Verification of a method for measurement of tritium in liquid effluent of nuclear power plants / 中国辐射卫生

Objective To explore the method for measurement of tritium in nuclear power plant liquid effluent purified by a mixed ion-exchange resin, to verify the feasibility of the method by experiments, and to provide technical support for the development of standard methods for the measurement of tritium in liquid effluent of nuclear power plants. Methods The purification effect of the mixed ion-exchange resin was determined by measuring the quenching factor, conductivity, and β-nuclide adsorption efficiency of the samples purified using the resin. A comparison was made between the ion-exchange resin method and the atmospheric distillation method for tritium determination. The precision and accuracy of the method were verified by calculating the relative standard deviation and the recovery in repeated measurement of samples with different activity concentrations and spiked samples. Results There were no significant differences in quenching factor, conductivity, and tritium activity concentration between the two methods. The adsorption efficiencies of EC20MB resin for common β-nuclides such as carbon, iron, nickel, strontium, yttrium, and cesium ranged from 99.28% to 99.88%. Repeated measurement of the same sample showed relative standard deviations of 5.2%-9.4% and recoveries of 86.8%-107%. Conclusion There were no significant differences between the results of the ion-exchange resin purification method and the atmospheric distillation method. The precision and accuracy of the method met the requirements of the ecological and environmental management authorities for monitoring tritium in liquid effluent from nuclear power plants. This method can be widely used in daily monitoring work.

Analysis of the current situation of occupational stress of radiation workers in typical nuclear power plants / 中国辐射卫生

Objective To investigate the current situation of occupational stress among radiation workers in nuclear power plants in China, to explore the factors influencing occupational stress, and to provide a reference for improving occupational stress. Methods A convenient sampling method was adopted to investigate the occupational stress of 100 radiation workers in two nuclear power plants in Fujian and Liaoning, using the general situation questionnaire, effort-reward imbalance questionnaire, and the radiation protection knowledge questionnaire. Independent samples t-test, one-way analysis of variance, chi-square test, and binary logistic regression analysis were used to examine the current situation of occupational stress and the influencing factors. Results The average value of effort-reward imbalance was 0.99 ± 0.15 and 47 (47%) radiation workers had occupational stress. There were significant differences in the detection rate of occupational stress among radiation workers with different ages, years of radiation work, monthly incomes, sleep durations (day), and exercise habits (P < 0.05). Logistic regression analysis showed that monthly income, sleep duration (day), and exercise habits were the influencing factors for occupational stress. Conclusion The occupational stress of radiation workers in nuclear power plants is a serious issue influenced by many factors. Attention should be given to this issue, and targeted interventions should be implemented to improve the social and working environment of this occupational group and reduce the level of occupational stress.

Background radioactivity levels of gross α and gross β in foods around Zhangzhou nuclear power plant, China / 中国辐射卫生

Objective To investigate the radioactivity levels of gross α and gross β in foods around Zhangzhou nuclear power plant, China before operation. Methods Forty-nine samples from 33 kinds of foods in 5 categories of daily food around Zhangzhou nuclear power plant were collected, pretreated, dried, and ashed. The radioactivity levels of gross α and gross β were measured by the low-background α and β measuring instrument. The atomic absorption technique was employed to measure the level of potassium (K), and the radioactivity level of gross β (subtracting 40K) was calculated with K concentrations in different foods consulted from the nutritional dietary system. Results The radioactivity levels of gross α in vegetables and fruits, grain, poultry and livestock, aquatic products, and tea around Zhangzhou nuclear power plant were < minimum detectable level (MDL)-7.97, < MDL-6.82, < MDL, < MDL-20.76, and 11.90-23.08 Bq/kg, respectively; the radioactivity levels of gross β were 34.56-122.81, 13.05-188.96, 56.00-108.34, 17.86-169.01, and 123.74-171.63 Bq/kg, respectively; the radioactivity levels of gross β (subtracting 40K) were not detected (ND)-14.27, ND-27.86, ND-48.72, ND-45.85, and 6.69-13.79 Bq/kg, respectively. Conclusion The radioactivity of gross α and gross β in foods around Zhangzhou nuclear power plant before operation is basically at the same level as that in other areas of China.

A practice case of monitoring waste resin clearance in a nuclear power plant / 中国辐射卫生

Objective To establishment a process of monitoring waste resin clearance in nuclear power plants, and to meet clearance requirements and simplify the monitoring work. Methods In accordance with the requirements specified in current laws, regulations, and standards in China, as well as the practice of slightly polluted waste resins generated during the operation of nuclear power plants, in-depth discussion was conducted on sampling methods, sample uniformity and representativeness tests, radiation monitoring contents and methods, and simplified monitoring processes, in order to accurately monitor the radionuclide activity of waste resins to be cleared. Results A process was established to monitor waste resin clearance in nuclear power plants. A total of 55 barrels of waste resins were cleared and the radiation levels met the requirements. Conclusion An effective clearance process can facilitate the sampling of representative resins, improve the accuracy of monitoring data, differentiate radioactive waste from cleared waste, and simplify the monitoring process. Our results provide a basis and reference for future waste resin clearance.

Investigation on total radioactivity in drinking water following operation of the second phase expansion project at Qinshan Nuclear Power Plant / 中华放射医学与防护杂志

Objective:To investigate and analyze the level of the gross radioactivity, and its variation trend, in surrounding drinking water since the second phase expansion project at Qinshan Nuclear Power Plant was officially put into operation.Methods:From 2010 to 2022, the source water, factory water and tap water within 30 km of Qinshan Nuclear Power Plant were collected in the flood season (May) and dry period (October) every year. The total α and total β radioactivity concentrations in drinking water was measured and analyzed. The levels of total radioactivity in drinking water around different nuclear power plants in China and around non-nuclear power plant areas was compared.Results:The mean radioactivity concentrations of total α and total β were (0.021±0.019) and (0.204±0.058) Bq/L in source water, (0.010±0.005) and (0.185±0.056) Bq/L in factory water , and (0.012±0.007) and (0.170±0.058) Bq/L in tap water, respectively, all lower than the limits stipulated in the Sanitary Standards for Drinking Water. There were no significant differences in the monitoring result of betweem the three types of water samples both in the flood and dry periods ( P> 0.05). The total radioactivity level in drinking water around Qinshan Nuclear Power Plant site was close to that in drinking water around different nuclear power plants in China and around areas without nuclear power plants. Conclusions:Following the second phase of the expansion project officially being put into operation, the total α and β radioactivity level in drinking water around the Qinshan Nuclear Power Plant has been in a stable trend and lower than the guidance level given in national standard.

Radioactivity in marine organisms around Qinshan Nuclear Power Plant / 中国辐射卫生

@#<b>Objective</b> 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. <b>Methods</b> 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. <b>Results</b> 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. <b>Conclusion</b> 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.

The radioactivity levels of food and the dose in residents due to food intake around Shidaowan Nuclear Power Plant / 中国辐射卫生

Objective To analyze the radionuclide levels in food and the committed effective dose due to food intake in residents around the Shidaowan Nuclear Power Plant (SNPP). Methods Daily food samples were collected within 30 km radius around the nuclear power plant in 2019—2022. The radioactivity levels before and after the operation of SNPP were determined. The data were combined with the dietary consumption of residents in Shandong province, China to estimate the committed effective dose. Results The radionuclides 238U, 232Th, 226Ra, and 40K in food were at normal background levels, and the average radioactivity was (0.062 ± 0.004), (0.121 ± 0.007), (0.162 ± 0.010), and (92.4 ± 5.5) Bq/kg fresh weight. Trace 137Cs and 90Sr were detected in some food samples and the average radioactivity was (0.047 ± 0.003) and (0.193 ± 0.200) Bq/kg fresh weight. The levels of radionuclides did not increase after the operation of SNPP compared with that before operation. The estimated committed effective dose in residents due to food intake was 0.205 mSv. Conclusion The radioactivity of food in the area around SNPP shows no difference before and after operation, and the dose burden is low in local residents.

Analysis of gross radioactivity levels in drinking water around Shidao Bay Nuclear Power Plant, 2018-2021 / 中国辐射卫生

Objective To investigate the gross alpha and gross beta radioactivity levels in drinking water around Shidao Bay Nuclear Power Plant before its operation. Methods Ten sampling sites were set up within 30 km of Shidao Bay Nuclear Power Plant. From 2018 to 2021, samples were collected during the dry season and wet season each year and were tested in a laboratory according to Standard examination methods for drinking water—radiological parameters (GB/T 5750.13—2006). Results From 2018 to 2021, the gross alpha radioactivity in drinking water within 30 km of Shidao Bay Nuclear Power Plant was within the range of about 0.004-0.420 Bq/L, which does not exceed the guided gross alpha radioactivity specified in the National Standard; from 2018 to 2021, the gross beta radioactivity level was about 0.008-1.050 Bq/L. In 2018, the gross beta radioactivity at the sampling site 4.7 km from the Nuclear Power Plant exceeded the guided level specified in the National Standards for Drinking Water Quality (GB 5749—2006), but it fell within the guided level in a repeat laboratory test after deducting the effect of 40K on the gross beta radioactivity. Conclusion After deducting the effect of 40K on the gross beta radioactivity, the gross alpha and gross beta radioactivity levels in drinking water within 30 km of Shidao Bay Nuclear Power Plant are within the guided levels specified in the National Standards.

Terrestrial gamma radiation level around Shidaowan nuclear power plant, China and influencing factors / 中国辐射卫生

@#<b>Objective</b> To monitor the cumulative terrestrial γ radiation dose around Shidaowan nuclear power plant, Shandong, China before operation, to analyze the dose levels and influencing factors, and to estimate the annual effective dose to local residents. <b>Methods</b> Fifty-six monitoring sites were selected within 30 km around the nuclear power plant. The environmental γ radiation dose was measured by the thermoluminescence dosimeter monitoring method. The γ radiation dose levels were investigated for 369 days in four monitoring periods (January 16 to April 14, April 15 to July 20, July 21 to October 21, 2021, and October 22, 2021 to January 20, 2022 for periods I to IV, respectively). Relations between γ radiation and monitoring time, altitude, distance from the nuclear power plant were analyzed, and the annual effective dose of terrestrial γ radiation to residents was estimated to reflect the background terrestrial γ radiation level in the area. <b>Results</b> The average values of terrestrial γ radiation dose rate in the four monitoring periods in the area were (76.196 ± 3.366), (81.773 ± 6.144), (93.554 ± 7.449), and (97.604 ± 9.396) nGy/h, respectively, and the terrestrial γ radiation dose rate in the whole year was (87.282 ± 6.589) nGy/h. The effective dose to residents was 0.428 mSv. The terrestrial γ radiation level was high from July 2021 to January 2022. There was no significant difference in the γ radiation dose rate at the monitoring sites with different distance from the nuclear power plant. No impact upon the terrestrial γ radiation dose by the altitude was observed in this study. <b>Conclusion</b> The terrestrial γ radiation level around Shidaowan nuclear power plant in 2021 was at the background level.

Psychological crisis intervention for emergency rescue workers during major nuclear power plant accident / 中国辐射卫生

The nuclear accidents in Chernobyl and Fukushima had great impacts on the mental health of emergency rescue workers, who experienced a series of psychological problems shared by the accident victims. This paper analyzes the psychological symptoms suffered by emergency rescue workers in Chernobyl and Fukushima nuclear accidents, as well as the psychological crisis interventions for rescue personnel involved in major natural disasters and pandemics. Based on the special situations faced by emergency rescue workers in nuclear accidents, we propose psychological crisis interventions for rescue personnel during major nuclear accidents. These interventions include mental health assessment and training before accident, psychological assistance, self-adjustment, and crisis intervention during accident, and long-term psychological assistance after accident. The psychological impacts on emergency rescue workers can be reduced by effective psychological interventions.

Public communication in the recovery process after the Fukushima Daiichi Nuclear Power Plant accident / 中国辐射卫生

The Fukushima Daiichi Nuclear Power Plant accident in Japan resulted in the release of large amounts of radioactive substances into the surrounding environment and caused contamination. In the accident recovery process, Japan had made great efforts in public communication, including the government’s promotion of organization and planning the popularization and publicity of scientific knowledge in various forms, multi-channel information disclosure, and all-round communication and exchange, which can provide a reference for the development of relevant work in China. The nuclear-related public communication work in China can get four enlightenments. Firstly, the public communication system should be improved, and corresponding policies and mechanisms should be clarified. Secondly the popularization of nuclear science knowledge should be taken as the foundation for early and long-term development. Thirdly, the operators of nuclear facilities shall disclose relevant information according to the law and confront the curiosity or doubts of the public. Finally, multi-channel, multi-level and multi-frequency exchanges and interactions should be conducted to seek unity of understanding and balance of interests between the two sides.

Improvement and application of radiation work permit software in nuclear power plants / 中国辐射卫生

Objective To improve the efficiency of radiation work preparation, promote the comprehensive and whole-process control of radiation risk, strengthen the accumulation of experience feedback data, and improve the timeliness of approval. Methods According to the application of radiation work permits in Tianwan Nuclear Power Plant and other nuclear power plants, the radiation work permit software in Tianwan Nuclear Power Plant was improved in terms of work order connection, examination and approval process integration, approval of radiation work at different levels, unification of level classification standard, radiation risk database establishment and maintenance, and closed loop management and mobile approval of radiation work permit. Results A radiation work permit software for nuclear power plant was developed according to the requirement of radiation risk control. Conclusion The radiation work permit software effectively improves the radiation work regarding work preparation efficiency, risk control, experience feedback data accumulation, and timeliness of approval. Subsequently, information transmission efficiency and experience sharing can be improved through connection and communication with other software in nuclear power plants.

Analysis of occupational health examination of workers in a nuclear power plant in Guangdong, China / 中国辐射卫生

@#<b>Objective</b> To analyze the abnormality of radiation damage sensitive indices in radiation workers after operation of a third-generation nuclear power plant in Guangdong Province, China, and to provide a basis for promoting the occupational health management of radiation workers. <b>Methods</b> A two-way cohort study (2019—2021) was conducted to compare the radiation sensitive indices of occupational health examination in the exposed group (453 subjects) and the control group (160 subjects). <b>Results</b> In 2021, the free triiodothyronine (FT3) level of the exposed group was significantly higher than that of the control group [(5.57 ± 0.56) pmol/L <i>vs</i> (5.42 ± 0.60) pmol/L, <i> t</i> = 0.59, <i>P</i> < 0.05]. From 2019 to 2021, the exposed group showed significant changes in the average levels of platelet, hemoglobin, FT3, free thyroxine (FT4), and thyroid-stimulating hormone (<i>P</i> < 0.05); FT3 and FT4 first increased and then decreased, while TSH decreased continuously. <b>Conclusion</b> Long-term exposure to low-dose ionizing radiation from nuclear power plants can affect the platelet, hemoglobin, FT3, FT4, and thyroid-stimulating hormone of radiation workers, and the effect is relatively prominent on thyroid function by causing a tendency to hypothyroidism.

Organization and thinking of provincial-level on-sit and off-sit joint exercises for nuclear emergency / 中国辐射卫生

By reviewing the organization and implementation of “Hongsha-2021” Guangxi nuclear emergency joint exercises, this article summarizes the experience in the organization process and puts forward some thoughts and suggestions in order to improve the depth of provincial-level on-site and off-site joint exercises for nuclear emergency at nuclear power plants and further enhance the emergency response capacity of nuclear emergency organizations at all levels.

Investigation of gross α and β radioactivity levels in foods around Fuqing nuclear power plant site / 中华放射医学与防护杂志

Objective:To ascertain the activity concentration of gross α and β in foods around Fuqing nuclear power plant (NPP) site.Methods:Totally 167 food samples of 25 kinds within 6 categories were collected from the surveillance areas and control areas around Fuqing NPP site. The total radioactivity was analyzed using the food samples. Paired rank sum test was used to determine the influence of the operation of Fuqing NPP on the total radioactivity in foods in surrounding areas. The multiple local rank sum test was used to assess the difference in total radioactivity in different types of foods.Results:The average gross α in poultry meat, vegetables, crops, aquatic products, milk and tea was 0.65, 1.96, 1.41, 3.80, 1.33, 7.67 Bq/kg in surveillance areas and 0.56, 3.24, 2.04, 3.70, 2.24, 9.05 Bq/kg in reference areas, respectively, around Fuqing NPP site. The average gross β (subtracting 40K) in poultry meat, vegetables, crops, aquatic products, milk and tea was 7.0, 10.5, 6.1, 23.5, 24.7, 8.6 Bq/kg in surveillance areas and 7.4, 8.3, 14.5, 22.1, 21.3, 11.0 Bq/kg in reference areas, respectively, around Fuqing NPP site. The Wilcoxon paired rank test showed that there was no significant difference in the gross α and β in foods between surveillance and reference areas around Fuqing NPP site ( P>0.05). The Kruskal-Wallis H test showed that the radioactivity of gross α and β in different foods was statistically significant ( χ2=23.325, 13.918, P<0.05). Conclusions:The increase was not found in total radioactivity in the surrounding foods since the operation of Fuqing NPP in 2015.

Analysis of monitored results of death cause in residents around Sanmen nuclear power plant from 2015 to 2019 / 中华放射医学与防护杂志

Objective:To investigate the data on death cause of residents around Sanmen nuclear power plant from 2015 to 2019.Methods:The data on death cause of residents in Sanmen county from 2015 to 2019 were collected, and the top 10 diseases in death causes ranking and radiation-related malignant tumors were analyzed.Results:The average mortality rate of residents in Sanmen county was 575.87 per 100 000 population from 2015 to 2019, lower than the national level and close to that in Zhejiang Province. The top 10 death causes remain unchanged, higher than 95.79% of total deaths. The mortality rate of malignant tumor increased from 159.23 per 100 000 population in 2015 to 191.51 per 100 000 population in 2019 (χ 2=15.889, P<0.05). There was no significant difference in the proportion of mortality from radiation-related tumor(leukemia and thyroid cancer) in Sanmen county in recent 5 years ( P>0.05). Conclusions:From 2015 to 2019, the death rates of residents in Sanmen county were relatively stable. The effects of the operation of the nuclear power plant on the health of the local residents need to be continuously monitored.

Radioactivity levels in foods during 2013 to 2020 around Hongyanhe Nuclear Power Plant and study on internal doses to the public / 中华放射医学与防护杂志

Objective:To evaluate the impacts of radioactivity in foods since begining of the operation of the Hongyanhe Nuclear Power Plant (HNPP).Methods:The levels of radioactivity in foods collected within 30 km of HNPP from 2013 to 2020 were analyzed by comparison of the control samples and those collected before the operation. The impacts on the operation of the HNPP on foods were evaluated.Results:The man-made radionuclides such as 131I, 134Cs, 60Co, 58Co, 110Ag m were not found in food samples. The nautral radionuclides such as 238U, 226Ra, 232Th, 40K were at the normal levels, with the average levels of (0.088±0.053), (0.155±0.178), (0.314±0.388)and(81.3±18.1)Bq/kg(fresh weight)in foods, respectively. The average levels of man-made nuclide 137Cs in foods were (0.013±0.010) Bq/kg (fresh weight). There was no increase in radionuclide levels compared with the control samples and the samples before the operation. Conclusions:The impacts on foods due to the operation of HNPP was not found.

Psychological first aid during severe nuclear power plant accident / 中国辐射卫生

The past three severe nuclear power plant accidents showed that the social psychological impact on the public is the most serious consequence of severe nuclear power plant accidents. When a severe nuclear power plant accident occurs, individuals / groups in the affected area may experience various stress reactions. Timely and effective psychological first-aid can help the victims to survive the crisis effectively and actively respond to the current life. Referring to the World Health Organization guide psychological first aid: guide for field workerand other national guidance, this paper introduces how emergency rescue personnel carry out emergency psychological assistance in case of severe nuclear accident.

Three nuclear power plant accidents in history and related public books / 中国辐射卫生

The peaceful use of nuclear energy has a history of nearly 80 years, and the development of nuclear energy in China has been actively and steadily promoted. Up to now, there have been three major nuclear power plant accidents in human history: Three Mile Island nuclear accident in the United States, Chernobyl nuclear accident in the former Soviet Union and Fukushima nuclear accident in Japan. However, the public in our country knows little about the three nuclear accidents. This paper introduces some books on the three nuclear accidents for the general public, which help the public understand the nuclear accidents from a non-professional point of view.

The investigation on the radioactivity level of 90Sr in tea leaves in the vicinity of Ningde nuclear power plant / 中国辐射卫生

Objective To investigation the radioactivity level of 90Sr in tea leaves within and outside 30 km range of Ningde nuclear power plant. Methods The tea leaves within and outside the 30 km range of Ningde Nuclear Power Plant were collected from 2013 to 2018. According to“Radiochemical analysis of strontium-90 in water and ash of biological samples” (HJ 815—2016), the separation and analysis of 90Sr-90Y were carried outusing the method of di (2-ethylhexyl) phosphate (HDEHP) chromatography. Results During the period of 2013-2018, the radioactivity concentrations of 90Sr in the tea leaves within the range of 30 km around the Ningde nuclear power plant were 0.486～13.29 Bq/kg and that of 90Sr in the tea leaves outside the range of 30 km around the nuclear power station were 1.021～17.19 Bq/kg. Conclusion During the six years of operation in Ningde Nuclear Power Plant, there was no increase in the radioactivity level of 90Sr in the tea leaves around the nuclear power plant.