The IAEA Safety Standards Series with 145 safety standards and a logical top-down relationship have been largely accomplished according to the 2008 Long Term Structure. Meanwhile, a new Long term structure looking into next 10-15 years will be ready in 2026, fitting to the emerging of artificial intelligence, climate change, new types of reactor, and so on. The main work of IAEA Radiation Safety Standards Committee (RASSC) is introduced and recent concerns on radiation safety issues are discussed in this paper. A new comprehensive safety guide is being developed by RASSC to address the challenges in identification and management of existing exposure situations. Although the International Commission on Radiological Protection (ICRP) has updated the internal dose coefficients for occupational exposure, RASSC will not revise relative safety standards in the near future and will continue to collect the experience feedback of member countries. With the application of new radiotherapy technologies, RASSC has also focused on radiation protection in radionuclide therapy and the secondary malignancies of radiotherapy survivors.

Radioactive cobalt (Co) is the main nuclide among the radioactive nuclides produced in the primary loop of nuclear power plants and it will be transferred to the decontamination liquid after the decontamination of the primary loop pipeline. By investigating the adsorption materials of Co²⁺, the adsorption effect of different adsorption materials was compared and analyzed, and the performance of different adsorption materials was clarified, which provided a basis for the research of absorption materials for Co²⁺ in waste water. The results showed that: the adsorption capacity of minerals and biological adsorbents was small; metal oxides did not show adsorption performance under acidic conditions; the adsorption rate of ion exchange resin was slow; activated carbon had both fast adsorption rate and high adsorption, but it could not show good adsorption performance under acidic conditions, and the research of other carbon materials was still in the laboratory stage. In view of the above, it is suggested to use inorganic nanometer materials with strong stability, boron nitride and graphene oxide, as the base material to synthesize materials with level pore structure, and to carry out functional modification on this basis, so as to synthesize adsorption materials with high adsorption performance under harsh conditions such as or strong acid.

With the rise of the concept of “great health”, radioactive springs such as radon hot springs have become an emerging health tourism and convalescence way to meet the needs of people seeking natural, non-pharmacological therapies, which has great potential and application value. Meanwhile, radon in water is an important source of indoor radon, which is classified as one of the carcinogens by the World Health Organization, and the concentration limit and effective dose of radon have become scientific issues of concern in the field of environmental and ecotoxicological toxicology, which restricts the development of radon springs in terms of medical treatment. This paper centers on the development of radon spring bath therapy, the formation and distribution of radon springs, the non-specific and biological mechanism of radon springs on human body, the efficacy of radon springs, and the progress of radon springs dose limit. This paper focuses on the review of radon springs for the course of treatment of different types of diseases and the clinical effect. On the basis of the review, the effective dose due to the inhalation of radon and its daughters by convalescents and the results of the effect of radon on different organs or tissues are calculated; the relationship between the concentration and annual effective dose of radon and the effects on different organs or tissues are analyzed. This paper also analyzes the relationship between radon concentration and annual effective dose and residence time, so as to provide theoretical and technical support for the public to safely and scientifically utilize the benefits of radon springs.

²³⁹Pu in seawater was measured by accelerator mass spectrometry (AMS) system independently developed by China Institute of Atomic Energy. The ²³⁹Pu in seawater samples was separated and purified by anion resin, and the target samples were prepared by ferric hydroxide co-precipitation method. A set of tap water samples was prepared as blank samples to evaluate the measurement method with a detection limit of 0.9 fg (2.0 μBq). By this method, ²³⁹Pu in seawater samples was measured and analyzed. And the uncertainty of the measurement method was analyzed.

In this paper, a 30 MHz to 6 GHz EMF vehicle survey was carried out in two administrative districts of Beijing. More than 1.33 million data records of electric field intensity were obtained, which were fell into 22 subdistricts and towns in each of the two administrative districts based on geographical location information. The average RF total value was calculated. The average ranges are (0.43-1.67) V/m, (0.56-1.51) V/m respectively; The correlation coefficients with the population density and base station density of each subdistricts and towns are all higher than 0.8, indicating a strong positive correlation. On the other hand, a 24 hour 30 MHz to 6 GHz vehicle survey was carried out in a business district of Beijing, and the total RF value and base station RF value of 24 groups with a total of more than 145,000 points were obtained. The measured values ranged from (0.70-1.46) V/m and (0.67-1.31) V/m, respectively; The hourly population density was calculated by analyzing the heat map of Baidu population flow, which ranged from (6.58-46.54) human/hm². It is found that the correlation coefficients between hourly population density and hourly RF and base station RF values are as high as 0.901. Obviously, the regional electromagnetic level is strongly correlated with the spatial distribution of population density and the 24 hour fluctuation of regional electromagnetic level is strongly correlated with the variation trend of population flow concentration density.

A wind tunnel experimental study was performed in small scale for representative nuclear power plant site. The influence of buildings and terrain to radioactive material diffusion in the near field was studied. The model rate is 1∶600, and the similar demand of model and physical prototype is satisfied by correcting profile of wind and turbulence. 6 wind directions were studied for disturbing of building and terrain to horizontal and vertical flow field under condition of the annual average wind speed and light wind speed. The experimental results show that the wind speed is deficit and turbulence intensity is improved in WNW to ESE axis wind direction. The different sample sites have different impact to wind speed and turbulence intensity. The distribution of stack emission and ground-level emission in ground axis were different in the condition of annual mean wind speed and light wind speed. The axial maximum diffusion factor is 4.05×10^-5 s/m³ under stack emission condition, and the distance presented is 240 m. The axial maximum diffusion factor is 4.79×10^-3 s/m³ under ground emission condition, and the distance presented is 45 m.

High-level radioactive waste repository has a long service period and complex geological conditions. It is difficult for general tests to obtain the evolution trend of the swelling performance of bentonite buffer barrier under the working conditions of the repository. This paper attempts to use machine learning algorithms to research it. The model is trained by ten machine learning algorithms which is more mature in material performance prediction, the coefficient of determination and root mean square error of the above algorithms are compared and analyzed. The feasibility of machine learning algorithms in predicting the swelling performance of bentonite is discussed, and the neural network algorithm is selected as the best one. The geochemical condition of Beishan candidate repository in China is introduced. It is predicted that the swelling pressure evolution trend of Gaomiaozi bentonite during the service of high-level radioactive repository is ‘S’ type. The results show that considering the influence of dry density, montmorillonite content, initial moisture content and temperature, the recommended value of initial dry density of buffer barrier is not less than 1.58 g/cm³. If the effect of Fe(II) release from the iron container is further considered, the initial dry density of the buffer barrier should be further increased. This study can provide a theoretical basis for the in-situ experiment and buffer barrier performance evaluation of the underground laboratory of Beishan high-level waste radioactive repository in China.

M310 reactor units are the earliest Nuclear Power Units introduced in China. Although their radioactive wastewater treatment systems are operating stably, they face challenges such as high operating costs, unstable efficiency, low decontamination factors, and high solid waste output, etc. In particular the low decontamination factors, current processes and equipment are no longer able to meet the demand for further reducing the total amount of radioactive nuclides emitted into the environment. There is still a considerable gap compared to advanced countries and regions. This paper summarizes the current operational status and considers the mature and advanced wastewater treatment technologies at home and abroad, with the aim to elaborate the optimization direction and suggestions for the radioactive wastewater treatment system of M310 Nuclear Power Units.

Cesium is easily soluble in water, and has a good migration rate and a low boiling point, making it difficult to dispose of safely. The safe disposal of radioactive cesium is an urgent problem to be solved. Current technologies used for cement fixation and solidification, and ion exchange have certain shortcomings in the treatment of cesium containing waste liquid, and further optimization is urgently needed. Pollucite belongs to the zeolite type molecular sieve, with a suitable pore size. Without damaging the structure of pollucite, radioactive cesium cannot diffuse out of it. Many studies have shown that it is one of the potential ultimate choices for disposing of radioactive cesium. In previous studies, pollucite needs to be synthesized at high temperatures above 1 000 ℃, which can cause the volatilization of cesium and increase the difficulty of tail gas treatment. This study used hydrothermal method to simulate the generation environment of molecular sieve zeolites in nature and achieved the synthesis of pollucite at lower temperatures. Through a 2 L/batch treatment device, the cesium containing waste liquid is treated, with a removal rate of over 99% for cesium in the wastewater. This study also tested the leaching resistance, thermal stability, and radiation resistance of cesium, confirming its strong stability and suitability as a radioactive disposal material.

PprI gene has obvious prevention and control effect on acute radiation damage caused by neutron and gamma rays in mammals. In this study, the PprI gene was directed cloned into the shuttle plasmid pADV-mCMV-MCS-3xFLAG using the non-replicating adenovirus vector system AdMax packaging system, and then co-transfected into HEK293 cells with the adenovirus skeleton plasmid for homologous recombination. The recombinant adenovirus pAdMax-PprI was obtained and identified. The PprI protein was bioinformatics analyzed. PCR results of recombinant adenovirus pAdMax-PprI showed that the inserted fragment was consistent with the size of the PprI gene fragment, and sequencing showed that the inserted fragment was consistent with the PprI gene sequence. Western blot results showed that PprI protein was immunogenic with a molecular weight of about 45 kDa. Bioinformatics analysis showed that PprI gene encodes a hydrophilic protein composed of 163 amino acid residues, which exists in cell membrane, has no signal peptide and transmembrane structure, and has 5 antigenic epitopes. The secondary structure includes three forms of random curling, α-helix and β-folding. Random curl (46.73%) and α helix (28.83%) were the main structures. The prediction results of tertiary structure were consistent with those of secondary structure. The results laid a foundation for further studies on the function of PprI and its radiation resistance.