As one of the missions entrusted to it via the French Environment Code, IRSN carries out ongoing monitoring activities to assess human and environmental exposure to ionizing radiation. Each year, the Institute writes up its findings in reports and implements actions designed to improve the protection of people and biodiversity. This work enables us, for example, to gain a better understanding of the state of radioactivity, whether natural or linked to human activity, particularly near nuclear facilities, as well as the exposure of workers to ionizing radiation. As part of this approach, the Institute is also committed to equipping itself with tools for better assessing or controlling the emission of ionizing radiation. In 2022, for example, IRSN re-examined its environmental monitoring strategy and modernized the use of data related to this monitoring. In the medical field, several studies and analyses have been published, aimed at ensuring better protection of patients of all ages exposed to ionizing radiation for diagnostic or therapeutic purposes.
Striving to continously improve the quality of radiological monitoring of workers exposed to ionizing radiation, IRSN has developed a new version of its RPL-neutron dosimeter, which came into service in January 2022. The result of two years of R&D and user feedback, the new dosimeter is both stronger and lighter. It combines radiophotoluminescence (RPL) and neutron detection technology, enabling workers exposed to X-rays, gamma, and beta radiation, as well as neutron radiation, to be monitored in the course of their professional activities, mainly in industry or research. Its casing, 100% designed and produced by French companies, is made of recyclable plastic. It has a new, more ergonomic and robust attachment system. Alongside these innovations, IRSN is continuing its R&D work to produce a dosimeter offering even better metrological properties for the neutron component.
At the request of the ASN, IRSN has drawn up a guide to familiarize radiotherapy teams with new equipment and techniques. In the context of rapid changes in treatment techniques using ionizing radiation, this document is designed to help healthcare professionals keep up to speed with these changes, which often go hand-in-hand with changes to their professional practices. The aim is to make it easier for radiotherapy professionals to understand and adopt state-of-the-art techniques while ensuring patient safety, and without adding significantly to their workload.
The drafting of this guide has mobilized various skills within the Institute, involving both medical physics and the organizational and human factors. After a data collection phase in different types of radiotherapy centers, IRSN experts, accompanied by an operational task force made up of healthcare professionals practicing radiotherapy, developed a guide organized according to the four major phases of a project for making modifications to radiotherapy equipment or techniques: project initiation, preparation for clinical deployment, deployment, and consolidating long-term appropriation of the innovation.
This guide is designed to be an easy-to-use, operational tool. It was developed to be suitable for use by all types of radiotherapy centers, regardless of their status or size. Each section of the guide, dedicated to a particular phase of the change related project, is structured in a similar way around recommendations (on the organization, the resources to be allocated, the actions to be taken), accompanied by frequently asked questions to guide teams in the implementation of their project. In addition, the guide proposes inserts to illustrate concepts relating to organizational and human factors in order to flesh out the recommendations.
This guide provides professionals with recommendations from the field, supplemented by information to help understand what the recommendations are based on and questions aimed at guiding the professionals in their reflections.
This guide provides professionals with recommendations drawn from the field, supplemented by information to help them understand their underlying principles and questions to guide their thinking.
In order to help optimize the radiological exposure of patients undergoing mammography or tomosynthesis mammography (a new technology that enables 3D breast images to be obtained by reconstruction from multiple cross sections) as part of breast cancer screening, IRSN has worked, in response to an ASN referral, on updating or creating diagnostic reference levels (DRLs) for these examinations. DRLs are designed to help medical imaging practitioners optimize the exposure induced by radiological examinations, taking into account technological developments in the devices used and practices. DRLs constitute neither dose limits nor indicators of radiological risk. These levels are established on the basis of a technical analysis of the dosimetric data collected by IRSN and are updated periodically, in accordance with the French Public Health Code.
To this end, the Institute conducted a study based on data from 5,300 examinations performed on 80 “CR” mammography units with indirect scanning and 77 “DR” digital mammography units with direct scanning, and 3009 examinations performed on 44 tomosynthesis systems. Prior to January 2021, doses in digital mammography were assessed based on measurements taken as part of the external quality control of the devices. For “DR” units delivering lower doses for better image quality, the dose display on the mammogram now makes it possible to target a clinical collection of doses administered to patients and obtain up-to-date values.
Among the recommendations issued, IRSN proposes to take measures to avoid the commissioning of new “CR” mammography units, using an older technology delivering higher doses, and encourages the replacement of those in operation with newer “DR” mammography units.
With regard to tomosynthesis, which generates greater radiological exposure, IRSN proposes the creation of a DRL.
IRSN had its role as a WHO collaborating center for radiation protection renewed in 2022 for a four-year term. This fourth consecutive renewal testifies to the WHO’s recognition of the quality of IRSN’s scientific and technical expertise. For the coming years, four priority work areas have been identified: medical and healthcare preparation and response to radiological and nuclear emergencies; mental health and psycho-social support in post-accident situations; the safe use of ionizing radiation in the medical field; and the health risk linked to existing exposure situations.
As part of this collaboration, IRSN contributed in 2022 to the development, critical review, and translation of various WHO recommendation documents: “WHO stockpile policy advice”, “Handbook for health risk communication about food safety after radiation emergency” and “Communicating radiation risks in pediatric imaging: information to support health care discussions about benefit and risk”.
IRSN IS RENEWED FOR THE 4TH CONSECUTIVE TIME AS A WHO COLLABORATING CENTER
The overhaul of SISERI (Information system for monitoring exposure to ionizing radiation), begun in September 2020 with the assistance of IRSN Lab – the IRSN innovation laboratory – is being finalized with the test phases of new features and interoperability by the various user communities: employers, accredited bodies, and operators. This overhaul meets government expectations for the modernization and simplification of public services. The main objective is to optimize data consolidation in order to facilitate the traceability of worker exposure.
The EIVIC project for whole-body counting intercomparison was completed in June 2022. Organized within the framework of the European Radiation Dosimetry Group (EURADOS[1]) by IRSN, the project started in October 2019 and included 43 laboratories from 21 European countries. It consisted of six exercises for the identification and quantification of radionuclides in different internal exposure scenarios. This project made it possible to review the situation and test the technical capacities of the laboratories. All the technical information from these laboratories has been collated in a database that will facilitate exchanges between teams in the event of a large-scale accident.
[1] EURADOS: European Radiation Dosimetry Group comprising 80 European institutions and more than 600 scientists.
IRSN intervened in September 2022, at the request of the IAEA, to coordinate a medical assistance mission and provide expertise in the management of a South American patient suffering from severe radiological burns following an interventional radiology procedure. The patient was admitted to the Percy Army Training Hospital in Clamart (Hauts-de-Seine) by a multidisciplinary team. He received surgical care combined with cell therapy treatment. This mission highlights once again the IAEA’s recognition of French excellence in medical assistance.
In 2022, IRSN published a specific study of CT scan procedures carried out on children under the age of 16 in France between 2012 and 2018. In addition to periodic analyses of the medical exposure of the population carried out by the Institute, such as the ExPRI study, this study made it possible to assess in particular the changes in frequency of CT scan procedures in this particularly radiosensitive population. The results of this study first show a relatively constant annual frequency of computed tomography examinations (with an average of 14 procedures per year for 1,000 children) over the study period, with some variations depending on the age of the patients. The results then show a gradual transfer of certain CT procedures toward MRI, since these two imaging techniques have many common indications and the recommendations of professionals are pointing in this direction. In fact, the annual frequency of MRI procedures increased by 59% over the study period.
Also in 2022, new epidemiological results published as part of the “Child Scanner” cohort (launched in 2009 by IRSN to study the risk of radiation-induced cancer from exposure to computed tomography in childhood) confirm the low excess risk of leukemia and brain tumors. This cohort is part of the European EPI-CT project, the results of which show that the increased risk of developing this type of tumor according to the dose received by the child in the head area remains very low when set against the diagnostic benefits of CT scans.
Every year, IRSN publishes its report on occupational exposure to artificial or natural sources of ionizing radiation in France. For 2021, 392,180 employees underwent dosimetric monitoring (a 1.2% increase in subjects compared to 2020). First, the IRSN report shows that the collective dose for all workers monitored in 2021 was 82.7 hSv (vs. 72.5 hSv in 2020). This increase of 14% concerns all areas of activity. Its main origin is the increase in the volume of maintenance work in the nuclear field, after less activity in 2020 due to the Covid-19 health crisis. For the same reasons, the average individual dose was 0.85 mSv, up 9%. With regard to the individual dose, 24,419 workers received an annual dose greater than 1 mSv (regulatory annual limit set for the general population) and, among them, 2712 workers received an annual dose greater than 5 mSv, including one medical worker who received a dose greater than the occupational exposure limit of 20 mSv. One case exceeding the effective dose equivalent limit on the skin (500 mSv) and a second on the lens of the eye (50 mSv) were also recorded.
As part of internal exposure monitoring, out of the 232,140 analyses carried out routinely in 2021, three workers presented a committed effective dose greater than or equal to 1 mSv. As in the previous year, this report is supplemented by thematic focus areas addressing in more detail certain aspects of exposure monitoring, for example in veterinary medicine or in nuclear fuel manufacturing facilities.
In January 2022, IRSN and ASN published a guide on assessing the radiological risk to wild fauna and flora near nuclear facilities. Entitled: “Methodological guide for the assessment of radiological risk to wild fauna and flora: Concepts, basic information and implementation within the impact study”, this guide was drawn up by a multi-disciplinary and multi-stakeholder group, mirroring the profile of potential users of such a method.
This guide proposes a methodology to assess the level of protection of wild fauna and flora against their exposure to ionizing radiation, and more particularly, the assessment associated with releases from a facility which is operating normally. It provides tools that can be used to carry out environmental impact studies on nuclear facilities and activities.
To assess the radiological impact studies of cyclotron releases on populations, IRSN has defined a methodology to determine the expectations of such studies. Developed on the basis of feedback from recently processed files at the Institute, the document covers the main stages of a radiological impact study and details the key points impacting the quality of the assessment. This document is made available to operators to help them come up with a more realistic assessment of the impact on populations located in the immediate environment of a facility releasing radionuclides. Additional work has been carried out to define, at the request of the ASN, the technical requirements to be implemented by operators in order to assess their releases.
As part of the National Action Plan for Radon Risk Management (2020 – 2024), IRSN has published a report which identifies geographical sectors where the data is deemed insufficient, based on the various radon measurement campaigns in buildings and the geogenic radon potential[2] map. This work will serve as a guide for future radon measurement campaigns in private homes.
[2] Geogenic radon potential: potential of rocks to produce and facilitate the transfer of radon to the atmosphere.
The Institute held a public meeting, attended by more than 150 people, on March 9, 2022 in Saint-Maurice-l’Exil (Isère) to present the results of the environmental radiation study of the Saint-Alban Saint-Maurice-l’Exil nuclear power plant. This event was an opportunity for discussion with local stakeholders on the lessons learned from this innovative study undertaken by IRSN in 2019, to supplement ongoing monitoring of the plant’s environment.
The main objectives of this RSS were to improve scientific knowledge on the impact of the plant’s radioactive releases on its environment, authorized as part of its normal operation, to evaluate more realistically the exposure of neighboring populations taking into account local specifics, and to involve local actors in order to field their questions and provide them with clear answers. To this end, the Institute implemented sampling and metrology methods to detect trace radioactivity and measure the relative contribution of the nuclear facility in relation to the radiological background noise of the geographical area concerned.
During this three-year (2019 – 2021) study, more than 960 samples were taken from the different environments (land, water, atmosphere) and more than 1,200 analyses were carried out. Almost 270 people were interviewed to gather information on their dietary habits (composition of meals, percentage of local produce consumed, etc.) and their use of space and time (time spent in the area concerned, indoors and outdoors, etc.).
Among the initial lessons learned from this work, it appears that all the results obtained are consistent with the radiological activities expected in the environment of a nuclear power plant and with the measurements routinely made as part of the radiological monitoring of nuclear power plants. Another strong point worth mentioning is this study’s scientific interest, since it was able to validate, by measurement, evaluations based on calculation models, despite the very low levels of radioactive marking, which are by their very nature difficult to detect. Another noteworthy factor is the extent of participation by local stakeholders – local information commissions, elected officials, associations, local residents, farmers, utilities managers, etc. – which was key to the success of the operation. Co-constructing the study in conjunction with these actors – experts in local knowledge, data providers and/or sampling facilitators – significantly improved the field knowledge needed by the Institute and, by extension, the overall quality of the work carried out. In summary, the radiological study of the Saint Alban site provided an opportunity for dialogue with the population which enabled IRSN to assert its credentials locally as an actor capable of co-producing, with local stakeholders, scientific insight into the radiological influence of the power plant and the resulting exposure of local residents.
In addition to the public meeting, the results of the study were written up in reports, and a web tool, inspired by the work carried out with IRSN Lab, was specially developed for the occasion.
This participatory research approach was a prizewinner in the 2022 Trophées de la participation et de la concertation (“Participation and collaboration awards”). Each year, this event, organized by the “Décider Ensemble” (“Deciding Together”) association, rewards innovative citizen participation and collaboration initiatives.
IRSN has published a knowledge synthesis relating to the basic levels, designated “background noise”, of artificial radionuclides in metropolitan France. This work was based on many measurements made over time, including for the regional radiological observations conducted by the Institute from 2008 to 2018. This makes it possible to estimate the exposures of populations resulting from the presence in the environment of these radionuclides, which originate mainly from fallout from atmospheric testing of nuclear weapons carried out by the United States, the Soviet Union, the United Kingdom, China, and France from 1945 to 1980, and the fallout from the Chornobyl accident in 1986. Furthermore, this knowledge enables us to obtain a baseline from which it is possible to estimate the additional radiological activity due to authorized discharges from nuclear facilities operating normally as well as those that could result from an accident, an untimely discharge, or any other cause of an increase in this background noise.
The report shows that the background noise has decreased since the end of atmospheric fallout. Furthermore, while the spatial heterogeneity of the initial fallout tends to fade over time, measurements show that there are still limited areas of France where concentrations of radionuclides in soils and in certain types of foodstuffs can still be significantly higher than elsewhere, without however constituting any major health risk.
During the review of its environmental radiation monitoring actions since 2009, IRSN presented an update of its monitoring strategy which underscores the utility of some of the previous objectives (maintaining monitoring networks in good condition, acting with reactivity and flexibility, maintaining its status as a metrology specialist, contributing to public policies) while adding new objectives: implementation of radiological studies of sites, adapting its monitoring in response to singular situations (nuclear incidents or accidents), and reinforcing data use. This work was presented to the High Committee for Transparency and Information on Nuclear Safety (HCTSIN) at its plenary meeting on October 18, 2022. In addition, the ODISCE committee submitted its first notice to the IRSN Director General on the involvement of society in this radiological monitoring on November 28, 2022 (see chapter “A responsible and civic-minded Institute”).
The Institute has published the results of ongoing radiation monitoring across France, established on the basis of collecting and analyzing of its own data. The Institute has also undertaken to modernize the presentation of its annual environmental monitoring plan with the dual aim of making it more interactive for users and easier to understand in terms of the data collected.
The implementation of this monitoring plan fulfills the missions entrusted to the Institute by the public authorities. The plan is designed to monitor the evolution of radioactivity levels in the environment, near nuclear facilities, but also more generally throughout the country. This monitoring also makes it possible to analyze the impact of any events, in France or abroad. The results obtained show that the activity levels measured near the sites monitored remain relatively constant or on the decrease. Looking at metropolitan France as a whole, the activities measured are consistent with changes in environmental levels observed over the past several years.
All the results of the monitoring are accessible on the website of the French national network for environmental radioactivity measurements (www.mesure-radioactivite.fr/en#/expert).
In 2022, the Institute’s teams also improved their operating tools, namely for producing statistics, and tools for representing data collected as part of IRSN’s ongoing monitoring system.
The update of the environmental radiological monitoring strategy of IRSN involved a wide range of knowledge and skills in environmental monitoring, analysis and metrology. This cross-functional exercise also involved data scientists and computer scientists. Although the tool is still in the test phase, initial feedback on ease of access and meeting user needs is very positive.
