Objective To study whether the disinfection methods for thermoluminescence dosimeters used by major hospitals during the COVID-19 pandemic had an impact on monitoring personal dose of external irradiation, and to screen for the disinfection procedures suitable for use during the pandemic. Methods Hospitals with fever clinics during the epidemic in Shandong Province were selected from March to October 2020, we investigated the disinfection methods as well as the types and frequency of use of disinfection supplies used for thermoluminescence dosimeters during the pandemic in hospitals. Simulations were performed in experimental and control groups. Results The average doses measured by the disc dosimeter with different disinfection methods and the control group were 0.92-0.99 mSv and 0.98 mSv, respectively, and the deviation was ≤ 6%. The average doses measured by the glass tube dosimeter with different disinfection methods and the control group were 0.20-0.22 and 0.21, respectively, and the deviation was ≤ 5%. Conclusion The results showed that the commonly used disinfection methods had no influence on personal dose monitoring, but some disinfection measures were not suitable for dosimeters.

Objective To analyze the process of intercomparison of national personal dose monitoring, evaluate the ability of personal dose monitoring, and ensure the accuracy and reliability of monitoring results in our laboratory. Methods In accordance with the intercomparison protocol for 2019—2021, an energy-discriminant thermoluminescence dosimeter was used for measurement at different doses. The uncertainty of measurement was evaluated and compared with the reference value. Results H_p(10) was measured for intercomparison in 2019—2021. In 2019, the single group performance difference was −0.02 to 0.02 and the comprehensive performance was 0.02. These values were 0.02-0.10 and 0.05 in 2020, and −0.02 to 0.02 and 0.01 in 2021. The intercomparison results were rated as excellent in the three consecutive years. Conclusion The personal dose monitoring system in our laboratory was in good condition, and the monitoring results were accurate and reliable. Improving the knowledge of personnel and cultivating a serious working attitude are important for intercomparison and personal dose monitoring.

Objective To determine the radioactive enrichment level in marine biological media around Qinshan Nuclear Power Plant and to evaluate the impact of effluent on marine biological media in the surrounding sea area based on the discharge of effluent from the nuclear power plant over the years and the monitoring level of surrounding marine media. Methods The monitoring data of ³H, ¹⁴C, ⁹⁰Sr, ¹³⁷Cs, and ^110mAg in the environmental media monitored in Qinshan Nuclear Power Plant from 2008 to 2017 were collected, and the data were processed and analyzed by IBM SPSS Statistics 26. Results The activity concentrations of tritium in mullet and oyster in the sea area around Qinshan Nuclear Power Plant were 0.5-2.9 Bq/kg and 0.55-8.2 Bq/kg, respectively, and the activity concentrations of tritium in both increased generally under the influence of effluent from the nuclear power plant. The activity concentrations of ¹⁴C, ¹³⁷Cs, and ⁹⁰Sr in the monitored organisms were lower than the background values. The results of correlation analysis showed that the effluent from the nuclear power plant had almost no effect on ¹⁴C. The activity level of ^110mAg decreased significantly year by year in oyster, and remained below the background level in mullet. Conclusion Qinshan Nuclear Power Plant is the longest operating nuclear power plant in mainland China. Most of the nuclides in biological media in the surrounding sea area are lower than the background levels, and the effluents from the nuclear power plant have little influence on marine biological media in the surrounding sea area.

Objective To investigate the indoor radon concentration and its changing trend in northeastern China. Methods We measured indoor radon levels cumulatively for over three months by solid state nuclear track detection in a total of 261 houses in multi-story or high-rise buildings in Shenyang, Changchun, Harbin, Heihe, and Yichun in northeastern China. The measurement lasted one year in Changchun for seasonal changes. Results The average indoor radon concentration in the five cities was 88 Bq/m³, ranging from 12 to 558 Bq/m³. The indoor radon concentrations were ≤ 100 Bq/m³ in 75.1% of the houses, and ≤ 300 Bq/m³ in 97.7% of the houses. The indoor radon concentration increased with the age of buildings. The indoor radon concentration was highest in winter, and it was higher in summer than in autumn and spring. Conclusion The indoor radon concentration in northeastern China increased compared with the data of 1980s and 1990s. It is highest in the winter heating season, and higher in summer than in spring and autumn. Indoor radon exposure deserves attention.

Objective To obtain the medical exposure frequency data of residents through a questionnaire survey on mobile phone networks in the community, and to analyze the main influencing factors. Methods A snowball sampling method was used to expand the sampling from medical staff in a county hospital to the community. The questionnaire included personal information such as occupation category, type of medical insurance, and education level as well as basic radiation-related knowledge and medical exposure type and frequency of respondents received in 2021. A logistic regression model was used to analyze the influencing factors of medical exposure. Results A total of 223 respondents were investigated, and 12.56% of them received radiological diagnosis and radiotherapy in 2021. The proportion of males receiving medical exposure was significantly higher than that of females (19.64% vs 10.18%). The likelihood of the person receiving medical exposure increased considerably with age, with the proportion of residents receiving medical exposure at 20, 30, 40, and 50 years of age being 6.25%, 7.95%, 19.23%, and 33.33%, respectively. Of persons who received medical exposure, 57.14% underwent CT scans. Persons participating in the new rural cooperative medical system were likely less to receive radiological diagnosis and radiotherapy than urban workers and residents (OR = 0.55, CI:0.13-2.23, P > 0.05). Conclusion Questionnaire survey in the community can obtain more information about the medical exposure of residents, and age and type of medical insurance are important factors affecting the frequency of medical exposure.

Objective To investigate radiation resources in medical diagnosis and treatment and their use frequency in medical institutions in Hangzhou, China, and to provide a basis for relevant departments to rationally allocate and scientifically supervise the resources. Methods From April 1, 2019 to March 31, 2020, a survey was conducted on the basic information, radiation staff, equipment configuration, and frequency of radiation diagnosis and treatment of all medical institutions in Hangzhou using a questionnaire. Results There were 1001 institutions with radiation services in Hangzhou, with 6714 radiation staff members and 2742 pieces of radiation equipment. The frequency of conventional X-ray diagnosis was 788.43 per 1000 population. The frequency of computed tomography diagnosis was 531.93 per 1000 population. The frequency of mammography and dental photography diagnosis was 246.34 per 1000 population. The frequency of interventional diagnosis and treatment was 10.01 per 1000 population. The frequency of radiotherapy was 2.39 per 1000 population. The frequency of nuclear medicine diagnosis was 8.90 per 1000 population. The frequency of nuclear medicine treatment was 0.99 per 1000 population. Conclusion Medical institutions have developed rapidly in Hangzhou, but with an unbalanced situation. In order to better protect the health of examinees, we recommend relevant departments optimize resource allocation and strengthen supervision on radiation protection in medical institutions.

Objective To apply a phantom for dose measurement in interventional therapy for pediatric vascular diseases, and calculate the effective dose (E) and conversion coefficient of dose area product (DAP) to E, and to provide a dose reference for studying radiation dose and radiation protection in children. Methods Thermoluminescent dosimeters were placed in the organs of the phantom. Low-, medium-, and high-dose groups were set for three types of vascular anomalies based on the duration of fluoroscopy. Digital subtraction angiography was used to simulate exposure conditions at different dose levels. The organ dose was measured, and the effective dose was calculated. Results For the three groups of vascular anomalies in the head and face, the red bone marrow doses were 8.15, 30.34, and 43.53 mGy, respectively, the effective doses were 12.88, 47.84, and 73.12 mSv, respectively; and the average conversion coefficient of DAP to E was 2.16. For the three groups of vascular anomalies in the trunk, the red bone marrow doses were 2.11, 15.62, and 31.21 mGy, respectively; the effective doses were 12.39, 70.56, and 134.60 mSv, respectively, and the average conversion coefficient of DAP to E was 3.03. For the three groups of vascular anomalies in the lower extremities, the red bone marrow doses were 3.58, 6.50, and 12.28 mGy, respectively, the effective doses were 3.64, 7.04, and 14.85 mSv, respectively, and the average conversion coefficient of DAP to E was 0.73. Conclusion Patient dose and DAP-to-E conversion coefficient are in the following order: vascular anomalies in the trunk > vascular anomalies in the head and face > vascular anomalies in the lower extremities. The dose data obtained can be used to estimate children’s radiation exposure.

Objective To complete the Monte Carlo design and preliminary test of X-ray protective rubber. Methods According to the characteristics of X-ray energy spectrum for interventional therapy, the shielding effects of lead rubber, tungsten and bismuth composite rubber, and gadolinium and bismuth composite rubber samples were calculated by Monte Carlo simulation. The variation law of lead equivalent of lead-free rubber and lead rubber with X-ray peak tube voltage was obtained through actual measurement. Results Within the peak tube voltage range of 60-110 kV, lead-free rubber effectively replaced lead rubber. Conclusion The shielding and attenuation effect of the existing lead-free protective rubber on low-energy stray X-rays is better than that of lead rubber. Considering the inherent defects of lead rubber, flexible X-ray protective materials with thermoplastic elastomer as filler will have broad development prospects.

Radiation protection is an important requirement in the design of spent nuclear fuel reprocessing plant. The design of all main process plants should consider the impact of radiation on staff and environment, while radiation protection is not required in the design of general industrial and civil buildings. This difference puts forward higher requirements for the architectural design of spent nuclear fuel reprocessing plant. From the perspective of architectural design, this paper analyzed the differences between spent nuclear fuel reprocessing plant and ordinary plant, as well as the compatibility of radiation protection requirements and current architectural design specifications. We proposed corresponding countermeasures based on our engineering experience, and summarized important design principles related to radiation protection requirements, which can be used as a reference by architectural designers in designing spent nuclear fuel reprocessing plants.

Objective To make the preparation method for coatings more convenient in the field where the requirements for tritium permeation resistance are not high, this paper proposes a method for preparing Al-Al₂O₃ tritium permeation barriers by thermal spraying technology and conducts a performance analysis. Methods The tritium permeation resistance and adhesion of Al-Al₂O₃ coatings prepared by thermal spraying were verified by experiments. Results The tritium permeability was reduced by one order of magnitude after a 0.2-mm Al-Al₂O₃ coating was sprayed on the stainless steel surface, and the tritium permeation resistance had no significant improvement with the increase in coating thickness; the adhesion of the coating was determined in the range of 5-10 N by scratch tests. Conclusion In this paper, a simple preparation method for tritium permeation barrier is proposed, and the tritium permeation resistance performance of Al-Al₂O₃ coatings prepared by thermal spraying technology is determined, which provides a reference for the selection of tritium permeation barrier in the field of tritium-containing solid waste storage.