Korea operates a fleet of 26 nuclear reactors at 5 nuclear power complexes, which provide approximately 30% of Korea’s electricity.1 As of 2024, over 10 000 institutions have received permits or made notifications for the use of radioactive isotopes exceeding certain concentrations and amounts, as well as radiation-generating devices, according to their intended purposes.2 With the expanding use of nuclear and radiation-related technologies in energy and other industries, the potential risks associated have concurrently increased. Radiation accidents or acts of radiological terrorism could result in large-scale casualties, emphasizing the critical need for a comprehensive National Radiological Emergency Medical System. The Chernobyl and Fukushima disasters serve as stark reminders of the necessity for an effective emergency medical response system, demonstrating how deficient preparedness can significantly magnify the scale of such disasters. Although a large-scale nuclear accident has not occurred in Korea, the importance of medical responses during radiation emergencies has been highlighted by incidents such as the Fukushima accident in neighboring Japan,Reference Tsujiguchi, Kitajima and Tminsawa3 the radon mattress incident,Reference Seo, Ha and Kang4 and the threat posed by North Korea’s nuclear weapons.
In 2002, the NREMC was established under the Korea Institute of Radiological & Medical Sciences (KIRAMS), and subsequently, the National Radiation Emergency Medical System was founded based on a nationwide network of radiation emergency medical institutions in accordance with the Act on Physical Protection and Radiological Emergency (APPRE). The NREMC currently consists of approximately 60 personnel, including those in the fields of radiological emergency medicine, dosimetry, research, and administration. An overview of the background and operational scope of Korea’s National Radiological Emergency Medical System can be found in the study by Cho et al. (2018).Reference Cho, Seong and Park5 This article describes the current status of the National Radiological Emergency Medical System, highlighting recent advancements in education, training, and research activities aimed at facilitating effective responses to nuclear and radiological emergencies.
National Radiological Emergency Medical System
The National Radiological Emergency Response System is a national-level framework designed to manage and respond to radiological disasters efficiently. It is composed of the National Emergency Management Committee (NEMC) and its sub-sections, including the Off-site Emergency Management Center (OEMC), the Local Emergency Management Center, the Radiological Emergency Technical Advisory Center, the Radiological Emergency Medical Support Center (REMSC) of KIRAMS and the Emergency Operations Facility of the nuclear licensee. NEMC is tasked with implementing the national radiological emergency response plan and declaring and managing radiological disasters. The OEMC coordinates on-site emergency response activities and makes decisions on protective actions for the public, such as sheltering, evacuation, and food restrictions, in collaboration with relevant organizations.
In the event of a radiological disaster, the Nuclear Safety and Security Commission (NSSC) oversees all affairs, including the Korea Institute of Nuclear Safety (KINS) for radiation protection technical support and the KIRAMS for medical support related to radiological emergency preparedness and response. Particularly in radiological medical responses, the KIRAMS establishes the REMSC in accordance with the National Radiological Emergency Medical System (Figure 1), with the NREMC taking a leading role in medical response activities. The REMSC Command Center is responsible for making key decisions regarding patient referrals and the allocation of hospital facilities, as well as gathering information related to the radiological emergency and disseminating situational updates to radiological emergency medical institutions. Off-site Radiation Emergency Medical Support Group is responsible for dispatching medical support to the disaster site, providing consultation, and facilitating emergency medical care. As part of the protective operations for the population affected by radiological accidents, in addition to physical medical response, psychological counseling and mental health support are provided within the medical response framework. To achieve this, through cooperation between local governments and radiation-related specialized organizations, including the NREMC, the Radiation Health Counseling Service is established and operated within a shelter. This service engages with the community to provide reassurance, reduce fear, and ensure proper understanding of radiation risks, contributing to a comprehensive radiological emergency response.

Figure 1. National Radiological Emergency Medical System.
As of December 2024, 31 radiological emergency medical institutions have been designated by the NSSC as part of the national radiation emergency medical network. Considering the number and geographical location of nuclear facilities across the country, the network comprises 14 primary institutions and 17 secondary institutions (Figure 2).Reference Choi, Yoo and Yang6 These institutions are designated in accordance with the Enforcement Decree of the APPRE [Annex 4: Functions and Designation Criteria of the National Radiation Emergency Medical Center, Primary, and Secondary Radiological Emergency Medical Institutions (Article 36, Paragraph 3)]. In the event of a radiation emergency, these institutions are responsible for providing emergency care to exposed patients, documenting and retaining case records, and reporting the records to the NSSC via the NREMC. Primary institutions triage patients, treat those with mild symptoms, and transfer those with severe symptoms to secondary institutions. Secondary institutions manage patients transferred from primary institutions and those with severe or complex injuries and conduct follow-up monitoring of these patients, which may subsequently transfer patients to the NREMC if necessary. The NREMC oversees the entire network, providing these institutions with funding to support their participation in education and training, as well as equipment (e.g., personal dosimeters, surface contamination monitors, cardiac defibrillators, inflatable medical tents) for radiological emergency preparedness and response, with NSSC’s approval.

Figure 2. Radiation emergency medicine hospital network in Korea.
Adapted from Int J Environ Res Public Health. 2021(18)Reference Choi, Yoo and Yang6
The Korea-Radiation Emergency Medical Assistance Team (K-REMAT), operated by the NREMC, responds to incidents requiring urgent medical support. Currently, 2 teams are in operation, each composed of 6-10 members, including doctors, nurses, paramedics, health physicists, and administrative staff, depending on the severity of the emergency situation. The equipment and supplies include a van, ambulance, personal dosimeters, portable gamma spectrometry, surface contamination monitors, first-aid kits, decontamination kits, personal protective equipment, radios, stretchers, lighting, and food supplies. The teams are deployed to accident sites to conduct triage, decontamination, and treatment of the injured, thereby enhancing radiological emergency response capacity.
The emergency medical personnel involved in the radiological emergency response network consist of staff from the REMSC and personnel from the radiological emergency medical institutions. The number of radiological emergency medical personnel has increased from approximately 200 in 2004 to 800 in 2023. This team includes medical doctors, nurses, paramedics, health physicists, and administrative staff. The NREMC provides these personnel with education and training to enhance their response capabilities. To manage emergency personnel and related resources efficiently, the NREMC operates the Radiation Emergency Medical Information System (REMIS) in 2 primary ways. First, REMIS is used to provide online education and related materials to emergency medical personnel. Second, it serves to register and manage data from radiological emergency medical institutions, including information on human resources, equipment, budget status, training records, and the availability of radioprotective and decorporation agents, including Potassium Iodide, Ca-DTPA, Zn-DTPA, and Prussian Blue.
In addition, the NREMC is responsible for stockpiling and managing iodine thyroid blocking agents (ITBAs) based on the standards outlined in Annex 6-2 of the Enforcement Rules of the APPRE: Stockpile and Management Standards for Thyroid Protective Agents (related to Article 18-2, Paragraph 1). ITBAs are stockpiled in radiological emergency planning zones with consideration of the population size within each jurisdiction. To enhance preparedness, the NREMC conducts biannual checks on stockpiles and separates and disposes of any medications nearing expiration. In addition to ITBAs, the NREMC maintains stocks of decorporation agents such as Ca-DTPA, Zn-DTPA, and Prussian Blue, necessary for the treatment of internal radiation exposure from cesium, plutonium, and other radioactive materials.
It is critical to provide accurate information and guidance regarding the health effects of radiation exposure to individuals who have been exposed or are potentially at risk during a radiological incident. Recognizing the need for radiation exposure counseling following the Fukushima nuclear accident, the NREMC has operated a 24/7 hotline (+82-2-3399-5959) for radiation exposure cases as well as working hours for a regular consultation line (+82-1522-2300) during non-emergency periods since 2011. Through this service, the NREMC offers consultations to the public on the health impacts of radiation exposure and provides comprehensive information related to radiation safety. In addition, the NREMC implements Radiation Effect Clinics to provide medical care and conduct specialized assessments for suspected radiation exposure or contamination cases, including health check-ups. The patient demographic includes not only individuals who are regularly exposed to radiation, such as radiation workers but also those who experience anxiety over potential radiation exposure. Radiation Effect Clinic consultations and visits rose following the 2011 Fukushima nuclear accident and the 2018 domestic radon mattress incident, indicating heightened public demand for consultations and medical services in response to radiation-related social concerns.
Advanced Education Programs and Radiation Emergency Drills
The NREMC oversees the medical response to radiological accidents and conducts training programs to develop a specialized response workforce for emergency situations. The training curriculum encompasses topics such as the health impact of radiation, case studies, relevant legal frameworks, and practical sessions focused on contamination assessment and decontamination. The NREMC also offers various training formats, including basic Radiation Emergency Medical (REM) courses, refresher REM courses, and role-specific training for first responders such as firefighters through in-person as well as online classes. Designated medical personnel are required to complete 18 hours of initial education during their first year, followed by 8 hours of continuing education annually to maintain their expertise.
In addition to its educational initiatives, the NREMC leads and participates in several radiation emergency drills aimed at ensuring a swift response and early containment of incidents, providing prompt protection for the public in the event of a radiological disaster. These drills primarily focus on the medical treatment of radiation injuries, decontamination, and patient transport. A unified drill is conducted annually under the direction of the NSSC, while regional governments organize integrated drills every 2 years. The NREMC conducts 1 to 2 intensive medical drills each year alongside specialized drills such as those aimed at terrorism response.
Recently, the NREMC has developed XR (VR, AR, MR)Footnote a educational materials to enhance its training programs and improve the effectiveness of education for radiological emergencies (Figure 3). These materials simulate specialized and complex procedures, such as triage based on radiological symptoms, contamination measurement using surface contamination monitors, and dry and wound decontamination. Utilizing advanced technologies such as VR, AR, and MR, these scenarios are constructed based on real cases and scientific evidence allowing learners to engage interactively and repeatedly through head-mounted displays or smartphones. This immersive learning experience helps improve competency in radiological emergency response. The introduction of XR-based education, designed to adapt to new technologies and paradigms, offers the advantage of self-paced, repetitive learning without time and spatial constraints. This next-generation educational approach complements existing training programs and is poised for wider adoption in the industry.

Figure 3. Example of a virtual reality training program screen.
Regulation on Radiation Emergency Medicine
The NREMC is commissioned by the NSSC to conduct reviews and inspections and provide support for training evaluations related to radiological emergency medical plans for nuclear licensees.Reference Choi, Yoo and Yang6 These reviews include the approval and modification of radiological emergency plans submitted by nuclear licensees. Inspections ensure compliance with obligations, assess facilities and equipment for radiological disaster response, and involve a review of documentation, interviews, and on-site checks related to radiological emergency education and training. Furthermore, support for training evaluations includes reviewing training scenarios prepared by nuclear licensees, overseeing unified, integrated, and comprehensive drills, and reporting the results of these evaluations to the NSSC, which governs the regulations on radiation emergency medicine.
Additionally, NREMC emphasizes the training and qualification of nuclear inspectors to ensure effective enforcement of the radiological emergency medical regulations. As part of regulatory activities on a legal basis, nuclear inspectors conduct document reviews, interviews, and on-site evaluations to assess the radiological emergency medical preparedness and response capabilities of nuclear licensees, such as maintaining medical service facilities, equipment, and staff for emergency workers and helpers in accordance with the nuclear licensee’s emergency plan. To become certified as a nuclear inspector, individuals must possess at least 2 years of inspection experience, which may include support roles and must complete specialized training. Currently, the NREMC has approximately 20 certified nuclear inspectors. To enhance efficiency and manage regulatory data, the NREMC also operates a computerized management system. This legally grounded (APPRE) regulatory oversight of radiological emergency medical preparedness for nuclear licensees represents the first of its kind globally. By systematically reviewing emergency medical preparedness at nuclear facilities, this system contributes to protecting personnel during radiological exposure incidents.
Physical and Biological Dosimetry
In the aftermath of nuclear or radiological accidents, radiation dose assessment is necessary to implement effective radiation protection for affected individuals. This assessment is crucial for ensuring proper medical management of victims and long-term monitoring of the delayed health effects. It requires specialized methods and instruments to assess individual radiation doses. To facilitate this, NREMC operates laboratories of health physics and biological dosimetry to conduct dose assessments for radiation emergency preparedness.
The laboratory of health physics performs internal and external dose assessments based on the physical dosimetry methods. in-vivo and in-vitro radiobioassay services are provided for internal dose assessment, including whole-body counting, thyroid measurement, and urine radiobioassay. A mobile radiobioassay laboratory unit aids population monitoring because it can be deployed to various regions. For external dose assessment, electron paramagnetic resonance dosimetry and Monte Carlo dosimetry with computational human phantoms are utilized to assess individual doses and reconstruct doses in accidents. In preparation for mass casualty incidents, the NREMC is developing various retrospective assessment techniques. These include a virtual calibration method using Monte Carlo simulations,Reference Park, Yoo and Kim7 as well as retrospective dosimetry techniques utilizing thermoluminescence (TLD) and optically stimulated luminescence (OSL) methods, which can be applied to personal belongings, such as the electronic components of mobile phones and smart chip cards.
The biological dosimetry laboratory provides absorbed dose information to inform the medical intervention plan for the individuals exposed to radiation. The laboratory has employed 2 internationally standardized methods: the dicentric chromosome assay (ISO 19238) and the translocation assay (ISO 20046), utilizing peripheral blood. These assays are utilized for radiation workers suspected of exposure and individuals involved in societal issues—residents living close to nuclear power plants and the defectors from the nuclear testing sites of North Korea. Due to the time-intensive limits of cytogenetic assays and the need for highly skilled experts for the analysis, the laboratory is actively developing several automation methods using artificial intelligence, to improve efficiency and expedite the analysis.
To ensure the accuracy and reliability of dose assessments, both the physical and biological dosimetry laboratories at the NREMC have acquired accreditation from the International Standard of Organization, ISO 17025 for physical dosimetry and ISO 15189 for biological dosimetry, respectively. Moreover, in preparation for large-scale, mass-casualty accidents, the laboratories have adopted a collaborative response mechanism by engaging in interlaboratory-comparison exercises with both domestic and international organizations. Furthermore, the biological dosimetry laboratory launched the K-BioDos (Korean Biological Dosimetry Network) in 2022 to facilitate technical harmonization, conduct training programs for analysis experts, and operate a chromosome image bank to support technical advancements in the field of biological dosimetry.
Research and Development
The multidisciplinary team at the KIRAMS has been researching and developing therapeutic technologies for radiation injury to improve medical services for radiation-exposed patients since 2014. Focused on improving survival rates and the quality of life for acute radiation syndrome patients, advancements have been made in diagnostic and therapeutic strategies. Key development areas include biomarkers for radiation exposure diagnosis,Reference Kwak, Park and Won8 mesenchymal stem cell therapy with significantly enhanced functionality,Reference Lee, Shim and Jang9 and the establishment of organoid models for a new drug screening system.Reference Kim, Han and Kim10 Additionally, drugs targeting radiation-induced hematopoietic syndromeReference Hwang, Shin and Kim11 and gastrointestinal syndromeReference Kim, Kim and Oh12, Reference Kwak, Jang and Park13 have been explored using animal models, including the mini-pig.
In addition, the NREMC has developed a sustainable long-term strategy to investigate radiation-induced health risks, particularly in low dose ranges below 100 mSv for radiation protection. This strategy is rooted in a legal foundation and involves multidisciplinary studies in epidemiology, dosimetry, and biology. One of the main studies is the Korean Radiation Workers Study (KRWS) which is a large-scale national cohort designed in a retrospective and prospective manner that tracks approximately 190 000 workers.Reference Lee, Cha and Park14 The study population and outcomes have been extended to the entire radiation workers (except for diagnostic medical radiation workers) and comprehensive disease states including cancer, non-cancer, and death following the initial preliminary study of 20 608 workers.Reference Seo, Lim and Lee15 Additionally, epidemiologic studies of aircrews and residents living near nuclear facilities began in 2023, and baseline studies are now being conducted. These studies involve the construction of an aircrew cohort and comparison of cancer incidence by distance from nuclear facilities with an ecological study design. Although this research primarily aims to contribute to a better understanding of health effects in low dose ranges in daily life, it is also expected to be a useful groundwork to implement health surveillance and epidemiologic studies in nuclear emergencies.
International Cooperation
Given the scale of potential national-level disasters, the risk of widespread radiation exposure affecting many countries, and the possibility of prolonged crises during large-scale radiological accidents such as nuclear disasters, international cooperation within the radiological emergency medical system is essential. The number of reactors in South Korea, China, and Japan collectively account for 22% of the world’s reactors in operation.16 This high reactor density underscores the need for proactive, collaborative preparation for such incidents in this region. By establishing collaborative frameworks with other nations and international organizations, these countries can enhance their response capabilities through timely information exchange and the sharing of expertise and technologies, ultimately facilitating the development of more effective joint response strategies. As the IAEA Capacity Building Centre for Medical Management of Radiation Exposure and Dose Assessment designated in 2016 and the WHO Collaborating Centre for Radiation Emergency Preparedness and Response designated in 2017, NREMC has played a key role in fostering international collaboration, including providing specialized training and supporting the development of coordinated response strategies. Additionally, we are continuously strengthening international cooperation through Memorandums of Understanding, which facilitate research collaboration and personnel exchanges in the field of radiological emergency response (Table 1). A major research collaboration involves inter-laboratory comparisons (ILC) to evaluate the proficiency of internal and cytogenetic biological dosimetry laboratories in dose assessment through the Running the European Network of Biological and Retrospective Physical Dosimetry (RENEB) and the Asian Radiation Dosimetry Group (ARADOS) which serve international research platforms dedicated to advancing radiation dosimetry.Reference Endesfelder, Oestreicher and Bucher17-Reference Port, Barquinero and Endesfelder20 In particular, the NREMC plays a leading role in coordinating working groups to enhance dosimetry capabilities among institutions participating in the ARADOS.
Table 1. International institutions with Memorandums of Understanding for cooperation in radiological emergency response

Conclusion
Korea’s National Radiological Emergency Medical System is operated by the NREMC under the KIRAMS and a nationwide network of 31 emergency medical institutions under the governance of the NSSC. In response to the growing complexity of radiological incidents and potential mass casualties in recent years, including radiological terrorism and nuclear threats, enhancing this system is vital. Plans are underway to expand the current network of institutions to strengthen the radiological emergency response framework. This will include continuous education and training for designated medical personnel, utilizing advanced simulation tools such as VR and AR, along with field exercises. Moreover, NREMC will prioritize research and development in dose assessment and health impact evaluation to ensure accurate, rapid assessments during emergencies and to devise strategies for health promotion and post-incident recovery. Efforts to strengthen international collaboration with key organizations will also continue, consolidating the coordinated responses to large-scale accidents in Korea and globally. These initiatives are designed to enhance Korea’s capacity to swiftly and effectively manage radiological emergencies, ensuring public safety and mitigating damage.
Author contribution
M.C: Conceptualization and funding acquisition; H.K, S.S, M.S.P, Y.L, J.K, S.B.L, and E.S.C: Writing the draft; S.S, E.S.C, and W.I.J: Development of research; E.S.C, K.H.P, G.C.J, K.M.S, M.Y, and S.K: Data collection; All the authors reviewed and edited the manuscript.
Haewon Kong MA and Songwon Seo PhD contributed equally as first authors.
Acknowledgments
We would like to express our sincere gratitude to all the radiological emergency medical personnel who participated in the National Radiological Emergency Medical System. Special thanks to Dr. Geun Ryang Bae, the director of the Department of Radiation Emergency Medicine at KIRAMS, for his valuable input and contributions to enhancing radiological emergency preparedness and response. This study was supported by a grant from the Korea Institute of Radiological and Medical Sciences, funded by the Ministry of Science and ICT (No. 50445).
Competing interests
None.
Ethical standard
This study is non-clinical and is based on a review of articles that previously received the approval of the Institutional Review Board of the Korea Institute of Radiological and Medical Sciences.