFOMP-IAEA collaboration in the field of Nuclear Medicine dosimetry is very active. Amongst other activities, the collaboration to disseminate knowledge can be seen in the IAEA support of ESMPE lectures in Prague, and EFOMP participation to ICTP-IAEA courses. In addition, EFOMP supports the IAEA project of a book focused on Molecular Radiotherapy dosimetry. The IAEA recently launched a Coordinated Research Project (CRP E2.30.05) on “Dosimetry in Radiopharmaceutical Therapy for personalized patient treatment” to support the standardization and dissemination of dosimetric methods in nuclear medicine therapy. The CRP will assist Member States in testing and adopting harmonized dosimetric protocols and to assess the typical accuracy with which dosimetry can be reached in nuclear medicine practice. Methods Within the CRP, Common activities will aim at: 1. Identify software and analysis methods appropriate for dosimetry of RPT. 2. Perform all the tasks needed to estimate tumour and normal organ absorbed doses on clinical and simulated data sets 3. Provide a written report, identifying the most challenging steps, or those that are subject to the greatest uncertainty. 4. Select one or more patient cases for whom dosimetry has been calculated at all the participating sites and assess the variability in absorbed dose determination. 5. Help disseminate each site’s experience, producing teaching material and tutorial documents on dosimetry for molecular radiotherapy based on the experience gained during the CRP. Conclusions The Call for Proposals, which included tentative research topics and the scoring methodology, was extensively advertised for CRP participants. Among the 33 research projects proposals received, 10 participating institutions have been selected from Colombia, Croatia, Cuba, France, India, Indonesia, South Africa and USA. The project has a 4 years duration, and the first Research Coordination Meeting took place in November 2017. All participants are currently working to derive the dosimetry of a set of clinical images. Discussions between participants are ongoing to define the prerequisite for the generation of simulated datasets.

Региональнoe совещание МАГАТЭ по обеспечению безопасности и качества в лучевой диагностике в рамках регионального проекта RER 9/135 «укрепление радиационной защиты пациентов и контроль медицинского облучения»

Региональнoe совещание МАГАТЭ по обеспечению безопасности и качества в лучевой диагностике в рамках регионального проекта RER 9/135 «укрепление радиационной защиты пациентов и контроль медицинского облучения»

Societal constraints related to environmental remediation and decommissioning programmes

The decisions related to decommissioning or environmental remediation projects (D/ER) cannot be isolated from the socio-political and cultural environment. Experiences of the IAEA Member States point out the importance of giving due attention to the societal aspects in project planning and implementation. The purpose of this paper is threefold: i) to systematically review societal constraints that some organisations in different IAEA Member States encounter when implementing D/ER programmes, ii) to identify different approaches to overcome these constraints and iii) to collect examples of existing practices related to the integration of societal aspects in D/ER programmes worldwide. The research was conducted in the context of the IAEA project Constraints to Decommissioning and Environmental Remediation (CIDER). The research results show that societal constraints arise mostly as a result of the different perceptions, attitudes, opinions and concerns of stakeholders towards the risks and benefits of D/ER programmes and due to the lack of stakeholder involvement in planning. There are different approaches to address these constraints, however all approaches have common points: early involvement, respect for different views, mutual understanding and learning. These results are relevant for all on-going and planned D/ER programmes.

New fit of thermal neutron constants (TNC) for233,235U,239,241Pu and252Cf(sf): Microscopic vs. maxwellian data

An IAEA project to update the Neutron Standards is near completion. Traditionally, the Thermal Neutron Constants (TNC) evaluated data by Axton for thermal-neutron scattering, capture and fission on four fissile nuclei and the total nu-bar of 252 Cf(sf) are used as input in the combined least-square fit with neutron cross section standards. The evaluation by Axton (1986) was based on a least-square fit of both thermal-spectrum averaged cross sections (Maxwellian data) and microscopic cross sections at 2200 m/s. There is a second Axton evaluation based exclusively on measured microscopic cross sections at 2200 m/s (excluding Maxwellian data). Both evaluations disagree within quoted uncertainties for fission and capture cross sections and total multiplicities of uranium isotopes. There are two factors, which may lead to such difference: Westcott g-factors with estimated 0.2% uncertainties used in the Axton's fit, and deviation of the thermal spectra from Maxwellian shape. To exclude or mitigate the impact of these factors, a new combined GMA fit of standards was undertaken with Axton's TNC evaluation based on 2200 m/s data used as a prior. New microscopic data at the thermal point, available since 1986, were added to the combined fit. Additionally, an independent evaluation of TNC was undertaken using CONRAD code. Both GMA and CONRAD results are consistent within quoted uncertainties. New evaluation shows a small increase of fission and capture thermal cross sections, and a corresponding decrease in evaluated thermal nubar for uranium isotopes and 239 Pu.

RADON AND PROGENY SOURCED DOSE ASSESSMENT OF SPA EMPLOYEES IN BALNEOLOGICAL SITES.

This study was conducted in the scope of IAEA project with the name 'Establishing a Systematic Radioactivity Survey and Total Effective Dose Assessment in Natural Balneological Sites' (TUR/9/018), at the Health Physics department of Sarayköy Nuclear Research and Training Center (SANAEM). The aim of this study is estimation of radon and progeny sourced effective dose for the people who are working at the spa facilities by measuring radon activity concentration (RAC) at the ambient air of indoor spa pools and dressing rooms. As it is known, the source of the radon gas is the radium content of the earth crust. Therefore, thermal waters coming from ground may contain dissolved radon and the radon can diffuse water to air. So the ambient air of spa pools can contain serious RAC that depends on a lot of parameters. In this regard, RAC measurements were executed at the 70 spa facilities in Turkey. The measurements were done with both active and passive methods at ambient air of spa pools and dressing rooms. Thus, active measurements were carried out by using the Alphaguard(®) with diffusion mode during half an hour, and passive measurements were carried out by using the humidity resistive CR-39 radon detectors during 2 months. Results show that RAC values at ambient air of spa pools varies between 13 Bq m(-3) and 10 kBq m(-3) Because long-term measurements are more reliable, if it is available, for dose calculations passive radon measurements (with CR-39 detectors) at ambient air of spa pools and dressing rooms were used, otherwise active measurement results were used. With the measurement by the conversion coefficients of ICRP 65 and occupational data of the employees has got from questionary forms, effective dose values were calculated. According to the calculations, spa employees are exposed to annual average dose between 0.05 and 29 mSv because of radon and progeny.

Optimal radiotherapy utilisation rate in developing countries: An IAEA study

Optimal radiotherapy utilisation rate (RTU) is the proportion of all cancer cases that should receive radiotherapy. Optimal RTU was estimated for 9 Middle Income Countries as part of a larger IAEA project to better understand RTU and stage distribution.

Guidelines for Integrity and Lifetime Assessment of Components and Piping in WWER NPPs during Operation (VERLIFE)

VERLIFE – “Unified Procedure for Lifetime Assessment of Components and Piping in WWER NPPs during Operation “was developed within the 5th Framework Programme of the European Union in 2003 and later upgraded within the 6th Framework Programme “COVERS – Safety of WWER NPPs” of the European Union in 2008.This Procedure has to fill the gap in original Soviet/Russian Codes and Rules for WWER type NPPs, as these codes were developed only for design and manufacture and were not changed since their second edition in 1989.VERLIFE Procedure is based on these Russian codes but incorporates also new developments in research, mainly in fracture mechanics, and also some principal approaches used in PWR codes.To assure that VERLIFE Procedure will remain a living document, new 3-years IAEA project (in close co-operation with another project 6th Framework Programme of the European Union “NULIFE – Plant Life Management of NPPs”) started in 2009.Within this project, upgrading/updating of the VERLIFE procedure is prepared together with the extension by (at least) following procedures:-Lifetime of reactor pressure vessel internals-Leak-before-break concept for WWER NPPs-No-break-zone for WWER NPPs-Probabilistic approach for failure and lifetime assessment of WWER reactor pressure vessels and primary piping (including Risk-informed ISI)-Qualification of NDT procedures-Thermal fatigue evaluation-Supports of components and pipingFinal document, after its approval by expert groups of the IAEA and NULIFE, will be issued in 2014 as “IAEA VERLIFE Guidelines for Integrity and Lifetime Assessment of Components and Piping in WWER NPPs”.

WE‐C‐211‐01: International Radiation Safety Standards and Systems

International organizations play an important role in establishing roles, responsibilities and needs of medical physicists, be it for radiation protection or functional needs. The international Standards of safety (Basic Safety Standards‐BSS) steered by the IAEA and the European BSS provide requirements that may be mandatory directly or indirectly. In addition, International Commission on Radiological Protection (ICRP) provides principles of radiation protection. Both the IAEA and the EC have provided requirements for medical physicist to be in place, previously dominantly for radiotherapy and more recently for diagnostic radiology, nuclear medicine and other practices that utilize ionizing radiations. There are a number of new requirements in both BSS that are likely to be released in 2012–2013 but drafts are available. Besides requirements, international organizations provide means to meet requirements. These are training material and actions directed at both human resource development and development and enrichment of skills, capacity building through provision of equipment, publications and guidelines to promote rational and safer practice. A large number of IAEA and EC projects provide assistance towards the goals of organizations and there are many publications of IAEA, EC and ICRP that medical physicists should be aware of. Recent statement of the ICRP on tissue reaction lowering threshold and dose limit for lens of the eye and circulatory disease is of interest. EC has developed guideline on medical physics expert. The talk will review activities of IAEA, EC, and ICRP with focus on medical physicists and the impact in less resourced countries.Learning Objectives:1. To understand the system that has influence on countries outside US pertaining to activities of interest to medical physicists2. To become familiar with actions pertaining to medical physics experts and requirements on radiation protection3. To become familiar with new information from ICRP on thresholds and dose limits for tissue reaction4. To understand the potential role you can play in international activities

Patient exposure tracking: the IAEA smart card project

The existing approach of radiation protection is largely based on the collective dose to the population with provisions for protection at an individual level through justification and optimisation. With the individual patient dose now exceeding the life-long occupational dose to a worker in a typical radiology practice, there is a need to establish approaches based on the protection of an individual patient. Radiation exposure tracking seems a way forward in this respect. Technological advances in recent years have provided opportunities for tracking to becoming a reality. The IAEA project on Smart Card/SmartRadTrack is described in this paper. The tracking is now a reality in a few dozen centres in many countries connected by picture archiving and communication systems, and there is hope that this will extend to cover other countries and continents.

Image quality and dose in mammography in 17 countries in Africa, Asia and Eastern Europe: Results from IAEA projects

PurposeThe objective is to study mammography practice from an optimisation point of view by assessing the impact of simple and immediately implementable corrective actions on image quality. Materials and methodsThis prospective multinational study included 54 mammography units in 17 countries. More than 21,000 mammography images were evaluated using a three-level image quality scoring system. Following initial assessment, appropriate corrective actions were implemented and image quality was re-assessed in 24 units. ResultsThe fraction of images that were considered acceptable without any remark in the first phase (before the implementation of corrective actions) was 70% and 75% for cranio-caudal and medio-lateral oblique projections, respectively. The main causes for poor image quality before corrective actions were related to film processing, damaged or scratched image receptors, or film-screen combinations that are not spectrally matched, inappropriate radiographic techniques and lack of training. Average glandular dose to a standard breast was 1.5mGy (mean and range 0.59–3.2mGy). After optimisation the frequency of poor quality images decreased, but the relative contributions of the various causes remained similar. Image quality improvements following appropriate corrective actions were up to 50 percentage points in some facilities. ConclusionsPoor image quality is a major source of unnecessary radiation dose to the breast. An increased awareness of good quality mammograms is of particular importance for countries that are moving towards introduction of population-based screening programmes. The study demonstrated how simple and low-cost measures can be a valuable tool in improving of image quality in mammography.

TU-B-211-01: Patient Radiation Exposure Tracking

The concept of “radiation passport” or something similar has been around for over a decade but the current impetus is based on a) realization of increased radiation doses to individual patients in diagnostic and interventional procedures and b) possibility of electronic means to achieve tracking of procedures. Further, the existing approach of radiation protection is largely based on collective dose to the population with provisions for protection at an individual level through justification and optimization. There is now a need to establish approaches based on protection of an individual patient. Radiation exposure tracking seems a way forward in this respect. Technological advances in recent years have provided opportunities for tracking to becoming a reality. The IAEA project on Smart Card/SmartRadTrack will be discussed. The tracking is now a reality in a few dozen centers in many countries connected by picture achieving and communication system (PACS) and there is hope that this will get extended to cover other countries and continents. It is clear that there is immense interest in achieving patient exposure tracking as per survey conducted by the IAEA in which 76 countries responded and all showing interest in the project. The commitment that is shown by national and international organizations dealing with radiation protection of patients, the actions taken by the IAEA in last few years to create awareness all indicate that in coming few years there are going to be many successful examples. While situation of patient exposure tracking in radiological examination looks very promising, major actions are needed to include radiation doses from nuclear medicine examinations. The talk will review the situation in global context and describe solutions at different level of development of technology Learning Objectives: 1. Understand the underlying basis for the project on cumulative assessment of radiation exposure of the patient in series of examinations and procedures. 2. Understand the issues involved in tracking of series of radiological procedures and radiation doses. 3. To become familiar with the current status globally and understand the way forward to achieve tracking of radiological procedures for an individual patient.

Radiation protection of patients in diagnostic radiology: Status of practice in five Eastern-European countries, based on IAEA project

The purpose of this work was to investigate status of imaging technology and practice in five countries in Eastern-European region and evaluate the impact of IAEA projects on radiation protection of patients. Information collected using standardized IAEA protocol included status of technology, practices and patient dose levels in interventional procedure, radiography, mammography and computed tomography (CT). In spite of increased number of digital units, single phase generators or units older than 30 year are still in use. Examples of obsolete practice such as using fluoroscopy for positioning, photofluorography, chest fluoroscopy and soft-beam technique for chest radiography are also in use. Modern multi-slice CT or digital mammography units are available; however, there is lack of adequate radiation protection and medical physics support in hospitals. Information on patient doses in interventional procedures, conventional radiography, mammography and CT was collected to have baseline data and corrective measures were proposed with appropriate follow up actions taken.

Multilateral Assessment of the Fast Reactor System as a Component of the Future Sustainable Nuclear Energy and Paths for the System Deployment

The paper reviews main findings of the Joint Assessment Study on a Nuclear Energy System (NES) based on a Closed Nuclear Fuel Cycle with Fast Reactors (CNFC-FRs) that was performed within the IAEA project INPRO.

Multilateral Assessment of the Fast Reactor System as a Component of the Future Sustainable Nuclear Energy and Paths for the System Deployment

The paper reviews main findings of the Joint Assessment Study on a Nuclear Energy System (NES) based on a Closed Nuclear Fuel Cycle with Fast Reactors (CNFC-FRs) that was performed within the IAEA project INPRO.