:This article mainly introduced the establishment of a protective level X-ray metrology laboratory, which verifies various performance indicators such as field diameter, uniformity, and scattered radiation through physical experimental methods. The results indicated that under the condition of narrow beam spectrum series X-ray reference radiation, the standard deviation between the measured N-60 spectrum and the theoretical curve was 0.54%. The contribution of scattered radiation was less than 3.4%. 95% field diameter at a 10 cm aperture in the N-100 spectrum was 9 cm. Conclusion: The X-ray metrology laboratory discussed in this article meets the requirements of GB/T 12162.1—2000 in terms of key technical indicators such as field diameter, field uniformity, and scattering.

The radioactivity level of U-238, Th-232, Ra-226, K-40, Sr-90 and Cs-137 in surface water, groundwater, sediment and biological samples from 45 monitoring points in the Yellow River basin within Inner Mongolia were investigated. The results show that the content of natural and artificial radioactive substances in the Yellow River basin within Inner Mongolia is at the environmental background level, except that the activity concentration of K-40 and the total radioactivity level are higher in the irrigation area due to agricultural production and fertilization.

In order to understand the distribution levels and changing trends of radionuclides in foods commonly eaten by residents around a decommissioned uranium mine in Hunan Province, radionuclides in four categories of foods (rice, tea, meat, vegetables) commonly eaten by residents were analyzed from 2019 to 2023. Radionuclides were analyzed and the level of annual accumulated effective dose to residents caused by radionuclides in food was estimated. Gamma energy spectroscopy is used to analyze natural radionuclides (²³⁸U, ²³²Th, ²²⁶Ra, ⁴⁰K) and artificial radionuclides (¹³⁷Cs) in food. The contents of radionuclides in food are all within the standard range of the "Standard for Concentration Limit of Radioactive Substances in Food" (GB 14880—1994). The annual accumulated effective dose due to ingestion by residents around uranium mines is 172.7 μSv. The levels of radionuclides in the four types of food for residents around decommissioned uranium mines and the resulting annual accumulated effective doses for residents are all at natural background levels; residents around uranium mines will not get any harm if they eat these foods.

In order to reduce the quantity of scrap stainless steel folding wave pre-filter in the air supply system of a thermal machinery repair building of a nuclear power plant, and to increase the service life, a reuse process of stainless steel folding wave pre-filter was studied through experiments. The experiments include washing, ultrasonic vibration, high temperature dust removal, drying and other processes. The filtration resistance and weight efficiency of the pre-filter with 15 times reuse were studied. The results show that: The composite process of washing, ultrasonic vibration, high temperature dust removal and drying can effectively remove the artificial dust and fiber flocculent pellets accumulated in the stainless steel folding wave pre-filter, and the processed and reused pre-filter can restore the resistance of the clean pre-filter and the parameter requirements of the weight efficiency. When the number of reuse is less than 15 times, the weight efficiency is maintained above 86.11%. The number of reuse can reach more than 15 times. It is found that artificial dust tends to accumulate and clog the metal fiber pores on the surface of the filter, and this phenomenon gradually decreases as it extends to the inside of the filter layer.

In consideration with radiation safety practice and experience feedback during the construction phase of a HPR1000 nuclear power unit, this paper summarizes the radiation safety management during the engineering construction stage of a nuclear power plant. This paper introduces several innovative practices in radiation safety management during this stage, which could provide good reference for the construction of domestic nuclear power units.

This paper introduces the structure of refueling water tank used in a CPR1000 nuclear power unit, the defects treatment plan for the tank bottom plate, as well as the treatment process and results. This paper also analyzes the causes of the defects and provides suggestions for improvement of such issues.

Objective To analyze the identification of major abnormal results in occupational health examinations for radiation workers, and provide a basis for scientific protection for radiation workers. Methods Physical examination data of radiation workers who participated in pre-employment and on-the-job radiation occupational health examinations at our hospital from January 2018 to December 2022 were collected, and the identification of major abnormal results and suspected occupational diseases in their radiation occupational health examinations were retrospectively analyzed. Results A total of 28 055 physical examination data were collected, among them 365 people (1.30%) were detected with major abnormal results. Within the 365 people, 175 people (47.95%) with abnormal blood routine, 108 people (29.59%) with severe visual impairment, 75 people (20.54%) with severe thyroid disease, and 20 people (5.48%) with lens opacity; Two individuals were suspected of having occupational radiation-induced cataracts. There was no statistically significant difference in the detection rate of major abnormalities in blood routine, thyroid, and lens between males and females during their employment; Except for 2020, there was a statistically significant difference in the detection rate of major abnormal physical examination results among different age groups during their employment, with the highest detection rate in the age group of ≥50 years old; There is no statistically significant difference in the detection rate of major abnormal results during physical examinations for employees with different radiation work experience. Conclusion Attention should be paid to the occupational health examination of radiation workers, especially the occupational health status of pre-employment, elderly, and high seniority personnel. Early intervention should be carried out for personnel who are not suitable for radiation work to effectively ensure the occupational health and safety of radiation workers.

The proficiency testing project for the analysis of gamma nuclides in biological ash was designed and implemented. The results of homogeneity and stability were analyzed by one-way ANOVA and t-test and the results submitted by the participant laboratories were evaluated by z-value. The results showed that the homogeneity and stability of the sample met the requirements for proficiency testing, the results of the participant laboratories were satisfactory, and the participant laboratories were able to accurately measure the activity concentration of gamma nuclides in biological ash.

Statistics and analysis of radiation monitoring results using statistical methods are effective quality assurance means to check the reasonableness of data. Monitoring of activity concentrations of natural nuclides in soil was carried out in area A of southern Guangdong, which was randomly selected. The monitoring data were statistically examined using the rank correlation coefficient method. The results showed that the activity concentrations of natural nuclides in soil for this survey belonged to the normal environmental level. Since ²³⁸U ²²⁶Ra and ²¹⁰Po belong to the same uranium family and are in equilibrium in natural soil, the results of the rank correlation coefficient method show that the trend of the monitoring results of ²²⁶Ra and ²¹⁰Po with the monitoring results of ²³⁸U are of great significance, which are in line with the theoretical expectation, and further verified the reasonableness of the monitoring results.