[The advantages of the fire department nurse in managing a CBRN event]

Nuclear, radiological, biological and chemical hazards are caused by agents of very different origins. They can be blatant or insidious, difficult to detect, accidental or intentional. In all cases, in addition to treating victims, the aim is to avoid contamination of hospital services. Faced with these risks, which are often seen as unlikely or too complex, the firefighter nurse represents an asset for his or her establishment, in terms of both crisis anticipation and management.

The NIAID/RNCP Biodosimetry Program: An Overview

Established in 2004, the Radiation and Nuclear Countermeasures Program (RNCP), within the National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health has the central mission to advance medical countermeasure mitigators/therapeutics, and biomarkers and technologies to assess, triage, and inform medical management of patients experiencing acute radiation syndrome and/or the delayed effects of acute radiation exposure. The RNCP biodosimetry mission space encompasses: (1) basic research to elucidate novel approaches for rapid and accurate assessment of radiation exposure, (2) studies to support advanced development for US Food and Drug Administration (FDA) clearance of promising triage or treatment devices/approaches, (3) characterization of biomarkers and/or assays to determine degree of tissue or organ dose that can predict outcome of radiation injuries (i.e., organ failure, morbidity, and/or mortality), and (4) outreach efforts to facilitate interactions with researchers developing cutting edge biodosimetry approaches. Thus far, no biodosimetry device has been FDA cleared for use during a radiological/nuclear incident. At NIAID, advancement of radiation biomarkers and biodosimetry approaches is facilitated by a variety of funding mechanisms (grants, contracts, cooperative and interagency agreements, and Small Business Innovation Research awards), with the objective of advancing devices and assays toward clearance, as outlined in the FDA's Radiation Biodosimetry Medical Countermeasure Devices Guidance. The ultimate goal of the RNCP biodosimetry program is to develop and establish accurate and reliable biodosimetry tools that will improve radiation preparedness and ultimately save lives during a radiological or nuclear incident.

On the value and costs of protective actions in a nuclear emergency

This paper reviews the current orthodoxy for the prompt application of shelter and evacuation advice in the event of a nuclear emergency in the light of the reassessment of the perceived costs and benefits of these protective actions that followed the Fukushima event. In particular, it discusses the mechanisms and criteria for the withdrawal of protective action advice or their continuation for more than a few hours and their impact on public perception. It suggests that lack of thought given to this area may lead to protective actions being kept in place for longer than necessary leading to more harm than good. It also considers the language used to recommend protective actions and to modify them as the event unfolds. Would over strong language used at the start of the event to encourage compliance contribute to public concerns later? Finally, the report poses some discussion points.

Radiation risks and information needs of pregnant and lactating women

This a historical review and current information regarding risks and effects of ionizing radiation in the context of human pregnancy and in particular the information needed for pregnant women to understand the type and magnitude of risks placing them in a realistic context. Much of our understanding comes from early animal studies but has been supported by studies of human exposure to medical radiation, radiation accidents and nuclear weapons.

Radioactive contamination in feral dogs in the Chernobyl exclusion zone: Population body-burden survey and implications for human radiation exposure

This report describes a two-year effort to survey the internal 137Cs and external β-emitter contamination present in the feral dog population near the Chernobyl nuclear power plant (ChNPP) site, and to understand the potential for human radiation exposure from this contamination. This work was performed as an integral part of the radiation safety and control procedures of an animal welfare oriented trap-neuter-release (TNR) program. The measurement program focused on external contamination surveys using handheld β-sensitive probes, and internal contamination studies using a simple whole-body counter. Internal 137Cs burden was measured non-invasively during post-surgical observation and recovery. External β contamination surveys performed during intake showed that 21/288 animals had significant, removable external contamination, though not enough to pose a large hazard for incidental contact. Measurements with the whole-body counter indicated internal 137Cs body burdens ranging from undetectable (minimum detection level ∼100 Bq/kg in 2017, ∼30 Bq/kg in 2018) to approximately 30,000 Bq/kg. A total of 33 animals had 137Cs body-burdens above 1 kBq/kg, though none posed an external exposure hazard. The large variation in the 137Cs concentration in these animals is not well-understood, could be due to prey selection, access to human food scraps, or extended residence in highly contaminated areas. The small minority of animals with external contamination may pose a contamination risk allowing exposures in excess of regulatory standards.

Chemical species of cesium and iodine in condensed vaporized microparticles formed by melting nuclear fuel components with concrete materials

In this study, we report chemical species of Cs and I in condensed vaporized particles (CVPs) produced by melting experiments using nuclear fuel components containing CsI with concrete. Analyses of CVPs by SEM with EDX showed the formation of many round particles containing Cs and I of diameters less than ∼20 μm. X-ray absorption near-edge-structure and SEM-EDX analyses showed two kinds of particles: one containing large amounts of Cs and I, suggesting the presence of CsI, and the other containing small amounts of Cs and I with large Si content. When CVSs were placed in contact with deionized water, most of the CsI from both particles was dissolved. In contrast, some fractions of Cs remained from the latter particles and possessed different chemical species from CsI. In addition, the remaining Cs was concomitantly present with Si, resembling chemical components in the highly radioactive cesium-rich microparticles (CsMPs) released by nuclear plant accidents into the surrounding environments. These results strongly suggest that Cs was incorporated in CVSs along with Si by melting nuclear fuel components to form sparingly-soluble CVMPs.

Development and application of an in-situ shipboard device for the measurement of gamma-ray emitters in seawater

An optimized device based on an HPGe detector and an electro-mechanical cooler combined with a small-sized lead shield was developed for flow-through seawater gamma radionuclide measurement. The system was optimized to operate in mobile or underway mode with suitable integration on available ships. The background spectrum, detection efficiency, and the impact of acquisition time on the minimum detectable activity were obtained at sea. The system MDAs in a 1 h acquisition period for ¹³⁷Cs (661.7 KeV) and ⁶⁰Co (1332.5 KeV) in seawater were 0.45 Bq/L and 0.24 Bq/L, and the MDAs in 20 min were 0.73 Bq/L and 0.47Bq/L, respectively. This device could be used as an efficient tool in emergency monitoring in response to a nuclear accident.

Combined radiation injury and its impacts on radiation countermeasures and biodosimetry

PURPOSE

Preparedness for medical responses to major radiation accidents and the increasing threat of nuclear warfare worldwide necessitates an understanding of the complexity of combined radiation injury (CI) and identifying drugs to treat CI is inevitably critical. The vital sign and survival after CI were presented. The molecular mechanisms, such as microRNA pathways, NF-κB-iNOS-IL-18 pathway, C3 production, the AKT-MAPK cross-talk, and TLR/MMP increases, underlying CI in relation to organ injury and mortality were analyzed. At present, no FDA-approved drug to protect, mitigate, or treat CI is available. The development of CI-specific medical countermeasures was reviewed. Because of the worsened acute radiation syndrome resulting from CI, diagnostic triage can be problematic. Therefore, biodosimetry and CI are bundled together with the need to establish effective triage methods with CI.

CONCLUSIONS

CI mouse model studies at AFRRI are reviewed addressing molecular responses, findings from medical countermeasures, and a proposed plasma proteomic biodosimetry approach based on a panel of radiation-responsive biomarkers (i.e., CD27, Flt-3L, GM-CSF, CD45, IL-12, TPO) negligibly influenced by wounding in an algorithm used for dose predictions is described.

The delayed effects of acute radiation exposure (DEARE): characteristics, mechanisms, animal models, and promising medical countermeasures

PURPOSE

Terrorist use of nuclear weapons and radiation accidents put the human population at risk for exposure to life-threatening levels of radiation. Victims of lethal radiation exposure face potentially lethal acute injury, while survivors of the acute phase are plagued with chronic debilitating multi-organ injuries for years after exposure. Developing effective medical countermeasures (MCM) for the treatment of radiation exposure is an urgent need that relies heavily on studies conducted in reliable and well-characterized animal models according to the FDA Animal Rule. Although relevant animal models have been developed in several species and four MCM for treatment of the acute radiation syndrome are now FDA-approved, animal models for the delayed effects of acute radiation exposure (DEARE) have only recently been developed, and there are no licensed MCM for DEARE. Herein, we provide a review of the DEARE including key characteristics of the DEARE gleaned from human data as well as animal, mechanisms common to multi-organ DEARE, small and large animal models used to study the DEARE, and promising new or repurposed MCM under development for alleviation of the DEARE.

CONCLUSIONS

Intensification of research efforts and support focused on better understanding of mechanisms and natural history of DEARE are urgently needed. Such knowledge provides the necessary first steps toward the design and development of MCM that effectively alleviate the life-debilitating consequences of the DEARE for the benefit of humankind worldwide.

Semi-mechanistic analysis of emergency planning zones for 20 MWe lead-cooled fast reactor by hypothetical accidents during Korea's arctic exploration

Small modular reactors or micro modular reactors have been considered as an alternative power source for merchant ships because of minimal carbon emission and a long lifecycle without refueling. Ahead of the operation, however, their emergency planning zones (EPZs) should be optimally set and approved to ensure both radiological safety and cost efficiency in case of nuclear accidents. Thus, the required size of EPZs was analyzed based on semi-mechanistic assumptions for hypothetical accidents with MicroURANUS, a micro modular fast reactor type of 20-MW lead-bismuth-cooled, used to power an icebreaker during Korea's Arctic missions. For meteorological data, actual icebreaker data acquired in 2020s Artic exploration were utilized. The results showed that EPZ sizes, rationalized in terms of stability class, wind directions, and inherent radioprotection design, ranged within the assumed icebreaker boundary. When comparing various regulations among countries and the International Atomic Energy Agency, dose criteria of Korea (10 mSv/2 d) were found to be strictest. Since major contribution to the whole-body dose was from noble gases (over 96%), a high-quality air filtration system in addition to external shielding would significantly reduce hazards. The emergency situation could be successfully controlled without evacuation and sheltering, avoiding overestimated socioeconomic costs.

PROBLEMATIC ASPECTS, COMPLICATIONS, MISCONCEPTIONS AND DEBATABLE ISSUES OF IODINE PROPHYLAXIS IN RADIATION EVENTS (REVIEW)

Prerequisite. Since the advent of nuclear energy, industry and weapons, a possibility of radiation events i.e. incidents and accidents had emerged. Given the presence of radioactive iodine as part of environmental contamination, the response of authorities and medical services consists, in particular, in carrying out the emergency iodine prophylaxis among specialists and general population. And along with the fact that emergency iodine prophylaxis is a generally accepted measure in radiation events accompanied by the release of radioactive iodine, some methods of its implementation were and remain in certain sources and instructions/recommendations contradictory and even false. Such inconsistency increases the potential risks of health effects of radioactive iodine and exacerbates the sense of fear and uncertainty among the population involved in the incident.

OBJECTIVE

to consider and review the essence of emergency iodine prophylaxis during radiation events, physiological aspects of iodine metabolism in the body, properties of individual iodine prophylaxis agents that are recommended, and to justify the rationality of using some of them along with absurdity/inadmissibility of others; substantiate the creation of a unified preventive information strategy regarding the event in order to reduce anxiety and other negative psychological consequences among the affected population.

MATERIALS AND METHODS

The review was performed by searching the abstract and scientometric databases and printed publications.

RESULTS

In the event of serious radiation events at nuclear power plants and industry facilities, radioactive iodine is highly likely to enter the environment. With the threat of radioactive iodine incorporation or with its incorporation that has already begun, it is absolutely necessary to carry out the emergency iodine prophylaxis. Such prevention should be carried out with stable iodine preparations such as potassium iodide or potassium iodate in special pharmaceutical formulas. Dosing of drugs in age and population groups should be carried out by specialists in radiation medicine and radiation safety in accordance with internationally recognized guidelines. The use of iodinecontaining food additives, iodine solution for external use and Lugol's solution is categorically unacceptable due to complete ineffectiveness, impracticality of implementation, and sometimes due to the threat of serious harm to health.

CONCLUSIONS

Clear preparedness plans for possible radiation accidents and incidents, as well as successfullyimplemented appropriate preventive measures, including emergency iodine prophylaxis, are crucial for the effective and successful response to such events. Emergency iodine prophylaxis during radiation events should be carried out exclusively under the guidance of specialists in radiation medicine and radiation safety using special pharmaceutical formulas of potassium iodide or potassium iodate in doses recognized by the international scientific community. Other means of emergency iodine prophylaxis, including «handicraft»/home preparations, are absolutely unacceptable. Implementation of this protective measure should be accompanied by a coordinated information campaign in order to minimize purely radiation risks and to preserve the psychological well-being of the population.

Combined radiation burn injuries: A note

Combined radiation injury occurs when radiation is accompanied by any other form of trauma. The past experiences of Hiroshima, Nagasaki, and Chernobyl have revealed that a large number of victims of such nuclear accidents or attacks suffer from combined radiation injuries. The possibility of a nuclear attack seems very far-fetched, but the destruction that would occur in such an event would be massive, with a huge lossof lives. Therefore, preparedness for the same should be done beforehand. The severity of combined radiation depends upon various factors, such as radiation dose, type, tissues affected, and traumas. The article focuses on combined radiation burn injury (CRBI) which may arise due to the combination of ionising radiation with thermal burns. CRBI can have varied effects on different organs like the hematopoietic, digestive, lymphatic, cardiovascular, and respiratory systems. Some of the most profound lethal effects are hematopoietic dysfunction, gastrointestinal leakage, bacterial translocation to other organ sites, pulmonary fibrosis, and pneumonitis. In this article, we have attempted to accumulate the knowledge of ongoing research on the functioning of different organ systems, which are affected due to CRBI and possible countermeasures to minimize the effects, thus improving survival.

Radiological risk evaluation applied to aerial evacuation procedures in a nuclear scenario

This study evaluates the risk assessment of a hypothetical scenario where an off-site radioactive release occurs at a nuclear power plant. By using the code Accident Reporting and Guiding Operational System (Prolog Development Center - PDC/ARGOS) a numerical simulation was performed to simulate exposure conditions in an atmospheric plume of contamination. Crews on a rescue mission traverse the plume through a pre-defined path to evaluate the risk from a hypothetical radiological exposure. Applying a sophisticated epidemiological assessment methodology, radiation doses and risks on the teams were evaluated. Core variables such as gender, age and radiation dose were considered in relation to specific morbidities. It was possible to propose a methodology capable of contributing to the reduction of risks to the personnel involved by connecting the results from the computer simulation and the epidemiological risk assessment.

ESTIMATION OF RADIATION DOSES IN THE AREA OF THE MAIN PRODUCTION BLOCK OF THE NUCLEAR POWER PLANT AFTER A REACTOR ACCIDENT

The aim of this work is to propose methodology for estimations the characteristics of the radiation fields (and derived quantities from the field of dosimetry and radiation protection) in knowledge of a distribution of radionuclides released into the main production unit (or just a containment) area after a nuclear reactor accident. For such task stochastic Monte Carlo method has been chosen. Because of dimensions and thick shielding (concrete) barriers in the facility, application of the variance reduction techniques has been necessary. Monte Carlo code Monaco in sequence MAVRIC (from package SCALE 6.2.3) with variance reduction techniques using CADIS methodology has been employed for designing the proposed methodology. Procedure has been tested on a simulation model of a main production unit described by inspiration from the block of a nuclear power plant with a VVER-1000 reactor (installed in the Czech Republic, Central Europe).

Reliability of Questionnaire-Based Dose Reconstruction: Human Factor Uncertainties in the Radiation Dosimetry of Chernobyl Cleanup Workers

This original study aims to quantify the human factor uncertainties in radiation doses for Chernobyl cleanup workers that are associated with errors in direct or proxy personal interviews due to poor memory recall a long time after exposure. Two types of doses due to external irradiation during cleanup mission were calculated independently. First, a "reference" dose, that was calculated using the historical description of cleanup activities reported by 47 cleanup workers shortly after the completion of the cleanup mission. Second, a "current" dose that was calculated using information reported by 47 cleanup workers and respective 24 proxies (colleagues) nominated by cleanup workers during a personal interview conducted more recently, as part of this study, i.e., 25-30 years after their cleanup missions. The Jaccard similarity coefficient for reference and current doses was moderate: the arithmetic mean ± standard deviation was 0.29 ± 0.18 (median = 0.31) and 0.23 ± 0.18 (median = 0.22) for the cleanup worker's and proxy's interviews, respectively. The agreement between two doses was better if the cleanup worker was interviewed rather than his proxy: the median ratio of current to reference dose was 1.0 and 0.56 for cleanup workers and proxies, respectively. The present study has shown that human factor uncertainties lead to underestimation or overestimation of the "true" reference dose for most cleanup workers up to 3 times. In turn, the potential impact of these errors on radiation-related risk estimates should be assessed.

Mental health and psychosocial consequences linked to radiation emergencies-increasingly recognised concerns

A major radiological or nuclear emergency may, apart from causing a substantial loss of life and physical damage, also put a substantial strain on affected societies with social, economic and political consequences. Although such emergencies are relatively uncommon, it is now being increasingly recognised that their subsequent psychosocial impact can be widespread and long lasting. Mental health effects, such as depression, anxiety and post-traumatic stress disorder, are highly represented in a population affected by a radiation disaster. In order to reach the majority of the people affected by radiation accidents, we need to be aware of how to distribute relevant and accurate information related to both short- and long-term medical effects. Effective risk communication is associated with improved compliance with any given recommendations. It is important to protect the public from physical radiation damage, but it is also essential to take into account the social and mental health effects that radiation disasters may induce. This article provides a brief review of recent reporting on the psychological consequences after a major radiation emergency.

Citizens’ Communication Needs and Attitudes to Risk in a Nuclear Accident Scenario: A Mixed Methods Study

The potential devastation that a nuclear accident can cause to public health and the surrounding environment demands robust emergency preparedness. This includes gaining a greater knowledge of citizens’ needs in situations involving radiation risk. The present study examines citizens’ attitudes to a remediation scenario and their information and communication needs, using focus group data (n = 39) and survey data (n = 2291) from Sweden. The focus groups uniquely showed that adults of all ages express health concerns regarding young children, and many also do so regarding domestic animals. Said protective sentiments stem from a worry that even low-dose radiation is a transboundary, lingering health risk. It leads to doubts about living in a decontaminated area, and high demands on fast, continuous communication that in key phases of decontamination affords dialogue. Additionally, the survey results show that less favorable attitudes to the remediation scenario—worry over risk, doubt about decontamination effectiveness, and preferences to move away from a remediation area—are associated with the need for in-person meetings and dialogue. Risk managers should thus prepare for the need for both in-person meetings and frequent information provision tasks, but also that in-person, citizen meetings are likely to feature an over-representation of critical voices, forming very challenging communication tasks.

Returning Home after Decontamination? Applying the Protective Action Decision Model to a Nuclear Accident Scenario

Studies of the aftermath of nuclear power plant accidents show that affected citizens assess higher risks and adopt more risk-avoidant behaviors than authorities expect. This results in differences between the planned recovery and actual outcomes. Based on this knowledge, this study examined the factors that affect citizens’ preference to continue living in a decontaminated area. Testing the key aspects of the protective action decision model (PADM), this study analyzed Swedish survey data (N = 2291) regarding such an accident scenario. Several aspects of the PADM, from the layperson’s view of threats and protective actions, to stakeholders and situational factors, were strongly supported. The most influential variables affecting settlement choices are perceptions of radiation risk, perceptions of decontamination effectiveness, government information, living with certain restrictions, and attachment to an area because of one’s work. A novel contribution of this study is that it ranked the significance of such effects on behavioral intentions in an emergency scenario. Regarding the policy recommendations, this study concluded that a recovery program must facilitate most aspects of people’s lives and provide trustworthy information on decontamination efficiency. As some people will avoid potential health risks and leave a decontaminated area, planning to implement one solution for everyone would likely not be optimal.

Atmospheric dispersion modeling for an accidental release from a SLOWPOKE-2 research reactor: a case study

Atmospheric dispersion modeling was performed for a postulated design basis accident at a SLOWPOKE research reactor. The MCNP-5 computer code was used to estimate the neutron flux spectrum which was then used in the ORIGEN-S code to perform core depletion calculations and determine the radiological source term. The HotSpot health physics code was then used to model the atmospheric transport of the radioactive material released to estimate the resulting doses to the population downwind of the reactor. The highest total effective dose (TED) for a release from the reactor's exhaust stack in predominant meteorological conditions, stability class C, was 0.37 mSv, while a maximum TED of 4.29 mSv was estimated for a release at ground level. Ground deposition was estimated to be 3900 kBq/m². It was shown that any hypothetical release of radioactive material resulting from such an accident would have no significant adverse effect on the municipal water reservoir close to the reactor.

EPR dosimetry in glass: a review

Electron Paramagnetic Resonance (EPR) spectroscopy enables detection of paramagnetic centers generated in solids by ionising radiation. In the last years, the ubiquity of glass in personal utility items increased significance of fortuities retrospective dosimetry based on EPR in glass parts of mobile phones and watches. Despite of fading of the signals and their susceptibility to light, it enables dosimetry at medical triage level of 1-2 Gy. In this article information relevant for assessment of applicability and planning of the EPR dosimetry is presented-particularly at dose levels typical for radiation accidents. Reported data on fading of the radiation-induced spectral components are presented and compared. Effects of light on background spectra and on the dosimetric signals are also presented. It is concluded that when properly accounting for the fading and for the obscuring effects of light, the EPR dosimetry in glasses from mobile phones and watches can be used in dose assessment after radiation accidents.

Improving the estimation accuracy of multi-nuclide source term estimation method for severe nuclear accidents using temporal convolutional network optimized by Bayesian optimization and hyperband

During a nuclear accident, estimating the source terms using environmental measurements is vital for emergency decision-making. In this study, we propose a forecasting model based on a temporal convolutional network to estimate the release rates of seven radionuclides (Kr-88, Te-132, I-131, Xe-133, Cs-137, Ba-140, and Ce-144) based on off-site sequential gamma dose rates and meteorological monitoring data. To determine the best structure of the neural network, Bayesian optimization and hyperband (BOHB) was used on the hyperparameters of the model to reduce the testing loss. Additionally, a gradient boosting regression model was used to predict missing gamma dose rates to ensure the model offers a relatively reliable estimate under certain circumstances. The international radiological assessment system (InterRAS) was used to generate datasets for model training and testing. The results showed that the optimal hyperparameters selected by BOHB can reduce the valid loss of the model to 0.0153, and the mean absolute percentage error of prediction for the seven radionuclides was below 12%, three of which (Kr-88, Te-132, Cs-137) reached 8% at 10 h. When the first and second time-steps of the data were missing, the mean absolute percentage error of the prediction for all radionuclides was less than 30% after using a gradient boosting regression.

SEED: An Operational Numerical Tool for Dosimetric Reconstruction in Case of External Radiological Overexposure

ABSTRACT

In the event of a radiological accident involving external exposure of one or more victims and potential high doses, it is essential to know the dose distribution within the body in order to sort the victims according to the severity of the irradiation and then to take them to the most suitable medical facilities. However, there are currently few techniques that can be rapidly deployed on field and capable of characterizing an irradiation. Therefore, a numerical simulation tool has been designed. It can be implemented by a doctor/physicist pairing, projected within a limited time as close as possible to the irradiation accident and emergency response teams. Called SEED (Simulation of External Exposures & Dosimetry), this tool (dedicated to dose reconstruction in case of external exposure) allows a rapid modeling of the irradiation scene and a visual exchange with the victims and witnesses of the event. The user can navigate in three dimensions in the accident scene thanks to a graphical user interface including a "first person" camera. To validate the performance of the SEED tool, two dosimetric benchmarking exercises were performed. The first consisted in comparing the dose value provided by SEED to that given by a reference calculation code: MCNPX. The purpose of the second validation was to perform an experiment irradiating a physical dummy equipped with dosimeters and to reconstruct this irradiation using SEED. These two validation protocols have shown satisfactory results with mean difference less than 2% and 12% for the first and second exercises, respectively. They confirm that this new tool is able to provide useful information to medical teams in charge of dosimetric triage in case of a major external exposure event.