Institute for Radiation Protection and Nuclear Safety (IRSN)
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Radiotherapy for non-cancer diseases: benefits and long-term risks
No full textInternational audiencePurpose: The discovery of X-rays was followed by a variety of attempts to treat infectious diseases and various other non-cancer diseases with ionizing radiation, in addition to cancer. There has been a recent resurgence of interest in the use of such radiotherapy for non-cancer diseases. Non-cancer diseases for which use of radiotherapy has currently been proposed include refractory ventricular tachycardia, neurodegenerative diseases (e.g. Alzheimer's disease and dementia), and Coronavirus Disease 2019 (COVID-19) pneumonia, all with ongoing clinical studies that deliver radiation doses of 0.5-25 Gy in a single fraction or in multiple daily fractions. In addition to such non-cancer effects, historical indications predominantly used in some countries (e.g. Germany) include osteoarthritis and degenerative diseases of the bones and joints. This narrative review gives an overview of the biological rationale and ongoing preclinical and clinical studies for radiotherapy proposed for various non-cancer diseases, discusses the plausibility of the proposed biological rationale, and considers the long-term radiation risks of cancer and non-cancer diseases.Conclusions: A growing body of evidence has suggested that radiation represents a double-edged sword, not only for cancer, but also for non-cancer diseases. At present, clinical evidence has shown some beneficial effects of radiotherapy for ventricular tachycardia, but there is little or no such evidence of radiotherapy for other newly proposed non-cancer diseases (e.g. Alzheimer's disease, COVID-19 pneumonia). Patients with ventricular tachycardia and COVID-19 pneumonia have thus far been treated with radiotherapy when they are an urgent life threat with no efficient alternative treatment, but some survivors may encounter a paradoxical situation where patients were rescued by radiotherapy but then get harmed by radiotherapy. Further studies are needed to justify the clinical use of radiotherapy for non-cancer diseases, and optimize dose to diseased tissue while minimizin
Exposition in utero aux rayonnements ionisants et régulation métabolique : perspectives pour les futures études sur les effets multi et transgénérationnels
No full textInternational audiencePurpose: The radiation protection community has been particularly attentive to the risks of delayed effects on offspring from low dose or low dose-rate exposures to ionizing radiation. Despite this, the current epidemiologic studies and scientific data are still insufficient to provide the necessary evidence for improving risk assessment guidelines. This literature review aims to inform future studies on multigenerational and transgenerational effects. It primarily focuses on animal studies involving in utero exposure and discusses crucial elements for interpreting the results. These elements include in utero exposure scenarios relative to the developmental stages of the embryo/fetus, and the primary biological mechanisms responsible for transmitting heritable or hereditary effects to future generations. The review addresses several issues within the contexts of both multigenerational and transgenerational effects, with a focus on hereditary perspectives.Conclusions: Knowledge consolidation in the field of Developmental Origins of Health and Disease (DOHaD) has led us to propose a new study strategy. This strategy aims to address the transgenerational effects of in utero exposure to low dose and low dose-rate radiation. Within this concept, there is a possibility that disruption of epigenetic programming in embryonic and fetal cells may occur. This disruption could lead to metabolic dysfunction, which in turn may cause abnormal responses to future environmental challenges, consequently increasing disease risk. Lastly, we discuss methodological limitations in our studies. These limitations are related to cohort size, follow-up time, model radiosensitivity, and analytical techniques. We propose scientific and analytical strategies for future research in this field.La communauté de la radioprotection s'est montrée particulièrement attentive aux risques d'effets différés sur la progéniture en cas d'exposition à des rayonnements ionisants à faible dose ou à faible débit de dose. Malgré cela, les études épidémiologiques et les données scientifiques actuelles sont encore insuffisantes pour fournir les preuves nécessaires à l'amélioration des lignes directrices en matière d'évaluation des risques. Cette revue de la littérature vise à éclairer les études futures sur les effets multigénérationnels et transgénérationnels. Elle se concentre principalement sur les études animales impliquant une exposition in utero et examine les éléments cruciaux pour l'interprétation des résultats. Ces éléments comprennent les scénarios d'exposition in utero par rapport aux stades de développement de l'embryon/du fœtus, et les principaux mécanismes biologiques responsables de la transmission des effets héréditaires aux générations futures. L'étude aborde plusieurs questions dans le contexte des effets multigénérationnels et transgénérationnels, en mettant l'accent sur les perspectives héréditaires.Conclusions : La consolidation des connaissances dans le domaine des origines développementales de la santé et de la maladie (DOHaD) nous a conduits à proposer une nouvelle stratégie d'étude. Cette stratégie vise à étudier les effets transgénérationnels de l'exposition in utero à des rayonnements à faible dose et à faible débit de dose. Dans le cadre de ce concept, il est possible que la programmation épigénétique des cellules embryonnaires et fœtales soit perturbée. Cette perturbation pourrait conduire à un dysfonctionnement métabolique qui, à son tour, pourrait provoquer des réponses anormales aux défis environnementaux futurs, augmentant ainsi le risque de maladie. Enfin, nous discutons des limites méthodologiques de nos études. Ces limites sont liées à la taille de la cohorte, à la durée du suivi, à la radiosensibilité du modèle et aux techniques d'analyse. Nous proposons des stratégies scientifiques et analytiques pour les recherches futures dans ce domaine
Ionizing radiation exposure effects across multiple generations: evidence and lessons from non-human biota
No full textInternational audienceA Task Group (TG121) of the International Commission on Radiological Protection (ICRP) Committee 1 was launched in 2021 to study the effects of ionizing radiation in offspring and next generations. In this report, we summarize the evidence of multi- and trans-generational effects in non-human biota species that was discussed at the ICRP workshop entitled “Effects of Ionizing Radiation Exposure in Offspring and Next Generations” in June 2022. Epigenetic changes, includ- ing changes in DNA methylation, have been observed in trans- and multi-generational irradiation studies in both plants and animals. There were also reports of changes in offspring survival and reproduction. The reported evidence for altered reproduction is an area of potential concern, due to possible effects at the population or ecosystem level. Different considerations are also discussed regarding non-human biota data, such as transferability of data between different species or extending knowledge to humans, differences in species radiosensitivity, the presence of adaptive responses, and dose reconstruction for exposures that occur across multiple generations. Overall, there is a diverse range of available data of the effects in non-human biota, and it will require careful consideration when incorporating this evidence into the system of radiological protection of humans and of the environment
Mettre en évidence l'impact de l'histoire de la construction d'un bâtiment du patrimoine culturel grâce à un modèle aux éléments finis calibré à partir de mesures vibratoires via une une optimisation par essaims particulaires
No full textInternational audienceNumerical models play a primary role in Cultural Heritage preservation. Nevertheless, the design of a realistic model remains challenging due not only to the complex behavior of masonry but also to the asynchronous building phases, the damage induced by natural and anthropic aggression, and the associated repairs. This paper discusses the impact of the information provided by an in-depth analysis of the construction history on the updating process of a Finite Element building model. The case study is the church of Sant'Agata del Mugello (Italy); for this building, a previous historical-archaeological study identified and recorded the asynchronous construction phases, the repair techniques, and the damage induced by three historical earthquakes (1542, 1611, and 1919)—moreover, a dense ambient vibration survey allowed to identify the modal parameters. The information from previous works is summarized in five Finite Element models with increasing complexity. A vibration-based model updating methodology based on a Particle Swarm Algorithm is developed. This work shows that the best minimization of the difference between the numerical and experimental modal parameters is obtained with the numerical model considering the identified construction techniques, repair phases, and connection relations between the bell tower and the nave
Effect of operating conditions on the retention of ruthenium tetroxide (RuO4) by different solid traps
No full textInternational audienceMitigation of gaseous RuO4 is an important issue in nuclear safety in order to reduce potential radiological consequences, either in the context of severe accident arising on pressurized water reactors (oxidizing conditions) or in reprocessing plants (loss of cooling of fission product storage tanks). For the first time, RuO4 trapping was compared using three kinds of materials acting as solid traps: a functionalized MOF UiO-66-NH2, an amine-modified silica and a commercial cerium dioxide. Different experimental conditions of temperature, humidity and gas composition were investigated in order to mimic those prevailing under accident conditions at filtered containment venting system (FCVS) level or in ventilation ducts (gas mixture). At 50 °C, the efficiency of UiO-66-NH2 for RuO4 trapping was both very high in dry gas and in presence of steam with decontamination factor (DF) in the range 10 4-10 5. Under more severe conditions, the retention performances slightly decrease, especially when NO2 was present in the feed gas due to some poisoning of adsorption sites. In presence of amino-modified silica, breakthrough of RuO4(g) occurred at an earlier stage due to its inferior adsorption capacity but the performances of the trap did not deteriorate in presence of steam and NO2 in gas mixture. Under similar conditions, cerium dioxide showed no retention of RuO4(g)
Flame Spread Experiments on a Horizontal Preheated Cable Layer
No full textInternational audienceElectrical cables are one of the main fire hazards in nuclear power plants (NPPs) and in many other industrial sectors. To assess the potential damages of the cable fires, models are required to forecast the fire spread over multiple cable trays and the resulting heat release rate. A new test device, called CISCCO, was developed to conduct flame spread experiments on a preheated horizontal cable layer to support the development and validation of the models. The characteristics of the CISCCO device are first presented before the description of four series of experiments that first investigated the temperature dependence of the flame spread velocity. The series involved a cable layer composed of either a polyvinyl chloride (PVC)-based cable, named PVC cable or a halogen free flame retardant (HFFR) poly(ethylene–vinyl acetate)/polyethylene-based cable, labelled HFFR cable. Temperature measurements performed in the solid phase (cable outer sheath) and in the gas phase (above the cable layer) allowed to assess the preheated cable layer temperature and the flame spread velocity. A first attempt of flame heat flux measurements was also conducted in this work. All series highlighted a temperature dependence of the flame spread velocity according to experimental power laws. The flame spread velocities were measured higher for the PVC cable (0 to 5.5 mm/s) than for the HFFR cable (0 to 1.5 mm/s) while the related preheated cable temperatures suitable for spreading were measured lower for the former (170 to 250°C) than for the latter (280 to 370°C). Finally, one of the four test series that used the PVC cable and implemented heat release rate measurements, revealed that the cable fire growth rate is also temperature dependent according to a power law and is linearly correlated to the flame spread velocity
Carbon-14 cycling in a nuclearized river: A first study in the downstream part of the Rhône River (France)
No full text(IF 8.2; Q1)International audienceCarbon-14 (14C) has a natural origin but is also anthropogenically released from civil nuclear facilities. Due to its long decay period (half-life: 5700 ± 30 years), it is a persistent radionuclide in the environment. In rivers, the complex speciation of carbon makes the fate of industrial 14C difficult to track. This study reports a first overview of artificial 14C cycling in a nuclearized river. A one-year sampling campaign was conducted on the French nuclearized Rhône River and two of its non-nuclearized tributaries (Durance and Ardèche rivers). Isotopic (δ13C, Δ14C) and carbon concentrations analyses were performed on the particulate organic carbon (POC), dissolved organic carbon (DOC) and dissolved inorganic carbon (DIC). Chlorophyll-a (Chl-a) and tritium analyses were performed to assess the dynamic of aquatic organic matter and the nuclear industry contribution, respectively. Comparisons of Δ14C data obtained from the Rhône River with those from the tributaries highlight significant industrial radiocarbon labelling in all carbon forms, with medians of 142, 130 and 42 ‰ for POC, DOC and DIC, that are 2–3 times higher than those of the tributaries. The high values of Chl-a/POC ratios with Δ14C-enriched POC suggest a biological uptake of artificial Δ14C in DIC by aquatic photosynthesis. The relationship of Δ14C-DIC with tritium activity indicates a response to recent releases and enables the contribution of nuclear power plants to be estimated at a median of 26 %. Sampling at the Rhône's mouth would reinforce our understanding of the fate of riverine 14C when entering the marine environment
Measurement of the response function of a custom plastic scintillator using monoenergetic neutron and proton sources
No full textInternational audienceAn experimental study was carried out to determine the light output function of the protons deposited energy in a custom triple discriminating (thermal neutrons/fast neutrons/gamma rays) plastic scintillator. Two response functions of the plastic scintillator were measured and compared using monoenergetic sources of either neutrons or protons. The response function to neutrons was measured at the IRSN Amande facility in CEA Cadarache using the monoenergetic neutron generator. The response matrix was based on six incident neutron energies that ranged from 953 keV to 14.8 MeV. The low-energy threshold for detecting neutrons is evaluated at around 1 MeV. The second response function was measured utilizing the Cyrcé cyclotron at IPHC located in Strasbourg. The response matrix was obtained based on six incident proton energies ranging from 5.9 to 19.97 MeV. The response function measured using monoenergetic neutrons has a nearly rectangular shape that extends from the light output of the low-energy discrimination threshold to the light output of the full incident neutron energy. The pulse height spectra acquired with monoenergetic protons exhibit a Gaussian shape, where the average value corresponds to the light output of the incident protons’ energy. The exponential curve used to fit the light output data acquired from the monoenergetic neutron field generator aligns well with the light output data obtained from the monoenergetic proton beam
Effects of moderate doses of ionizing radiation on experimental abdominal aortic aneurysm
No full textInternational audienceExposure to ionizing radiation has been linked to cardiovascular diseases. However, the impact of moderate doses of radiation on abdominal aortic aneurysm (AAA) remains unknown. Angiotensin II-infused Apoe -/-mice were irradiated (acute, 1 Gray) either 3 days before (Day-3) or 1 day after (Day+1) pomp implantation. Isolated primary aortic vascular smooth muscle cells (VSMCs) were irradiated (acute 1 Gray) for mechanistic studies and functional testing in vitro.Results. Day-3 and Day+1 irradiation resulted in a significant reduction in aorta dilation (Control: 1.39 +/-0.12; Day-3: 1.12+/-0.11; Day+1: 1.15+/-0.08 mm, P<0.001) and AAA incidence (Control: 81.0%; Day-3: 33.3%, Day+1: 53.3%) compared to the non-irradiated group. Day-3 and Day +1 irradiation led to an increase in collagen content in the adventitia (Thickness control: 23.64+/-2.9; Day-3: 54.39+/-15.5; Day+1 37.55+/-10.8 mm, P = 0.006). However, the underlying protective mechanisms were different between Day-3 and Day+1 groups. Irradiation before Angiotensin II (AngII) infusion mainly modulated vascular smooth muscle cell (VSMC) phenotype with a decrease in contractile profile and enhanced proliferative and migratory activity. Irradiation after AngII infusion led to an increase in macrophage content with a local anti-inflammatory phenotype characterized by the upregulation of M2-like gene and IL-10 expression