IAEA Research Articles

Formulating a national position statement and guide on modern theranostics in the Philippines.

Barriers to the establishment of advanced technologies in developing countries were overcome when modern theranostics pertaining to the use of Ga-68 and Lu-177 PSMA and DOTATATE were first offered to patients in the Philippines in early 2018. However, significant growth was not experienced at St. Luke's Medical Center for five years and lutetium was not yet distributed to other institutions by a radiopharmaceutical supplier. Due to the relative novelty and rapid expansion of theranostics worldwide, position statements were released by the Australasian Association of Nuclear Medicine Specialists, European Association of Nuclear Medicine, Society of Nuclear Medicine and Molecular Imaging, and International Atomic Energy Agency primarily to uphold patient safety and ensure a level of standard among its practitioners. Subsequently in the latter half of 2022, these were adopted and modified according to what is feasible and applicable locally within the Philippine Society of Nuclear Medicine, considering the current status and future possibilities. Different representatives were involved, and several groups were mobilized for successful implementation. A liability clause was incorporated to discourage unprofessional acts.

Requirement for diagnostic medical physicists in Vietnam

This paper mentions the status of diagnostic medical physicists, estimating the lack of this work in Vietnam. The evaluation method is based on International Atomic Energy Agency documents and typical hospital models in Vietnam. In 2021, there were no diagnostic medical physicists. The roles and responsibilities of diagnostic medical physicists are currently performed by radiologists, biomedical engineers, and medical physicists in radiation oncology or nuclear medicine. This job is still a potential profession in Vietnam.

Радиоэкологическое моделирование динамики активности I-131 в молоке в центральной части Мазовии по материалам «Варшавского» сценария проекта МАГАТЭ EMRAS: реконструкция, верификация, оценки достоверности

The work was aimed to the study the Cs-137 and I-131 transport dynamics along the trophic chain, from the atmosphere to soil, vegetation, dairy cattle, milk, and the human body. This was done with the use of the radioecological simulation model based on instrumental data from the "Warsaw" scenario of the International Atomic Energy Agency's (IAEA) EMRAS project, which were collected after the Chernobyl nuclear accident. The created simulated radioecological model was used for reconstruction of the I-131 radioactivity in dairy cattle milk in the Warsaw and Ostroleka areas located in the central part of Mazovia, where the cattle dairy milk radiometry was performed in April-May 1986. The aim of the study was to verify the radioecological model, to assess the reliability and uncertainty of the milk block of the computed model. It was found that the successive account of discrepancies between computed and reconstructed instrumental data of I-131 radioactivity dynamics in green fodder on farms in Mazovia areas and the shortage of clean fodder stocks harvest lead to a successive improvement of the agreement between computed and instrumental data of 131I activity in the dairy milk. For all variants of accounting correction the ratio of computed data to instrumental data with recalculated I-131 activities in the atmosphere of the Ostroleka Area is on average 2.5-3 times closer to their ideal value of 1 than in calculations with instrumental data for a cloud. The prognostic properties of the computational model at the stage of reconstruction of the specific 131I activity in milk, estimated as the ratio of computed data to instrumental data, can be estimated as 1.05+/-2.0; the values of these ratios for correction of thyroid radiation doses to the population due to the contaminated milk consumption are estimated as 1.3+/-2.5.

Combining Nuclear Medicine With Other Modalities: Future Prospect for Multimodality Imaging.

This meeting report summarizes a consultants meeting that was held at International Atomic Energy Agency Headquarters, Vienna, in July 2022 to provide an update on the development of multimodality imaging by combining nuclear medicine imaging agents with other nonradioactive molecular probes and/or biomedical imaging techniques.

Evolution of zoning philosophy for emergency planning around nuclear power plants

Emergency planning zones (EPZs) serve as vital geographic framework within nuclear emergency preparedness and response (EPR) strategies, facilitating the swift implementation of protective measures across varying levels of urgency during nuclear emergencies. Over the years, nations have undergone thorough reassessments of these zones, in the light of evolving evaluation methods, reactor technology, and lessons learned from accidents, leading to the refinement of methodologies for delineating EPZ distances. Adherence to the International Atomic Energy Agency safety guidelines regarding EPZ size has demonstrated effectiveness in protecting both the public and environment surrounding existing nuclear power plants. As the landscape of nuclear energy evolves with the advent of small modular reactors, characterized by reduced power capacity and innovative safety features, there is enough potential for smaller EPZs. However, the determination of EPZ also depends on national policies, public acceptance, and nuanced risk criteria. This paper seeks to synthesize current insights into the evolution of EPZs and explores avenues for resizing them to accommodate emerging reactor technologies. Its findings hold relevance for reactor designers, risk analysts, and experts in nuclear EPR, offering guidance for future planning and implementation efforts.

Regulatory and Legal Support of International Nuclear Law

Between the first regulatory and legal development of international nuclear law in 1957 and modern achievements, three main stages of this process can be distinguished.
 The first period of development of international nuclear law corresponds to the period of development of nuclear energy and guarantees of its peaceful use by all non-nuclear weapon states. This dual purpose was legally confirmed by the establishment of the International Atomic Energy Agency (IAEA) in 1957 and the entry into force of the Treaty on the Non-Proliferation of Nuclear Weapons (NPT) in 1970.
 The first stage in the development of international nuclear law was complemented by a second growth phase aimed at increasing collective resilience to the dangers of nuclear energy. The Three Mile Island accident in 1979 and especially the Chernobyl disaster in 1986 triggered intense regulatory activity aimed at preventing nuclear accidents and better managing their consequences on an international scale.
 As a result, several international conventions have been adopted in this area: The Convention on Early Notification of a Nuclear Accident and the Convention on Assistance in the Case of a Nuclear Accident or Radiological Emergency, the Convention on Nuclear Safety and the Joint Convention on the Safety of Spent Fuel Management and on the Safety of Radioactive Waste Management.
 Unlike the first-generation nuclear nonpro­liferation treaties, these norms do not violate the essential sovereignty of the states parties. By merging binding provisions and flexible legislation, a cooperative system was created for flexible and decentralized management of nuclear activities on an international scale.
 The third stage of the development of inter­national nuclear law, in which we are currently located, is characterized by both negative and positive elements.
 On the negative side, there are problems that affect the effectiveness of international nuclear law. The most alarming issue in this area is the independence of nuclear regulatory authorities in several countries, although it is regulated by Article 8 of the Convention on Nuclear Safety and Article 20 of the Joint Convention on Nuclear Safety.

Realistic application of short-lived fission product delayed neutron, gamma-ray analysis for simultaneous nondestructive trace quantification of U, Pu mixtures on cellulose swipes

Detection and characterization of fissile traces are of interest to the international nuclear nonproliferation community, including the International Atomic Energy Agency. Pre-inspection check samples are analyzed by neutron activation analysis at the High Flux Isotope Reactor operated by the Oak Ridge National Laboratory under the umbrella of the IAEA Network of Analytical Laboratories. The simultaneous quantification of U and Pu mixtures was accomplished using the combined delayed neutron (DN) delayed gamma-ray (DG) method to analyze cellulose swipes with actinide loading <1 ng in a blind field trial. The total fissile quantity was measured by the DN counts and the relative proportions of U, Pu were determined by calibration of the 104Tc/141Ba fission product count ratio using known mixtures. The DNDG method demonstrated high accuracy in flagging the presence of 239Pu in uranium down to <100 pg mass loading. Peak significance tests helped to control false positive Pu flagging and simultaneous quantification of U and Pu loading was accomplished on samples that passed the significance tests.

Estimating Local Diagnostic Reference Levels for Mammography in Dubai.

As the total volume of mammograms in Dubai is increasing consistently, it is crucial to focus on the process of dose optimization by determining dose reference levels for such sensitive radiographic examinations as mammography. This work aimed to determine local diagnostic reference levels (DRLs) for mammography procedures in Dubai at different ranges of breast thickness. A total of 2599 anonymized mammograms were randomly retrieved from a central dose survey database. Mammographic cases for screening women aged from 40 to 69 years were included, while cases of breast implants and breast thickness outside the range of 20-100 mm were excluded. Mean, median, and 75 percentiles were obtained for the mean glandular dose (MGD) distribution of each mammography projection for all compressed breast thickness (CBT) ranges. The local DRLs for mammography in Dubai were found to be between 0.80 mGy and 0.82 mGy for the craniocaudal (CC) projection and between 0.89 mGy and 0.971.8 mGy for the mediolateral oblique (MLO) projection. Local DRLs were proposed according to different breast thicknesses, starting from 20 to 100 mm. All groups of CBT showed a slight difference in MGD values, with higher values in MLO views rather than CC views. The local DRLs in this study were lower than some other Middle Eastern countries and lower than the standard reference levels reported by the International Atomic Energy Agency (IAEA) at 3 mGy/view.

Water quality management program for IPR-R1 TRIGA® research reactor

The IPR-R1 Triga nuclear research reactor of the Nuclear Technology Development Center (CDTN) is one of the oldest reactors in operation in the world. It is a compact and inherently safe reactor that operates at a continuous power level of 100 kW with a solid homogeneous General Atomic (GA) fuel element of zirconium hydride moderator homogeneously combined with 20% enriched uranium. The reactor core is at the bottom of a tank under approximately 6.0 meters of shielding water. The long operation time of the reactor, 63 years, and the contact of the water with the core, can induce corrosive processes in the IPR-R1 reactor and affect its safe operation. To keep the water quality according to the chemical-physical recommended standards, a quality management program, as recommended by the International Atomic Energy Agency (IAEA), was implemented. The water quality management program is a guideline of good practices applied to nuclear reactors, targeting to keep their water coolants at specified physical-chemical standard. The main aim of the present work is to introduce IPR-R1 Triga’s water chemistry program results from the second half of 2022 till the first half of 2023, when the installation returned to its regular activities after the Covid-19 pandemic. The physical-chemical parameters evaluated (e.g.: pH, alpha and beta radiation, electrical conductivity and gamma emitters) shows that the IPR-R1 reactor operates within recommended safety standards.

Detecting Unauthorized Movement of Radioactive Material Packages in Transport with an Adam-Optimized BP Neural Network Model

The rapid expansion of nuclear technology across various sectors due to global economic growth has led to a substantial rise in the transportation of radioactive materials. The International Atomic Energy Agency (IAEA) estimates that approximately 20 million shipments of radioactive materials occur annually. In this context, ensuring the safety and security of radioactive material transportation is of significant importance. IAEA’s “Security of Radioactive Materials in Transport” (Nuclear Security Series No. 9-G) mandates that an effective transport security system should provide immediate detection of any unauthorized removal of the packages. In the present study, an innovative Adam-optimized BP neural network model is developed for detecting unauthorized movements of radioactive material packages. To analyze the performance of the proposed algorithm, numerous experiments were conducted. The results demonstrate that the proposed method achieves a 99.17% accuracy rate in detecting unauthorized movements of radioactive materials, with a missed alarm rate of 0.72% and a false alarm rate of 0.1%. This method also enables real-time detection of unauthorized removal of radioactive materials and effectively enhances the security of radioactive materials during transport to reduce the risks of theft, loss, diversion, or sabotage.

Chest X-Ray ESD and ESAK Assessment in A Few Diagnostic Radiological Facilities in Delta State

Background: The utilization of X-rays in medical procedures has sparked apprehension regarding their potential adverse consequences, despite their undeniable advantages in the realms of diagnosis and therapy. The present study aimed to evaluate the levels of Entrance Skin Dose (ESD) and Entrance Skin Air Kerma (ESAK) associated with chest X-ray examinations conducted in diagnostic radiological facilities located within Delta State. The present study employed a standardized approach to describe the materials and methods used in the research. The dose assessment was performed on a sample of 700 patients who were 18 years of age or older. These patients were selected from 10 operational facilities located throughout the State. The findings of the study are as follows: The effective dose (ESD), ascertained through the utilization of patient anatomical data and exposure parameters, fell within the recommended reference dose limits of 1 mGy (National Nuclear Regulatory Agency) and 0.4 mGy (International Atomic Energy Agency) for the majority of healthcare facilities. Nevertheless, certain centers demonstrated elevated dose levels, which can be attributed to factors such as increased exposure rates, aging x-ray tubes, and inadequate technician competency. The effective dose values (ESD) exhibited a range of 0.018 to 1.671 mGy for males and 0.084 to 1.542 mGy for females. The range of Entrance Skin Air Kerma (ESAK) values for males was found to be between 0.019 and 0.085 mGy, while for females it ranged from 0.016 to 0.098 mGy. These values were observed to be within the recommended dose limits. In conclusion, this study emphasizes the significance of surveillance of radiation exposure and the implementation of quality assurance protocols in order to safeguard patient well-being and mitigate potential hazards linked to chest X-ray procedures conducted in diagnostic radiological establishments.

Uranium Isotope Characterization in Volcanic Deposits in a High Natural Background Radiation Area, Mamuju, Indonesia

Mamuju is an area of high natural radiation in Indonesia with high natural radiation levels (average 613 nSv h−1). Mamuju is anomalous due to its high average 238U and 232Th concentrations of 22,882 and 33,549 Bq kg−1, respectively, in laterite and rock. High natural radionuclide concentrations of 238U, 232Th, and 40K have also been reported in soil samples from several locations in Mamuju, including Botteng, Northern Botteng, Takandeang, Ahu, and Taan. High radiation levels are related to radioactive mineral occurrences in the Adang volcanic complex, comprised of phonolitoid and foiditoid lithologies. According to the International Atomic Energy Agency (IAEA), uranium deposits can be classified into several types, among them a volcanic-related deposits, which include three sub-types: stratabound, structure-bound, and volcano-sedimentary deposits. This study aims to characterize volcanic rock deposit sub-types in the Mamuju area based on uranium radioisotope measurements. The uranium isotopes were measured using a tandem quadrupole inductively coupled plasma mass spectrometer combined with chemical separation by extraction chromatography using UTEVA resin. The analytical results for the 234U/238U ratios are used to determine the formation characteristics of minerals in each deposit sub-type based on mineral formation age, post-formation processes, and disturbances that affected the formation processes. Based on geochronological calculations using 234U/238U mineralization age, the deposits in the Mamuju area are 0.914–1.11 million years old and are classified as recent mineralization. These data have important implications for tracing uranium source rocks in the Mamuju area and may explain the anomalously high radiation levels in the Mamuju area.

An Assessment of Deep Borehole Disposal Post-Closure Safety

Around the world, deep borehole disposal is being evaluated for intermediate level-waste (ILW), high-level waste, and spent nuclear fuel. To facilitate a disposal concept options analysis for ILW in Australia, desktop and lab-based geoscientific investigations, together with generic post-closure safety assessments of deep borehole disposal of long-lived ILW, have been undertaken. This paper reports on geoscientific data obtained on crystalline rock and rock salt as model rocks for geological disposal. Petrophysical and mineralogical properties for these rocks have been investigated to provide realistic data for evaluation and input to post-closure safety assessments. For crystalline rock samples originating from depths between 700 to 1900 m, very low hydraulic conductivity (2 × 10−12 to 3 × 10−11 m/s) and very low porosity (0.02% to 1.2%) were obtained. The noble gas isotopic composition of fluid inclusions from the same depth interval confirmed the rock had been devoid of recent interaction with meteoric water, thus providing potentially suitable conditions for geological disposal. Rock salt from a 802-m (heterogeneous sample with 40% halite) and a 1100-m (sample with 98% halite) depth also had a low hydraulic conductivity (5 × 10−10 to 5 × 10−9 m/s at 802 m and 10−11 to 2 × 10−10 m/s at 1100 m) and very low porosity (~0.8% for the heterogenous sample and ~0.2% for the pure halite sample). Post-closure safety assessments based on numerical modeling provided bounding conditions around the thermal evolution of the disposal environment in crystalline rock for low heat generating ILW (50 W per 180-L vitrified waste canister), including exploring the sensitivity of temperature evolution within the borehole and rock environment to parameters such as heat load, borehole depth, geothermal gradients, and rock thermal conductivity. The coupling of heat transport with radionuclide migration to account for buoyancy-driven transport was shown to have a limited impact on radionuclide migration. For a disposal borehole in crystalline rock, the radionuclide concentrations and annual dose rates from key radionuclides (99Tc and 79Se) for a 500-m, 1000-m, or 3000-m deep borehole were negligible (i.e., many orders of magnitude smaller than the threshold dose the International Atomic Energy Agency considers insignificant for humans, 0.01 mSv/year). For disposal in rock salt, a suite of numerical model scenarios explored the effectiveness of the engineered barriers, including the glass matrix, primary package, and overpack, assuming diffusion-dominated transport. These scenarios illustrated that the performance of the disposal system was insensitive to the presence or absence of engineered barriers, as dose rates at late time (>105 years) were nearly identical for all scenarios. These results indicate that the natural barrier provided by the salt is very effective at containing radionuclides, while the engineered barriers serve mainly to delay the arrival of the peak dose. While the results are preliminary, the post-closure safety assessments, supported by measured data from crystalline rock and rock salt, give confidence that deep borehole disposal of long-lived ILW would result in dose rates considered insignificant for humans within a few meters from the borehole.

Technical specifications of dose management systems: An international atomic energy agency survey.

Dose management systems (DMS) have been introduced in radiological services to facilitate patient radiation dose management and optimization in medical imaging. The purpose of this study was to gather as much information as possible on the technical characteristics of DMS currently available, regarding features that may be considered essential for simply ensuring regulatory compliance or desirable to fully utilize the potential role of DMS in optimization of many aspects of radiological examinations. A technical survey was carried out and all DMS developers currently available (both commercial and open source) were contacted and were asked to participate. An extensive questionnaire was prepared and uploaded in the IAEA International Research Integration System (IRIS) online platform which was used for data collection process. Most of the questions (93%) required a "Yes/No" answer, to facilitate an objective analysis of the survey results. Some free text questions and comments' slots were also included, to allow participants to give additional information and clarifications where necessary. Depending on the answer, they were considered either as "Yes" or "No." Given the way that the questions were posed, every positive response indicated that a feature was offered. Thus, the percentage of positive responses was used as a measure of adherence. The percentages of positive answers per section (and sub-section) are presented in graphs and limitations of this type of analysis are discussed in detail. The results of this survey clearly exhibit that large differences exist between the various DMS developers. Consequently, potential end users of a DMS should carefully determine which of the features available are essential for their needs, prioritize desirable features, but also consider their infrastructure, the level of support required and the budget available before selecting a DMS.

Studi Penerapan General Safety Requirement Part 7 IAEA untuk PLTN Apung

Land use is a growing concern due to population growth, infrastructure development, and the decline of forestry and agricultural sectors, with the energy sector, including nuclear power plant (NPP) construction, gaining prominence. Because of this, more and more nuclear power plant designs are being developed, including the floating nuclear power plant. Behind the benefits, one of the safety aspects that must be fulfilled in nuclear power plant design is nuclear emergency preparedness and response. The Nuclear Energy Supervisory Agency (Bapeten) is currently preparing a revision of Government Regulation Number 2 of 2014 concerning the Safety and Security of Nuclear Installations and Regulation of the Head of Bapeten Number 1 of 2010 concerning Nuclear Emergency Preparedness and Management, which contains nuclear emergency preparedness and response. As an international atomic energy agency, the IAEA has also published General Safety Requirements (GSR) Part 7 concerning Preparedness and Response For a Nuclear or Radiological Emergency. Considering the different complexities and challenges, it is necessary to study the implementation of GSR Part 7 on floating nuclear power plants, which can provide input for revising these regulations. This paper was prepared to elaborate on the application of GSR Part 7 for this nuclear power plant design. From the results of the study, it was found that several things need to be implemented for the design of the floating nuclear power plant, such as the nuclear emergency zone, nuclear emergency expansion zone, public communication, and handling of radioactive waste. Keywords: NPP, Floating NPP, preparedness of nuclear emergency,response fornuclear emergency

Measurement of Entrance Surface Air Kerma of plain abdominal radiography in some Nigerian health facilities

Background : Patient dose assessments in many Nigerian radiological departments have shown large inter- and intra-hospital variations for the same type of radiological examinations, hence, there is a need for regular monitoring of radiological equipment and measurement of patient dose in our health facilities. The main objective of this survey was to evaluate the Entrance Surface Dose Air Kerma (ESAK) of the patients who underwent abdominal (anteroposterior; AP) radiography in ten health facilities in Southern Nigeria.&#x0D; Material and Methods: A total of ten health facilities comprising private and public health facilities were included in this investigation. A total of 223 adult patients who weighed within 70±5kg `were considered in this survey. The ESAK was calculated from the tube output of the x-ray machines and the exposure parameters utilized during examinations according to the International Atomic Energy Agency code of practice.&#x0D; Results : The mean ESAK values obtained from the health centres ranged from 1.00 milligray (mGy) to 17.21mGy. The maximum/minimum ratio of individual ESAK which is the range factor (RF) varied from 1.3 to 6.1.&#x0D; Conclusion and Recommendation : Variations were observed in patient dose values among radiological units. The entrance surface air kerma (ESAK) obtained in the study were comparable with the dose values in the UK- 2010 review in most cases. The intra-radiological unit patient dose variations, as revealed by the range factor show that the operation technique employed was not fully optimized and that dose reduction is possible without degrading image quality. Therefore, there is a need for regular monitoring of radiographic equipment and periodic surveys of the patient dose.

Arrangements for Telephone Consultation on Radiation Health Effects in a Nuclear Emergency in Japan: Lessons Learned from the Nuclear Accident in Fukushima, Japan, 2011

The Japan Atomic Energy Agency (JAEA) established a telephone consultation system at the request of the Ministry of Education, Culture, Sports, Science and Technology in response to residents’ concerns about the radiation health effects following the nuclear accidents at the Fukushima Daiichi Nuclear Power Station of the Tokyo Electric Power Company (TEPCO) in March 2011. Eight toll-free telephone lines were established and employees with knowledge of radiation health effects were assigned for consultation. The JAEA expert response group for telephone inquiries comprised a telephone response team, a question-and-answer team, and a manager. Approximately 35,000 consultations were conducted from March 17, 2011 to September 18, 2012. Japan’s Basic Disaster Prevention Plan was revised following the accident, where one of the JAEA’s roles for nuclear emergency response was to provide telephone consultation on radiation health effects. The JAEA’s system for telephone consultation was improved following this experience. The description of telephone hotlines in the International Atomic Energy Agency’s guide, GSG-14, published in 2020, was discussed for further improvement in the JAEA’s telephone consultation system.

Оцінка культури безпеки у вітчизняній охороні здоров’я: триангуляційний підхід

The aim of the study. To evaluate the safety culture in domestic health care using a mixed approach, that is, using a questionnaire survey, document analysis, as well as an analysis of the state of safety of patients and medical personnel. Materials and methods. The evaluation of safety culture in Ukrainian healthcare has been carried out based on the methodology of the IAEA (International Atomic Energy Agency), specifically employing a triangulation approach involving questionnaire surveys, document analysis, as well as an analysis of patient and medical personnel safety conditions. Our analysis and assessment of the regulatory framework for safety provision in the hospital environment from 1994 to 2020, as well as the safety status of patients from 2003 to 2020 and medical personnel from 2002 to 2018, formed the basis of the material used in this study. Additionally, the evaluation of safety culture was conducted through a questionnaire survey involving 199 healthcare professionals from various healthcare facilities. Research results. The study revealed that safety culture in domestic healthcare facilities is at an early stage of formation and requires systematic improvement. Developing a more comprehensive methodology for assessing safety culture in the medical field is an important and promising direction for future research. The results of our study confirmed the effectiveness of employing a triangulation approach to assess the level of safety culture excellence in healthcare facilities. Conclusions. Strengthening the identified weaknesses in safety culture within the domestic medical industry can become the goal and foundation of a future strategy to create a safe hospital environment based on improving and enhancing safety culture.

Soil-to-organic Sangyod rice grain transfer factors (TF values) of natural and anthropogenic radionuclides in Phatthalung province, Thailand

The specific activities of natural (40K 226Ra and 232Th) and anthropogenic (137Cs) radionuclides in paddy soil and organic Sangyod rice grain were measured and analyzed in this study with an aim to determine the soil-to-organic Sangyod rice grain transfer factors (TF values) of all required radionuclides in Don Pradu sub-district, Pak Phayun district in Phatthalung province in the south of Thailand. The high purity germanium (HPGe) detector and gamma-ray spectrometry analysis system which were installed and used in advanced laboratory at TINT were used to conduct experiments to measure and analyze of all required radionuclides in this research. The average concentrations of 40K 226Ra, 232Th, and 137Cs in paddy soil were found to have a value of 657.30 ± 23.03, 180.01 ± 4.39, 162.02 ± 3.84 and < 1.81 Bq/kg respectively while in organic Sangyod rice grain, their values were 24.11 ± 2.01, 0.28 ± 0.07, 0.17 ± 0.06 and 0.10 ± 0.03 Bq/kg respectively. For TF values were calculated and found to be 0.037, 0.002, 0.001, and 0.055 for 40K, 226Ra, 232Th, and 137Cs, respectively. Furthermore, four important radiological hazard indices which are gamma-absorbed dose rate (D), radium equivalent activity (Raeq), external hazard index (Hex) and annual external effective dose rate (AEDout) were also evaluated by using the average values of 40K, 226Ra and 232Th. In addition, by using the AEDout value, the excess lifetime cancer risk (ELCR (outdoor)) in paddy soil in the study area would be also studied, evaluated and presented. Moreover, the evaluated TF values of required radionuclides were higher than that reported by the International Atomic Energy Agency (IAEA) in 2010 but the values were much lower than those in the study in Malaysia.

Sulphate-reducing bacteria (SRB) in interim storage of spent nuclear fuel

Interim Storage of Spent Nuclear Fuel (ISSF) is an installation for temporarily storing spent nuclear fuels. Nuclear fuel storage pools must be free from contamination by corrosion-causing microorganisms such as Sulphate Reduction Bacteria (SRB). This research aims to detect SRB on the pool’s wall, floor, and spent nuclear fuel racks. The measured parameters consisted of physicochemical, total bacteria, total SRB, and detection of SRB on the wall, floor, and spent fuel rack in the pool using the SRB kit. The results showed that the quality of the water chemistry in the pool was within limits according to the provisions of the International Atomic Energy Agency, except for the total bacteria (> 1000 CFU/ml). In the water pools around the racks of spent fuels, SRB was also detected at 30 CFU/ml, while the level of SRB on the walls, floors, and spent nuclear fuel racks showed varied values from moderate to severe. This research is important especially to identify corrosion-causing microbes for water and biofilm samples. This is the first step in understanding the problem of biofilm formation and contamination of microorganisms in spent fuel storage pools.